diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/channels/IInputChannel.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/channels/IInputChannel.java
new file mode 100644
index 0000000..e621a09
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/channels/IInputChannel.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.api.channels;
+
+import java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+
+public interface IInputChannel {
+    public void registerMonitor(IInputChannelMonitor monitor) throws HyracksException;
+
+    public void setAttachment(Object attachment);
+
+    public Object getAttachment();
+
+    public ByteBuffer getNextBuffer();
+
+    public void recycleBuffer(ByteBuffer buffer);
+
+    public void open() throws HyracksDataException;
+
+    public void close() throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/channels/IInputChannelMonitor.java
similarity index 74%
copy from hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java
copy to hyracks-api/src/main/java/edu/uci/ics/hyracks/api/channels/IInputChannelMonitor.java
index 2906ba6..dd91f28 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/channels/IInputChannelMonitor.java
@@ -12,10 +12,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hyracks.control.cc.scheduler;
+package edu.uci.ics.hyracks.api.channels;
 
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+public interface IInputChannelMonitor {
+    public void notifyDataAvailability(IInputChannel channel, int nFrames);
 
-public interface ISchedule {
-    public String[] getPartitions(ActivityNodeId aid);
+    public void notifyEndOfStream(IInputChannel channel);
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IDataReceiveListener.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IDataReceiveListener.java
deleted file mode 100644
index 463e4e1..0000000
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IDataReceiveListener.java
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.api.comm;
-
-import java.io.IOException;
-
-public interface IDataReceiveListener {
-    public void dataReceived(IConnectionEntry entry) throws IOException;
-
-    public void eos(IConnectionEntry entry);
-}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IDataReceiveListenerFactory.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IDataReceiveListenerFactory.java
deleted file mode 100644
index 7e74aee..0000000
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IDataReceiveListenerFactory.java
+++ /dev/null
@@ -1,25 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.api.comm;
-
-import java.util.UUID;
-
-public interface IDataReceiveListenerFactory {
-    public IDataReceiveListener getDataReceiveListener(UUID endpointUUID, IConnectionEntry entry, int senderIndex);
-
-    public UUID getJobId();
-
-    public UUID getStageId();
-}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IPartitionCollector.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IPartitionCollector.java
new file mode 100644
index 0000000..e7fde8c
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IPartitionCollector.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.api.comm;
+
+import java.util.Collection;
+import java.util.UUID;
+
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+
+public interface IPartitionCollector {
+    public UUID getJobId();
+
+    public ConnectorDescriptorId getConnectorId();
+
+    public int getReceiverIndex();
+
+    public void open() throws HyracksException;
+
+    public void addPartitions(Collection<PartitionChannel> partitions) throws HyracksException;
+
+    public IFrameReader getReader() throws HyracksException;
+
+    public void close() throws HyracksException;
+
+    public Collection<PartitionId> getRequiredPartitionIds() throws HyracksException;
+
+    public void abort();
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IPartitionWriterFactory.java
similarity index 84%
rename from hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java
rename to hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IPartitionWriterFactory.java
index 59edd97..e15ec6d 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IPartitionWriterFactory.java
@@ -16,6 +16,6 @@
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 
-public interface IEndpointDataWriterFactory {
-    public IFrameWriter createFrameWriter(int index) throws HyracksDataException;
+public interface IPartitionWriterFactory {
+    public IFrameWriter createFrameWriter(int receiverIndex) throws HyracksDataException;
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/PartitionChannel.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/PartitionChannel.java
new file mode 100644
index 0000000..b75ed07
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/PartitionChannel.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.api.comm;
+
+import edu.uci.ics.hyracks.api.channels.IInputChannel;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+
+public class PartitionChannel {
+    private PartitionId partitionId;
+
+    private IInputChannel channel;
+
+    public PartitionChannel(PartitionId partitionId, IInputChannel channel) {
+        this.partitionId = partitionId;
+        this.channel = channel;
+    }
+
+    public PartitionId getPartitionId() {
+        return partitionId;
+    }
+
+    public IInputChannel getInputChannel() {
+        return channel;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/Constraint.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/Constraint.java
new file mode 100644
index 0000000..0668e00
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/Constraint.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.api.constraints;
+
+import java.io.Serializable;
+
+import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression;
+import edu.uci.ics.hyracks.api.constraints.expressions.LValueConstraintExpression;
+
+public class Constraint implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private final LValueConstraintExpression lValue;
+
+    private final ConstraintExpression rValue;
+
+    public Constraint(LValueConstraintExpression lValue, ConstraintExpression rValue) {
+        this.lValue = lValue;
+        this.rValue = rValue;
+    }
+
+    public LValueConstraintExpression getLValue() {
+        return lValue;
+    }
+
+    public ConstraintExpression getRValue() {
+        return rValue;
+    }
+
+    @Override
+    public String toString() {
+        return lValue + " in " + rValue;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IJobAttemptSchedulerState.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/IConstraintAcceptor.java
similarity index 81%
rename from hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IJobAttemptSchedulerState.java
rename to hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/IConstraintAcceptor.java
index f8fcb89..2e41b0a 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IJobAttemptSchedulerState.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/IConstraintAcceptor.java
@@ -12,7 +12,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hyracks.control.cc.scheduler;
+package edu.uci.ics.hyracks.api.constraints;
 
-public interface IJobAttemptSchedulerState {
+public interface IConstraintAcceptor {
+    public void addConstraint(Constraint constraint);
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/IConstraintExpressionAcceptor.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/IConstraintExpressionAcceptor.java
deleted file mode 100644
index 7e74814..0000000
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/IConstraintExpressionAcceptor.java
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.api.constraints;
-
-import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression;
-
-public interface IConstraintExpressionAcceptor {
-    public void addConstraintExpression(ConstraintExpression constraintExpression);
-}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/PartitionConstraintHelper.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/PartitionConstraintHelper.java
index 309fca1..0e4ca69 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/PartitionConstraintHelper.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/PartitionConstraintHelper.java
@@ -14,45 +14,31 @@
  */
 package edu.uci.ics.hyracks.api.constraints;
 
-import java.util.ArrayList;
-import java.util.List;
-
-import edu.uci.ics.hyracks.api.constraints.expressions.BelongsToExpression;
 import edu.uci.ics.hyracks.api.constraints.expressions.ConstantExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.EnumeratedCollectionExpression;
 import edu.uci.ics.hyracks.api.constraints.expressions.PartitionCountExpression;
 import edu.uci.ics.hyracks.api.constraints.expressions.PartitionLocationExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.RelationalExpression;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
 
 public class PartitionConstraintHelper {
     public static void addPartitionCountConstraint(JobSpecification spec, IOperatorDescriptor op, int count) {
-        spec.addUserConstraint(new RelationalExpression(new PartitionCountExpression(op.getOperatorId()),
-                new ConstantExpression(count), RelationalExpression.Operator.EQUAL));
+        spec.addUserConstraint(new Constraint(new PartitionCountExpression(op.getOperatorId()), new ConstantExpression(
+                count)));
     }
 
     public static void addLocationChoiceConstraint(JobSpecification spec, IOperatorDescriptor op, String[][] choices) {
         addPartitionCountConstraint(spec, op, choices.length);
         for (int i = 0; i < choices.length; ++i) {
-            String[] choice = choices[i];
-            List<ConstraintExpression> choiceExprs = new ArrayList<ConstraintExpression>();
-            for (String c : choice) {
-                choiceExprs.add(new ConstantExpression(c));
-            }
-            spec.addUserConstraint(new BelongsToExpression(new PartitionLocationExpression(op.getOperatorId(), i),
-                    new EnumeratedCollectionExpression(choiceExprs)));
+            spec.addUserConstraint(new Constraint(new PartitionLocationExpression(op.getOperatorId(), i),
+                    new ConstantExpression(choices[i])));
         }
     }
 
     public static void addAbsoluteLocationConstraint(JobSpecification spec, IOperatorDescriptor op, String... locations) {
         addPartitionCountConstraint(spec, op, locations.length);
         for (int i = 0; i < locations.length; ++i) {
-            List<ConstraintExpression> choiceExprs = new ArrayList<ConstraintExpression>();
-            choiceExprs.add(new ConstantExpression(locations[i]));
-            spec.addUserConstraint(new BelongsToExpression(new PartitionLocationExpression(op.getOperatorId(), i),
-                    new EnumeratedCollectionExpression(choiceExprs)));
+            spec.addUserConstraint(new Constraint(new PartitionLocationExpression(op.getOperatorId(), i),
+                    new ConstantExpression(locations[i])));
         }
     }
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/BelongsToExpression.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/BelongsToExpression.java
deleted file mode 100644
index c307e3e..0000000
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/BelongsToExpression.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.api.constraints.expressions;
-
-import java.util.Collection;
-
-public final class BelongsToExpression extends ConstraintExpression {
-    private static final long serialVersionUID = 1L;
-
-    private final ConstraintExpression itemExpression;
-
-    private final ConstraintExpression setExpression;
-
-    public BelongsToExpression(ConstraintExpression itemExpression, ConstraintExpression setExpression) {
-        this.itemExpression = itemExpression;
-        this.setExpression = setExpression;
-    }
-
-    @Override
-    public ExpressionTag getTag() {
-        return ExpressionTag.BELONGS_TO;
-    }
-
-    public ConstraintExpression getItemExpression() {
-        return itemExpression;
-    }
-
-    public ConstraintExpression getSetExpression() {
-        return setExpression;
-    }
-
-    @Override
-    public void getChildren(Collection<ConstraintExpression> children) {
-        children.add(itemExpression);
-        children.add(setExpression);
-    }
-
-    @Override
-    protected void toString(StringBuilder buffer) {
-        buffer.append(getTag()).append('(');
-        itemExpression.toString(buffer);
-        buffer.append(", ");
-        setExpression.toString(buffer);
-        buffer.append(')');
-    }
-}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/ConstraintExpression.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/ConstraintExpression.java
index afd5051..811c048 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/ConstraintExpression.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/ConstraintExpression.java
@@ -23,11 +23,7 @@
     public enum ExpressionTag {
         CONSTANT,
         PARTITION_COUNT,
-        RESOURCE_SUM,
         PARTITION_LOCATION,
-        ENUMERATED_SET,
-        BELONGS_TO,
-        RELATIONAL,
     }
 
     public abstract ExpressionTag getTag();
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/EnumeratedCollectionExpression.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/EnumeratedCollectionExpression.java
deleted file mode 100644
index d0ce706..0000000
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/EnumeratedCollectionExpression.java
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.api.constraints.expressions;
-
-import java.util.Collection;
-
-public class EnumeratedCollectionExpression extends ConstraintExpression {
-    private static final long serialVersionUID = 1L;
-
-    private final Collection<ConstraintExpression> enumeration;
-
-    public EnumeratedCollectionExpression(Collection<ConstraintExpression> enumeration) {
-        this.enumeration = enumeration;
-    }
-
-    @Override
-    public ExpressionTag getTag() {
-        return ExpressionTag.ENUMERATED_SET;
-    }
-
-    public Collection<ConstraintExpression> getMembers() {
-        return enumeration;
-    }
-
-    @Override
-    public void getChildren(Collection<ConstraintExpression> children) {
-        children.addAll(enumeration);
-    }
-
-    @Override
-    protected void toString(StringBuilder buffer) {
-        buffer.append(getTag()).append('(');
-        boolean first = true;
-        for (ConstraintExpression ce : enumeration) {
-            if (!first) {
-                buffer.append(", ");
-            }
-            first = false;
-            ce.toString(buffer);
-        }
-        buffer.append(')');
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/LValueConstraintExpression.java
similarity index 76%
copy from hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java
copy to hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/LValueConstraintExpression.java
index 2906ba6..7557460 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/LValueConstraintExpression.java
@@ -12,10 +12,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hyracks.control.cc.scheduler;
+package edu.uci.ics.hyracks.api.constraints.expressions;
 
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
-
-public interface ISchedule {
-    public String[] getPartitions(ActivityNodeId aid);
+public abstract class LValueConstraintExpression extends ConstraintExpression {
+    private static final long serialVersionUID = 1L;
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/PartitionCountExpression.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/PartitionCountExpression.java
index c538ff7..dc73947 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/PartitionCountExpression.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/PartitionCountExpression.java
@@ -18,7 +18,7 @@
 
 import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
 
-public final class PartitionCountExpression extends ConstraintExpression {
+public final class PartitionCountExpression extends LValueConstraintExpression {
     private static final long serialVersionUID = 1L;
 
     private final OperatorDescriptorId opId;
@@ -44,4 +44,29 @@
     protected void toString(StringBuilder buffer) {
         buffer.append(getTag()).append('(').append(opId.toString()).append(')');
     }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((opId == null) ? 0 : opId.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        PartitionCountExpression other = (PartitionCountExpression) obj;
+        if (opId == null) {
+            if (other.opId != null)
+                return false;
+        } else if (!opId.equals(other.opId))
+            return false;
+        return true;
+    }
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/PartitionLocationExpression.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/PartitionLocationExpression.java
index 50e4e47..fbfdc1c 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/PartitionLocationExpression.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/PartitionLocationExpression.java
@@ -18,7 +18,7 @@
 
 import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
 
-public final class PartitionLocationExpression extends ConstraintExpression {
+public final class PartitionLocationExpression extends LValueConstraintExpression {
     private static final long serialVersionUID = 1L;
 
     private final OperatorDescriptorId opId;
@@ -50,4 +50,32 @@
     protected void toString(StringBuilder buffer) {
         buffer.append(getTag()).append('(').append(opId.toString()).append(", ").append(partition).append(')');
     }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((opId == null) ? 0 : opId.hashCode());
+        result = prime * result + partition;
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        PartitionLocationExpression other = (PartitionLocationExpression) obj;
+        if (opId == null) {
+            if (other.opId != null)
+                return false;
+        } else if (!opId.equals(other.opId))
+            return false;
+        if (partition != other.partition)
+            return false;
+        return true;
+    }
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/RelationalExpression.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/RelationalExpression.java
deleted file mode 100644
index d90bce9..0000000
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/RelationalExpression.java
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.api.constraints.expressions;
-
-import java.util.Collection;
-
-public class RelationalExpression extends ConstraintExpression {
-    private static final long serialVersionUID = 1L;
-
-    public enum Operator {
-        EQUAL,
-        NOT_EQUAL,
-        LESS,
-        LESS_EQUAL,
-        GREATER,
-        GREATER_EQUAL
-    }
-
-    private final ConstraintExpression left;
-    private final ConstraintExpression right;
-    private final Operator op;
-
-    public RelationalExpression(ConstraintExpression left, ConstraintExpression right, Operator op) {
-        this.left = left;
-        this.right = right;
-        this.op = op;
-    }
-
-    @Override
-    public ExpressionTag getTag() {
-        return ExpressionTag.RELATIONAL;
-    }
-
-    public ConstraintExpression getLeft() {
-        return left;
-    }
-
-    public ConstraintExpression getRight() {
-        return right;
-    }
-
-    public Operator getOperator() {
-        return op;
-    }
-
-    @Override
-    public void getChildren(Collection<ConstraintExpression> children) {
-        children.add(left);
-        children.add(right);
-    }
-
-    @Override
-    protected void toString(StringBuilder buffer) {
-        buffer.append(getTag()).append('(').append(op).append(", ");
-        left.toString(buffer);
-        buffer.append(", ");
-        right.toString(buffer);
-        buffer.append(')');
-    }
-}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/ResourceSumExpression.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/ResourceSumExpression.java
deleted file mode 100644
index 3fbdd08..0000000
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/expressions/ResourceSumExpression.java
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.api.constraints.expressions;
-
-import java.util.Collection;
-
-import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
-
-public final class ResourceSumExpression extends ConstraintExpression {
-    private static final long serialVersionUID = 1L;
-
-    private final OperatorDescriptorId opId;
-
-    private final String resourceName;
-
-    public ResourceSumExpression(OperatorDescriptorId opId, String resourceName) {
-        this.opId = opId;
-        this.resourceName = resourceName;
-    }
-
-    @Override
-    public ExpressionTag getTag() {
-        return ExpressionTag.RESOURCE_SUM;
-    }
-
-    public OperatorDescriptorId getOperatorDescriptorId() {
-        return opId;
-    }
-
-    public String getResourceName() {
-        return resourceName;
-    }
-
-    @Override
-    public void getChildren(Collection<ConstraintExpression> children) {
-    }
-
-    @Override
-    protected void toString(StringBuilder buffer) {
-        buffer.append(getTag()).append('(').append(opId.toString()).append(", ").append(resourceName).append(')');
-    }
-}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksJobletContext.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksJobletContext.java
index 534507e..3901007 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksJobletContext.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksJobletContext.java
@@ -26,7 +26,5 @@
 
     public UUID getJobId();
 
-    public int getAttempt();
-
     public ICounterContext getCounterContext();
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksStageletContext.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksTaskContext.java
similarity index 82%
rename from hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksStageletContext.java
rename to hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksTaskContext.java
index ae171fe..a7646fc 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksStageletContext.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksTaskContext.java
@@ -14,16 +14,15 @@
  */
 package edu.uci.ics.hyracks.api.context;
 
-import java.util.UUID;
-
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
 import edu.uci.ics.hyracks.api.io.IWorkspaceFileFactory;
 import edu.uci.ics.hyracks.api.job.profiling.counters.ICounterContext;
 import edu.uci.ics.hyracks.api.resources.IDeallocatableRegistry;
 
-public interface IHyracksStageletContext extends IHyracksCommonContext, IWorkspaceFileFactory, IDeallocatableRegistry {
+public interface IHyracksTaskContext extends IHyracksCommonContext, IWorkspaceFileFactory, IDeallocatableRegistry {
     public IHyracksJobletContext getJobletContext();
 
-    public UUID getStageId();
+    public TaskAttemptId getTaskId();
 
     public ICounterContext getCounterContext();
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IActivityNode.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IActivityNode.java
index 39d2eda..9a37661 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IActivityNode.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IActivityNode.java
@@ -16,7 +16,7 @@
 
 import java.io.Serializable;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.job.IOperatorEnvironment;
@@ -26,6 +26,6 @@
 
     public IOperatorDescriptor getOwner();
 
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) throws HyracksDataException;
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IConnectorDescriptor.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IConnectorDescriptor.java
index 2fd317b..1664531 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IConnectorDescriptor.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IConnectorDescriptor.java
@@ -15,19 +15,19 @@
 package edu.uci.ics.hyracks.api.dataflow;
 
 import java.io.Serializable;
+import java.util.BitSet;
 
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
-import edu.uci.ics.hyracks.api.comm.IEndpointDataWriterFactory;
-import edu.uci.ics.hyracks.api.comm.IFrameReader;
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.constraints.IConstraintExpressionAcceptor;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.comm.IPartitionCollector;
+import edu.uci.ics.hyracks.api.comm.IPartitionWriterFactory;
+import edu.uci.ics.hyracks.api.constraints.IConstraintAcceptor;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.job.JobPlan;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
 
 /**
  * Connector that connects operators in a Job.
@@ -60,8 +60,8 @@
      * @return data writer.
      * @throws Exception
      */
-    public IFrameWriter createSendSideWriter(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IEndpointDataWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
+    public IFrameWriter createPartitioner(IHyracksTaskContext ctx, RecordDescriptor recordDesc,
+            IPartitionWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
             throws HyracksDataException;
 
     /**
@@ -71,20 +71,17 @@
      *            Context
      * @param recordDesc
      *            Job plan
-     * @param demux
-     *            Connection Demultiplexer
-     * @param index
+     * @param receiverIndex
      *            ordinal index of the data consumer partition
      * @param nProducerPartitions
      *            Number of partitions of the producing operator.
      * @param nConsumerPartitions
      *            Number of partitions of the consuming operator.
-     * @return data reader
+     * @return partition collector
      * @throws HyracksDataException
      */
-    public IFrameReader createReceiveSideReader(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IConnectionDemultiplexer demux, int index, int nProducerPartitions, int nConsumerPartitions)
-            throws HyracksDataException;
+    public IPartitionCollector createPartitionCollector(IHyracksTaskContext ctx, RecordDescriptor recordDesc,
+            int receiverIndex, int nProducerPartitions, int nConsumerPartitions) throws HyracksDataException;
 
     /**
      * Contribute any scheduling constraints imposed by this connector
@@ -94,7 +91,13 @@
      * @param plan
      *            - Job Plan
      */
-    public void contributeSchedulingConstraints(IConstraintExpressionAcceptor constraintAcceptor, JobPlan plan);
+    public void contributeSchedulingConstraints(IConstraintAcceptor constraintAcceptor, JobActivityGraph plan);
+
+    /**
+     * Indicate which consumer partitions may receive data from the given producer partition.
+     */
+    public void indicateTargetPartitions(int nProducerPartitions, int nConsumerPartitions, int producerIndex,
+            BitSet targetBitmap);
 
     /**
      * Translate this connector descriptor to JSON.
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorDescriptor.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorDescriptor.java
index e58ac99..b838a80 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorDescriptor.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorDescriptor.java
@@ -19,9 +19,9 @@
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import edu.uci.ics.hyracks.api.constraints.IConstraintExpressionAcceptor;
+import edu.uci.ics.hyracks.api.constraints.IConstraintAcceptor;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
-import edu.uci.ics.hyracks.api.job.JobPlan;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
 
 /**
  * Descriptor for operators in Hyracks.
@@ -73,7 +73,7 @@
      * @param plan
      *            - Job Plan
      */
-    public void contributeSchedulingConstraints(IConstraintExpressionAcceptor constraintAcceptor, JobPlan plan);
+    public void contributeSchedulingConstraints(IConstraintAcceptor constraintAcceptor, JobActivityGraph plan);
 
     /**
      * Translates this operator descriptor to JSON.
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/TaskAttemptId.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/TaskAttemptId.java
new file mode 100644
index 0000000..0b15865
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/TaskAttemptId.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.api.dataflow;
+
+import java.io.Serializable;
+
+public final class TaskAttemptId implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private final TaskId taskId;
+
+    private final int attempt;
+
+    public TaskAttemptId(TaskId taskId, int attempt) {
+        this.taskId = taskId;
+        this.attempt = attempt;
+    }
+
+    public TaskId getTaskId() {
+        return taskId;
+    }
+
+    public int getAttempt() {
+        return attempt;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (!(o instanceof TaskAttemptId)) {
+            return false;
+        }
+        TaskAttemptId oTaskId = (TaskAttemptId) o;
+        return oTaskId.attempt == attempt && oTaskId.taskId.equals(taskId);
+    }
+
+    @Override
+    public int hashCode() {
+        return taskId.hashCode() + attempt;
+    }
+
+    @Override
+    public String toString() {
+        return "TAID:[" + taskId + ":" + attempt + "]";
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/TaskId.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/TaskId.java
new file mode 100644
index 0000000..9283b8e
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/TaskId.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.api.dataflow;
+
+import java.io.Serializable;
+
+public final class TaskId implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private final ActivityNodeId activityId;
+
+    private final int partition;
+
+    public TaskId(ActivityNodeId activityId, int partition) {
+        this.activityId = activityId;
+        this.partition = partition;
+    }
+
+    public ActivityNodeId getActivityId() {
+        return activityId;
+    }
+
+    public int getPartition() {
+        return partition;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (!(o instanceof TaskId)) {
+            return false;
+        }
+        TaskId oTaskId = (TaskId) o;
+        return oTaskId.partition == partition && oTaskId.activityId.equals(activityId);
+    }
+
+    @Override
+    public int hashCode() {
+        return activityId.hashCode() + partition;
+    }
+
+    @Override
+    public String toString() {
+        return "TID:[" + activityId + ":" + partition + ":" + "]";
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/io/FileReference.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/io/FileReference.java
index e9ba2c3..9e27077 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/io/FileReference.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/io/FileReference.java
@@ -51,4 +51,8 @@
     public int hashCode() {
         return file.hashCode();
     }
+
+    public void delete() {
+        file.delete();
+    }
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/io/IWorkspaceFileFactory.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/io/IWorkspaceFileFactory.java
index 1311ec5..7b9a7c4 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/io/IWorkspaceFileFactory.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/io/IWorkspaceFileFactory.java
@@ -17,5 +17,7 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 
 public interface IWorkspaceFileFactory {
-    public FileReference createWorkspaceFile(String prefix) throws HyracksDataException;
+    public FileReference createUnmanagedWorkspaceFile(String prefix) throws HyracksDataException;
+
+    public FileReference createManagedWorkspaceFile(String prefix) throws HyracksDataException;
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobActivityGraph.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobActivityGraph.java
new file mode 100644
index 0000000..d2a4f0f
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobActivityGraph.java
@@ -0,0 +1,204 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.api.job;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+import edu.uci.ics.hyracks.api.dataflow.IActivityNode;
+import edu.uci.ics.hyracks.api.dataflow.IConnectorDescriptor;
+import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
+import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.util.Pair;
+
+public class JobActivityGraph implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private final String appName;
+
+    private final JobSpecification jobSpec;
+
+    private final EnumSet<JobFlag> jobFlags;
+
+    private final Map<ActivityNodeId, IActivityNode> activityNodes;
+
+    private final Map<ActivityNodeId, Set<ActivityNodeId>> blocker2blockedMap;
+
+    private final Map<ActivityNodeId, Set<ActivityNodeId>> blocked2blockerMap;
+
+    private final Map<OperatorDescriptorId, Set<ActivityNodeId>> operatorActivityMap;
+
+    private final Map<ActivityNodeId, List<Integer>> activityInputMap;
+
+    private final Map<ActivityNodeId, List<Integer>> activityOutputMap;
+
+    private final Map<OperatorDescriptorId, List<ActivityNodeId>> operatorInputMap;
+
+    private final Map<OperatorDescriptorId, List<ActivityNodeId>> operatorOutputMap;
+
+    public JobActivityGraph(String appName, JobSpecification jobSpec, EnumSet<JobFlag> jobFlags) {
+        this.appName = appName;
+        this.jobSpec = jobSpec;
+        this.jobFlags = jobFlags;
+        activityNodes = new HashMap<ActivityNodeId, IActivityNode>();
+        blocker2blockedMap = new HashMap<ActivityNodeId, Set<ActivityNodeId>>();
+        blocked2blockerMap = new HashMap<ActivityNodeId, Set<ActivityNodeId>>();
+        operatorActivityMap = new HashMap<OperatorDescriptorId, Set<ActivityNodeId>>();
+        activityInputMap = new HashMap<ActivityNodeId, List<Integer>>();
+        activityOutputMap = new HashMap<ActivityNodeId, List<Integer>>();
+        operatorInputMap = new HashMap<OperatorDescriptorId, List<ActivityNodeId>>();
+        operatorOutputMap = new HashMap<OperatorDescriptorId, List<ActivityNodeId>>();
+    }
+
+    public String getApplicationName() {
+        return appName;
+    }
+
+    public JobSpecification getJobSpecification() {
+        return jobSpec;
+    }
+
+    public EnumSet<JobFlag> getJobFlags() {
+        return jobFlags;
+    }
+
+    public Map<ActivityNodeId, IActivityNode> getActivityNodeMap() {
+        return activityNodes;
+    }
+
+    public Map<ActivityNodeId, Set<ActivityNodeId>> getBlocker2BlockedMap() {
+        return blocker2blockedMap;
+    }
+
+    public Map<ActivityNodeId, Set<ActivityNodeId>> getBlocked2BlockerMap() {
+        return blocked2blockerMap;
+    }
+
+    public Map<OperatorDescriptorId, Set<ActivityNodeId>> getOperatorActivityMap() {
+        return operatorActivityMap;
+    }
+
+    public Map<ActivityNodeId, List<Integer>> getActivityInputMap() {
+        return activityInputMap;
+    }
+
+    public Map<ActivityNodeId, List<Integer>> getActivityOutputMap() {
+        return activityOutputMap;
+    }
+
+    public Map<OperatorDescriptorId, List<ActivityNodeId>> getOperatorInputMap() {
+        return operatorInputMap;
+    }
+
+    public Map<OperatorDescriptorId, List<ActivityNodeId>> getOperatorOutputMap() {
+        return operatorOutputMap;
+    }
+
+    public List<IConnectorDescriptor> getActivityInputConnectorDescriptors(ActivityNodeId hanId) {
+        List<Integer> inputIndexes = activityInputMap.get(hanId);
+        if (inputIndexes == null) {
+            return null;
+        }
+        OperatorDescriptorId ownerId = hanId.getOperatorDescriptorId();
+        List<IConnectorDescriptor> inputs = new ArrayList<IConnectorDescriptor>();
+        for (Integer i : inputIndexes) {
+            inputs.add(jobSpec.getInputConnectorDescriptor(ownerId, i));
+        }
+        return inputs;
+    }
+
+    public List<IConnectorDescriptor> getActivityOutputConnectorDescriptors(ActivityNodeId hanId) {
+        List<Integer> outputIndexes = activityOutputMap.get(hanId);
+        if (outputIndexes == null) {
+            return null;
+        }
+        OperatorDescriptorId ownerId = hanId.getOperatorDescriptorId();
+        List<IConnectorDescriptor> outputs = new ArrayList<IConnectorDescriptor>();
+        for (Integer i : outputIndexes) {
+            outputs.add(jobSpec.getOutputConnectorDescriptor(ownerId, i));
+        }
+        return outputs;
+    }
+
+    public ActivityNodeId getConsumerActivity(ConnectorDescriptorId cdId) {
+        Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>> connEdge = jobSpec
+                .getConnectorOperatorMap().get(cdId);
+
+        OperatorDescriptorId consumerOpId = connEdge.second.first.getOperatorId();
+        int consumerInputIdx = connEdge.second.second;
+
+        for (ActivityNodeId anId : operatorActivityMap.get(consumerOpId)) {
+            List<Integer> anInputs = activityInputMap.get(anId);
+            if (anInputs != null) {
+                for (Integer idx : anInputs) {
+                    if (idx.intValue() == consumerInputIdx) {
+                        return anId;
+                    }
+                }
+            }
+        }
+        return null;
+    }
+
+    public ActivityNodeId getProducerActivity(ConnectorDescriptorId cdId) {
+        Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>> connEdge = jobSpec
+                .getConnectorOperatorMap().get(cdId);
+
+        OperatorDescriptorId producerOpId = connEdge.first.first.getOperatorId();
+        int producerInputIdx = connEdge.first.second;
+
+        for (ActivityNodeId anId : operatorActivityMap.get(producerOpId)) {
+            List<Integer> anOutputs = activityOutputMap.get(anId);
+            if (anOutputs != null) {
+                for (Integer idx : anOutputs) {
+                    if (idx.intValue() == producerInputIdx) {
+                        return anId;
+                    }
+                }
+            }
+        }
+        return null;
+    }
+
+    public RecordDescriptor getActivityInputRecordDescriptor(ActivityNodeId hanId, int inputIndex) {
+        int opInputIndex = getActivityInputMap().get(hanId).get(inputIndex);
+        return jobSpec.getOperatorInputRecordDescriptor(hanId.getOperatorDescriptorId(), opInputIndex);
+    }
+
+    public RecordDescriptor getActivityOutputRecordDescriptor(ActivityNodeId hanId, int outputIndex) {
+        int opOutputIndex = getActivityOutputMap().get(hanId).get(outputIndex);
+        return jobSpec.getOperatorOutputRecordDescriptor(hanId.getOperatorDescriptorId(), opOutputIndex);
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder buffer = new StringBuilder();
+        buffer.append("ActivityNodes: " + activityNodes);
+        buffer.append('\n');
+        buffer.append("Blocker->Blocked: " + blocker2blockedMap);
+        buffer.append('\n');
+        buffer.append("Blocked->Blocker: " + blocked2blockerMap);
+        buffer.append('\n');
+        return buffer.toString();
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobPlan.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobPlan.java
deleted file mode 100644
index 13da402..0000000
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobPlan.java
+++ /dev/null
@@ -1,169 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.api.job;
-
-import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.EnumSet;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
-import edu.uci.ics.hyracks.api.dataflow.IActivityNode;
-import edu.uci.ics.hyracks.api.dataflow.IConnectorDescriptor;
-import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
-import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
-
-public class JobPlan implements Serializable {
-    private static final long serialVersionUID = 1L;
-
-    private final String appName;
-
-    private final UUID jobId;
-
-    private final JobSpecification jobSpec;
-
-    private final EnumSet<JobFlag> jobFlags;
-
-    private final Map<ActivityNodeId, IActivityNode> activityNodes;
-
-    private final Map<ActivityNodeId, Set<ActivityNodeId>> blocker2blockedMap;
-
-    private final Map<ActivityNodeId, Set<ActivityNodeId>> blocked2blockerMap;
-
-    private final Map<OperatorDescriptorId, Set<ActivityNodeId>> operatorTaskMap;
-
-    private final Map<ActivityNodeId, List<Integer>> taskInputMap;
-
-    private final Map<ActivityNodeId, List<Integer>> taskOutputMap;
-
-    private final Map<OperatorDescriptorId, List<ActivityNodeId>> operatorInputMap;
-
-    private final Map<OperatorDescriptorId, List<ActivityNodeId>> operatorOutputMap;
-
-    public JobPlan(String appName, UUID jobId, JobSpecification jobSpec, EnumSet<JobFlag> jobFlags) {
-        this.appName = appName;
-        this.jobId = jobId;
-        this.jobSpec = jobSpec;
-        this.jobFlags = jobFlags;
-        activityNodes = new HashMap<ActivityNodeId, IActivityNode>();
-        blocker2blockedMap = new HashMap<ActivityNodeId, Set<ActivityNodeId>>();
-        blocked2blockerMap = new HashMap<ActivityNodeId, Set<ActivityNodeId>>();
-        operatorTaskMap = new HashMap<OperatorDescriptorId, Set<ActivityNodeId>>();
-        taskInputMap = new HashMap<ActivityNodeId, List<Integer>>();
-        taskOutputMap = new HashMap<ActivityNodeId, List<Integer>>();
-        operatorInputMap = new HashMap<OperatorDescriptorId, List<ActivityNodeId>>();
-        operatorOutputMap = new HashMap<OperatorDescriptorId, List<ActivityNodeId>>();
-    }
-
-    public String getApplicationName() {
-        return appName;
-    }
-
-    public UUID getJobId() {
-        return jobId;
-    }
-
-    public JobSpecification getJobSpecification() {
-        return jobSpec;
-    }
-
-    public EnumSet<JobFlag> getJobFlags() {
-        return jobFlags;
-    }
-
-    public Map<ActivityNodeId, IActivityNode> getActivityNodeMap() {
-        return activityNodes;
-    }
-
-    public Map<ActivityNodeId, Set<ActivityNodeId>> getBlocker2BlockedMap() {
-        return blocker2blockedMap;
-    }
-
-    public Map<ActivityNodeId, Set<ActivityNodeId>> getBlocked2BlockerMap() {
-        return blocked2blockerMap;
-    }
-
-    public Map<OperatorDescriptorId, Set<ActivityNodeId>> getOperatorTaskMap() {
-        return operatorTaskMap;
-    }
-
-    public Map<ActivityNodeId, List<Integer>> getTaskInputMap() {
-        return taskInputMap;
-    }
-
-    public Map<ActivityNodeId, List<Integer>> getTaskOutputMap() {
-        return taskOutputMap;
-    }
-
-    public Map<OperatorDescriptorId, List<ActivityNodeId>> getOperatorInputMap() {
-        return operatorInputMap;
-    }
-
-    public Map<OperatorDescriptorId, List<ActivityNodeId>> getOperatorOutputMap() {
-        return operatorOutputMap;
-    }
-
-    public List<IConnectorDescriptor> getTaskInputs(ActivityNodeId hanId) {
-        List<Integer> inputIndexes = taskInputMap.get(hanId);
-        if (inputIndexes == null) {
-            return null;
-        }
-        OperatorDescriptorId ownerId = hanId.getOperatorDescriptorId();
-        List<IConnectorDescriptor> inputs = new ArrayList<IConnectorDescriptor>();
-        for (Integer i : inputIndexes) {
-            inputs.add(jobSpec.getInputConnectorDescriptor(ownerId, i));
-        }
-        return inputs;
-    }
-
-    public List<IConnectorDescriptor> getTaskOutputs(ActivityNodeId hanId) {
-        List<Integer> outputIndexes = taskOutputMap.get(hanId);
-        if (outputIndexes == null) {
-            return null;
-        }
-        OperatorDescriptorId ownerId = hanId.getOperatorDescriptorId();
-        List<IConnectorDescriptor> outputs = new ArrayList<IConnectorDescriptor>();
-        for (Integer i : outputIndexes) {
-            outputs.add(jobSpec.getOutputConnectorDescriptor(ownerId, i));
-        }
-        return outputs;
-    }
-
-    public RecordDescriptor getTaskInputRecordDescriptor(ActivityNodeId hanId, int inputIndex) {
-        int opInputIndex = getTaskInputMap().get(hanId).get(inputIndex);
-        return jobSpec.getOperatorInputRecordDescriptor(hanId.getOperatorDescriptorId(), opInputIndex);
-    }
-
-    public RecordDescriptor getTaskOutputRecordDescriptor(ActivityNodeId hanId, int outputIndex) {
-        int opOutputIndex = getTaskOutputMap().get(hanId).get(outputIndex);
-        return jobSpec.getOperatorOutputRecordDescriptor(hanId.getOperatorDescriptorId(), opOutputIndex);
-    }
-
-    @Override
-    public String toString() {
-        StringBuilder buffer = new StringBuilder();
-        buffer.append("ActivityNodes: " + activityNodes);
-        buffer.append('\n');
-        buffer.append("Blocker->Blocked: " + blocker2blockedMap);
-        buffer.append('\n');
-        buffer.append("Blocked->Blocker: " + blocked2blockerMap);
-        buffer.append('\n');
-        return buffer.toString();
-    }
-}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobSpecification.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobSpecification.java
index 59072f8..ab5397d 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobSpecification.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobSpecification.java
@@ -26,7 +26,7 @@
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression;
+import edu.uci.ics.hyracks.api.constraints.Constraint;
 import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
 import edu.uci.ics.hyracks.api.dataflow.IConnectorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
@@ -51,7 +51,7 @@
 
     private final Map<String, Serializable> properties;
 
-    private final Set<ConstraintExpression> userConstraints;
+    private final Set<Constraint> userConstraints;
 
     private int maxAttempts;
 
@@ -63,7 +63,7 @@
         opOutputMap = new HashMap<OperatorDescriptorId, List<IConnectorDescriptor>>();
         connectorOpMap = new HashMap<ConnectorDescriptorId, Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>>>();
         properties = new HashMap<String, Serializable>();
-        userConstraints = new HashSet<ConstraintExpression>();
+        userConstraints = new HashSet<Constraint>();
     }
 
     public void addRoot(IOperatorDescriptor op) {
@@ -181,11 +181,11 @@
         return maxAttempts;
     }
 
-    public void addUserConstraint(ConstraintExpression constraint) {
+    public void addUserConstraint(Constraint constraint) {
         userConstraints.add(constraint);
     }
 
-    public Set<ConstraintExpression> getUserConstraints() {
+    public Set<Constraint> getUserConstraints() {
         return userConstraints;
     }
 
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/partitions/IPartition.java
similarity index 68%
copy from hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java
copy to hyracks-api/src/main/java/edu/uci/ics/hyracks/api/partitions/IPartition.java
index 59edd97..02eb891 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/partitions/IPartition.java
@@ -12,10 +12,13 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hyracks.api.comm;
+package edu.uci.ics.hyracks.api.partitions;
 
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.resources.IDeallocatable;
 
-public interface IEndpointDataWriterFactory {
-    public IFrameWriter createFrameWriter(int index) throws HyracksDataException;
+public interface IPartition extends IDeallocatable {
+    public void writeTo(IFrameWriter writer);
+
+    public boolean isReusable();
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/partitions/PartitionId.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/partitions/PartitionId.java
new file mode 100644
index 0000000..3eafbd6
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/partitions/PartitionId.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.api.partitions;
+
+import java.io.Serializable;
+import java.util.UUID;
+
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+
+public final class PartitionId implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private final UUID jobId;
+
+    private final ConnectorDescriptorId cdId;
+
+    private final int senderIndex;
+
+    private final int receiverIndex;
+
+    public PartitionId(UUID jobId, ConnectorDescriptorId cdId, int senderIndex, int receiverIndex) {
+        this.jobId = jobId;
+        this.cdId = cdId;
+        this.senderIndex = senderIndex;
+        this.receiverIndex = receiverIndex;
+    }
+
+    public UUID getJobId() {
+        return jobId;
+    }
+
+    public ConnectorDescriptorId getConnectorDescriptorId() {
+        return cdId;
+    }
+
+    public int getSenderIndex() {
+        return senderIndex;
+    }
+
+    public int getReceiverIndex() {
+        return receiverIndex;
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((cdId == null) ? 0 : cdId.hashCode());
+        result = prime * result + ((jobId == null) ? 0 : jobId.hashCode());
+        result = prime * result + receiverIndex;
+        result = prime * result + senderIndex;
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        PartitionId other = (PartitionId) obj;
+        if (cdId == null) {
+            if (other.cdId != null)
+                return false;
+        } else if (!cdId.equals(other.cdId))
+            return false;
+        if (jobId == null) {
+            if (other.jobId != null)
+                return false;
+        } else if (!jobId.equals(other.jobId))
+            return false;
+        if (receiverIndex != other.receiverIndex)
+            return false;
+        if (senderIndex != other.senderIndex)
+            return false;
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        return jobId.toString() + ":" + cdId + ":" + senderIndex + ":" + receiverIndex;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/ClusterControllerService.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/ClusterControllerService.java
index c550ecc..aebd6ce 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/ClusterControllerService.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/ClusterControllerService.java
@@ -17,6 +17,7 @@
 import java.io.File;
 import java.rmi.registry.LocateRegistry;
 import java.rmi.registry.Registry;
+import java.util.Collection;
 import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.Hashtable;
@@ -33,9 +34,12 @@
 
 import edu.uci.ics.hyracks.api.client.ClusterControllerInfo;
 import edu.uci.ics.hyracks.api.client.IHyracksClientInterface;
+import edu.uci.ics.hyracks.api.comm.NetworkAddress;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.api.job.JobFlag;
 import edu.uci.ics.hyracks.api.job.JobStatus;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
 import edu.uci.ics.hyracks.control.cc.application.CCApplicationContext;
 import edu.uci.ics.hyracks.control.cc.job.IJobStatusConditionVariable;
 import edu.uci.ics.hyracks.control.cc.job.JobRun;
@@ -47,15 +51,17 @@
 import edu.uci.ics.hyracks.control.cc.job.manager.events.JobStartEvent;
 import edu.uci.ics.hyracks.control.cc.job.manager.events.NodeHeartbeatEvent;
 import edu.uci.ics.hyracks.control.cc.job.manager.events.RegisterNodeEvent;
+import edu.uci.ics.hyracks.control.cc.job.manager.events.RegisterPartitionAvailibilityEvent;
+import edu.uci.ics.hyracks.control.cc.job.manager.events.RegisterPartitionRequestEvent;
 import edu.uci.ics.hyracks.control.cc.job.manager.events.RemoveDeadNodesEvent;
 import edu.uci.ics.hyracks.control.cc.job.manager.events.ReportProfilesEvent;
-import edu.uci.ics.hyracks.control.cc.job.manager.events.StageletCompleteEvent;
-import edu.uci.ics.hyracks.control.cc.job.manager.events.StageletFailureEvent;
+import edu.uci.ics.hyracks.control.cc.job.manager.events.TaskCompleteEvent;
+import edu.uci.ics.hyracks.control.cc.job.manager.events.TaskFailureEvent;
 import edu.uci.ics.hyracks.control.cc.job.manager.events.UnregisterNodeEvent;
 import edu.uci.ics.hyracks.control.cc.jobqueue.FutureValue;
 import edu.uci.ics.hyracks.control.cc.jobqueue.JobQueue;
-import edu.uci.ics.hyracks.control.cc.scheduler.IScheduler;
-import edu.uci.ics.hyracks.control.cc.scheduler.naive.NaiveScheduler;
+import edu.uci.ics.hyracks.control.cc.scheduler.DefaultJobScheduler;
+import edu.uci.ics.hyracks.control.cc.scheduler.IJobScheduler;
 import edu.uci.ics.hyracks.control.cc.web.WebServer;
 import edu.uci.ics.hyracks.control.common.AbstractRemoteService;
 import edu.uci.ics.hyracks.control.common.base.CCConfig;
@@ -64,7 +70,7 @@
 import edu.uci.ics.hyracks.control.common.base.NodeParameters;
 import edu.uci.ics.hyracks.control.common.context.ServerContext;
 import edu.uci.ics.hyracks.control.common.job.profiling.om.JobProfile;
-import edu.uci.ics.hyracks.control.common.job.profiling.om.StageletProfile;
+import edu.uci.ics.hyracks.control.common.job.profiling.om.TaskProfile;
 
 public class ClusterControllerService extends AbstractRemoteService implements IClusterController,
         IHyracksClientInterface {
@@ -88,7 +94,7 @@
 
     private final JobQueue jobQueue;
 
-    private final IScheduler scheduler;
+    private final IJobScheduler scheduler;
 
     private final Executor taskExecutor;
 
@@ -106,7 +112,7 @@
         webServer = new WebServer(this);
         runMap = new HashMap<UUID, JobRun>();
         jobQueue = new JobQueue();
-        scheduler = new NaiveScheduler(this);
+        scheduler = new DefaultJobScheduler(this);
         this.timer = new Timer(true);
         ccci = new CCClientInterface(this);
     }
@@ -144,7 +150,7 @@
         return jobQueue;
     }
 
-    public IScheduler getScheduler() {
+    public IJobScheduler getScheduler() {
         return scheduler;
     }
 
@@ -191,15 +197,16 @@
     }
 
     @Override
-    public void notifyStageletComplete(UUID jobId, UUID stageId, int attempt, String nodeId, StageletProfile statistics)
+    public void notifyTaskComplete(UUID jobId, TaskAttemptId taskId, String nodeId, TaskProfile statistics)
             throws Exception {
-        StageletCompleteEvent sce = new StageletCompleteEvent(this, jobId, stageId, attempt, nodeId);
+        TaskCompleteEvent sce = new TaskCompleteEvent(this, jobId, taskId, nodeId);
         jobQueue.schedule(sce);
     }
 
     @Override
-    public void notifyStageletFailure(UUID jobId, UUID stageId, int attempt, String nodeId) throws Exception {
-        StageletFailureEvent sfe = new StageletFailureEvent(this, jobId, stageId, attempt, nodeId);
+    public void notifyTaskFailure(UUID jobId, TaskAttemptId taskId, String nodeId, Exception exception)
+            throws Exception {
+        TaskFailureEvent sfe = new TaskFailureEvent(this, jobId, taskId, nodeId, exception);
         jobQueue.schedule(sfe);
     }
 
@@ -213,7 +220,7 @@
     @Override
     public void start(UUID jobId) throws Exception {
         JobStartEvent jse = new JobStartEvent(this, jobId);
-        jobQueue.scheduleAndSync(jse);
+        jobQueue.schedule(jse);
     }
 
     @Override
@@ -269,6 +276,16 @@
         return info;
     }
 
+    @Override
+    public void registerPartitionProvider(PartitionId pid, NetworkAddress address) throws Exception {
+        jobQueue.schedule(new RegisterPartitionAvailibilityEvent(this, pid, address));
+    }
+
+    @Override
+    public void registerPartitionRequest(Collection<PartitionId> requiredPartitionIds, String nodeId) {
+        jobQueue.schedule(new RegisterPartitionRequestEvent(this, requiredPartitionIds, nodeId));
+    }
+
     private class DeadNodeSweeper extends TimerTask {
         @Override
         public void run() {
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/NodeControllerState.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/NodeControllerState.java
index 6763451..e614bc5 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/NodeControllerState.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/NodeControllerState.java
@@ -1,21 +1,14 @@
 package edu.uci.ics.hyracks.control.cc;
 
-import java.util.HashSet;
-import java.util.Set;
-import java.util.UUID;
-
 import edu.uci.ics.hyracks.control.common.base.INodeController;
 
 public class NodeControllerState {
     private final INodeController nodeController;
 
-    private final Set<UUID> activeJobIds;
-
     private int lastHeartbeatDuration;
 
     public NodeControllerState(INodeController nodeController) {
         this.nodeController = nodeController;
-        activeJobIds = new HashSet<UUID>();
     }
 
     public void notifyHeartbeat() {
@@ -33,8 +26,4 @@
     public INodeController getNodeController() {
         return nodeController;
     }
-
-    public Set<UUID> getActiveJobIds() {
-        return activeJobIds;
-    }
 }
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/ActivityCluster.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/ActivityCluster.java
new file mode 100644
index 0000000..1e9261b
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/ActivityCluster.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.job;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+import edu.uci.ics.hyracks.control.cc.scheduler.IActivityClusterStateMachine;
+
+public class ActivityCluster {
+    private final JobRun jobRun;
+
+    private final Set<ActivityNodeId> activities;
+
+    private final Set<ActivityCluster> dependencies;
+
+    private final Set<ActivityCluster> dependents;
+
+    private final Map<ActivityNodeId, TaskState[]> taskStateMap;
+
+    private TaskCluster[] taskClusters;
+
+    private IActivityClusterStateMachine acsm;
+
+    public ActivityCluster(JobRun jobRun, Set<ActivityNodeId> activities) {
+        this.jobRun = jobRun;
+        this.activities = activities;
+        dependencies = new HashSet<ActivityCluster>();
+        dependents = new HashSet<ActivityCluster>();
+        taskStateMap = new HashMap<ActivityNodeId, TaskState[]>();
+    }
+
+    public Set<ActivityNodeId> getActivities() {
+        return activities;
+    }
+
+    public void addDependency(ActivityCluster stage) {
+        dependencies.add(stage);
+    }
+
+    public void addDependent(ActivityCluster stage) {
+        dependents.add(stage);
+    }
+
+    public Set<ActivityCluster> getDependencies() {
+        return dependencies;
+    }
+
+    public Map<ActivityNodeId, TaskState[]> getTaskStateMap() {
+        return taskStateMap;
+    }
+
+    public TaskCluster[] getTaskClusters() {
+        return taskClusters;
+    }
+
+    public void setTaskClusters(TaskCluster[] taskClusters) {
+        this.taskClusters = taskClusters;
+    }
+
+    public IActivityClusterStateMachine getStateMachine() {
+        return acsm;
+    }
+
+    public void setStateMachine(IActivityClusterStateMachine acsm) {
+        this.acsm = acsm;
+    }
+
+    public JobRun getJobRun() {
+        return jobRun;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobPlanBuilder.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobActivityGraphBuilder.java
similarity index 62%
rename from hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobPlanBuilder.java
rename to hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobActivityGraphBuilder.java
index bafa7e5..9f9a2e3 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobPlanBuilder.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobActivityGraphBuilder.java
@@ -6,25 +6,24 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.UUID;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
 import edu.uci.ics.hyracks.api.dataflow.IActivityNode;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
 import edu.uci.ics.hyracks.api.job.JobFlag;
-import edu.uci.ics.hyracks.api.job.JobPlan;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
 
-public class JobPlanBuilder implements IActivityGraphBuilder {
-    private static final Logger LOGGER = Logger.getLogger(JobPlanBuilder.class.getName());
+public class JobActivityGraphBuilder implements IActivityGraphBuilder {
+    private static final Logger LOGGER = Logger.getLogger(JobActivityGraphBuilder.class.getName());
 
-    private JobPlan plan;
+    private JobActivityGraph jag;
 
     @Override
     public void addBlockingEdge(IActivityNode blocker, IActivityNode blocked) {
-        addToValueSet(plan.getBlocker2BlockedMap(), blocker.getActivityNodeId(), blocked.getActivityNodeId());
-        addToValueSet(plan.getBlocked2BlockerMap(), blocked.getActivityNodeId(), blocker.getActivityNodeId());
+        addToValueSet(jag.getBlocker2BlockedMap(), blocker.getActivityNodeId(), blocked.getActivityNodeId());
+        addToValueSet(jag.getBlocked2BlockerMap(), blocked.getActivityNodeId(), blocker.getActivityNodeId());
     }
 
     @Override
@@ -33,8 +32,8 @@
             LOGGER.finest("Adding source edge: " + task.getOwner().getOperatorId() + ":" + operatorInputIndex + " -> "
                     + task.getActivityNodeId() + ":" + taskInputIndex);
         }
-        insertIntoIndexedMap(plan.getTaskInputMap(), task.getActivityNodeId(), taskInputIndex, operatorInputIndex);
-        insertIntoIndexedMap(plan.getOperatorInputMap(), task.getOwner().getOperatorId(), operatorInputIndex,
+        insertIntoIndexedMap(jag.getActivityInputMap(), task.getActivityNodeId(), taskInputIndex, operatorInputIndex);
+        insertIntoIndexedMap(jag.getOperatorInputMap(), task.getOwner().getOperatorId(), operatorInputIndex,
                 task.getActivityNodeId());
     }
 
@@ -44,15 +43,15 @@
             LOGGER.finest("Adding target edge: " + task.getOwner().getOperatorId() + ":" + operatorOutputIndex + " -> "
                     + task.getActivityNodeId() + ":" + taskOutputIndex);
         }
-        insertIntoIndexedMap(plan.getTaskOutputMap(), task.getActivityNodeId(), taskOutputIndex, operatorOutputIndex);
-        insertIntoIndexedMap(plan.getOperatorOutputMap(), task.getOwner().getOperatorId(), operatorOutputIndex,
+        insertIntoIndexedMap(jag.getActivityOutputMap(), task.getActivityNodeId(), taskOutputIndex, operatorOutputIndex);
+        insertIntoIndexedMap(jag.getOperatorOutputMap(), task.getOwner().getOperatorId(), operatorOutputIndex,
                 task.getActivityNodeId());
     }
 
     @Override
     public void addTask(IActivityNode task) {
-        plan.getActivityNodeMap().put(task.getActivityNodeId(), task);
-        addToValueSet(plan.getOperatorTaskMap(), task.getOwner().getOperatorId(), task.getActivityNodeId());
+        jag.getActivityNodeMap().put(task.getActivityNodeId(), task);
+        addToValueSet(jag.getOperatorActivityMap(), task.getOwner().getOperatorId(), task.getActivityNodeId());
     }
 
     private <K, V> void addToValueSet(Map<K, Set<V>> map, K n1, V n2) {
@@ -71,8 +70,8 @@
         }
     }
 
-    public void init(String appName, UUID jobId, JobSpecification jobSpec, EnumSet<JobFlag> jobFlags) {
-        plan = new JobPlan(appName, jobId, jobSpec, jobFlags);
+    public void init(String appName, JobSpecification jobSpec, EnumSet<JobFlag> jobFlags) {
+        jag = new JobActivityGraph(appName, jobSpec, jobFlags);
     }
 
     private <K, V> void insertIntoIndexedMap(Map<K, List<V>> map, K key, int index, V value) {
@@ -85,7 +84,7 @@
         vList.set(index, value);
     }
 
-    public JobPlan getPlan() {
-        return plan;
+    public JobActivityGraph getActivityGraph() {
+        return jag;
     }
 }
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobAttempt.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobAttempt.java
deleted file mode 100644
index 5f5b89e..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobAttempt.java
+++ /dev/null
@@ -1,130 +0,0 @@
-package edu.uci.ics.hyracks.control.cc.job;
-
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.api.job.JobPlan;
-import edu.uci.ics.hyracks.control.cc.scheduler.IJobAttemptSchedulerState;
-import edu.uci.ics.hyracks.control.cc.scheduler.IScheduler;
-import edu.uci.ics.hyracks.control.common.job.profiling.om.JobProfile;
-
-public class JobAttempt {
-    private final JobRun jobRun;
-
-    private final JobPlan plan;
-
-    private final int attempt;
-
-    private final JobStage endStage;
-
-    private final JobProfile profile;
-
-    private final Map<UUID, JobStage> stageMap;
-
-    private final Map<UUID, JobStageAttempt> stageAttemptMap;
-
-    private final Set<UUID> pendingStages;
-
-    private final Set<UUID> completedStages;
-
-    private final Set<UUID> inProgressStages;
-
-    private final Set<String> participatingNodeIds;
-
-    private final IJobAttemptSchedulerState schedulerState;
-
-    public JobAttempt(JobRun jobRun, JobPlan plan, int attempt, IScheduler scheduler) {
-        this.jobRun = jobRun;
-        this.plan = plan;
-        this.attempt = attempt;
-        this.endStage = new JobPlanner().createStageDAG(plan);
-        stageMap = new HashMap<UUID, JobStage>();
-        stageAttemptMap = new HashMap<UUID, JobStageAttempt>();
-        completedStages = new HashSet<UUID>();
-        inProgressStages = new HashSet<UUID>();
-        profile = new JobProfile(plan.getJobId(), attempt);
-        populateJobStageMap(stageMap, endStage);
-        pendingStages = new HashSet<UUID>(stageMap.keySet());
-        participatingNodeIds = new HashSet<String>();
-        schedulerState = scheduler.createJobAttemptState(this);
-    }
-
-    private static void populateJobStageMap(Map<UUID, JobStage> stageMap, JobStage stage) {
-        stageMap.put(stage.getId(), stage);
-        for (JobStage s : stage.getDependencies()) {
-            populateJobStageMap(stageMap, s);
-        }
-    }
-
-    public JobRun getJobRun() {
-        return jobRun;
-    }
-
-    public JobPlan getPlan() {
-        return plan;
-    }
-
-    public int getAttempt() {
-        return attempt;
-    }
-
-    public JobStage getEndStage() {
-        return endStage;
-    }
-
-    public void findRunnableStages(Set<JobStage> runnableStages) {
-        findRunnableStages(runnableStages, endStage);
-    }
-
-    private void findRunnableStages(Set<JobStage> runnableStages, JobStage stage) {
-        if (completedStages.contains(stage.getId()) || inProgressStages.contains(stage.getId())
-                || runnableStages.contains(stage)) {
-            return;
-        }
-        boolean runnable = true;
-        for (JobStage s : stage.getDependencies()) {
-            if (!completedStages.contains(s.getId())) {
-                runnable = false;
-                findRunnableStages(runnableStages, s);
-            }
-        }
-        if (runnable) {
-            runnableStages.add(stage);
-        }
-    }
-
-    public Set<UUID> getPendingStageIds() {
-        return pendingStages;
-    }
-
-    public Set<UUID> getInProgressStageIds() {
-        return inProgressStages;
-    }
-
-    public Set<UUID> getCompletedStageIds() {
-        return completedStages;
-    }
-
-    public Map<UUID, JobStage> getStageMap() {
-        return stageMap;
-    }
-
-    public Map<UUID, JobStageAttempt> getStageAttemptMap() {
-        return stageAttemptMap;
-    }
-
-    public Set<String> getParticipatingNodeIds() {
-        return participatingNodeIds;
-    }
-
-    public JobProfile getJobProfile() {
-        return profile;
-    }
-
-    public IJobAttemptSchedulerState getSchedulerState() {
-        return schedulerState;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobPlanner.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobPlanner.java
deleted file mode 100644
index 900e5ee..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobPlanner.java
+++ /dev/null
@@ -1,153 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.job;
-
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
-import edu.uci.ics.hyracks.api.dataflow.IActivityNode;
-import edu.uci.ics.hyracks.api.dataflow.IConnectorDescriptor;
-import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
-import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
-import edu.uci.ics.hyracks.api.job.JobPlan;
-import edu.uci.ics.hyracks.api.job.JobSpecification;
-import edu.uci.ics.hyracks.api.util.Pair;
-
-public class JobPlanner {
-    private static final Logger LOGGER = Logger.getLogger(JobPlanner.class.getName());
-
-    private Pair<ActivityNodeId, ActivityNodeId> findMergePair(JobPlan plan, JobSpecification spec, Set<JobStage> eqSets) {
-        Map<ActivityNodeId, IActivityNode> activityNodeMap = plan.getActivityNodeMap();
-        for (JobStage eqSet : eqSets) {
-            for (ActivityNodeId t : eqSet.getTasks()) {
-                IOperatorDescriptor owner = activityNodeMap.get(t).getOwner();
-                List<Integer> inputList = plan.getTaskInputMap().get(t);
-                if (inputList != null) {
-                    for (Integer idx : inputList) {
-                        IConnectorDescriptor conn = spec.getInputConnectorDescriptor(owner, idx);
-                        OperatorDescriptorId producerId = spec.getProducer(conn).getOperatorId();
-                        int producerOutputIndex = spec.getProducerOutputIndex(conn);
-                        ActivityNodeId inTask = plan.getOperatorOutputMap().get(producerId).get(producerOutputIndex);
-                        if (!eqSet.getTasks().contains(inTask)) {
-                            return new Pair<ActivityNodeId, ActivityNodeId>(t, inTask);
-                        }
-                    }
-                }
-                List<Integer> outputList = plan.getTaskOutputMap().get(t);
-                if (outputList != null) {
-                    for (Integer idx : outputList) {
-                        IConnectorDescriptor conn = spec.getOutputConnectorDescriptor(owner, idx);
-                        OperatorDescriptorId consumerId = spec.getConsumer(conn).getOperatorId();
-                        int consumerInputIndex = spec.getConsumerInputIndex(conn);
-                        ActivityNodeId outTask = plan.getOperatorInputMap().get(consumerId).get(consumerInputIndex);
-                        if (!eqSet.getTasks().contains(outTask)) {
-                            return new Pair<ActivityNodeId, ActivityNodeId>(t, outTask);
-                        }
-                    }
-                }
-            }
-        }
-        return null;
-    }
-
-    private JobStage inferStages(JobPlan plan) {
-        JobSpecification spec = plan.getJobSpecification();
-
-        /*
-         * Build initial equivalence sets map. We create a map such that for each IOperatorTask, t -> { t }
-         */
-        Map<ActivityNodeId, JobStage> stageMap = new HashMap<ActivityNodeId, JobStage>();
-        Set<JobStage> stages = new HashSet<JobStage>();
-        for (Set<ActivityNodeId> taskIds : plan.getOperatorTaskMap().values()) {
-            for (ActivityNodeId taskId : taskIds) {
-                Set<ActivityNodeId> eqSet = new HashSet<ActivityNodeId>();
-                eqSet.add(taskId);
-                JobStage stage = new JobStage(eqSet);
-                stageMap.put(taskId, stage);
-                stages.add(stage);
-            }
-        }
-
-        boolean changed = true;
-        while (changed) {
-            changed = false;
-            Pair<ActivityNodeId, ActivityNodeId> pair = findMergePair(plan, spec, stages);
-            if (pair != null) {
-                merge(stageMap, stages, pair.first, pair.second);
-                changed = true;
-            }
-        }
-
-        JobStage endStage = new JobStage(new HashSet<ActivityNodeId>());
-        Map<ActivityNodeId, Set<ActivityNodeId>> blocker2BlockedMap = plan.getBlocker2BlockedMap();
-        for (JobStage s : stages) {
-            endStage.addDependency(s);
-            s.addDependent(endStage);
-            Set<JobStage> blockedStages = new HashSet<JobStage>();
-            for (ActivityNodeId t : s.getTasks()) {
-                Set<ActivityNodeId> blockedTasks = blocker2BlockedMap.get(t);
-                if (blockedTasks != null) {
-                    for (ActivityNodeId bt : blockedTasks) {
-                        blockedStages.add(stageMap.get(bt));
-                    }
-                }
-            }
-            for (JobStage bs : blockedStages) {
-                bs.addDependency(s);
-                s.addDependent(bs);
-            }
-        }
-        if (LOGGER.isLoggable(Level.INFO)) {
-            LOGGER.info("Inferred " + (stages.size() + 1) + " stages");
-            for (JobStage s : stages) {
-                LOGGER.info(s.toString());
-            }
-            LOGGER.info("SID: ENDSTAGE");
-        }
-        return endStage;
-    }
-
-    private void merge(Map<ActivityNodeId, JobStage> eqSetMap, Set<JobStage> eqSets, ActivityNodeId t1,
-            ActivityNodeId t2) {
-        JobStage stage1 = eqSetMap.get(t1);
-        Set<ActivityNodeId> s1 = stage1.getTasks();
-        JobStage stage2 = eqSetMap.get(t2);
-        Set<ActivityNodeId> s2 = stage2.getTasks();
-
-        Set<ActivityNodeId> mergedSet = new HashSet<ActivityNodeId>();
-        mergedSet.addAll(s1);
-        mergedSet.addAll(s2);
-
-        eqSets.remove(stage1);
-        eqSets.remove(stage2);
-        JobStage mergedStage = new JobStage(mergedSet);
-        eqSets.add(mergedStage);
-
-        for (ActivityNodeId t : mergedSet) {
-            eqSetMap.put(t, mergedStage);
-        }
-    }
-
-    public JobStage createStageDAG(JobPlan jag) {
-        JobStage endStage = inferStages(jag);
-        return endStage;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobRun.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobRun.java
index 5766288..fb7dbf8 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobRun.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobRun.java
@@ -14,53 +14,72 @@
  */
 package edu.uci.ics.hyracks.control.cc.job;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
 import java.util.Set;
+import java.util.UUID;
 
-import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression;
-import edu.uci.ics.hyracks.api.job.JobPlan;
+import edu.uci.ics.hyracks.api.comm.NetworkAddress;
+import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
 import edu.uci.ics.hyracks.api.job.JobStatus;
-import edu.uci.ics.hyracks.control.cc.scheduler.IScheduler;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+import edu.uci.ics.hyracks.control.cc.scheduler.IJobRunStateMachine;
+import edu.uci.ics.hyracks.control.common.job.profiling.om.JobProfile;
 
 public class JobRun implements IJobStatusConditionVariable {
-    private final JobPlan plan;
-    private final List<JobAttempt> attempts;
+    private final UUID jobId;
+
+    private final JobActivityGraph jag;
+
+    private final Map<PartitionId, NetworkAddress> partitionAvailabilityMap;
+
+    private final Map<PartitionId, String> partitionRequestorMap;
+
+    private final Set<String> participatingNodeIds;
+
+    private final JobProfile profile;
+
+    private final Map<ActivityNodeId, ActivityCluster> activityClusterMap;
+
+    private IJobRunStateMachine jsm;
+
     private JobStatus status;
-    private Set<ConstraintExpression> constraints;
 
-    public JobRun(JobPlan plan, Set<ConstraintExpression> constraints) {
-        this.plan = plan;
-        attempts = new ArrayList<JobAttempt>();
-        this.constraints = constraints;
+    private Exception exception;
+
+    public JobRun(UUID jobId, JobActivityGraph plan) {
+        this.jobId = jobId;
+        this.jag = plan;
+        partitionAvailabilityMap = new HashMap<PartitionId, NetworkAddress>();
+        partitionRequestorMap = new HashMap<PartitionId, String>();
+        participatingNodeIds = new HashSet<String>();
+        profile = new JobProfile(jobId);
+        activityClusterMap = new HashMap<ActivityNodeId, ActivityCluster>();
     }
 
-    public JobPlan getJobPlan() {
-        return plan;
+    public UUID getJobId() {
+        return jobId;
     }
 
-    public synchronized void setStatus(JobStatus status) {
+    public JobActivityGraph getJobActivityGraph() {
+        return jag;
+    }
+
+    public synchronized void setStatus(JobStatus status, Exception exception) {
         this.status = status;
+        this.exception = exception;
         notifyAll();
     }
 
-    public JobStatus getStatus() {
+    public synchronized JobStatus getStatus() {
         return status;
     }
 
-    public List<JobAttempt> getAttempts() {
-        return attempts;
-    }
-
-    public Set<ConstraintExpression> getConstraints() {
-        return constraints;
-    }
-
-    public JobAttempt createAttempt(IScheduler scheduler) {
-        int attemptNumber = attempts.size();
-        JobAttempt attempt = new JobAttempt(this, plan, attemptNumber, scheduler);
-        attempts.add(attempt);
-        return attempt;
+    public synchronized Exception getException() {
+        return exception;
     }
 
     @Override
@@ -68,5 +87,36 @@
         while (status != JobStatus.TERMINATED && status != JobStatus.FAILURE) {
             wait();
         }
+        if (exception != null) {
+            throw new HyracksException("Job Failed", exception);
+        }
+    }
+
+    public Set<String> getParticipatingNodeIds() {
+        return participatingNodeIds;
+    }
+
+    public JobProfile getJobProfile() {
+        return profile;
+    }
+
+    public void setStateMachine(IJobRunStateMachine jsm) {
+        this.jsm = jsm;
+    }
+
+    public IJobRunStateMachine getStateMachine() {
+        return jsm;
+    }
+
+    public Map<PartitionId, NetworkAddress> getPartitionAvailabilityMap() {
+        return partitionAvailabilityMap;
+    }
+
+    public Map<PartitionId, String> getPartitionRequestorMap() {
+        return partitionRequestorMap;
+    }
+
+    public Map<ActivityNodeId, ActivityCluster> getActivityClusterMap() {
+        return activityClusterMap;
     }
 }
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobStage.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobStage.java
deleted file mode 100644
index 8e4013d..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobStage.java
+++ /dev/null
@@ -1,89 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.job;
-
-import java.io.Serializable;
-import java.util.HashSet;
-import java.util.Set;
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
-
-public class JobStage implements Serializable {
-    private static final long serialVersionUID = 1L;
-
-    private final UUID id;
-
-    private final Set<ActivityNodeId> tasks;
-
-    private final Set<JobStage> dependencies;
-
-    private final Set<JobStage> dependents;
-
-    private boolean started;
-
-    public JobStage(Set<ActivityNodeId> tasks) {
-        this.id = UUID.randomUUID();
-        this.tasks = tasks;
-        dependencies = new HashSet<JobStage>();
-        dependents = new HashSet<JobStage>();
-    }
-
-    public UUID getId() {
-        return id;
-    }
-
-    public Set<ActivityNodeId> getTasks() {
-        return tasks;
-    }
-
-    public void addDependency(JobStage stage) {
-        dependencies.add(stage);
-    }
-
-    public void addDependent(JobStage stage) {
-        dependents.add(stage);
-    }
-
-    public Set<JobStage> getDependencies() {
-        return dependencies;
-    }
-
-    @Override
-    public int hashCode() {
-        return id == null ? 0 : id.hashCode();
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (!(o instanceof JobStage)) {
-            return false;
-        }
-        return id == ((JobStage) o).id;
-    }
-
-    @Override
-    public String toString() {
-        return "SID:" + id + ": " + tasks;
-    }
-
-    public boolean isStarted() {
-        return started;
-    }
-
-    public void setStarted() {
-        started = true;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobStageAttempt.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobStageAttempt.java
deleted file mode 100644
index 61db770..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/JobStageAttempt.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.job;
-
-import java.util.HashSet;
-import java.util.Set;
-
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
-import edu.uci.ics.hyracks.control.cc.scheduler.ISchedule;
-
-public class JobStageAttempt {
-    private final JobStage stage;
-
-    private final JobAttempt jobAttempt;
-
-    private final Set<String> participatingNodes;
-
-    private final Set<String> completedNodes;
-
-    private ISchedule schedule;
-
-    public JobStageAttempt(JobStage stage, JobAttempt jobAttempt) {
-        this.stage = stage;
-        this.jobAttempt = jobAttempt;
-        participatingNodes = new HashSet<String>();
-        completedNodes = new HashSet<String>();
-    }
-
-    public JobStage getJobStage() {
-        return stage;
-    }
-
-    public JobAttempt getJobAttempt() {
-        return jobAttempt;
-    }
-
-    public void setSchedule(ISchedule schedule) {
-        this.schedule = schedule;
-        for (ActivityNodeId aid : stage.getTasks()) {
-            String[] partitions = schedule.getPartitions(aid);
-            for (String nid : partitions) {
-                participatingNodes.add(nid);
-            }
-        }
-    }
-
-    public ISchedule getSchedule() {
-        return schedule;
-    }
-
-    public Set<String> getParticipatingNodes() {
-        return participatingNodes;
-    }
-
-    public Set<String> getCompletedNodes() {
-        return completedNodes;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskAttempt.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskAttempt.java
new file mode 100644
index 0000000..6d61ccb
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskAttempt.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.job;
+
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+
+public class TaskAttempt {
+    public enum TaskStatus {
+        INITIALIZED,
+        RUNNING,
+        COMPLETED,
+        FAILED,
+        ABORTED,
+    }
+
+    private final TaskAttemptId taskId;
+
+    private final TaskState taskState;
+
+    private String nodeId;
+
+    private TaskStatus status;
+
+    private Exception exception;
+
+    public TaskAttempt(TaskAttemptId taskId, TaskState taskState) {
+        this.taskId = taskId;
+        this.taskState = taskState;
+    }
+
+    public TaskAttemptId getTaskAttemptId() {
+        return taskId;
+    }
+
+    public TaskState getTaskState() {
+        return taskState;
+    }
+
+    public String getNodeId() {
+        return nodeId;
+    }
+
+    public void setNodeId(String nodeId) {
+        this.nodeId = nodeId;
+    }
+
+    public TaskStatus getStatus() {
+        return status;
+    }
+
+    public Exception getException() {
+        return exception;
+    }
+
+    public void setStatus(TaskStatus status, Exception exception) {
+        this.status = status;
+        this.exception = exception;
+    }
+
+    public void notifyTaskComplete() throws HyracksException {
+        taskState.getTaskCluster().notifyTaskComplete(this);
+    }
+
+    public void notifyTaskFailure(Exception exception) throws HyracksException {
+        taskState.getTaskCluster().notifyTaskFailure(this, exception);
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskCluster.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskCluster.java
new file mode 100644
index 0000000..78ac34b
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskCluster.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.job;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+
+public class TaskCluster {
+    private final ActivityCluster activityCluster;
+
+    private final TaskState[] tasks;
+
+    private final Set<TaskCluster> blockers;
+
+    private final Set<TaskCluster> dependencies;
+
+    private final List<TaskClusterAttempt> taskClusterAttempts;
+
+    public TaskCluster(ActivityCluster activityCluster, TaskState[] tasks) {
+        this.activityCluster = activityCluster;
+        this.tasks = tasks;
+        this.blockers = new HashSet<TaskCluster>();
+        this.dependencies = new HashSet<TaskCluster>();
+        taskClusterAttempts = new ArrayList<TaskClusterAttempt>();
+    }
+
+    public TaskState[] getTasks() {
+        return tasks;
+    }
+
+    public Set<TaskCluster> getDependencies() {
+        return dependencies;
+    }
+
+    public Set<TaskCluster> getBlockers() {
+        return blockers;
+    }
+
+    public List<TaskClusterAttempt> getAttempts() {
+        return taskClusterAttempts;
+    }
+
+    public void notifyTaskComplete(TaskAttempt ta) throws HyracksException {
+        activityCluster.getStateMachine().notifyTaskComplete(ta);
+    }
+
+    public void notifyTaskFailure(TaskAttempt ta, Exception exception) throws HyracksException {
+        activityCluster.getStateMachine().notifyTaskFailure(ta, exception);
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskClusterAttempt.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskClusterAttempt.java
new file mode 100644
index 0000000..f0d951e
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskClusterAttempt.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.job;
+
+
+public class TaskClusterAttempt {
+    public enum TaskClusterStatus {
+        INITIALIZED,
+        RUNNING,
+        COMPLETED,
+        FAILED,
+    }
+
+    private final TaskAttempt[] taskAttempts;
+
+    private TaskClusterStatus status;
+
+    private int pendingTaskCounter;
+
+    public TaskClusterAttempt(TaskAttempt[] taskAttempts) {
+        this.taskAttempts = taskAttempts;
+    }
+
+    public TaskAttempt[] getTaskAttempts() {
+        return taskAttempts;
+    }
+
+    public void setStatus(TaskClusterStatus status) {
+        this.status = status;
+    }
+
+    public TaskClusterStatus getStatus() {
+        return status;
+    }
+
+    public void initializePendingTaskCounter() {
+        pendingTaskCounter = taskAttempts.length;
+    }
+
+    public int getPendingTaskCounter() {
+        return pendingTaskCounter;
+    }
+
+    public int decrementPendingTasksCounter() {
+        return --pendingTaskCounter;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskState.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskState.java
new file mode 100644
index 0000000..3bbba36
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/TaskState.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.job;
+
+import edu.uci.ics.hyracks.api.dataflow.TaskId;
+
+public class TaskState {
+    private final TaskId taskId;
+
+    private TaskCluster taskCluster;
+
+    public TaskState(TaskId taskId) {
+        this.taskId = taskId;
+    }
+
+    public TaskId getTaskId() {
+        return taskId;
+    }
+
+    public TaskCluster getTaskCluster() {
+        return taskCluster;
+    }
+
+    public void setTaskCluster(TaskCluster taskCluster) {
+        this.taskCluster = taskCluster;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/JobLifecycleHelper.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/JobLifecycleHelper.java
deleted file mode 100644
index be42e22..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/JobLifecycleHelper.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package edu.uci.ics.hyracks.control.cc.job.manager;
-
-import java.util.Set;
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.job.manager.events.JobAttemptStartEvent;
-import edu.uci.ics.hyracks.control.cc.remote.RemoteRunner;
-import edu.uci.ics.hyracks.control.cc.remote.ops.JobletAborter;
-
-public class JobLifecycleHelper {
-    public static void abortJob(ClusterControllerService ccs, UUID jobId, int attempt, Set<String> targetNodes) {
-        if (!targetNodes.isEmpty()) {
-            JobletAborter[] jas = new JobletAborter[targetNodes.size()];
-            int i = 0;
-            for (String nodeId : targetNodes) {
-                jas[i++] = new JobletAborter(nodeId, jobId, attempt);
-            }
-            try {
-                RemoteRunner.runRemote(ccs, jas, null);
-            } catch (Exception e) {
-                e.printStackTrace();
-            }
-        }
-        ccs.getJobQueue().schedule(new JobAttemptStartEvent(ccs, jobId));
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobProfileJSONEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobProfileJSONEvent.java
index dc397ef..f53fb5f 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobProfileJSONEvent.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobProfileJSONEvent.java
@@ -14,14 +14,11 @@
  */
 package edu.uci.ics.hyracks.control.cc.job.manager.events;
 
-import java.util.List;
 import java.util.UUID;
 
 import org.json.JSONObject;
 
 import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
-import edu.uci.ics.hyracks.control.cc.job.JobRun;
 import edu.uci.ics.hyracks.control.cc.jobqueue.SynchronizableRunnable;
 
 public class GetJobProfileJSONEvent extends SynchronizableRunnable {
@@ -38,17 +35,7 @@
 
     @Override
     protected void doRun() throws Exception {
-        JobRun run = ccs.getRunMap().get(jobId);
         profile = new JSONObject();
-        if (run == null) {
-            return;
-        }
-        List<JobAttempt> attempts = run.getAttempts();
-        if (attempts.size() <= attempt) {
-            return;
-        }
-        JobAttempt ja = attempts.get(attempt);
-        profile = ja.getJobProfile().toJSON();
     }
 
     public JSONObject getProfile() {
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobSpecificationJSONEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobSpecificationJSONEvent.java
index 6248925..509dcd2 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobSpecificationJSONEvent.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobSpecificationJSONEvent.java
@@ -39,7 +39,7 @@
             spec = new JSONObject();
             return;
         }
-        spec = run.getJobPlan().getJobSpecification().toJSON();
+        spec = run.getJobActivityGraph().getJobSpecification().toJSON();
     }
 
     public JSONObject getSpecification() {
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobSummariesJSONEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobSummariesJSONEvent.java
index 74851e5..3c19f59 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobSummariesJSONEvent.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/GetJobSummariesJSONEvent.java
@@ -35,8 +35,7 @@
         for (JobRun run : ccs.getRunMap().values()) {
             JSONObject jo = new JSONObject();
             jo.put("type", "job-summary");
-            jo.put("id", run.getJobPlan().getJobId().toString());
-            jo.put("attempts", run.getAttempts().size());
+            jo.put("id", run.getJobId().toString());
             jo.put("status", run.getStatus().toString());
             summaries.put(jo);
         }
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobAbortEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobAbortEvent.java
deleted file mode 100644
index 9a0eff1..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobAbortEvent.java
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.job.manager.events;
-
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.NodeControllerState;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
-import edu.uci.ics.hyracks.control.cc.job.JobRun;
-import edu.uci.ics.hyracks.control.cc.job.manager.JobLifecycleHelper;
-
-public class JobAbortEvent implements Runnable {
-    private final ClusterControllerService ccs;
-
-    private final UUID jobId;
-
-    private final int attempt;
-
-    public JobAbortEvent(ClusterControllerService ccs, UUID jobId, int attempt) {
-        this.ccs = ccs;
-        this.jobId = jobId;
-        this.attempt = attempt;
-    }
-
-    @Override
-    public void run() {
-        Map<String, NodeControllerState> nodeMap = ccs.getNodeMap();
-        Map<UUID, JobRun> runMap = ccs.getRunMap();
-        final JobRun run = runMap.get(jobId);
-        final Set<String> targetNodes = new HashSet<String>();
-        if (run != null) {
-            List<JobAttempt> jas = run.getAttempts();
-            JobAttempt ja = jas.get(attempt);
-            for (String runningNodeId : ja.getParticipatingNodeIds()) {
-                if (nodeMap.containsKey(runningNodeId)) {
-                    targetNodes.add(runningNodeId);
-                    nodeMap.get(runningNodeId).getActiveJobIds().remove(jobId);
-                }
-            }
-        }
-
-        ccs.getExecutor().execute(new Runnable() {
-            @Override
-            public void run() {
-                JobLifecycleHelper.abortJob(ccs, jobId, attempt, targetNodes);
-            }
-        });
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobAttemptStartEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobAttemptStartEvent.java
deleted file mode 100644
index 7dc6496..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobAttemptStartEvent.java
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.job.manager.events;
-
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.api.job.JobStatus;
-import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
-import edu.uci.ics.hyracks.control.cc.job.JobRun;
-
-public class JobAttemptStartEvent implements Runnable {
-    private ClusterControllerService ccs;
-    private UUID jobId;
-
-    public JobAttemptStartEvent(ClusterControllerService ccs, UUID jobId) {
-        this.ccs = ccs;
-        this.jobId = jobId;
-    }
-
-    @Override
-    public void run() {
-        JobRun run = ccs.getRunMap().get(jobId);
-        int maxAttempts = run.getJobPlan().getJobSpecification().getMaxAttempts();
-        if (maxAttempts == 0) {
-            maxAttempts = ccs.getConfig().defaultMaxJobAttempts;
-        }
-        if (run.getAttempts().size() > maxAttempts) {
-            run.setStatus(JobStatus.FAILURE);
-            return;
-        }
-        JobAttempt attempt = run.createAttempt(ccs.getScheduler());
-        new ScheduleRunnableStagesEvent(ccs, jobId, attempt.getAttempt()).run();
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobCleanupEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobCleanupEvent.java
index c4ed077..87ba685 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobCleanupEvent.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobCleanupEvent.java
@@ -14,16 +14,13 @@
  */
 package edu.uci.ics.hyracks.control.cc.job.manager.events;
 
-import java.util.Map;
 import java.util.Set;
 import java.util.UUID;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.api.job.JobStatus;
 import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.NodeControllerState;
 import edu.uci.ics.hyracks.control.cc.application.CCApplicationContext;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
 import edu.uci.ics.hyracks.control.cc.job.JobRun;
 import edu.uci.ics.hyracks.control.cc.remote.RemoteRunner;
 import edu.uci.ics.hyracks.control.cc.remote.ops.JobCompleteNotifier;
@@ -31,21 +28,20 @@
 public class JobCleanupEvent implements Runnable {
     private ClusterControllerService ccs;
     private UUID jobId;
-    private int attempt;
     private JobStatus status;
+    private Exception exception;
 
-    public JobCleanupEvent(ClusterControllerService ccs, UUID jobId, int attempt, JobStatus status) {
+    public JobCleanupEvent(ClusterControllerService ccs, UUID jobId, JobStatus status, Exception exception) {
         this.ccs = ccs;
         this.jobId = jobId;
-        this.attempt = attempt;
         this.status = status;
+        this.exception = exception;
     }
 
     @Override
     public void run() {
         final JobRun run = ccs.getRunMap().get(jobId);
-        final JobAttempt ja = run.getAttempts().get(attempt);
-        Set<String> targetNodes = ja.getParticipatingNodeIds();
+        Set<String> targetNodes = run.getParticipatingNodeIds();
         final JobCompleteNotifier[] jcns = new JobCompleteNotifier[targetNodes.size()];
         int i = 0;
         for (String n : targetNodes) {
@@ -64,7 +60,8 @@
                 ccs.getJobQueue().schedule(new Runnable() {
                     @Override
                     public void run() {
-                        CCApplicationContext appCtx = ccs.getApplicationMap().get(ja.getPlan().getApplicationName());
+                        CCApplicationContext appCtx = ccs.getApplicationMap().get(
+                                run.getJobActivityGraph().getApplicationName());
                         if (appCtx != null) {
                             try {
                                 appCtx.notifyJobFinish(jobId);
@@ -72,12 +69,7 @@
                                 e.printStackTrace();
                             }
                         }
-                        Map<String, NodeControllerState> nodeMap = ccs.getNodeMap();
-                        for (String nodeId : ja.getParticipatingNodeIds()) {
-                            NodeControllerState state = nodeMap.get(nodeId);
-                            state.getActiveJobIds().remove(jobId);
-                        }
-                        run.setStatus(status);
+                        run.setStatus(status, exception);
                     }
                 });
             }
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobCreateEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobCreateEvent.java
index 3b03d25..d6b09db 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobCreateEvent.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobCreateEvent.java
@@ -15,24 +15,18 @@
 package edu.uci.ics.hyracks.control.cc.job.manager.events;
 
 import java.util.EnumSet;
-import java.util.HashSet;
-import java.util.Set;
 import java.util.UUID;
 
-import edu.uci.ics.hyracks.api.constraints.IConstraintExpressionAcceptor;
-import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression;
-import edu.uci.ics.hyracks.api.dataflow.IConnectorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
 import edu.uci.ics.hyracks.api.job.JobFlag;
-import edu.uci.ics.hyracks.api.job.JobPlan;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
 import edu.uci.ics.hyracks.api.job.JobStatus;
 import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
 import edu.uci.ics.hyracks.control.cc.application.CCApplicationContext;
-import edu.uci.ics.hyracks.control.cc.job.IConnectorDescriptorVisitor;
 import edu.uci.ics.hyracks.control.cc.job.IOperatorDescriptorVisitor;
-import edu.uci.ics.hyracks.control.cc.job.JobPlanBuilder;
+import edu.uci.ics.hyracks.control.cc.job.JobActivityGraphBuilder;
 import edu.uci.ics.hyracks.control.cc.job.JobRun;
 import edu.uci.ics.hyracks.control.cc.job.PlanUtils;
 import edu.uci.ics.hyracks.control.cc.jobqueue.SynchronizableRunnable;
@@ -60,51 +54,27 @@
             throw new HyracksException("No application with id " + appName + " found");
         }
         JobSpecification spec = appCtx.createJobSpecification(jobId, jobSpec);
-        JobRun run = plan(jobId, spec, jobFlags);
-        run.setStatus(JobStatus.INITIALIZED);
 
-        ccs.getRunMap().put(jobId, run);
-        appCtx.notifyJobCreation(jobId, spec);
-    }
-
-    public UUID getJobId() {
-        return jobId;
-    }
-
-    private JobRun plan(UUID jobId, JobSpecification jobSpec, EnumSet<JobFlag> jobFlags) throws Exception {
-        final JobPlanBuilder builder = new JobPlanBuilder();
-        builder.init(appName, jobId, jobSpec, jobFlags);
-        PlanUtils.visit(jobSpec, new IOperatorDescriptorVisitor() {
+        final JobActivityGraphBuilder builder = new JobActivityGraphBuilder();
+        builder.init(appName, spec, jobFlags);
+        PlanUtils.visit(spec, new IOperatorDescriptorVisitor() {
             @Override
             public void visit(IOperatorDescriptor op) {
                 op.contributeTaskGraph(builder);
             }
         });
-        final JobPlan plan = builder.getPlan();
+        final JobActivityGraph jag = builder.getActivityGraph();
 
-        final Set<ConstraintExpression> contributedConstraints = new HashSet<ConstraintExpression>();
-        final IConstraintExpressionAcceptor acceptor = new IConstraintExpressionAcceptor() {
-            @Override
-            public void addConstraintExpression(ConstraintExpression constraintExpression) {
-                contributedConstraints.add(constraintExpression);
-            }
-        };
-        PlanUtils.visit(jobSpec, new IOperatorDescriptorVisitor() {
-            @Override
-            public void visit(IOperatorDescriptor op) {
-                op.contributeSchedulingConstraints(acceptor, plan);
-            }
-        });
-        PlanUtils.visit(jobSpec, new IConnectorDescriptorVisitor() {
-            @Override
-            public void visit(IConnectorDescriptor conn) {
-                conn.contributeSchedulingConstraints(acceptor, plan);
-            }
-        });
-        contributedConstraints.addAll(jobSpec.getUserConstraints());
+        JobRun run = new JobRun(UUID.randomUUID(), jag);
 
-        JobRun run = new JobRun(plan, contributedConstraints);
+        run.setStatus(JobStatus.INITIALIZED, null);
 
-        return run;
+        ccs.getRunMap().put(jobId, run);
+        ccs.getScheduler().notifyJobCreation(run);
+        appCtx.notifyJobCreation(jobId, spec);
+    }
+
+    public UUID getJobId() {
+        return jobId;
     }
 }
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobStartEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobStartEvent.java
index 742885e..7b9a3c6 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobStartEvent.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/JobStartEvent.java
@@ -39,8 +39,7 @@
         if (run.getStatus() != JobStatus.INITIALIZED) {
             throw new Exception("Job already started");
         }
-        run.setStatus(JobStatus.RUNNING);
-
-        new JobAttemptStartEvent(ccs, jobId).run();
+        run.setStatus(JobStatus.RUNNING, null);
+        run.getStateMachine().schedule();
     }
 }
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/RegisterPartitionAvailibilityEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/RegisterPartitionAvailibilityEvent.java
new file mode 100644
index 0000000..0269122
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/RegisterPartitionAvailibilityEvent.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.job.manager.events;
+
+import java.util.Map;
+
+import edu.uci.ics.hyracks.api.comm.NetworkAddress;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
+import edu.uci.ics.hyracks.control.cc.NodeControllerState;
+import edu.uci.ics.hyracks.control.cc.job.JobRun;
+import edu.uci.ics.hyracks.control.common.base.INodeController;
+
+public class RegisterPartitionAvailibilityEvent implements Runnable {
+    private final ClusterControllerService ccs;
+    private final PartitionId pid;
+    private final NetworkAddress networkAddress;
+
+    public RegisterPartitionAvailibilityEvent(ClusterControllerService ccs, PartitionId pid,
+            NetworkAddress networkAddress) {
+        this.ccs = ccs;
+        this.pid = pid;
+        this.networkAddress = networkAddress;
+    }
+
+    @Override
+    public void run() {
+        JobRun run = ccs.getRunMap().get(pid.getJobId());
+        if (run == null) {
+            return;
+        }
+        Map<PartitionId, NetworkAddress> partitionAvailabilityMap = run.getPartitionAvailabilityMap();
+        partitionAvailabilityMap.put(pid, networkAddress);
+
+        Map<PartitionId, String> partitionRequestorMap = run.getPartitionRequestorMap();
+        String requestor = partitionRequestorMap.get(pid);
+        if (requestor != null) {
+            NodeControllerState ncs = ccs.getNodeMap().get(requestor);
+            if (ncs != null) {
+                try {
+                    INodeController nc = ncs.getNodeController();
+                    nc.reportPartitionAvailability(pid, networkAddress);
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/RegisterPartitionRequestEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/RegisterPartitionRequestEvent.java
new file mode 100644
index 0000000..4d34e6e
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/RegisterPartitionRequestEvent.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.job.manager.events;
+
+import java.util.Collection;
+import java.util.Map;
+
+import edu.uci.ics.hyracks.api.comm.NetworkAddress;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
+import edu.uci.ics.hyracks.control.cc.NodeControllerState;
+import edu.uci.ics.hyracks.control.cc.job.JobRun;
+import edu.uci.ics.hyracks.control.common.base.INodeController;
+
+public class RegisterPartitionRequestEvent implements Runnable {
+    private final ClusterControllerService ccs;
+    private final Collection<PartitionId> requiredPartitionIds;
+    private final String nodeId;
+
+    public RegisterPartitionRequestEvent(ClusterControllerService ccs, Collection<PartitionId> requiredPartitionIds,
+            String nodeId) {
+        this.ccs = ccs;
+        this.requiredPartitionIds = requiredPartitionIds;
+        this.nodeId = nodeId;
+    }
+
+    @Override
+    public void run() {
+        NodeControllerState ncs = ccs.getNodeMap().get(nodeId);
+        if (ncs != null) {
+            for (PartitionId pid : requiredPartitionIds) {
+                JobRun run = ccs.getRunMap().get(pid.getJobId());
+                if (run == null) {
+                    return;
+                }
+                Map<PartitionId, String> partitionRequestorMap = run.getPartitionRequestorMap();
+                partitionRequestorMap.put(pid, nodeId);
+
+                Map<PartitionId, NetworkAddress> partitionAvailabilityMap = run.getPartitionAvailabilityMap();
+                NetworkAddress networkAddress = partitionAvailabilityMap.get(pid);
+                if (networkAddress != null) {
+                    try {
+                        INodeController nc = ncs.getNodeController();
+                        nc.reportPartitionAvailability(pid, networkAddress);
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                    }
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/RemoveDeadNodesEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/RemoveDeadNodesEvent.java
index 38fb7ae..8a1703b 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/RemoveDeadNodesEvent.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/RemoveDeadNodesEvent.java
@@ -17,12 +17,10 @@
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
-import java.util.UUID;
 import java.util.logging.Logger;
 
 import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
 import edu.uci.ics.hyracks.control.cc.NodeControllerState;
-import edu.uci.ics.hyracks.control.cc.job.JobRun;
 
 public class RemoveDeadNodesEvent implements Runnable {
     private static Logger LOGGER = Logger.getLogger(RemoveDeadNodesEvent.class.getName());
@@ -46,12 +44,7 @@
         }
         for (String deadNode : deadNodes) {
             NodeControllerState state = nodeMap.remove(deadNode);
-            for (final UUID jid : state.getActiveJobIds()) {
-                JobRun run = ccs.getRunMap().get(jid);
-                int lastAttempt = run.getAttempts().size() - 1;
-                LOGGER.info("Aborting: " + jid);
-                ccs.getJobQueue().schedule(new JobAbortEvent(ccs, jid, lastAttempt));
-            }
+            // Deal with dead tasks.
         }
     }
 }
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/ReportProfilesEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/ReportProfilesEvent.java
index beb8732..24f884a 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/ReportProfilesEvent.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/ReportProfilesEvent.java
@@ -19,7 +19,6 @@
 import java.util.UUID;
 
 import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
 import edu.uci.ics.hyracks.control.cc.job.JobRun;
 import edu.uci.ics.hyracks.control.common.job.profiling.om.JobProfile;
 
@@ -37,10 +36,6 @@
         Map<UUID, JobRun> runMap = ccs.getRunMap();
         for (JobProfile profile : profiles) {
             JobRun run = runMap.get(profile.getJobId());
-            if (run != null) {
-                JobAttempt ja = run.getAttempts().get(profile.getAttempt());
-                ja.getJobProfile().merge(profile);
-            }
         }
     }
 }
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/ScheduleRunnableStagesEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/ScheduleRunnableStagesEvent.java
deleted file mode 100644
index ba1c711..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/ScheduleRunnableStagesEvent.java
+++ /dev/null
@@ -1,169 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.job.manager.events;
-
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-import java.util.logging.Logger;
-
-import edu.uci.ics.hyracks.api.comm.Endpoint;
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
-import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
-import edu.uci.ics.hyracks.api.dataflow.PortInstanceId;
-import edu.uci.ics.hyracks.api.exceptions.HyracksException;
-import edu.uci.ics.hyracks.api.job.JobPlan;
-import edu.uci.ics.hyracks.api.job.JobStatus;
-import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
-import edu.uci.ics.hyracks.control.cc.job.JobRun;
-import edu.uci.ics.hyracks.control.cc.job.JobStage;
-import edu.uci.ics.hyracks.control.cc.job.JobStageAttempt;
-import edu.uci.ics.hyracks.control.cc.remote.RemoteRunner;
-import edu.uci.ics.hyracks.control.cc.remote.ops.Phase1Installer;
-import edu.uci.ics.hyracks.control.cc.remote.ops.Phase2Installer;
-import edu.uci.ics.hyracks.control.cc.remote.ops.Phase3Installer;
-import edu.uci.ics.hyracks.control.cc.remote.ops.PortMapMergingAccumulator;
-import edu.uci.ics.hyracks.control.cc.remote.ops.StageStarter;
-import edu.uci.ics.hyracks.control.cc.scheduler.ISchedule;
-
-public class ScheduleRunnableStagesEvent implements Runnable {
-    private static final Logger LOGGER = Logger.getLogger(ScheduleRunnableStagesEvent.class.getName());
-
-    private ClusterControllerService ccs;
-    private UUID jobId;
-    private int attempt;
-
-    public ScheduleRunnableStagesEvent(ClusterControllerService ccs, UUID jobId, int attempt) {
-        this.ccs = ccs;
-        this.jobId = jobId;
-        this.attempt = attempt;
-    }
-
-    @Override
-    public void run() {
-        JobRun run = ccs.getRunMap().get(jobId);
-        JobAttempt ja = run.getAttempts().get(attempt);
-        Set<UUID> pendingStages = ja.getPendingStageIds();
-        Set<UUID> scheduledStages = ja.getInProgressStageIds();
-
-        LOGGER.info(jobId + ":" + attempt + ":Pending stages: " + pendingStages + " Scheduled stages: "
-                + scheduledStages);
-        if (pendingStages.size() == 1 && scheduledStages.isEmpty()) {
-            LOGGER.info(jobId + ":" + attempt + ":No more runnable stages");
-            ccs.getJobQueue().schedule(new JobCleanupEvent(ccs, jobId, attempt, JobStatus.TERMINATED));
-            return;
-        }
-
-        Map<UUID, JobStageAttempt> stageAttemptMap = ja.getStageAttemptMap();
-
-        Set<JobStage> runnableStages = new HashSet<JobStage>();
-        ja.findRunnableStages(runnableStages);
-        LOGGER.info(jobId + ":" + attempt + ": Found " + runnableStages.size() + " runnable stages");
-
-        Set<JobStageAttempt> runnableStageAttempts = new HashSet<JobStageAttempt>();
-        for (JobStage rs : runnableStages) {
-            UUID stageId = rs.getId();
-            LOGGER.info("Runnable Stage: " + jobId + ":" + rs.getId());
-            pendingStages.remove(stageId);
-            scheduledStages.add(stageId);
-            JobStageAttempt jsa = new JobStageAttempt(rs, ja);
-            stageAttemptMap.put(stageId, jsa);
-            runnableStageAttempts.add(jsa);
-        }
-
-        try {
-            ccs.getScheduler().schedule(runnableStageAttempts);
-        } catch (HyracksException e) {
-            e.printStackTrace();
-            ccs.getJobQueue().schedule(new JobAbortEvent(ccs, jobId, attempt));
-            return;
-        }
-
-        final JobPlan plan = run.getJobPlan();
-        for (final JobStageAttempt jsa : runnableStageAttempts) {
-            ISchedule schedule = jsa.getSchedule();
-            final Map<OperatorDescriptorId, Integer> partCountMap = new HashMap<OperatorDescriptorId, Integer>();
-            final Map<String, Map<ActivityNodeId, Set<Integer>>> targetMap = new HashMap<String, Map<ActivityNodeId, Set<Integer>>>();
-            for (ActivityNodeId aid : jsa.getJobStage().getTasks()) {
-                String[] locations = schedule.getPartitions(aid);
-                partCountMap.put(aid.getOperatorDescriptorId(), locations.length);
-                int nLoc = locations.length;
-                for (int i = 0; i < nLoc; ++i) {
-                    Map<ActivityNodeId, Set<Integer>> target = targetMap.get(locations[i]);
-                    if (target == null) {
-                        target = new HashMap<ActivityNodeId, Set<Integer>>();
-                        targetMap.put(locations[i], target);
-                    }
-                    Set<Integer> partIdxs = target.get(aid);
-                    if (partIdxs == null) {
-                        partIdxs = new HashSet<Integer>();
-                        target.put(aid, partIdxs);
-                    }
-                    partIdxs.add(i);
-                }
-            }
-
-            Set<String> participatingNodeIds = ja.getParticipatingNodeIds();
-            for (String nid : targetMap.keySet()) {
-                ccs.getNodeMap().get(nid).getActiveJobIds().add(jobId);
-                participatingNodeIds.add(nid);
-            }
-
-            ccs.getExecutor().execute(new Runnable() {
-                @Override
-                public void run() {
-                    Phase1Installer p1is[] = new Phase1Installer[targetMap.size()];
-                    int i = 0;
-                    for (String nid : targetMap.keySet()) {
-                        p1is[i] = new Phase1Installer(nid, plan.getJobId(), plan.getApplicationName(), plan, jsa
-                                .getJobStage().getId(), jsa.getJobAttempt().getAttempt(), targetMap.get(nid),
-                                partCountMap);
-                        ++i;
-                    }
-                    LOGGER.info("Stage start - Phase 1");
-                    try {
-                        Map<PortInstanceId, Endpoint> globalPortMap = RemoteRunner.runRemote(ccs, p1is,
-                                new PortMapMergingAccumulator());
-
-                        Phase2Installer[] p2is = new Phase2Installer[targetMap.size()];
-                        Phase3Installer[] p3is = new Phase3Installer[targetMap.size()];
-                        StageStarter[] ss = new StageStarter[targetMap.size()];
-
-                        i = 0;
-                        for (String nid : targetMap.keySet()) {
-                            p2is[i] = new Phase2Installer(nid, plan.getJobId(), plan.getApplicationName(), plan, jsa
-                                    .getJobStage().getId(), targetMap.get(nid), partCountMap, globalPortMap);
-                            p3is[i] = new Phase3Installer(nid, plan.getJobId(), jsa.getJobStage().getId());
-                            ss[i] = new StageStarter(nid, plan.getJobId(), jsa.getJobStage().getId());
-                            ++i;
-                        }
-                        LOGGER.info("Stage start - Phase 2");
-                        RemoteRunner.runRemote(ccs, p2is, null);
-                        LOGGER.info("Stage start - Phase 3");
-                        RemoteRunner.runRemote(ccs, p3is, null);
-                        LOGGER.info("Stage start");
-                        RemoteRunner.runRemote(ccs, ss, null);
-                        LOGGER.info("Stage started");
-                    } catch (Exception e) {
-                        e.printStackTrace();
-                    }
-                }
-            });
-        }
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/StageletCompleteEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/StageletCompleteEvent.java
deleted file mode 100644
index 8f07d09..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/StageletCompleteEvent.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.job.manager.events;
-
-import java.util.Set;
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
-import edu.uci.ics.hyracks.control.cc.job.JobRun;
-import edu.uci.ics.hyracks.control.cc.job.JobStageAttempt;
-
-public class StageletCompleteEvent implements Runnable {
-    private final ClusterControllerService ccs;
-    private final UUID jobId;
-    private final UUID stageId;
-    private final int attempt;
-    private final String nodeId;
-
-    public StageletCompleteEvent(ClusterControllerService ccs, UUID jobId, UUID stageId, int attempt, String nodeId) {
-        this.ccs = ccs;
-        this.jobId = jobId;
-        this.stageId = stageId;
-        this.attempt = attempt;
-        this.nodeId = nodeId;
-    }
-
-    @Override
-    public void run() {
-        JobRun run = ccs.getRunMap().get(jobId);
-        JobAttempt jobAttempt = run.getAttempts().get(attempt);
-        JobStageAttempt jsAttempt = jobAttempt.getStageAttemptMap().get(stageId);
-
-        Set<String> participatingNodes = jsAttempt.getParticipatingNodes();
-        Set<String> completedNodes = jsAttempt.getCompletedNodes();
-        completedNodes.add(nodeId);
-
-        if (completedNodes.containsAll(participatingNodes)) {
-            Set<UUID> completedStageIds = jobAttempt.getCompletedStageIds();
-            completedStageIds.add(stageId);
-
-            Set<UUID> inProgressStageIds = jobAttempt.getInProgressStageIds();
-            inProgressStageIds.remove(stageId);
-
-            ccs.getJobQueue().schedule(new ScheduleRunnableStagesEvent(ccs, jobId, attempt));
-        }
-    }
-
-    @Override
-    public String toString() {
-        return "StageletCompleteEvent[" + jobId + ":" + stageId + ":" + attempt + ":" + nodeId + "]";
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/StageletFailureEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/StageletFailureEvent.java
deleted file mode 100644
index 34dbeb4..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/StageletFailureEvent.java
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.job.manager.events;
-
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.NodeControllerState;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
-import edu.uci.ics.hyracks.control.cc.job.JobRun;
-import edu.uci.ics.hyracks.control.cc.job.manager.JobLifecycleHelper;
-
-public class StageletFailureEvent implements Runnable {
-    private final ClusterControllerService ccs;
-    private final UUID jobId;
-    private final UUID stageId;
-    private final int attempt;
-    private final String nodeId;
-
-    public StageletFailureEvent(ClusterControllerService ccs, UUID jobId, UUID stageId, int attempt, String nodeId) {
-        this.ccs = ccs;
-        this.jobId = jobId;
-        this.stageId = stageId;
-        this.attempt = attempt;
-        this.nodeId = nodeId;
-    }
-
-    @Override
-    public void run() {
-        final JobRun run = ccs.getRunMap().get(jobId);
-        List<JobAttempt> attempts = run.getAttempts();
-        JobAttempt ja = attempts.get(attempt);
-        final Set<String> targetNodes = new HashSet<String>(ja.getParticipatingNodeIds());
-        Map<String, NodeControllerState> nodeMap = new HashMap<String, NodeControllerState>();
-        for (String nodeId : targetNodes) {
-            nodeMap.get(nodeId).getActiveJobIds().remove(jobId);
-        }
-        ccs.getExecutor().execute(new Runnable() {
-            @Override
-            public void run() {
-                JobLifecycleHelper.abortJob(ccs, jobId, attempt, targetNodes);
-            }
-        });
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/TaskCompleteEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/TaskCompleteEvent.java
new file mode 100644
index 0000000..f9fa355
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/TaskCompleteEvent.java
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.job.manager.events;
+
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+import edu.uci.ics.hyracks.api.dataflow.TaskId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
+import edu.uci.ics.hyracks.control.cc.job.ActivityCluster;
+import edu.uci.ics.hyracks.control.cc.job.JobRun;
+import edu.uci.ics.hyracks.control.cc.job.TaskAttempt;
+import edu.uci.ics.hyracks.control.cc.job.TaskCluster;
+import edu.uci.ics.hyracks.control.cc.job.TaskClusterAttempt;
+import edu.uci.ics.hyracks.control.cc.job.TaskState;
+
+public class TaskCompleteEvent implements Runnable {
+    private final ClusterControllerService ccs;
+    private final UUID jobId;
+    private final TaskAttemptId taId;
+    private final String nodeId;
+
+    public TaskCompleteEvent(ClusterControllerService ccs, UUID jobId, TaskAttemptId taId, String nodeId) {
+        this.ccs = ccs;
+        this.jobId = jobId;
+        this.taId = taId;
+        this.nodeId = nodeId;
+    }
+
+    @Override
+    public void run() {
+        JobRun run = ccs.getRunMap().get(jobId);
+        if (run != null) {
+            TaskId tid = taId.getTaskId();
+            Map<ActivityNodeId, ActivityCluster> activityClusterMap = run.getActivityClusterMap();
+            ActivityCluster ac = activityClusterMap.get(tid.getActivityId());
+            if (ac != null) {
+                Map<ActivityNodeId, TaskState[]> taskStateMap = ac.getTaskStateMap();
+                TaskState[] taskStates = taskStateMap.get(tid.getActivityId());
+                if (taskStates != null && taskStates.length > tid.getPartition()) {
+                    TaskState ts = taskStates[tid.getPartition()];
+                    TaskCluster tc = ts.getTaskCluster();
+                    List<TaskClusterAttempt> taskClusterAttempts = tc.getAttempts();
+                    if (taskClusterAttempts != null && taskClusterAttempts.size() > taId.getAttempt()) {
+                        TaskClusterAttempt tca = taskClusterAttempts.get(taId.getAttempt());
+                        TaskAttempt ta = tca.getTaskAttempts()[tid.getPartition()];
+                        try {
+                            ta.notifyTaskComplete();
+                        } catch (HyracksException e) {
+                            e.printStackTrace();
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "TaskCompleteEvent[" + jobId + ":" + taId + ":" + nodeId + "]";
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/TaskFailureEvent.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/TaskFailureEvent.java
new file mode 100644
index 0000000..710c2b1
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/job/manager/events/TaskFailureEvent.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.job.manager.events;
+
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+import edu.uci.ics.hyracks.api.dataflow.TaskId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
+import edu.uci.ics.hyracks.control.cc.job.ActivityCluster;
+import edu.uci.ics.hyracks.control.cc.job.JobRun;
+import edu.uci.ics.hyracks.control.cc.job.TaskAttempt;
+import edu.uci.ics.hyracks.control.cc.job.TaskCluster;
+import edu.uci.ics.hyracks.control.cc.job.TaskClusterAttempt;
+import edu.uci.ics.hyracks.control.cc.job.TaskState;
+
+public class TaskFailureEvent implements Runnable {
+    private final ClusterControllerService ccs;
+    private final UUID jobId;
+    private final TaskAttemptId taId;
+    private final String nodeId;
+    private final Exception exception;
+
+    public TaskFailureEvent(ClusterControllerService ccs, UUID jobId, TaskAttemptId taId, String nodeId, Exception exception) {
+        this.ccs = ccs;
+        this.jobId = jobId;
+        this.taId = taId;
+        this.nodeId = nodeId;
+        this.exception = exception;
+    }
+
+    @Override
+    public void run() {
+        JobRun run = ccs.getRunMap().get(jobId);
+        if (run != null) {
+            TaskId tid = taId.getTaskId();
+            Map<ActivityNodeId, ActivityCluster> activityClusterMap = run.getActivityClusterMap();
+            ActivityCluster ac = activityClusterMap.get(tid.getActivityId());
+            if (ac != null) {
+                Map<ActivityNodeId, TaskState[]> taskStateMap = ac.getTaskStateMap();
+                TaskState[] taskStates = taskStateMap.get(tid.getActivityId());
+                if (taskStates != null && taskStates.length > tid.getPartition()) {
+                    TaskState ts = taskStates[tid.getPartition()];
+                    TaskCluster tc = ts.getTaskCluster();
+                    List<TaskClusterAttempt> taskClusterAttempts = tc.getAttempts();
+                    if (taskClusterAttempts != null && taskClusterAttempts.size() > taId.getAttempt()) {
+                        TaskClusterAttempt tca = taskClusterAttempts.get(taId.getAttempt());
+                        TaskAttempt ta = tca.getTaskAttempts()[tid.getPartition()];
+                        try {
+                            ta.notifyTaskFailure(exception);
+                        } catch (HyracksException e) {
+                            e.printStackTrace();
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "TaskCompleteEvent[" + jobId + ":" + taId + ":" + nodeId + "]";
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/JobletAborter.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/JobletAborter.java
deleted file mode 100644
index 7885dcd..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/JobletAborter.java
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.remote.ops;
-
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.control.cc.remote.RemoteOp;
-import edu.uci.ics.hyracks.control.common.base.INodeController;
-
-public class JobletAborter implements RemoteOp<Void> {
-    private String nodeId;
-    private UUID jobId;
-    private int attempt;
-
-    public JobletAborter(String nodeId, UUID jobId, int attempt) {
-        this.nodeId = nodeId;
-        this.jobId = jobId;
-        this.attempt = attempt;
-    }
-
-    @Override
-    public Void execute(INodeController node) throws Exception {
-        node.abortJoblet(jobId, attempt);
-        return null;
-    }
-
-    @Override
-    public String toString() {
-        return jobId + " Aborting";
-    }
-
-    @Override
-    public String getNodeId() {
-        return nodeId;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/Phase1Installer.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/Phase1Installer.java
deleted file mode 100644
index 0373864..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/Phase1Installer.java
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.remote.ops;
-
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.api.comm.Endpoint;
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
-import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
-import edu.uci.ics.hyracks.api.dataflow.PortInstanceId;
-import edu.uci.ics.hyracks.api.job.JobPlan;
-import edu.uci.ics.hyracks.api.util.JavaSerializationUtils;
-import edu.uci.ics.hyracks.control.cc.remote.RemoteOp;
-import edu.uci.ics.hyracks.control.common.base.INodeController;
-
-public class Phase1Installer implements RemoteOp<Map<PortInstanceId, Endpoint>> {
-    private String nodeId;
-    private UUID jobId;
-    private String appName;
-    private JobPlan plan;
-    private UUID stageId;
-    private int attempt;
-    private Map<ActivityNodeId, Set<Integer>> tasks;
-    private Map<OperatorDescriptorId, Integer> opNumPartitions;
-
-    public Phase1Installer(String nodeId, UUID jobId, String appName, JobPlan plan, UUID stageId, int attempt,
-            Map<ActivityNodeId, Set<Integer>> tasks, Map<OperatorDescriptorId, Integer> opNumPartitions) {
-        this.nodeId = nodeId;
-        this.jobId = jobId;
-        this.appName = appName;
-        this.plan = plan;
-        this.stageId = stageId;
-        this.attempt = attempt;
-        this.tasks = tasks;
-        this.opNumPartitions = opNumPartitions;
-    }
-
-    @Override
-    public Map<PortInstanceId, Endpoint> execute(INodeController node) throws Exception {
-        return node.initializeJobletPhase1(appName, jobId, attempt, JavaSerializationUtils.serialize(plan), stageId,
-                tasks, opNumPartitions);
-    }
-
-    @Override
-    public String toString() {
-        return jobId + " Distribution Phase 1";
-    }
-
-    @Override
-    public String getNodeId() {
-        return nodeId;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/Phase2Installer.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/Phase2Installer.java
deleted file mode 100644
index 3f1c251..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/Phase2Installer.java
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.remote.ops;
-
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.api.comm.Endpoint;
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
-import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
-import edu.uci.ics.hyracks.api.dataflow.PortInstanceId;
-import edu.uci.ics.hyracks.api.job.JobPlan;
-import edu.uci.ics.hyracks.api.util.JavaSerializationUtils;
-import edu.uci.ics.hyracks.control.cc.remote.RemoteOp;
-import edu.uci.ics.hyracks.control.common.base.INodeController;
-
-public class Phase2Installer implements RemoteOp<Void> {
-    private String nodeId;
-    private UUID jobId;
-    private String appName;
-    private JobPlan plan;
-    private UUID stageId;
-    private Map<ActivityNodeId, Set<Integer>> tasks;
-    private Map<OperatorDescriptorId, Integer> opNumPartitions;
-    private Map<PortInstanceId, Endpoint> globalPortMap;
-
-    public Phase2Installer(String nodeId, UUID jobId, String appName, JobPlan plan, UUID stageId,
-            Map<ActivityNodeId, Set<Integer>> tasks, Map<OperatorDescriptorId, Integer> opNumPartitions,
-            Map<PortInstanceId, Endpoint> globalPortMap) {
-        this.nodeId = nodeId;
-        this.jobId = jobId;
-        this.appName = appName;
-        this.plan = plan;
-        this.stageId = stageId;
-        this.tasks = tasks;
-        this.opNumPartitions = opNumPartitions;
-        this.globalPortMap = globalPortMap;
-    }
-
-    @Override
-    public Void execute(INodeController node) throws Exception {
-        node.initializeJobletPhase2(appName, jobId, JavaSerializationUtils.serialize(plan), stageId, tasks,
-                opNumPartitions, globalPortMap);
-        return null;
-    }
-
-    @Override
-    public String toString() {
-        return jobId + " Distribution Phase 2";
-    }
-
-    @Override
-    public String getNodeId() {
-        return nodeId;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/Phase3Installer.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/Phase3Installer.java
deleted file mode 100644
index 3d98f0f..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/Phase3Installer.java
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.remote.ops;
-
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.control.cc.remote.RemoteOp;
-import edu.uci.ics.hyracks.control.common.base.INodeController;
-
-public class Phase3Installer implements RemoteOp<Void> {
-    private String nodeId;
-    private UUID jobId;
-    private UUID stageId;
-
-    public Phase3Installer(String nodeId, UUID jobId, UUID stageId) {
-        this.nodeId = nodeId;
-        this.jobId = jobId;
-        this.stageId = stageId;
-    }
-
-    @Override
-    public Void execute(INodeController node) throws Exception {
-        node.commitJobletInitialization(jobId, stageId);
-        return null;
-    }
-
-    @Override
-    public String toString() {
-        return jobId + " Distribution Phase 3";
-    }
-
-    @Override
-    public String getNodeId() {
-        return nodeId;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/StageStarter.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/StageStarter.java
deleted file mode 100644
index b614235..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/remote/ops/StageStarter.java
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.cc.remote.ops;
-
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.control.cc.remote.RemoteOp;
-import edu.uci.ics.hyracks.control.common.base.INodeController;
-
-public class StageStarter implements RemoteOp<Void> {
-    private String nodeId;
-    private UUID jobId;
-    private UUID stageId;
-
-    public StageStarter(String nodeId, UUID jobId, UUID stageId) {
-        this.nodeId = nodeId;
-        this.jobId = jobId;
-        this.stageId = stageId;
-    }
-
-    @Override
-    public Void execute(INodeController node) throws Exception {
-        node.startStage(jobId, stageId);
-        return null;
-    }
-
-    @Override
-    public String toString() {
-        return jobId + " Started Stage: " + stageId;
-    }
-
-    @Override
-    public String getNodeId() {
-        return nodeId;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/DefaultActivityClusterStateMachine.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/DefaultActivityClusterStateMachine.java
new file mode 100644
index 0000000..1e68f76
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/DefaultActivityClusterStateMachine.java
@@ -0,0 +1,259 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.scheduler;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import edu.uci.ics.hyracks.api.constraints.expressions.LValueConstraintExpression;
+import edu.uci.ics.hyracks.api.constraints.expressions.PartitionLocationExpression;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+import edu.uci.ics.hyracks.api.dataflow.TaskId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
+import edu.uci.ics.hyracks.api.util.JavaSerializationUtils;
+import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
+import edu.uci.ics.hyracks.control.cc.NodeControllerState;
+import edu.uci.ics.hyracks.control.cc.job.ActivityCluster;
+import edu.uci.ics.hyracks.control.cc.job.JobRun;
+import edu.uci.ics.hyracks.control.cc.job.TaskAttempt;
+import edu.uci.ics.hyracks.control.cc.job.TaskCluster;
+import edu.uci.ics.hyracks.control.cc.job.TaskClusterAttempt;
+import edu.uci.ics.hyracks.control.cc.job.TaskState;
+
+public class DefaultActivityClusterStateMachine implements IActivityClusterStateMachine {
+    private static final Logger LOGGER = Logger.getLogger(DefaultActivityClusterStateMachine.class.getName());
+
+    private final ClusterControllerService ccs;
+
+    private final DefaultJobRunStateMachine jsm;
+
+    private final ActivityCluster ac;
+
+    public DefaultActivityClusterStateMachine(ClusterControllerService ccs, DefaultJobRunStateMachine jsm,
+            ActivityCluster ac) {
+        this.ccs = ccs;
+        this.jsm = jsm;
+        this.ac = ac;
+    }
+
+    @Override
+    public void schedule() throws HyracksException {
+        startRunnableTaskClusters();
+    }
+
+    private void assignTaskLocations(TaskCluster tc, Map<String, List<TaskAttemptId>> taskAttemptMap)
+            throws HyracksException {
+        TaskState[] tasks = tc.getTasks();
+        List<TaskClusterAttempt> tcAttempts = tc.getAttempts();
+        int attempts = tcAttempts.size();
+        TaskAttempt[] taskAttempts = new TaskAttempt[tasks.length];
+        Map<TaskId, LValueConstraintExpression> locationMap = new HashMap<TaskId, LValueConstraintExpression>();
+        for (int i = 0; i < tasks.length; ++i) {
+            TaskState ts = tasks[i];
+            TaskId tid = ts.getTaskId();
+            TaskAttempt taskAttempt = new TaskAttempt(new TaskAttemptId(new TaskId(tid.getActivityId(),
+                    tid.getPartition()), attempts), ts);
+            locationMap.put(tid,
+                    new PartitionLocationExpression(tid.getActivityId().getOperatorDescriptorId(), tid.getPartition()));
+            taskAttempts[i] = taskAttempt;
+        }
+        PartitionConstraintSolver solver = jsm.getSolver();
+        solver.solve(locationMap.values());
+        for (int i = 0; i < tasks.length; ++i) {
+            TaskState ts = tasks[i];
+            TaskId tid = ts.getTaskId();
+            TaskAttempt taskAttempt = taskAttempts[i];
+            LValueConstraintExpression pLocationExpr = locationMap.get(tid);
+            Object location = solver.getValue(pLocationExpr);
+            String nodeId = null;
+            Set<String> liveNodes = ccs.getNodeMap().keySet();
+            if (location == null) {
+                // pick any
+                nodeId = liveNodes.toArray(new String[liveNodes.size()])[Math.abs(new Random().nextInt())
+                        % liveNodes.size()];
+            } else if (location instanceof String) {
+                nodeId = (String) location;
+                if (!liveNodes.contains(nodeId)) {
+                    throw new HyracksException("Node " + nodeId + " not live");
+                }
+            } else if (location instanceof String[]) {
+                for (String choice : (String[]) location) {
+                    if (liveNodes.contains(choice)) {
+                        nodeId = choice;
+                        break;
+                    }
+                }
+                if (nodeId == null) {
+                    throw new HyracksException("No satisfiable location found for " + taskAttempt.getTaskAttemptId());
+                }
+            } else {
+                throw new HyracksException("Unknown type of value for " + pLocationExpr + ": " + location + "("
+                        + location.getClass() + ")");
+            }
+            taskAttempt.setNodeId(nodeId);
+            List<TaskAttemptId> taIds = taskAttemptMap.get(nodeId);
+            if (taIds == null) {
+                taIds = new ArrayList<TaskAttemptId>();
+                taskAttemptMap.put(nodeId, taIds);
+            }
+            taIds.add(taskAttempt.getTaskAttemptId());
+        }
+        TaskClusterAttempt tcAttempt = new TaskClusterAttempt(taskAttempts);
+        tcAttempt.initializePendingTaskCounter();
+        tcAttempts.add(tcAttempt);
+
+    }
+
+    @Override
+    public void notifyTaskComplete(TaskAttempt ta) throws HyracksException {
+        TaskAttemptId taId = ta.getTaskAttemptId();
+        TaskCluster tc = ta.getTaskState().getTaskCluster();
+        List<TaskClusterAttempt> tcAttempts = tc.getAttempts();
+        int lastAttempt = tcAttempts.size() - 1;
+        if (taId.getAttempt() == lastAttempt) {
+            TaskClusterAttempt tcAttempt = tcAttempts.get(lastAttempt);
+            TaskAttempt.TaskStatus taStatus = ta.getStatus();
+            if (taStatus == TaskAttempt.TaskStatus.RUNNING) {
+                ta.setStatus(TaskAttempt.TaskStatus.COMPLETED, null);
+                if (tcAttempt.decrementPendingTasksCounter() == 0) {
+                    tcAttempt.setStatus(TaskClusterAttempt.TaskClusterStatus.COMPLETED);
+                    startRunnableTaskClusters();
+                }
+            } else {
+                LOGGER.warning("Spurious task complete notification: " + taId + " Current state = " + taStatus);
+            }
+        } else {
+            LOGGER.warning("Ignoring task complete notification: " + taId + " -- Current last attempt = " + lastAttempt);
+        }
+    }
+
+    private void startRunnableTaskClusters() throws HyracksException {
+        TaskCluster[] taskClusters = ac.getTaskClusters();
+
+        Map<String, List<TaskAttemptId>> taskAttemptMap = new HashMap<String, List<TaskAttemptId>>();
+        for (TaskCluster tc : taskClusters) {
+            Set<TaskCluster> dependencies = tc.getDependencies();
+            boolean runnable = true;
+            for (TaskCluster depTC : dependencies) {
+                List<TaskClusterAttempt> tcAttempts = depTC.getAttempts();
+                if (tcAttempts.isEmpty()) {
+                    runnable = false;
+                    break;
+                }
+                TaskClusterAttempt tcAttempt = tcAttempts.get(tcAttempts.size() - 1);
+                if (tcAttempt.getStatus() != TaskClusterAttempt.TaskClusterStatus.COMPLETED) {
+                    runnable = false;
+                    break;
+                }
+            }
+            if (runnable) {
+                assignTaskLocations(tc, taskAttemptMap);
+            }
+        }
+
+        startTasks(taskAttemptMap);
+    }
+
+    private void startTasks(Map<String, List<TaskAttemptId>> taskAttemptMap) {
+        Executor executor = ccs.getExecutor();
+        JobRun jobRun = ac.getJobRun();
+        final UUID jobId = jobRun.getJobId();
+        final JobActivityGraph jag = jobRun.getJobActivityGraph();
+        final String appName = jag.getApplicationName();
+        for (Map.Entry<String, List<TaskAttemptId>> e : taskAttemptMap.entrySet()) {
+            String nodeId = e.getKey();
+            final List<TaskAttemptId> taskIds = e.getValue();
+            final NodeControllerState node = ccs.getNodeMap().get(nodeId);
+            if (node != null) {
+                executor.execute(new Runnable() {
+                    @Override
+                    public void run() {
+                        try {
+                            node.getNodeController().startTasks(appName, jobId, JavaSerializationUtils.serialize(jag),
+                                    taskIds, null);
+                        } catch (IOException e) {
+                            e.printStackTrace();
+                        } catch (Exception e) {
+                            e.printStackTrace();
+                        }
+                    }
+                });
+            }
+        }
+    }
+
+    @Override
+    public void notifyTaskFailure(TaskAttempt ta, Exception exception) throws HyracksException {
+        TaskAttemptId taId = ta.getTaskAttemptId();
+        TaskCluster tc = ta.getTaskState().getTaskCluster();
+        List<TaskClusterAttempt> tcAttempts = tc.getAttempts();
+        int lastAttempt = tcAttempts.size() - 1;
+        if (taId.getAttempt() == lastAttempt) {
+            TaskClusterAttempt tcAttempt = tcAttempts.get(lastAttempt);
+            TaskAttempt.TaskStatus taStatus = ta.getStatus();
+            Map<String, List<TaskAttemptId>> abortTaskAttemptMap = new HashMap<String, List<TaskAttemptId>>();
+            if (taStatus == TaskAttempt.TaskStatus.RUNNING) {
+                ta.setStatus(TaskAttempt.TaskStatus.FAILED, exception);
+                for (TaskAttempt ta2 : tcAttempt.getTaskAttempts()) {
+                    if (ta2.getStatus() == TaskAttempt.TaskStatus.RUNNING
+                            || ta2.getStatus() == TaskAttempt.TaskStatus.INITIALIZED) {
+                        ta2.setStatus(TaskAttempt.TaskStatus.ABORTED, null);
+                        List<TaskAttemptId> abortTaskAttempts = abortTaskAttemptMap.get(ta2.getNodeId());
+                        if (abortTaskAttempts == null) {
+                            abortTaskAttempts = new ArrayList<TaskAttemptId>();
+                            abortTaskAttemptMap.put(ta2.getNodeId(), abortTaskAttempts);
+                        }
+                        abortTaskAttempts.add(ta2.getTaskAttemptId());
+                    }
+                }
+                JobRun jobRun = ac.getJobRun();
+                final UUID jobId = jobRun.getJobId();
+                for (Map.Entry<String, List<TaskAttemptId>> e : abortTaskAttemptMap.entrySet()) {
+                    final NodeControllerState node = ccs.getNodeMap().get(e.getKey());
+                    final List<TaskAttemptId> abortTaskAttempts = e.getValue();
+                    if (node != null) {
+                        ccs.getExecutor().execute(new Runnable() {
+                            @Override
+                            public void run() {
+                                try {
+                                    node.getNodeController().abortTasks(jobId, abortTaskAttempts);
+                                } catch (Exception e) {
+                                    e.printStackTrace();
+                                }
+                            }
+                        });
+                    }
+                }
+                tcAttempt.setStatus(TaskClusterAttempt.TaskClusterStatus.FAILED);
+                Map<String, List<TaskAttemptId>> taskAttemptMap = new HashMap<String, List<TaskAttemptId>>();
+                assignTaskLocations(tc, taskAttemptMap);
+                startTasks(taskAttemptMap);
+            } else {
+                LOGGER.warning("Spurious task complete notification: " + taId + " Current state = " + taStatus);
+            }
+        } else {
+            LOGGER.warning("Ignoring task complete notification: " + taId + " -- Current last attempt = " + lastAttempt);
+        }
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/DefaultJobRunStateMachine.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/DefaultJobRunStateMachine.java
new file mode 100644
index 0000000..9e70b42
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/DefaultJobRunStateMachine.java
@@ -0,0 +1,457 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.scheduler;
+
+import java.util.ArrayList;
+import java.util.BitSet;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import edu.uci.ics.hyracks.api.constraints.Constraint;
+import edu.uci.ics.hyracks.api.constraints.IConstraintAcceptor;
+import edu.uci.ics.hyracks.api.constraints.expressions.LValueConstraintExpression;
+import edu.uci.ics.hyracks.api.constraints.expressions.PartitionCountExpression;
+import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+import edu.uci.ics.hyracks.api.dataflow.IActivityNode;
+import edu.uci.ics.hyracks.api.dataflow.IConnectorDescriptor;
+import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
+import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+import edu.uci.ics.hyracks.api.dataflow.TaskId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
+import edu.uci.ics.hyracks.api.job.JobSpecification;
+import edu.uci.ics.hyracks.api.job.JobStatus;
+import edu.uci.ics.hyracks.api.util.Pair;
+import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
+import edu.uci.ics.hyracks.control.cc.job.ActivityCluster;
+import edu.uci.ics.hyracks.control.cc.job.IConnectorDescriptorVisitor;
+import edu.uci.ics.hyracks.control.cc.job.IOperatorDescriptorVisitor;
+import edu.uci.ics.hyracks.control.cc.job.JobRun;
+import edu.uci.ics.hyracks.control.cc.job.PlanUtils;
+import edu.uci.ics.hyracks.control.cc.job.TaskAttempt;
+import edu.uci.ics.hyracks.control.cc.job.TaskCluster;
+import edu.uci.ics.hyracks.control.cc.job.TaskState;
+import edu.uci.ics.hyracks.control.cc.job.manager.events.JobCleanupEvent;
+import edu.uci.ics.hyracks.control.common.job.dataflow.IConnectorPolicy;
+
+public class DefaultJobRunStateMachine implements IJobRunStateMachine {
+    private static final Logger LOGGER = Logger.getLogger(DefaultJobRunStateMachine.class.getName());
+
+    private final ClusterControllerService ccs;
+
+    private final JobRun jobRun;
+
+    private final Set<ActivityCluster> completedClusters;
+
+    private final Set<ActivityCluster> inProgressClusters;
+
+    private PartitionConstraintSolver solver;
+
+    private ActivityCluster rootActivityCluster;
+
+    public DefaultJobRunStateMachine(ClusterControllerService ccs, JobRun jobRun) {
+        this.ccs = ccs;
+        this.jobRun = jobRun;
+        completedClusters = new HashSet<ActivityCluster>();
+        inProgressClusters = new HashSet<ActivityCluster>();
+    }
+
+    public PartitionConstraintSolver getSolver() {
+        return solver;
+    }
+
+    private static Pair<ActivityNodeId, ActivityNodeId> findMergePair(JobActivityGraph jag, JobSpecification spec,
+            Set<ActivityCluster> eqSets) {
+        Map<ActivityNodeId, IActivityNode> activityNodeMap = jag.getActivityNodeMap();
+        for (ActivityCluster eqSet : eqSets) {
+            for (ActivityNodeId t : eqSet.getActivities()) {
+                IOperatorDescriptor owner = activityNodeMap.get(t).getOwner();
+                List<Integer> inputList = jag.getActivityInputMap().get(t);
+                if (inputList != null) {
+                    for (Integer idx : inputList) {
+                        IConnectorDescriptor conn = spec.getInputConnectorDescriptor(owner, idx);
+                        OperatorDescriptorId producerId = spec.getProducer(conn).getOperatorId();
+                        int producerOutputIndex = spec.getProducerOutputIndex(conn);
+                        ActivityNodeId inTask = jag.getOperatorOutputMap().get(producerId).get(producerOutputIndex);
+                        if (!eqSet.getActivities().contains(inTask)) {
+                            return new Pair<ActivityNodeId, ActivityNodeId>(t, inTask);
+                        }
+                    }
+                }
+                List<Integer> outputList = jag.getActivityOutputMap().get(t);
+                if (outputList != null) {
+                    for (Integer idx : outputList) {
+                        IConnectorDescriptor conn = spec.getOutputConnectorDescriptor(owner, idx);
+                        OperatorDescriptorId consumerId = spec.getConsumer(conn).getOperatorId();
+                        int consumerInputIndex = spec.getConsumerInputIndex(conn);
+                        ActivityNodeId outTask = jag.getOperatorInputMap().get(consumerId).get(consumerInputIndex);
+                        if (!eqSet.getActivities().contains(outTask)) {
+                            return new Pair<ActivityNodeId, ActivityNodeId>(t, outTask);
+                        }
+                    }
+                }
+            }
+        }
+        return null;
+    }
+
+    private ActivityCluster inferStages(JobActivityGraph jag) {
+        JobSpecification spec = jag.getJobSpecification();
+
+        /*
+         * Build initial equivalence sets map. We create a map such that for each IOperatorTask, t -> { t }
+         */
+        Map<ActivityNodeId, ActivityCluster> stageMap = new HashMap<ActivityNodeId, ActivityCluster>();
+        Set<ActivityCluster> stages = new HashSet<ActivityCluster>();
+        for (Set<ActivityNodeId> taskIds : jag.getOperatorActivityMap().values()) {
+            for (ActivityNodeId taskId : taskIds) {
+                Set<ActivityNodeId> eqSet = new HashSet<ActivityNodeId>();
+                eqSet.add(taskId);
+                ActivityCluster stage = new ActivityCluster(jobRun, eqSet);
+                stageMap.put(taskId, stage);
+                stages.add(stage);
+            }
+        }
+
+        boolean changed = true;
+        while (changed) {
+            changed = false;
+            Pair<ActivityNodeId, ActivityNodeId> pair = findMergePair(jag, spec, stages);
+            if (pair != null) {
+                merge(stageMap, stages, pair.first, pair.second);
+                changed = true;
+            }
+        }
+
+        ActivityCluster endStage = new ActivityCluster(jobRun, new HashSet<ActivityNodeId>());
+        Map<ActivityNodeId, Set<ActivityNodeId>> blocker2BlockedMap = jag.getBlocker2BlockedMap();
+        for (ActivityCluster s : stages) {
+            endStage.addDependency(s);
+            s.addDependent(endStage);
+            Set<ActivityCluster> blockedStages = new HashSet<ActivityCluster>();
+            for (ActivityNodeId t : s.getActivities()) {
+                Set<ActivityNodeId> blockedTasks = blocker2BlockedMap.get(t);
+                if (blockedTasks != null) {
+                    for (ActivityNodeId bt : blockedTasks) {
+                        blockedStages.add(stageMap.get(bt));
+                    }
+                }
+            }
+            for (ActivityCluster bs : blockedStages) {
+                bs.addDependency(s);
+                s.addDependent(bs);
+            }
+        }
+        if (LOGGER.isLoggable(Level.INFO)) {
+            LOGGER.info("Inferred " + (stages.size() + 1) + " stages");
+            for (ActivityCluster s : stages) {
+                LOGGER.info(s.toString());
+            }
+            LOGGER.info("SID: ENDSTAGE");
+        }
+        return endStage;
+    }
+
+    private void merge(Map<ActivityNodeId, ActivityCluster> eqSetMap, Set<ActivityCluster> eqSets, ActivityNodeId t1,
+            ActivityNodeId t2) {
+        ActivityCluster stage1 = eqSetMap.get(t1);
+        Set<ActivityNodeId> s1 = stage1.getActivities();
+        ActivityCluster stage2 = eqSetMap.get(t2);
+        Set<ActivityNodeId> s2 = stage2.getActivities();
+
+        Set<ActivityNodeId> mergedSet = new HashSet<ActivityNodeId>();
+        mergedSet.addAll(s1);
+        mergedSet.addAll(s2);
+
+        eqSets.remove(stage1);
+        eqSets.remove(stage2);
+        ActivityCluster mergedStage = new ActivityCluster(jobRun, mergedSet);
+        eqSets.add(mergedStage);
+
+        for (ActivityNodeId t : mergedSet) {
+            eqSetMap.put(t, mergedStage);
+        }
+    }
+
+    private void findRunnableClusters(Set<ActivityCluster> frontier, ActivityCluster candidate) {
+        if (completedClusters.contains(candidate) || frontier.contains(candidate)) {
+            return;
+        }
+        boolean runnable = true;
+        for (ActivityCluster s : candidate.getDependencies()) {
+            if (!completedClusters.contains(s)) {
+                runnable = false;
+                findRunnableClusters(frontier, s);
+            }
+        }
+        if (runnable && candidate != rootActivityCluster) {
+            frontier.add(candidate);
+        }
+    }
+
+    private void findRunnableClusters(Set<ActivityCluster> frontier) {
+        findRunnableClusters(frontier, rootActivityCluster);
+    }
+
+    @Override
+    public void schedule() throws HyracksException {
+        try {
+            solver = new PartitionConstraintSolver();
+            final JobActivityGraph jag = jobRun.getJobActivityGraph();
+            JobSpecification spec = jag.getJobSpecification();
+            final Set<Constraint> contributedConstraints = new HashSet<Constraint>();
+            final IConstraintAcceptor acceptor = new IConstraintAcceptor() {
+                @Override
+                public void addConstraint(Constraint constraint) {
+                    contributedConstraints.add(constraint);
+                }
+            };
+            PlanUtils.visit(spec, new IOperatorDescriptorVisitor() {
+                @Override
+                public void visit(IOperatorDescriptor op) {
+                    op.contributeSchedulingConstraints(acceptor, jag);
+                }
+            });
+            PlanUtils.visit(spec, new IConnectorDescriptorVisitor() {
+                @Override
+                public void visit(IConnectorDescriptor conn) {
+                    conn.contributeSchedulingConstraints(acceptor, jag);
+                }
+            });
+            contributedConstraints.addAll(spec.getUserConstraints());
+            solver.addConstraints(contributedConstraints);
+
+            rootActivityCluster = inferStages(jag);
+            Set<ActivityCluster> runnableClusters = new HashSet<ActivityCluster>();
+            findRunnableClusters(runnableClusters);
+            if (runnableClusters.isEmpty() && inProgressClusters.isEmpty()) {
+                ccs.getJobQueue().schedule(new JobCleanupEvent(ccs, jobRun.getJobId(), JobStatus.TERMINATED, null));
+                return;
+            }
+            for (ActivityCluster ac : runnableClusters) {
+                inProgressClusters.add(ac);
+                buildTaskClusters(ac);
+                IActivityClusterStateMachine acsm = new DefaultActivityClusterStateMachine(ccs, this, ac);
+                ac.setStateMachine(acsm);
+                acsm.schedule();
+            }
+        } catch (Exception e) {
+            ccs.getJobQueue().schedule(new JobCleanupEvent(ccs, jobRun.getJobId(), JobStatus.FAILURE, e));
+            throw new HyracksException(e);
+        }
+    }
+
+    private Map<ActivityNodeId, Integer> computePartitionCounts(ActivityCluster ac) throws HyracksException {
+        Set<LValueConstraintExpression> lValues = new HashSet<LValueConstraintExpression>();
+        for (ActivityNodeId anId : ac.getActivities()) {
+            lValues.add(new PartitionCountExpression(anId.getOperatorDescriptorId()));
+        }
+        solver.solve(lValues);
+        Map<OperatorDescriptorId, Integer> nPartMap = new HashMap<OperatorDescriptorId, Integer>();
+        for (LValueConstraintExpression lv : lValues) {
+            Object value = solver.getValue(lv);
+            if (value == null) {
+                throw new HyracksException("No value found for " + lv);
+            }
+            if (!(value instanceof Number)) {
+                throw new HyracksException("Unexpected type of value bound to " + lv + ": " + value.getClass() + "("
+                        + value + ")");
+            }
+            int nParts = ((Number) value).intValue();
+            if (nParts <= 0) {
+                throw new HyracksException("Unsatisfiable number of partitions for " + lv + ": " + nParts);
+            }
+            nPartMap.put(((PartitionCountExpression) lv).getOperatorDescriptorId(), Integer.valueOf(nParts));
+        }
+        Map<ActivityNodeId, Integer> activityPartsMap = new HashMap<ActivityNodeId, Integer>();
+        for (ActivityNodeId anId : ac.getActivities()) {
+            activityPartsMap.put(anId, nPartMap.get(anId.getOperatorDescriptorId()));
+        }
+        return activityPartsMap;
+    }
+
+    private void buildTaskClusters(ActivityCluster ac) throws HyracksException {
+        Map<ActivityNodeId, Integer> pcMap = computePartitionCounts(ac);
+        Map<ActivityNodeId, TaskState[]> taskStateMap = ac.getTaskStateMap();
+
+        for (ActivityNodeId anId : ac.getActivities()) {
+            int nParts = pcMap.get(anId);
+            TaskState[] taskStates = new TaskState[nParts];
+            for (int i = 0; i < nParts; ++i) {
+                taskStates[i] = new TaskState(new TaskId(anId, i));
+            }
+            taskStateMap.put(anId, taskStates);
+        }
+
+        Set<ActivityNodeId> activities = ac.getActivities();
+
+        Map<ConnectorDescriptorId, IConnectorPolicy> connectorPolicies = new HashMap<ConnectorDescriptorId, IConnectorPolicy>();
+
+        Map<TaskId, Set<TaskId>> taskClusterMap = new HashMap<TaskId, Set<TaskId>>();
+        for (ActivityNodeId anId : activities) {
+            TaskState[] taskStates = taskStateMap.get(anId);
+            for (TaskState ts : taskStates) {
+                Set<TaskId> cluster = new HashSet<TaskId>();
+                cluster.add(ts.getTaskId());
+                taskClusterMap.put(ts.getTaskId(), cluster);
+            }
+        }
+
+        Map<TaskId, List<Pair<TaskId, IConnectorPolicy>>> connectionInfo = new HashMap<TaskId, List<Pair<TaskId, IConnectorPolicy>>>();
+        JobActivityGraph jag = jobRun.getJobActivityGraph();
+        BitSet targetBitmap = new BitSet();
+        for (ActivityNodeId ac1 : activities) {
+            TaskState[] ac1TaskStates = taskStateMap.get(ac1);
+            int nProducers = ac1TaskStates.length;
+            List<IConnectorDescriptor> outputConns = jag.getActivityOutputConnectorDescriptors(ac1);
+            if (outputConns != null) {
+                for (IConnectorDescriptor c : outputConns) {
+                    ConnectorDescriptorId cdId = c.getConnectorId();
+                    IConnectorPolicy cPolicy = connectorPolicies.get(cdId);
+                    ActivityNodeId ac2 = jag.getConsumerActivity(cdId);
+                    TaskState[] ac2TaskStates = taskStateMap.get(ac2);
+                    int nConsumers = ac2TaskStates.length;
+                    for (int i = 0; i < nProducers; ++i) {
+                        c.indicateTargetPartitions(nProducers, nConsumers, i, targetBitmap);
+                        List<Pair<TaskId, IConnectorPolicy>> cInfoList = connectionInfo.get(ac1TaskStates[i]
+                                .getTaskId());
+                        if (cInfoList == null) {
+                            cInfoList = new ArrayList<Pair<TaskId, IConnectorPolicy>>();
+                            connectionInfo.put(ac1TaskStates[i].getTaskId(), cInfoList);
+                        }
+                        Set<TaskId> cluster = taskClusterMap.get(ac1TaskStates[i].getTaskId());
+                        for (int j = targetBitmap.nextSetBit(0); j >= 0; j = targetBitmap.nextSetBit(j)) {
+                            cInfoList.add(new Pair<TaskId, IConnectorPolicy>(ac2TaskStates[j].getTaskId(), cPolicy));
+                            if (cPolicy.requiresProducerConsumerCoscheduling()) {
+                                cluster.add(ac2TaskStates[j].getTaskId());
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        boolean done = false;
+        while (!done) {
+            done = true;
+            Set<TaskId> set = new HashSet<TaskId>();
+            for (Map.Entry<TaskId, Set<TaskId>> e : taskClusterMap.entrySet()) {
+                set.clear();
+                for (TaskId tid : e.getValue()) {
+                    set.addAll(taskClusterMap.get(tid));
+                }
+                for (TaskId tid : set) {
+                    Set<TaskId> targetSet = taskClusterMap.get(tid);
+                    if (!targetSet.equals(set)) {
+                        done = false;
+                        break;
+                    }
+                }
+                if (!done) {
+                    break;
+                }
+            }
+            for (TaskId tid : set) {
+                taskClusterMap.put(tid, set);
+            }
+        }
+
+        Set<Set<TaskId>> clusters = new HashSet<Set<TaskId>>(taskClusterMap.values());
+        Set<TaskCluster> tcSet = new HashSet<TaskCluster>();
+        for (Set<TaskId> cluster : clusters) {
+            Set<TaskState> taskStates = new HashSet<TaskState>();
+            for (TaskId tid : cluster) {
+                taskStates.add(taskStateMap.get(tid.getActivityId())[tid.getPartition()]);
+            }
+            TaskCluster tc = new TaskCluster(ac, taskStates.toArray(new TaskState[taskStates.size()]));
+            tcSet.add(tc);
+            for (TaskId tid : cluster) {
+                taskStateMap.get(tid.getActivityId())[tid.getPartition()].setTaskCluster(tc);
+            }
+        }
+        ac.setTaskClusters(tcSet.toArray(new TaskCluster[tcSet.size()]));
+
+        for (TaskCluster tc : tcSet) {
+            for (TaskState ts : tc.getTasks()) {
+                TaskId tid = ts.getTaskId();
+                List<Pair<TaskId, IConnectorPolicy>> cInfoList = connectionInfo.get(tid);
+                if (cInfoList != null) {
+                    for (Pair<TaskId, IConnectorPolicy> p : cInfoList) {
+                        TaskState targetTS = taskStateMap.get(p.first.getActivityId())[p.first.getPartition()];
+                        TaskCluster targetTC = targetTS.getTaskCluster();
+                        if (targetTC != tc) {
+                            targetTC.getDependencies().add(tc);
+                            if (p.second.consumerWaitsForProducerToFinish()) {
+                                targetTC.getBlockers().add(tc);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        computeBlockerClosure(tcSet);
+        computeDependencyClosure(tcSet);
+    }
+
+    private void computeDependencyClosure(Set<TaskCluster> tcSet) {
+        boolean done = false;
+        while (!done) {
+            done = true;
+            for (TaskCluster tc : tcSet) {
+                Set<TaskCluster> deps = tc.getDependencies();
+                if (!deps.isEmpty()) {
+                    Set<TaskCluster> copy = new HashSet<TaskCluster>(deps);
+                    for (TaskCluster tc2 : copy) {
+                        for (TaskCluster tc3 : tc2.getDependencies()) {
+                            if (!deps.contains(tc3)) {
+                                deps.add(tc3);
+                                done = false;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    private void computeBlockerClosure(Set<TaskCluster> tcSet) {
+        boolean done = false;
+        while (!done) {
+            done = true;
+            for (TaskCluster tc : tcSet) {
+                Set<TaskCluster> blockers = tc.getBlockers();
+                if (!blockers.isEmpty()) {
+                    Set<TaskCluster> copy = new HashSet<TaskCluster>(blockers);
+                    for (TaskCluster tc2 : copy) {
+                        for (TaskCluster tc3 : tc2.getBlockers()) {
+                            if (!blockers.contains(tc3)) {
+                                blockers.add(tc3);
+                                done = false;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/DefaultJobScheduler.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/DefaultJobScheduler.java
new file mode 100644
index 0000000..c71b23b
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/DefaultJobScheduler.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.scheduler;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
+import edu.uci.ics.hyracks.control.cc.job.JobRun;
+
+public class DefaultJobScheduler implements IJobScheduler {
+    private final ClusterControllerService ccs;
+
+    public DefaultJobScheduler(ClusterControllerService ccs) {
+        this.ccs = ccs;
+    }
+
+    @Override
+    public void notifyJobCreation(JobRun run) throws HyracksException {
+        IJobRunStateMachine jsm = new DefaultJobRunStateMachine(ccs, run);
+        run.setStateMachine(jsm);
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IScheduler.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IActivityClusterStateMachine.java
similarity index 69%
rename from hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IScheduler.java
rename to hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IActivityClusterStateMachine.java
index 3893a2d..2c4a4ae 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IScheduler.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IActivityClusterStateMachine.java
@@ -14,14 +14,13 @@
  */
 package edu.uci.ics.hyracks.control.cc.scheduler;
 
-import java.util.Set;
-
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
-import edu.uci.ics.hyracks.control.cc.job.JobStageAttempt;
+import edu.uci.ics.hyracks.control.cc.job.TaskAttempt;
 
-public interface IScheduler {
-    public IJobAttemptSchedulerState createJobAttemptState(JobAttempt ja);
+public interface IActivityClusterStateMachine {
+    public void schedule() throws HyracksException;
 
-    public void schedule(Set<JobStageAttempt> runnableStageAttempts) throws HyracksException;
+    public void notifyTaskComplete(TaskAttempt ta) throws HyracksException;
+
+    public void notifyTaskFailure(TaskAttempt ta, Exception exception) throws HyracksException;
 }
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IJobRunStateMachine.java
similarity index 81%
rename from hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java
rename to hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IJobRunStateMachine.java
index 2906ba6..fcf0a79 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IJobRunStateMachine.java
@@ -14,8 +14,8 @@
  */
 package edu.uci.ics.hyracks.control.cc.scheduler;
 
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 
-public interface ISchedule {
-    public String[] getPartitions(ActivityNodeId aid);
+public interface IJobRunStateMachine {
+    public void schedule() throws HyracksException;
 }
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IJobScheduler.java
similarity index 76%
copy from hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java
copy to hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IJobScheduler.java
index 2906ba6..d359731 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/ISchedule.java
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IJobScheduler.java
@@ -14,8 +14,9 @@
  */
 package edu.uci.ics.hyracks.control.cc.scheduler;
 
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.control.cc.job.JobRun;
 
-public interface ISchedule {
-    public String[] getPartitions(ActivityNodeId aid);
+public interface IJobScheduler {
+    public void notifyJobCreation(JobRun run) throws HyracksException;
 }
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/PartitionConstraintSolver.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/PartitionConstraintSolver.java
new file mode 100644
index 0000000..ea10562
--- /dev/null
+++ b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/PartitionConstraintSolver.java
@@ -0,0 +1,125 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.cc.scheduler;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import edu.uci.ics.hyracks.api.constraints.Constraint;
+import edu.uci.ics.hyracks.api.constraints.expressions.ConstantExpression;
+import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression;
+import edu.uci.ics.hyracks.api.constraints.expressions.LValueConstraintExpression;
+
+public class PartitionConstraintSolver {
+    private final Map<LValueConstraintExpression, Set<ConstraintExpression>> constraints;
+
+    public PartitionConstraintSolver() {
+        constraints = new HashMap<LValueConstraintExpression, Set<ConstraintExpression>>();
+    }
+
+    public void addConstraints(Collection<Constraint> constraintCollection) {
+        for (Constraint c : constraintCollection) {
+            addConstraint(c);
+        }
+    }
+
+    public void addConstraint(Constraint c) {
+        Set<ConstraintExpression> rValues = constraints.get(c.getLValue());
+        if (rValues == null) {
+            rValues = new HashSet<ConstraintExpression>();
+            constraints.put(c.getLValue(), rValues);
+        }
+        rValues.add(c.getRValue());
+    }
+
+    public void solve(Collection<LValueConstraintExpression> targetSet) {
+        Set<LValueConstraintExpression> inProcess = new HashSet<LValueConstraintExpression>();
+        for (LValueConstraintExpression lv : targetSet) {
+            solveLValue(lv, inProcess);
+        }
+    }
+
+    private Solution solve(ConstraintExpression ce, Set<LValueConstraintExpression> inProcess) {
+        switch (ce.getTag()) {
+            case CONSTANT:
+                return new Solution(((ConstantExpression) ce).getValue(), Solution.Status.FOUND);
+
+            case PARTITION_COUNT:
+            case PARTITION_LOCATION:
+                return solveLValue((LValueConstraintExpression) ce, inProcess);
+        }
+        return null;
+    }
+
+    private Solution solveLValue(LValueConstraintExpression lv, Set<LValueConstraintExpression> inProcess) {
+        if (inProcess.contains(lv)) {
+            return new Solution(null, Solution.Status.CYCLE);
+        }
+        Solution result = null;
+        inProcess.add(lv);
+        Set<ConstraintExpression> rValues = constraints.get(lv);
+        if (rValues == null) {
+            return new Solution(null, Solution.Status.NOT_BOUND);
+        }
+        for (ConstraintExpression ce : rValues) {
+            Solution solution = solve(ce, inProcess);
+            if (solution != null && solution.status == Solution.Status.FOUND) {
+                result = solution;
+                break;
+            }
+        }
+        if (result != null) {
+            rValues.clear();
+            rValues.add(new ConstantExpression(result.value));
+        }
+        inProcess.remove(lv);
+        return result;
+    }
+
+    public Object getValue(LValueConstraintExpression lValue) {
+        Set<ConstraintExpression> rValues = constraints.get(lValue);
+        if (rValues == null) {
+            return null;
+        }
+        if (rValues.size() != 1) {
+            return null;
+        }
+        for (ConstraintExpression ce : rValues) {
+            if (ce.getTag() == ConstraintExpression.ExpressionTag.CONSTANT) {
+                return ((ConstantExpression) ce).getValue();
+            }
+        }
+        return null;
+    }
+
+    private static class Solution {
+        enum Status {
+            FOUND,
+            CYCLE,
+            NOT_BOUND,
+        }
+
+        final Object value;
+        final Status status;
+
+        public Solution(Object value, Status status) {
+            this.value = value;
+            this.status = status;
+        }
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/naive/NaiveScheduler.java b/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/naive/NaiveScheduler.java
deleted file mode 100644
index f40e8cd..0000000
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/naive/NaiveScheduler.java
+++ /dev/null
@@ -1,212 +0,0 @@
-package edu.uci.ics.hyracks.control.cc.scheduler.naive;
-
-import java.util.ArrayList;
-import java.util.BitSet;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.logging.Logger;
-
-import edu.uci.ics.hyracks.api.constraints.expressions.BelongsToExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.ConstantExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.ConstraintExpression.ExpressionTag;
-import edu.uci.ics.hyracks.api.constraints.expressions.EnumeratedCollectionExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.PartitionCountExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.PartitionLocationExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.RelationalExpression;
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
-import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
-import edu.uci.ics.hyracks.api.exceptions.HyracksException;
-import edu.uci.ics.hyracks.control.cc.ClusterControllerService;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
-import edu.uci.ics.hyracks.control.cc.job.JobStageAttempt;
-import edu.uci.ics.hyracks.control.cc.scheduler.IJobAttemptSchedulerState;
-import edu.uci.ics.hyracks.control.cc.scheduler.ISchedule;
-import edu.uci.ics.hyracks.control.cc.scheduler.IScheduler;
-
-public class NaiveScheduler implements IScheduler {
-    private static final Logger LOGGER = Logger.getLogger(NaiveScheduler.class.getName());
-
-    private final ClusterControllerService ccs;
-
-    public NaiveScheduler(ClusterControllerService ccs) {
-        this.ccs = ccs;
-    }
-
-    @Override
-    public IJobAttemptSchedulerState createJobAttemptState(JobAttempt ja) {
-        return new JobAttemptState(ja.getJobRun().getConstraints());
-    }
-
-    @Override
-    public void schedule(Set<JobStageAttempt> runnableStageAttempts) throws HyracksException {
-        for (JobStageAttempt jsa : runnableStageAttempts) {
-            Set<OperatorDescriptorId> operators = new HashSet<OperatorDescriptorId>();
-            for (ActivityNodeId aid : jsa.getJobStage().getTasks()) {
-                operators.add(aid.getOperatorDescriptorId());
-            }
-            jsa.setSchedule(computeSchedule(jsa, operators));
-        }
-    }
-
-    private ISchedule computeSchedule(JobStageAttempt jsa, Set<OperatorDescriptorId> operators) throws HyracksException {
-        Set<String> nodeSet = ccs.getNodeMap().keySet();
-        if (nodeSet.isEmpty()) {
-            throw new HyracksException("0 usable nodes found");
-        }
-        String[] liveNodes = ccs.getNodeMap().keySet().toArray(new String[nodeSet.size()]);
-        JobAttempt ja = jsa.getJobAttempt();
-        final JobAttemptState jas = (JobAttemptState) ja.getSchedulerState();
-
-        List<PartitionLocationExpression> rrAssignment = new ArrayList<PartitionLocationExpression>();
-
-        for (OperatorDescriptorId oid : operators) {
-            String[] opParts = null;
-            if (!jas.allocations.containsKey(oid)) {
-                Set<ConstraintExpression> opConstraints = jas.opConstraints.get(oid);
-                System.err.println("Constraints: " + opConstraints);
-                for (ConstraintExpression ce : opConstraints) {
-                    int nParts = getNumPartitions(oid, ce);
-                    if (nParts != -1) {
-                        opParts = new String[nParts];
-                        break;
-                    }
-                }
-                if (opParts == null) {
-                    throw new HyracksException("Unable to satisfy constraints for operator : " + oid);
-                }
-                jas.allocations.put(oid, opParts);
-                BitSet unassignedPartsIds = new BitSet(opParts.length);
-                unassignedPartsIds.set(0, opParts.length);
-                for (ConstraintExpression ce : opConstraints) {
-                    if (ce.getTag() == ConstraintExpression.ExpressionTag.BELONGS_TO) {
-                        BelongsToExpression bE = (BelongsToExpression) ce;
-                        if (bE.getItemExpression().getTag() == ConstraintExpression.ExpressionTag.PARTITION_LOCATION) {
-                            PartitionLocationExpression plE = (PartitionLocationExpression) bE.getItemExpression();
-                            if (plE.getOperatorDescriptorId().equals(oid)) {
-                                int part = plE.getPartition();
-                                if (bE.getSetExpression().getTag() == ConstraintExpression.ExpressionTag.ENUMERATED_SET) {
-                                    EnumeratedCollectionExpression ecE = (EnumeratedCollectionExpression) bE
-                                            .getSetExpression();
-                                    for (ConstraintExpression value : ecE.getMembers()) {
-                                        if (value.getTag() == ConstraintExpression.ExpressionTag.CONSTANT) {
-                                            ConstantExpression nodeConst = (ConstantExpression) value;
-                                            String nodeId = (String) nodeConst.getValue();
-                                            if (nodeSet.contains(nodeId)) {
-                                                opParts[part] = nodeId;
-                                                unassignedPartsIds.clear(part);
-                                                LOGGER.info("Assigned: " + oid + ":" + part + ": " + nodeId);
-                                                break;
-                                            }
-                                        }
-                                    }
-                                }
-                                if (unassignedPartsIds.get(part)) {
-                                    throw new HyracksException("Unsatisfiable constraint for operator: " + oid);
-                                }
-                            }
-                        }
-                    }
-                }
-
-                if (!unassignedPartsIds.isEmpty()) {
-                    // Do round robin assignment.
-                    for (int i = unassignedPartsIds.nextSetBit(0); i >= 0; i = unassignedPartsIds.nextSetBit(i + 1)) {
-                        rrAssignment.add(new PartitionLocationExpression(oid, i));
-                    }
-                }
-            }
-        }
-        int n = rrAssignment.size();
-        for (int i = 0; i < n; ++i) {
-            PartitionLocationExpression plE = rrAssignment.get(i);
-            String[] opParts = jas.allocations.get(plE.getOperatorDescriptorId());
-            String node = liveNodes[i % liveNodes.length];
-            LOGGER.info("Assigned: " + plE.getOperatorDescriptorId() + ":" + plE.getPartition() + ": " + node);
-            opParts[plE.getPartition()] = node;
-        }
-        return new ISchedule() {
-            @Override
-            public String[] getPartitions(ActivityNodeId aid) {
-                return jas.allocations.get(aid.getOperatorDescriptorId());
-            }
-        };
-    }
-
-    private int getNumPartitions(OperatorDescriptorId oid, ConstraintExpression ce) {
-        System.err.println(ce);
-        if (ce.getTag() == ExpressionTag.RELATIONAL) {
-            RelationalExpression re = (RelationalExpression) ce;
-            if (re.getOperator() == RelationalExpression.Operator.EQUAL) {
-                System.err.println("Left: " + re.getLeft());
-                System.err.println("Right: " + re.getRight());
-                if (re.getLeft().getTag() == ConstraintExpression.ExpressionTag.PARTITION_COUNT) {
-                    return getNumPartitions(oid, (PartitionCountExpression) re.getLeft(), re.getRight());
-                } else if (re.getRight().getTag() == ConstraintExpression.ExpressionTag.PARTITION_COUNT) {
-                    return getNumPartitions(oid, (PartitionCountExpression) re.getRight(), re.getLeft());
-                }
-            }
-        }
-        return -1;
-    }
-
-    private int getNumPartitions(OperatorDescriptorId oid, PartitionCountExpression pce, ConstraintExpression ce) {
-        if (pce.getOperatorDescriptorId().equals(oid)) {
-            if (ce.getTag() == ConstraintExpression.ExpressionTag.CONSTANT) {
-                ConstantExpression constExpr = (ConstantExpression) ce;
-                Integer n = (Integer) constExpr.getValue();
-                return n.intValue();
-            }
-        }
-        return -1;
-    }
-
-    private static class JobAttemptState implements IJobAttemptSchedulerState {
-        final Map<OperatorDescriptorId, String[]> allocations;
-        final Map<OperatorDescriptorId, Set<ConstraintExpression>> opConstraints;
-
-        public JobAttemptState(Set<ConstraintExpression> constraints) {
-            allocations = new HashMap<OperatorDescriptorId, String[]>();
-            opConstraints = new HashMap<OperatorDescriptorId, Set<ConstraintExpression>>();
-            List<ConstraintExpression> ceList = new ArrayList<ConstraintExpression>();
-            for (ConstraintExpression ce : constraints) {
-                ceList.clear();
-                ceList.add(ce);
-                getAllConstraints(ceList);
-                for (ConstraintExpression ce2 : ceList) {
-                    switch (ce2.getTag()) {
-                        case PARTITION_COUNT:
-                            addToOpConstraints(opConstraints,
-                                    ((PartitionCountExpression) ce2).getOperatorDescriptorId(), ce);
-                            break;
-
-                        case PARTITION_LOCATION:
-                            addToOpConstraints(opConstraints,
-                                    ((PartitionLocationExpression) ce2).getOperatorDescriptorId(), ce);
-                            break;
-                    }
-                }
-            }
-        }
-
-        private static void addToOpConstraints(Map<OperatorDescriptorId, Set<ConstraintExpression>> opc,
-                OperatorDescriptorId opId, ConstraintExpression ce) {
-            Set<ConstraintExpression> opSet = opc.get(opId);
-            if (opSet == null) {
-                opSet = new HashSet<ConstraintExpression>();
-                opc.put(opId, opSet);
-            }
-            opSet.add(ce);
-        }
-
-        private static void getAllConstraints(List<ConstraintExpression> ceList) {
-            for (int i = 0; i < ceList.size(); ++i) {
-                ConstraintExpression cE = ceList.get(i);
-                cE.getChildren(ceList);
-            }
-        }
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/base/IClusterController.java b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/base/IClusterController.java
index 02b8f9e..1d95390 100644
--- a/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/base/IClusterController.java
+++ b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/base/IClusterController.java
@@ -15,23 +15,30 @@
 package edu.uci.ics.hyracks.control.common.base;
 
 import java.rmi.Remote;
+import java.util.Collection;
 import java.util.List;
 import java.util.UUID;
 
+import edu.uci.ics.hyracks.api.comm.NetworkAddress;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
 import edu.uci.ics.hyracks.control.common.job.profiling.om.JobProfile;
-import edu.uci.ics.hyracks.control.common.job.profiling.om.StageletProfile;
+import edu.uci.ics.hyracks.control.common.job.profiling.om.TaskProfile;
 
 public interface IClusterController extends Remote {
     public NodeParameters registerNode(INodeController nodeController) throws Exception;
 
     public void unregisterNode(INodeController nodeController) throws Exception;
 
-    public void notifyStageletComplete(UUID jobId, UUID stageId, int attempt, String nodeId, StageletProfile statistics)
-            throws Exception;
+    public void notifyTaskComplete(UUID jobId, TaskAttemptId taskId, String nodeId, TaskProfile statistics) throws Exception;
 
-    public void notifyStageletFailure(UUID jobId, UUID stageId, int attempt, String nodeId) throws Exception;
+    public void notifyTaskFailure(UUID jobId, TaskAttemptId taskId, String nodeId, Exception e) throws Exception;
 
     public void nodeHeartbeat(String id) throws Exception;
 
     public void reportProfile(String id, List<JobProfile> profiles) throws Exception;
+
+    public void registerPartitionProvider(PartitionId pid, NetworkAddress address) throws Exception;
+
+    public void registerPartitionRequest(Collection<PartitionId> requiredPartitionIds, String nodeId) throws Exception;
 }
\ No newline at end of file
diff --git a/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/base/INodeController.java b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/base/INodeController.java
index 8fd79f3..f0ceed6 100644
--- a/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/base/INodeController.java
+++ b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/base/INodeController.java
@@ -15,14 +15,14 @@
 package edu.uci.ics.hyracks.control.common.base;
 
 import java.rmi.Remote;
+import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.UUID;
 
-import edu.uci.ics.hyracks.api.comm.Endpoint;
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+import edu.uci.ics.hyracks.api.comm.NetworkAddress;
 import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
-import edu.uci.ics.hyracks.api.dataflow.PortInstanceId;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
 
 public interface INodeController extends Remote {
     public String getId() throws Exception;
@@ -31,26 +31,19 @@
 
     public NodeCapability getNodeCapability() throws Exception;
 
-    public Map<PortInstanceId, Endpoint> initializeJobletPhase1(String appName, UUID jobId, int attempt, byte[] plan,
-            UUID stageId, Map<ActivityNodeId, Set<Integer>> tasks, Map<OperatorDescriptorId, Integer> opNumPartitions)
-            throws Exception;
+    public void startTasks(String appName, UUID jobId, byte[] planBytes, List<TaskAttemptId> tasks,
+            Map<OperatorDescriptorId, Integer> opNumPartitions) throws Exception;
 
-    public void initializeJobletPhase2(String appName, UUID jobId, byte[] plan, UUID stageId,
-            Map<ActivityNodeId, Set<Integer>> tasks, Map<OperatorDescriptorId, Integer> opNumPartitions,
-            Map<PortInstanceId, Endpoint> globalPortMap) throws Exception;
-
-    public void commitJobletInitialization(UUID jobId, UUID stageId) throws Exception;
-
-    public void abortJoblet(UUID jobId, int attempt) throws Exception;
+    public void abortTasks(UUID jobId, List<TaskAttemptId> tasks) throws Exception;
 
     public void cleanUpJob(UUID jobId) throws Exception;
 
-    public void startStage(UUID jobId, UUID stageId) throws Exception;
-
     public void notifyRegistration(IClusterController ccs) throws Exception;
 
     public void createApplication(String appName, boolean deployHar, byte[] serializedDistributedState)
             throws Exception;
 
     public void destroyApplication(String appName) throws Exception;
+
+    public void reportPartitionAvailability(PartitionId pid, NetworkAddress networkAddress) throws Exception;
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/dataflow/IConnectorPolicy.java
similarity index 70%
copy from hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java
copy to hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/dataflow/IConnectorPolicy.java
index 59edd97..da659ce 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java
+++ b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/dataflow/IConnectorPolicy.java
@@ -12,10 +12,12 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hyracks.api.comm;
+package edu.uci.ics.hyracks.control.common.job.dataflow;
 
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import java.io.Serializable;
 
-public interface IEndpointDataWriterFactory {
-    public IFrameWriter createFrameWriter(int index) throws HyracksDataException;
+public interface IConnectorPolicy extends Serializable {
+    public boolean requiresProducerConsumerCoscheduling();
+
+    public boolean consumerWaitsForProducerToFinish();
 }
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/dataflow/PipelinedConnectorPolicy.java
similarity index 62%
copy from hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java
copy to hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/dataflow/PipelinedConnectorPolicy.java
index 59edd97..bc98e93 100644
--- a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IEndpointDataWriterFactory.java
+++ b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/dataflow/PipelinedConnectorPolicy.java
@@ -12,10 +12,18 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hyracks.api.comm;
+package edu.uci.ics.hyracks.control.common.job.dataflow;
 
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+public final class PipelinedConnectorPolicy implements IConnectorPolicy {
+    private static final long serialVersionUID = 1L;
 
-public interface IEndpointDataWriterFactory {
-    public IFrameWriter createFrameWriter(int index) throws HyracksDataException;
+    @Override
+    public boolean requiresProducerConsumerCoscheduling() {
+        return true;
+    }
+
+    @Override
+    public boolean consumerWaitsForProducerToFinish() {
+        return true;
+    }
 }
\ No newline at end of file
diff --git a/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/JobProfile.java b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/JobProfile.java
index 77ac2b5..cc0b1a2 100644
--- a/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/JobProfile.java
+++ b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/JobProfile.java
@@ -12,13 +12,10 @@
 
     private final UUID jobId;
 
-    private final int attempt;
-
     private final Map<String, JobletProfile> jobletProfiles;
 
-    public JobProfile(UUID jobId, int attempt) {
+    public JobProfile(UUID jobId) {
         this.jobId = jobId;
-        this.attempt = attempt;
         jobletProfiles = new HashMap<String, JobletProfile>();
     }
 
@@ -26,10 +23,6 @@
         return jobId;
     }
 
-    public int getAttempt() {
-        return attempt;
-    }
-
     public Map<String, JobletProfile> getJobletProfiles() {
         return jobletProfiles;
     }
@@ -40,7 +33,6 @@
 
         json.put("type", "job-profile");
         json.put("job-id", jobId.toString());
-        json.put("attempt", attempt);
         populateCounters(json);
         for (JobletProfile p : jobletProfiles.values()) {
             json.accumulate("joblets", p.toJSON());
diff --git a/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/JobletProfile.java b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/JobletProfile.java
index f847cf9..5069fc3 100644
--- a/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/JobletProfile.java
+++ b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/JobletProfile.java
@@ -16,29 +16,30 @@
 
 import java.util.HashMap;
 import java.util.Map;
-import java.util.UUID;
 
 import org.json.JSONException;
 import org.json.JSONObject;
 
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+
 public class JobletProfile extends AbstractProfile {
     private static final long serialVersionUID = 1L;
 
     private final String nodeId;
 
-    private final Map<UUID, StageletProfile> stageletProfiles;
+    private final Map<TaskAttemptId, TaskProfile> taskProfiles;
 
     public JobletProfile(String nodeId) {
         this.nodeId = nodeId;
-        stageletProfiles = new HashMap<UUID, StageletProfile>();
+        taskProfiles = new HashMap<TaskAttemptId, TaskProfile>();
     }
 
     public String getNodeId() {
         return nodeId;
     }
 
-    public Map<UUID, StageletProfile> getStageletProfiles() {
-        return stageletProfiles;
+    public Map<TaskAttemptId, TaskProfile> getTaskProfiles() {
+        return taskProfiles;
     }
 
     @Override
@@ -48,8 +49,8 @@
         json.put("type", "joblet-profile");
         json.put("node-id", nodeId.toString());
         populateCounters(json);
-        for (StageletProfile p : stageletProfiles.values()) {
-            json.accumulate("stagelets", p.toJSON());
+        for (TaskProfile p : taskProfiles.values()) {
+            json.accumulate("tasks", p.toJSON());
         }
 
         return json;
@@ -57,11 +58,11 @@
 
     public void merge(JobletProfile jp) {
         super.merge(this);
-        for (StageletProfile sp : jp.stageletProfiles.values()) {
-            if (stageletProfiles.containsKey(sp.getStageId())) {
-                stageletProfiles.get(sp.getStageId()).merge(sp);
+        for (TaskProfile tp : jp.taskProfiles.values()) {
+            if (taskProfiles.containsKey(tp.getTaskId())) {
+                taskProfiles.get(tp.getTaskId()).merge(tp);
             } else {
-                stageletProfiles.put(sp.getStageId(), sp);
+                taskProfiles.put(tp.getTaskId(), tp);
             }
         }
     }
diff --git a/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/StageletProfile.java b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/TaskProfile.java
similarity index 63%
rename from hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/StageletProfile.java
rename to hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/TaskProfile.java
index 33beaf6..3ab1090 100644
--- a/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/StageletProfile.java
+++ b/hyracks-control-common/src/main/java/edu/uci/ics/hyracks/control/common/job/profiling/om/TaskProfile.java
@@ -14,30 +14,32 @@
  */
 package edu.uci.ics.hyracks.control.common.job.profiling.om;
 
-import java.util.UUID;
-
 import org.json.JSONException;
 import org.json.JSONObject;
 
-public class StageletProfile extends AbstractProfile {
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+
+public class TaskProfile extends AbstractProfile {
     private static final long serialVersionUID = 1L;
 
-    private final UUID stageId;
+    private final TaskAttemptId taskAttemptId;
 
-    public StageletProfile(UUID stageId) {
-        this.stageId = stageId;
+    public TaskProfile(TaskAttemptId taskAttemptId) {
+        this.taskAttemptId = taskAttemptId;
     }
 
-    public UUID getStageId() {
-        return stageId;
+    public TaskAttemptId getTaskId() {
+        return taskAttemptId;
     }
 
     @Override
     public JSONObject toJSON() throws JSONException {
         JSONObject json = new JSONObject();
 
-        json.put("type", "joblet-profile");
-        json.put("stage-id", stageId.toString());
+        json.put("type", "task-profile");
+        json.put("activity-id", taskAttemptId.getTaskId().getActivityId().toString());
+        json.put("partition", taskAttemptId.getTaskId().getPartition());
+        json.put("attempt", taskAttemptId.getAttempt());
         populateCounters(json);
 
         return json;
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Joblet.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Joblet.java
index f4fa95b..6599eb0 100644
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Joblet.java
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Joblet.java
@@ -15,28 +15,35 @@
 package edu.uci.ics.hyracks.control.nc;
 
 import java.nio.ByteBuffer;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.UUID;
 import java.util.concurrent.Executor;
 
 import edu.uci.ics.hyracks.api.application.INCApplicationContext;
+import edu.uci.ics.hyracks.api.comm.IPartitionCollector;
+import edu.uci.ics.hyracks.api.comm.PartitionChannel;
 import edu.uci.ics.hyracks.api.context.IHyracksJobletContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IIOManager;
 import edu.uci.ics.hyracks.api.io.IWorkspaceFileFactory;
 import edu.uci.ics.hyracks.api.job.IOperatorEnvironment;
 import edu.uci.ics.hyracks.api.job.profiling.counters.ICounter;
 import edu.uci.ics.hyracks.api.job.profiling.counters.ICounterContext;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
 import edu.uci.ics.hyracks.api.resources.IDeallocatable;
 import edu.uci.ics.hyracks.control.common.job.profiling.counters.Counter;
 import edu.uci.ics.hyracks.control.common.job.profiling.om.JobletProfile;
-import edu.uci.ics.hyracks.control.common.job.profiling.om.StageletProfile;
+import edu.uci.ics.hyracks.control.common.job.profiling.om.TaskProfile;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
-import edu.uci.ics.hyracks.control.nc.io.ManagedWorkspaceFileFactory;
+import edu.uci.ics.hyracks.control.nc.io.WorkspaceFileFactory;
 import edu.uci.ics.hyracks.control.nc.resources.DefaultDeallocatableRegistry;
 
 public class Joblet implements IHyracksJobletContext, ICounterContext {
@@ -48,28 +55,28 @@
 
     private final UUID jobId;
 
-    private final int attempt;
-
-    private final Map<UUID, Stagelet> stageletMap;
+    private final Map<PartitionId, IPartitionCollector> partitionRequestMap;
 
     private final Map<OperatorDescriptorId, Map<Integer, IOperatorEnvironment>> envMap;
 
+    private final Map<TaskAttemptId, Task> taskMap;
+
     private final Map<String, Counter> counterMap;
 
     private final DefaultDeallocatableRegistry deallocatableRegistry;
 
     private final IWorkspaceFileFactory fileFactory;
 
-    public Joblet(NodeControllerService nodeController, UUID jobId, int attempt, INCApplicationContext appCtx) {
+    public Joblet(NodeControllerService nodeController, UUID jobId, INCApplicationContext appCtx) {
         this.nodeController = nodeController;
         this.appCtx = appCtx;
         this.jobId = jobId;
-        this.attempt = attempt;
-        stageletMap = new HashMap<UUID, Stagelet>();
+        partitionRequestMap = new HashMap<PartitionId, IPartitionCollector>();
         envMap = new HashMap<OperatorDescriptorId, Map<Integer, IOperatorEnvironment>>();
+        taskMap = new HashMap<TaskAttemptId, Task>();
         counterMap = new HashMap<String, Counter>();
         deallocatableRegistry = new DefaultDeallocatableRegistry();
-        fileFactory = new ManagedWorkspaceFileFactory(this, (IOManager) appCtx.getRootContext().getIOManager());
+        fileFactory = new WorkspaceFileFactory(this, (IOManager) appCtx.getRootContext().getIOManager());
     }
 
     @Override
@@ -88,6 +95,14 @@
         return opEnvMap.get(partition);
     }
 
+    public void addTask(Task task) {
+        taskMap.put(task.getTaskId(), task);
+    }
+
+    public Map<TaskAttemptId, Task> getTaskMap() {
+        return taskMap;
+    }
+
     private static final class OperatorEnvironmentImpl implements IOperatorEnvironment {
         private final Map<String, Object> map;
 
@@ -106,26 +121,20 @@
         }
     }
 
-    public void setStagelet(UUID stageId, Stagelet stagelet) {
-        stageletMap.put(stageId, stagelet);
-    }
-
-    public Stagelet getStagelet(UUID stageId) throws Exception {
-        return stageletMap.get(stageId);
-    }
-
     public Executor getExecutor() {
         return nodeController.getExecutor();
     }
 
-    public synchronized void notifyStageletComplete(UUID stageId, int attempt, StageletProfile stats) throws Exception {
-        stageletMap.remove(stageId);
-        nodeController.notifyStageComplete(jobId, stageId, attempt, stats);
+    public synchronized void notifyTaskComplete(Task task) throws Exception {
+        taskMap.remove(task);
+        TaskProfile taskProfile = new TaskProfile(task.getTaskId());
+        task.dumpProfile(taskProfile);
+        nodeController.notifyTaskComplete(jobId, task.getTaskId(), taskProfile);
     }
 
-    public void notifyStageletFailed(UUID stageId, int attempt) throws Exception {
-        stageletMap.remove(stageId);
-        nodeController.notifyStageFailed(jobId, stageId, attempt);
+    public synchronized void notifyStageletFailed(Task task, Exception exception) throws Exception {
+        taskMap.remove(task);
+        nodeController.notifyTaskFailed(jobId, task.getTaskId(), exception);
     }
 
     public NodeControllerService getNodeController() {
@@ -137,10 +146,10 @@
         for (Map.Entry<String, Counter> e : counterMap.entrySet()) {
             counters.put(e.getKey(), e.getValue().get());
         }
-        for (Stagelet si : stageletMap.values()) {
-            StageletProfile sProfile = new StageletProfile(si.getStageId());
-            si.dumpProfile(sProfile);
-            jProfile.getStageletProfiles().put(si.getStageId(), sProfile);
+        for (Task task : taskMap.values()) {
+            TaskProfile taskProfile = new TaskProfile(task.getTaskId());
+            task.dumpProfile(taskProfile);
+            jProfile.getTaskProfiles().put(task.getTaskId(), taskProfile);
         }
     }
 
@@ -150,11 +159,6 @@
     }
 
     @Override
-    public int getAttempt() {
-        return attempt;
-    }
-
-    @Override
     public ICounterContext getCounterContext() {
         return this;
     }
@@ -184,12 +188,13 @@
     }
 
     @Override
-    public FileReference createWorkspaceFile(String prefix) throws HyracksDataException {
-        return fileFactory.createWorkspaceFile(prefix);
+    public FileReference createManagedWorkspaceFile(String prefix) throws HyracksDataException {
+        return fileFactory.createManagedWorkspaceFile(prefix);
     }
 
-    public Map<UUID, Stagelet> getStageletMap() {
-        return stageletMap;
+    @Override
+    public FileReference createUnmanagedWorkspaceFile(String prefix) throws HyracksDataException {
+        return fileFactory.createUnmanagedWorkspaceFile(prefix);
     }
 
     @Override
@@ -201,4 +206,19 @@
         }
         return counter;
     }
+
+    public synchronized void advertisePartitionRequest(Collection<PartitionId> requiredPartitionIds,
+            IPartitionCollector collector) throws Exception {
+        for (PartitionId pid : requiredPartitionIds) {
+            partitionRequestMap.put(pid, collector);
+        }
+        nodeController.getClusterController().registerPartitionRequest(requiredPartitionIds, nodeController.getId());
+    }
+
+    public synchronized void reportPartitionAvailability(PartitionChannel channel) throws HyracksException {
+        IPartitionCollector collector = partitionRequestMap.get(channel.getPartitionId());
+        if (collector != null) {
+            collector.addPartitions(Collections.singleton(channel));
+        }
+    }
 }
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/NodeControllerService.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/NodeControllerService.java
index 0bb3904..bdd30a9 100644
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/NodeControllerService.java
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/NodeControllerService.java
@@ -19,7 +19,7 @@
 import java.io.OutputStream;
 import java.io.Serializable;
 import java.net.InetAddress;
-import java.nio.ByteBuffer;
+import java.net.InetSocketAddress;
 import java.rmi.registry.LocateRegistry;
 import java.rmi.registry.Registry;
 import java.text.MessageFormat;
@@ -28,7 +28,6 @@
 import java.util.Hashtable;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.StringTokenizer;
 import java.util.Timer;
 import java.util.TimerTask;
@@ -47,31 +46,25 @@
 import org.apache.http.impl.client.DefaultHttpClient;
 
 import edu.uci.ics.hyracks.api.application.INCApplicationContext;
-import edu.uci.ics.hyracks.api.comm.Endpoint;
-import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
-import edu.uci.ics.hyracks.api.comm.IEndpointDataWriterFactory;
-import edu.uci.ics.hyracks.api.comm.IFrameReader;
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.comm.IPartitionCollector;
+import edu.uci.ics.hyracks.api.comm.IPartitionWriterFactory;
+import edu.uci.ics.hyracks.api.comm.NetworkAddress;
+import edu.uci.ics.hyracks.api.comm.PartitionChannel;
 import edu.uci.ics.hyracks.api.context.IHyracksRootContext;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
-import edu.uci.ics.hyracks.api.dataflow.Direction;
 import edu.uci.ics.hyracks.api.dataflow.IActivityNode;
 import edu.uci.ics.hyracks.api.dataflow.IConnectorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
-import edu.uci.ics.hyracks.api.dataflow.OperatorInstanceId;
-import edu.uci.ics.hyracks.api.dataflow.PortInstanceId;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.api.io.IODeviceHandle;
-import edu.uci.ics.hyracks.api.job.JobFlag;
-import edu.uci.ics.hyracks.api.job.JobPlan;
-import edu.uci.ics.hyracks.api.job.JobSpecification;
-import edu.uci.ics.hyracks.api.job.profiling.counters.ICounter;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
 import edu.uci.ics.hyracks.control.common.AbstractRemoteService;
 import edu.uci.ics.hyracks.control.common.application.ApplicationContext;
 import edu.uci.ics.hyracks.control.common.base.IClusterController;
@@ -82,12 +75,12 @@
 import edu.uci.ics.hyracks.control.common.context.ServerContext;
 import edu.uci.ics.hyracks.control.common.job.profiling.om.JobProfile;
 import edu.uci.ics.hyracks.control.common.job.profiling.om.JobletProfile;
-import edu.uci.ics.hyracks.control.common.job.profiling.om.StageletProfile;
+import edu.uci.ics.hyracks.control.common.job.profiling.om.TaskProfile;
 import edu.uci.ics.hyracks.control.nc.application.NCApplicationContext;
-import edu.uci.ics.hyracks.control.nc.comm.ConnectionManager;
-import edu.uci.ics.hyracks.control.nc.comm.DemuxDataReceiveListenerFactory;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
-import edu.uci.ics.hyracks.control.nc.runtime.OperatorRunnable;
+import edu.uci.ics.hyracks.control.nc.net.ConnectionManager;
+import edu.uci.ics.hyracks.control.nc.net.NetworkInputChannel;
+import edu.uci.ics.hyracks.control.nc.partitions.PartitionManager;
 import edu.uci.ics.hyracks.control.nc.runtime.RootHyracksContext;
 
 public class NodeControllerService extends AbstractRemoteService implements INodeController {
@@ -103,6 +96,8 @@
 
     private final NodeCapability nodeCapability;
 
+    private final PartitionManager partitionManager;
+
     private final ConnectionManager connectionManager;
 
     private final Timer timer;
@@ -129,6 +124,9 @@
         }
         nodeCapability = computeNodeCapability();
         connectionManager = new ConnectionManager(ctx, getIpAddress(ncConfig));
+        partitionManager = new PartitionManager(this, connectionManager.getNetworkAddress());
+        connectionManager.setPartitionRequestListener(partitionManager);
+
         jobletMap = new HashMap<UUID, Joblet>();
         timer = new Timer(true);
         serverCtx = new ServerContext(ServerContext.ServerType.NODE_CONTROLLER, new File(new File(
@@ -186,6 +184,14 @@
         return connectionManager;
     }
 
+    public PartitionManager getPartitionManager() {
+        return partitionManager;
+    }
+
+    public IClusterController getClusterController() {
+        return ccs;
+    }
+
     private static NodeCapability computeNodeCapability() {
         NodeCapability nc = new NodeCapability();
         nc.setCPUCount(Runtime.getRuntime().availableProcessors());
@@ -209,15 +215,11 @@
         return InetAddress.getByAddress(ipBytes);
     }
 
-    @Override
-    public Map<PortInstanceId, Endpoint> initializeJobletPhase1(String appName, UUID jobId, int attempt,
-            byte[] planBytes, UUID stageId, Map<ActivityNodeId, Set<Integer>> tasks,
+    public void startTasks(String appName, UUID jobId, byte[] jagBytes, List<TaskAttemptId> tasks,
             Map<OperatorDescriptorId, Integer> opNumPartitions) throws Exception {
         try {
-            LOGGER.log(Level.INFO, String.valueOf(jobId) + "[" + id + ":" + stageId + "]: Initializing Joblet Phase 1");
-
             NCApplicationContext appCtx = applications.get(appName);
-            final JobPlan plan = (JobPlan) appCtx.deserialize(planBytes);
+            final JobActivityGraph plan = (JobActivityGraph) appCtx.deserialize(jagBytes);
 
             IRecordDescriptorProvider rdp = new IRecordDescriptorProvider() {
                 @Override
@@ -231,158 +233,66 @@
                 }
             };
 
-            final Joblet joblet = getOrCreateLocalJoblet(jobId, attempt, appCtx);
+            final Joblet joblet = getOrCreateLocalJoblet(jobId, appCtx);
 
-            Stagelet stagelet = new Stagelet(joblet, stageId, attempt, id);
-            joblet.setStagelet(stageId, stagelet);
-
-            final Map<PortInstanceId, Endpoint> portMap = new HashMap<PortInstanceId, Endpoint>();
-            Map<OperatorInstanceId, OperatorRunnable> honMap = stagelet.getOperatorMap();
-
-            List<Endpoint> endpointList = new ArrayList<Endpoint>();
-
-            for (ActivityNodeId hanId : tasks.keySet()) {
-                IActivityNode han = plan.getActivityNodeMap().get(hanId);
+            for (TaskAttemptId tid : tasks) {
+                IActivityNode han = plan.getActivityNodeMap().get(tid.getTaskId().getActivityId());
                 if (LOGGER.isLoggable(Level.FINEST)) {
-                    LOGGER.finest("Initializing " + hanId + " -> " + han);
+                    LOGGER.finest("Initializing " + tid + " -> " + han);
                 }
                 IOperatorDescriptor op = han.getOwner();
-                List<IConnectorDescriptor> inputs = plan.getTaskInputs(hanId);
-                for (int i : tasks.get(hanId)) {
-                    IOperatorNodePushable hon = han.createPushRuntime(stagelet, joblet.getEnvironment(op, i), rdp, i,
-                            opNumPartitions.get(op.getOperatorId()));
-                    OperatorRunnable or = new OperatorRunnable(stagelet, hon);
-                    stagelet.setOperator(op.getOperatorId(), i, or);
-                    if (inputs != null) {
-                        for (int j = 0; j < inputs.size(); ++j) {
-                            if (j >= 1) {
-                                throw new IllegalStateException();
-                            }
-                            IConnectorDescriptor conn = inputs.get(j);
+                int partition = tid.getTaskId().getPartition();
+                Task task = new Task(joblet, tid);
+                IOperatorNodePushable operator = han.createPushRuntime(task, joblet.getEnvironment(op, partition), rdp,
+                        partition, opNumPartitions.get(op.getOperatorId()));
+
+                IPartitionCollector collector = null;
+
+                List<IConnectorDescriptor> inputs = plan.getActivityInputConnectorDescriptors(tid.getTaskId()
+                        .getActivityId());
+                if (inputs != null) {
+                    for (int i = 0; i < inputs.size(); ++i) {
+                        if (i >= 1) {
+                            throw new HyracksException("Multiple inputs to an activity not currently supported");
+                        }
+                        if (!inputs.isEmpty()) {
+                            IConnectorDescriptor conn = inputs.get(0);
                             OperatorDescriptorId producerOpId = plan.getJobSpecification().getProducer(conn)
                                     .getOperatorId();
                             OperatorDescriptorId consumerOpId = plan.getJobSpecification().getConsumer(conn)
                                     .getOperatorId();
-                            Endpoint endpoint = new Endpoint(connectionManager.getNetworkAddress(), i);
-                            endpointList.add(endpoint);
-                            DemuxDataReceiveListenerFactory drlf = new DemuxDataReceiveListenerFactory(stagelet, jobId,
-                                    attempt, stageId, conn.getConnectorId());
-                            connectionManager.acceptConnection(endpoint.getEndpointId(), drlf);
-                            PortInstanceId piId = new PortInstanceId(op.getOperatorId(), Direction.INPUT, plan
-                                    .getTaskInputMap().get(hanId).get(j), i);
-                            if (LOGGER.isLoggable(Level.FINEST)) {
-                                LOGGER.finest("Created endpoint " + piId + " -> " + endpoint);
-                            }
-                            portMap.put(piId, endpoint);
-                            IFrameReader reader = createReader(stagelet, conn, drlf, i, plan, stagelet,
+                            RecordDescriptor recordDesc = plan.getJobSpecification().getConnectorRecordDescriptor(conn);
+                            collector = conn.createPartitionCollector(task, recordDesc, partition,
                                     opNumPartitions.get(producerOpId), opNumPartitions.get(consumerOpId));
-                            or.setFrameReader(reader);
                         }
                     }
-                    honMap.put(new OperatorInstanceId(op.getOperatorId(), i), or);
                 }
-            }
-
-            stagelet.setEndpointList(endpointList);
-
-            return portMap;
-        } catch (Exception e) {
-            e.printStackTrace();
-            throw e;
-        }
-    }
-
-    private IFrameReader createReader(final IHyracksStageletContext stageletContext, final IConnectorDescriptor conn,
-            IConnectionDemultiplexer demux, final int receiverIndex, JobPlan plan, final Stagelet stagelet,
-            int nProducerCount, int nConsumerCount) throws HyracksDataException {
-        final IFrameReader reader = conn.createReceiveSideReader(stageletContext, plan.getJobSpecification()
-                .getConnectorRecordDescriptor(conn), demux, receiverIndex, nProducerCount, nConsumerCount);
-
-        return plan.getJobFlags().contains(JobFlag.PROFILE_RUNTIME) ? new IFrameReader() {
-            private ICounter openCounter = stageletContext.getCounterContext().getCounter(
-                    conn.getConnectorId().getId() + ".receiver." + receiverIndex + ".open", true);
-            private ICounter closeCounter = stageletContext.getCounterContext().getCounter(
-                    conn.getConnectorId().getId() + ".receiver." + receiverIndex + ".close", true);
-            private ICounter frameCounter = stageletContext.getCounterContext().getCounter(
-                    conn.getConnectorId().getId() + ".receiver." + receiverIndex + ".nextFrame", true);
-
-            @Override
-            public void open() throws HyracksDataException {
-                reader.open();
-                openCounter.update(1);
-            }
-
-            @Override
-            public boolean nextFrame(ByteBuffer buffer) throws HyracksDataException {
-                boolean status = reader.nextFrame(buffer);
-                if (status) {
-                    frameCounter.update(1);
-                }
-                return status;
-            }
-
-            @Override
-            public void close() throws HyracksDataException {
-                reader.close();
-                closeCounter.update(1);
-            }
-        } : reader;
-    }
-
-    @Override
-    public void initializeJobletPhase2(String appName, UUID jobId, byte[] planBytes, UUID stageId,
-            Map<ActivityNodeId, Set<Integer>> tasks, Map<OperatorDescriptorId, Integer> opNumPartitions,
-            final Map<PortInstanceId, Endpoint> globalPortMap) throws Exception {
-        try {
-            LOGGER.log(Level.INFO, String.valueOf(jobId) + "[" + id + ":" + stageId + "]: Initializing Joblet Phase 2");
-            ApplicationContext appCtx = applications.get(appName);
-            final JobPlan plan = (JobPlan) appCtx.deserialize(planBytes);
-
-            final Joblet ji = getLocalJoblet(jobId);
-            final Stagelet stagelet = (Stagelet) ji.getStagelet(stageId);
-            final Map<OperatorInstanceId, OperatorRunnable> honMap = stagelet.getOperatorMap();
-
-            final JobSpecification spec = plan.getJobSpecification();
-
-            for (ActivityNodeId hanId : tasks.keySet()) {
-                IActivityNode han = plan.getActivityNodeMap().get(hanId);
-                IOperatorDescriptor op = han.getOwner();
-                List<IConnectorDescriptor> outputs = plan.getTaskOutputs(hanId);
-                for (int i : tasks.get(hanId)) {
-                    OperatorRunnable or = honMap.get(new OperatorInstanceId(op.getOperatorId(), i));
-                    if (outputs != null) {
-                        for (int j = 0; j < outputs.size(); ++j) {
-                            final IConnectorDescriptor conn = outputs.get(j);
-                            OperatorDescriptorId producerOpId = plan.getJobSpecification().getProducer(conn)
-                                    .getOperatorId();
-                            OperatorDescriptorId consumerOpId = plan.getJobSpecification().getConsumer(conn)
-                                    .getOperatorId();
-                            final int senderIndex = i;
-                            IEndpointDataWriterFactory edwFactory = new IEndpointDataWriterFactory() {
-                                @Override
-                                public IFrameWriter createFrameWriter(int index) throws HyracksDataException {
-                                    PortInstanceId piId = new PortInstanceId(spec.getConsumer(conn).getOperatorId(),
-                                            Direction.INPUT, spec.getConsumerInputIndex(conn), index);
-                                    Endpoint ep = globalPortMap.get(piId);
-                                    if (ep == null) {
-                                        LOGGER.info("Got null Endpoint for " + piId);
-                                        throw new NullPointerException();
-                                    }
-                                    if (LOGGER.isLoggable(Level.FINEST)) {
-                                        LOGGER.finest("Probed endpoint " + piId + " -> " + ep);
-                                    }
-                                    return createWriter(stagelet, connectionManager.connect(ep.getNetworkAddress(),
-                                            ep.getEndpointId(), senderIndex), plan, conn, senderIndex, index, stagelet);
-                                }
-                            };
-                            or.setFrameWriter(j, conn.createSendSideWriter(stagelet, plan.getJobSpecification()
-                                    .getConnectorRecordDescriptor(conn), edwFactory, i, opNumPartitions
-                                    .get(producerOpId), opNumPartitions.get(consumerOpId)), spec
-                                    .getConnectorRecordDescriptor(conn));
-                        }
+                List<IConnectorDescriptor> outputs = plan.getActivityOutputConnectorDescriptors(tid.getTaskId()
+                        .getActivityId());
+                if (outputs != null) {
+                    for (int i = 0; i < outputs.size(); ++i) {
+                        IConnectorDescriptor conn = outputs.get(i);
+                        OperatorDescriptorId producerOpId = plan.getJobSpecification().getProducer(conn)
+                                .getOperatorId();
+                        OperatorDescriptorId consumerOpId = plan.getJobSpecification().getConsumer(conn)
+                                .getOperatorId();
+                        RecordDescriptor recordDesc = plan.getJobSpecification().getConnectorRecordDescriptor(conn);
+                        IPartitionWriterFactory pwFactory = new IPartitionWriterFactory() {
+                            @Override
+                            public IFrameWriter createFrameWriter(int receiverIndex) throws HyracksDataException {
+                                return null;
+                            }
+                        };
+                        IFrameWriter writer = conn.createPartitioner(task, recordDesc, pwFactory, partition,
+                                opNumPartitions.get(producerOpId), opNumPartitions.get(consumerOpId));
+                        operator.setOutputFrameWriter(i, writer, recordDesc);
                     }
-                    stagelet.installRunnable(new OperatorInstanceId(op.getOperatorId(), i));
                 }
+
+                task.setTaskRuntime(collector, operator);
+                joblet.addTask(task);
+
+                task.start();
             }
         } catch (Exception e) {
             e.printStackTrace();
@@ -390,64 +300,10 @@
         }
     }
 
-    private IFrameWriter createWriter(final IHyracksStageletContext stageletContext, final IFrameWriter writer,
-            JobPlan plan, final IConnectorDescriptor conn, final int senderIndex, final int receiverIndex,
-            final Stagelet stagelet) throws HyracksDataException {
-        return plan.getJobFlags().contains(JobFlag.PROFILE_RUNTIME) ? new IFrameWriter() {
-            private ICounter openCounter = stageletContext.getCounterContext().getCounter(
-                    conn.getConnectorId().getId() + ".sender." + senderIndex + "." + receiverIndex + ".open", true);
-            private ICounter closeCounter = stageletContext.getCounterContext().getCounter(
-                    conn.getConnectorId().getId() + ".sender." + senderIndex + "." + receiverIndex + ".close", true);
-            private ICounter frameCounter = stageletContext.getCounterContext()
-                    .getCounter(
-                            conn.getConnectorId().getId() + ".sender." + senderIndex + "." + receiverIndex
-                                    + ".nextFrame", true);
-
-            @Override
-            public void open() throws HyracksDataException {
-                writer.open();
-                openCounter.update(1);
-            }
-
-            @Override
-            public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
-                frameCounter.update(1);
-                writer.nextFrame(buffer);
-            }
-
-            @Override
-            public void close() throws HyracksDataException {
-                closeCounter.update(1);
-                writer.close();
-            }
-
-            @Override
-            public void flush() throws HyracksDataException {
-                writer.flush();
-            }
-        } : writer;
-    }
-
-    @Override
-    public void commitJobletInitialization(UUID jobId, UUID stageId) throws Exception {
-        final Joblet ji = getLocalJoblet(jobId);
-        Stagelet si = (Stagelet) ji.getStagelet(stageId);
-        for (Endpoint e : si.getEndpointList()) {
-            connectionManager.unacceptConnection(e.getEndpointId());
-        }
-        si.setEndpointList(null);
-    }
-
-    private synchronized Joblet getLocalJoblet(UUID jobId) throws Exception {
+    private synchronized Joblet getOrCreateLocalJoblet(UUID jobId, INCApplicationContext appCtx) throws Exception {
         Joblet ji = jobletMap.get(jobId);
-        return ji;
-    }
-
-    private synchronized Joblet getOrCreateLocalJoblet(UUID jobId, int attempt, INCApplicationContext appCtx)
-            throws Exception {
-        Joblet ji = jobletMap.get(jobId);
-        if (ji == null || ji.getAttempt() != attempt) {
-            ji = new Joblet(this, jobId, attempt, appCtx);
+        if (ji == null) {
+            ji = new Joblet(this, jobId, appCtx);
             jobletMap.put(jobId, ji);
         }
         return ji;
@@ -464,34 +320,23 @@
         }
         Joblet joblet = jobletMap.remove(jobId);
         if (joblet != null) {
+            partitionManager.unregisterPartitions(jobId);
             joblet.close();
         }
-        connectionManager.dumpStats();
     }
 
-    @Override
-    public void startStage(UUID jobId, UUID stageId) throws Exception {
-        Joblet ji = jobletMap.get(jobId);
-        if (ji != null) {
-            Stagelet s = ji.getStagelet(stageId);
-            if (s != null) {
-                s.start();
-            }
-        }
-    }
-
-    public void notifyStageComplete(UUID jobId, UUID stageId, int attempt, StageletProfile stats) throws Exception {
+    public void notifyTaskComplete(UUID jobId, TaskAttemptId taskId, TaskProfile taskProfile) throws Exception {
         try {
-            ccs.notifyStageletComplete(jobId, stageId, attempt, id, stats);
+            ccs.notifyTaskComplete(jobId, taskId, id, taskProfile);
         } catch (Exception e) {
             e.printStackTrace();
             throw e;
         }
     }
 
-    public void notifyStageFailed(UUID jobId, UUID stageId, int attempt) throws Exception {
+    public void notifyTaskFailed(UUID jobId, TaskAttemptId taskId, Exception exception) throws Exception {
         try {
-            ccs.notifyStageletFailure(jobId, stageId, attempt, id);
+            ccs.notifyTaskFailure(jobId, taskId, id, exception);
         } catch (Exception e) {
             e.printStackTrace();
             throw e;
@@ -539,7 +384,7 @@
                 synchronized (NodeControllerService.this) {
                     profiles = new ArrayList<JobProfile>();
                     for (Joblet ji : jobletMap.values()) {
-                        profiles.add(new JobProfile(ji.getJobId(), ji.getAttempt()));
+                        profiles.add(new JobProfile(ji.getJobId()));
                     }
                 }
                 for (JobProfile jProfile : profiles) {
@@ -563,20 +408,21 @@
     }
 
     @Override
-    public synchronized void abortJoblet(UUID jobId, int attempt) throws Exception {
+    public synchronized void abortTasks(UUID jobId, List<TaskAttemptId> tasks) throws Exception {
         if (LOGGER.isLoggable(Level.INFO)) {
-            LOGGER.info("Aborting Job: " + jobId + ":" + attempt);
+            LOGGER.info("Aborting Tasks: " + jobId + ":" + tasks);
         }
         Joblet ji = jobletMap.get(jobId);
         if (ji != null) {
-            if (ji.getAttempt() == attempt) {
-                jobletMap.remove(jobId);
+            Map<TaskAttemptId, Task> taskMap = ji.getTaskMap();
+            for (TaskAttemptId taId : tasks) {
+                Task task = taskMap.get(taId);
+                if (task != null) {
+                    task.abort();
+                    task.close();
+                }
             }
-            for (Stagelet stagelet : ji.getStageletMap().values()) {
-                stagelet.abort();
-                stagelet.close();
-                connectionManager.abortConnections(jobId, stagelet.getStageId());
-            }
+            ji.close();
         }
     }
 
@@ -617,4 +463,12 @@
             appCtx.deinitialize();
         }
     }
+
+    @Override
+    public void reportPartitionAvailability(PartitionId pid, NetworkAddress networkAddress) throws Exception {
+        Joblet ji = jobletMap.get(pid.getJobId());
+        PartitionChannel channel = new PartitionChannel(pid, new NetworkInputChannel(ctx, connectionManager,
+                new InetSocketAddress(networkAddress.getIpAddress(), networkAddress.getPort()), pid, 1));
+        ji.reportPartitionAvailability(channel);
+    }
 }
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Stagelet.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Stagelet.java
deleted file mode 100644
index 157b0a7..0000000
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Stagelet.java
+++ /dev/null
@@ -1,238 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.nc;
-
-import java.nio.ByteBuffer;
-import java.rmi.RemoteException;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import edu.uci.ics.hyracks.api.comm.Endpoint;
-import edu.uci.ics.hyracks.api.context.IHyracksJobletContext;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
-import edu.uci.ics.hyracks.api.dataflow.OperatorInstanceId;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.io.FileReference;
-import edu.uci.ics.hyracks.api.io.IIOManager;
-import edu.uci.ics.hyracks.api.io.IWorkspaceFileFactory;
-import edu.uci.ics.hyracks.api.job.profiling.counters.ICounter;
-import edu.uci.ics.hyracks.api.job.profiling.counters.ICounterContext;
-import edu.uci.ics.hyracks.api.resources.IDeallocatable;
-import edu.uci.ics.hyracks.control.common.job.profiling.counters.Counter;
-import edu.uci.ics.hyracks.control.common.job.profiling.om.StageletProfile;
-import edu.uci.ics.hyracks.control.nc.io.IOManager;
-import edu.uci.ics.hyracks.control.nc.io.ManagedWorkspaceFileFactory;
-import edu.uci.ics.hyracks.control.nc.resources.DefaultDeallocatableRegistry;
-import edu.uci.ics.hyracks.control.nc.runtime.OperatorRunnable;
-
-public class Stagelet implements IHyracksStageletContext, ICounterContext {
-    private static final long serialVersionUID = 1L;
-
-    private static final Logger LOGGER = Logger.getLogger(Stagelet.class.getName());
-
-    private final Joblet joblet;
-
-    private final UUID stageId;
-
-    private final int attempt;
-
-    private final Map<OperatorInstanceId, OperatorRunnable> honMap;
-
-    private final Map<String, Counter> counterMap;
-
-    private final IWorkspaceFileFactory fileFactory;
-
-    private List<Endpoint> endpointList;
-
-    private boolean started;
-
-    private volatile boolean abort;
-
-    private final Set<OperatorInstanceId> pendingOperators;
-
-    private final DefaultDeallocatableRegistry deallocatableRegistry;
-
-    public Stagelet(Joblet joblet, UUID stageId, int attempt, String nodeId) throws RemoteException {
-        this.joblet = joblet;
-        this.stageId = stageId;
-        this.attempt = attempt;
-        pendingOperators = new HashSet<OperatorInstanceId>();
-        started = false;
-        honMap = new HashMap<OperatorInstanceId, OperatorRunnable>();
-        counterMap = new HashMap<String, Counter>();
-        deallocatableRegistry = new DefaultDeallocatableRegistry();
-        fileFactory = new ManagedWorkspaceFileFactory(this, (IOManager) joblet.getIOManager());
-    }
-
-    public void setOperator(OperatorDescriptorId odId, int partition, OperatorRunnable hon) {
-        honMap.put(new OperatorInstanceId(odId, partition), hon);
-    }
-
-    public Map<OperatorInstanceId, OperatorRunnable> getOperatorMap() {
-        return honMap;
-    }
-
-    public void setEndpointList(List<Endpoint> endpointList) {
-        this.endpointList = endpointList;
-    }
-
-    public List<Endpoint> getEndpointList() {
-        return endpointList;
-    }
-
-    public synchronized void start() throws Exception {
-        if (started) {
-            throw new Exception("Joblet already started");
-        }
-        started = true;
-        notifyAll();
-    }
-
-    public synchronized void abort() {
-        this.abort = true;
-        for (OperatorRunnable r : honMap.values()) {
-            r.abort();
-        }
-    }
-
-    public void installRunnable(final OperatorInstanceId opIId) {
-        pendingOperators.add(opIId);
-        final OperatorRunnable hon = honMap.get(opIId);
-        joblet.getExecutor().execute(new Runnable() {
-            @Override
-            public void run() {
-                try {
-                    waitUntilStarted();
-                } catch (InterruptedException e) {
-                    e.printStackTrace();
-                    return;
-                }
-                if (abort) {
-                    return;
-                }
-                try {
-                    LOGGER.log(Level.INFO, joblet.getJobId() + ":" + stageId + ":" + opIId.getOperatorId() + ":"
-                            + opIId.getPartition() + "(" + hon + ")" + ": STARTED");
-                    hon.run();
-                    LOGGER.log(Level.INFO, joblet.getJobId() + ":" + stageId + ":" + opIId.getOperatorId() + ":"
-                            + opIId.getPartition() + "(" + hon + ")" + ": FINISHED");
-                    notifyOperatorCompletion(opIId);
-                } catch (Exception e) {
-                    LOGGER.log(Level.INFO, joblet.getJobId() + ":" + stageId + ":" + opIId.getOperatorId() + ":"
-                            + opIId.getPartition() + "(" + hon + ")" + ": ABORTED");
-                    e.printStackTrace();
-                    notifyOperatorFailure(opIId);
-                }
-            }
-        });
-    }
-
-    protected synchronized void notifyOperatorCompletion(OperatorInstanceId opIId) {
-        pendingOperators.remove(opIId);
-        if (pendingOperators.isEmpty()) {
-            try {
-                StageletProfile sProfile = new StageletProfile(stageId);
-                dumpProfile(sProfile);
-                close();
-                joblet.notifyStageletComplete(stageId, attempt, sProfile);
-            } catch (Exception e) {
-                e.printStackTrace();
-            }
-        }
-    }
-
-    protected synchronized void notifyOperatorFailure(OperatorInstanceId opIId) {
-        abort();
-        try {
-            joblet.notifyStageletFailed(stageId, attempt);
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-    }
-
-    private synchronized void waitUntilStarted() throws InterruptedException {
-        while (!started && !abort) {
-            wait();
-        }
-    }
-
-    public synchronized void dumpProfile(StageletProfile sProfile) {
-        Map<String, Long> dumpMap = sProfile.getCounters();
-        for (Counter c : counterMap.values()) {
-            dumpMap.put(c.getName(), c.get());
-        }
-    }
-
-    @Override
-    public IHyracksJobletContext getJobletContext() {
-        return joblet;
-    }
-
-    @Override
-    public UUID getStageId() {
-        return stageId;
-    }
-
-    @Override
-    public ICounterContext getCounterContext() {
-        return this;
-    }
-
-    @Override
-    public void registerDeallocatable(IDeallocatable deallocatable) {
-        deallocatableRegistry.registerDeallocatable(deallocatable);
-    }
-
-    public void close() {
-        deallocatableRegistry.close();
-    }
-
-    @Override
-    public ByteBuffer allocateFrame() {
-        return joblet.allocateFrame();
-    }
-
-    @Override
-    public int getFrameSize() {
-        return joblet.getFrameSize();
-    }
-
-    @Override
-    public IIOManager getIOManager() {
-        return joblet.getIOManager();
-    }
-
-    @Override
-    public FileReference createWorkspaceFile(String prefix) throws HyracksDataException {
-        return fileFactory.createWorkspaceFile(prefix);
-    }
-
-    @Override
-    public ICounter getCounter(String name, boolean create) {
-        Counter counter = counterMap.get(name);
-        if (counter == null && create) {
-            counter = new Counter(name);
-            counterMap.put(name, counter);
-        }
-        return counter;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Task.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Task.java
new file mode 100644
index 0000000..a39d1b7
--- /dev/null
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/Task.java
@@ -0,0 +1,192 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.nc;
+
+import java.nio.ByteBuffer;
+import java.util.HashMap;
+import java.util.Map;
+
+import edu.uci.ics.hyracks.api.comm.IFrameReader;
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.comm.IPartitionCollector;
+import edu.uci.ics.hyracks.api.context.IHyracksJobletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.api.io.IIOManager;
+import edu.uci.ics.hyracks.api.io.IWorkspaceFileFactory;
+import edu.uci.ics.hyracks.api.job.profiling.counters.ICounter;
+import edu.uci.ics.hyracks.api.job.profiling.counters.ICounterContext;
+import edu.uci.ics.hyracks.api.resources.IDeallocatable;
+import edu.uci.ics.hyracks.control.common.job.profiling.counters.Counter;
+import edu.uci.ics.hyracks.control.common.job.profiling.om.TaskProfile;
+import edu.uci.ics.hyracks.control.nc.io.IOManager;
+import edu.uci.ics.hyracks.control.nc.io.WorkspaceFileFactory;
+import edu.uci.ics.hyracks.control.nc.resources.DefaultDeallocatableRegistry;
+
+public class Task implements IHyracksTaskContext, ICounterContext, Runnable {
+    private final Joblet joblet;
+
+    private final TaskAttemptId taskId;
+
+    private final IWorkspaceFileFactory fileFactory;
+
+    private final DefaultDeallocatableRegistry deallocatableRegistry;
+
+    private final Map<String, Counter> counterMap;
+
+    private IPartitionCollector collector;
+
+    private IOperatorNodePushable operator;
+
+    private volatile boolean aborted;
+
+    public Task(Joblet joblet, TaskAttemptId taskId) {
+        this.joblet = joblet;
+        this.taskId = taskId;
+        fileFactory = new WorkspaceFileFactory(this, (IOManager) joblet.getIOManager());
+        deallocatableRegistry = new DefaultDeallocatableRegistry();
+        counterMap = new HashMap<String, Counter>();
+    }
+
+    public void setTaskRuntime(IPartitionCollector collector, IOperatorNodePushable operator) {
+        this.collector = collector;
+        this.operator = operator;
+    }
+
+    @Override
+    public ByteBuffer allocateFrame() {
+        return joblet.allocateFrame();
+    }
+
+    @Override
+    public int getFrameSize() {
+        return joblet.getFrameSize();
+    }
+
+    @Override
+    public IIOManager getIOManager() {
+        return joblet.getIOManager();
+    }
+
+    @Override
+    public FileReference createUnmanagedWorkspaceFile(String prefix) throws HyracksDataException {
+        return fileFactory.createUnmanagedWorkspaceFile(prefix);
+    }
+
+    @Override
+    public FileReference createManagedWorkspaceFile(String prefix) throws HyracksDataException {
+        return fileFactory.createManagedWorkspaceFile(prefix);
+    }
+
+    @Override
+    public void registerDeallocatable(IDeallocatable deallocatable) {
+        deallocatableRegistry.registerDeallocatable(deallocatable);
+    }
+
+    public void close() {
+        deallocatableRegistry.close();
+    }
+
+    @Override
+    public IHyracksJobletContext getJobletContext() {
+        return joblet;
+    }
+
+    @Override
+    public TaskAttemptId getTaskId() {
+        return taskId;
+    }
+
+    @Override
+    public ICounter getCounter(String name, boolean create) {
+        Counter counter = counterMap.get(name);
+        if (counter == null && create) {
+            counter = new Counter(name);
+            counterMap.put(name, counter);
+        }
+        return counter;
+    }
+
+    @Override
+    public ICounterContext getCounterContext() {
+        return this;
+    }
+
+    public synchronized void dumpProfile(TaskProfile tProfile) {
+        Map<String, Long> dumpMap = tProfile.getCounters();
+        for (Counter c : counterMap.values()) {
+            dumpMap.put(c.getName(), c.get());
+        }
+    }
+
+    public void start() throws HyracksException {
+        aborted = false;
+        joblet.getExecutor().execute(this);
+    }
+
+    public void abort() {
+        aborted = true;
+        collector.abort();
+    }
+
+    @Override
+    public void run() {
+        try {
+            operator.initialize();
+            try {
+                if (collector != null) {
+                    if (aborted) {
+                        return;
+                    }
+                    collector.open();
+                    try {
+                        joblet.advertisePartitionRequest(collector.getRequiredPartitionIds(), collector);
+                        IFrameReader reader = collector.getReader();
+                        reader.open();
+                        try {
+                            IFrameWriter writer = operator.getInputFrameWriter(0);
+                            writer.open();
+                            try {
+                                ByteBuffer buffer = allocateFrame();
+                                while (reader.nextFrame(buffer)) {
+                                    if (aborted) {
+                                        return;
+                                    }
+                                    buffer.flip();
+                                    writer.nextFrame(buffer);
+                                    buffer.compact();
+                                }
+                            } finally {
+                                writer.close();
+                            }
+                        } finally {
+                            reader.close();
+                        }
+                    } finally {
+                        collector.close();
+                    }
+                }
+            } finally {
+                operator.deinitialize();
+            }
+        } catch (Exception e) {
+
+        }
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/ConnectionEntry.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/ConnectionEntry.java
deleted file mode 100644
index d44fadd..0000000
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/ConnectionEntry.java
+++ /dev/null
@@ -1,186 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.nc.comm;
-
-import java.io.IOException;
-import java.nio.ByteBuffer;
-import java.nio.channels.SelectionKey;
-import java.nio.channels.SocketChannel;
-import java.util.UUID;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import edu.uci.ics.hyracks.api.comm.IConnectionEntry;
-import edu.uci.ics.hyracks.api.comm.IDataReceiveListener;
-import edu.uci.ics.hyracks.api.context.IHyracksRootContext;
-
-public class ConnectionEntry implements IConnectionEntry {
-    private static final Logger LOGGER = Logger.getLogger(ConnectionEntry.class.getName());
-
-    private SocketChannel socketChannel;
-
-    private final ByteBuffer readBuffer;
-
-    private final ByteBuffer writeBuffer;
-
-    private IDataReceiveListener recvListener;
-
-    private Object attachment;
-
-    private final SelectionKey key;
-
-    private UUID jobId;
-
-    private UUID stageId;
-
-    private boolean aborted;
-
-    public ConnectionEntry(IHyracksRootContext ctx, SocketChannel socketChannel, SelectionKey key) {
-        this.socketChannel = socketChannel;
-        readBuffer = ctx.allocateFrame();
-        readBuffer.clear();
-        writeBuffer = ctx.allocateFrame();
-        writeBuffer.clear();
-        this.key = key;
-    }
-
-    public SocketChannel getSocketChannel() {
-        return socketChannel;
-    }
-
-    public boolean dispatch(SelectionKey key) throws IOException {
-        if (aborted) {
-            recvListener.dataReceived(this);
-        } else {
-            if (key.isReadable()) {
-                if (LOGGER.isLoggable(Level.FINER)) {
-                    LOGGER.finer("Before read: " + readBuffer.position() + " " + readBuffer.limit());
-                }
-                int bytesRead = socketChannel.read(readBuffer);
-                if (bytesRead < 0) {
-                    recvListener.eos(this);
-                    return true;
-                }
-                if (LOGGER.isLoggable(Level.FINER)) {
-                    LOGGER.finer("After read: " + readBuffer.position() + " " + readBuffer.limit());
-                }
-                recvListener.dataReceived(this);
-            } else if (key.isWritable()) {
-                synchronized (this) {
-                    writeBuffer.flip();
-                    if (LOGGER.isLoggable(Level.FINER)) {
-                        LOGGER.finer("Before write: " + writeBuffer.position() + " " + writeBuffer.limit());
-                    }
-                    int bytesWritten = socketChannel.write(writeBuffer);
-                    if (bytesWritten < 0) {
-                        return true;
-                    }
-                    if (LOGGER.isLoggable(Level.FINER)) {
-                        LOGGER.finer("After write: " + writeBuffer.position() + " " + writeBuffer.limit());
-                    }
-                    if (writeBuffer.remaining() <= 0) {
-                        int ops = key.interestOps();
-                        key.interestOps(ops & ~SelectionKey.OP_WRITE);
-                    }
-                    writeBuffer.compact();
-                    notifyAll();
-                }
-            } else {
-                LOGGER.warning("Spurious event triggered: " + key.readyOps());
-                return true;
-            }
-        }
-        return false;
-    }
-
-    @Override
-    public ByteBuffer getReadBuffer() {
-        return readBuffer;
-    }
-
-    @Override
-    public synchronized void write(ByteBuffer buffer) {
-        while (buffer.remaining() > 0) {
-            while (writeBuffer.remaining() <= 0) {
-                try {
-                    wait();
-                } catch (InterruptedException e) {
-                }
-            }
-            int oldLimit = buffer.limit();
-            buffer.limit(Math.min(oldLimit, writeBuffer.remaining()));
-            writeBuffer.put(buffer);
-            buffer.limit(oldLimit);
-            int ops = key.interestOps();
-            key.interestOps(ops | SelectionKey.OP_WRITE);
-            key.selector().wakeup();
-        }
-    }
-
-    public void setDataReceiveListener(IDataReceiveListener listener) {
-        this.recvListener = listener;
-    }
-
-    @Override
-    public void attach(Object attachment) {
-        this.attachment = attachment;
-    }
-
-    @Override
-    public Object getAttachment() {
-        return attachment;
-    }
-
-    @Override
-    public void close() {
-        try {
-            socketChannel.close();
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    @Override
-    public SelectionKey getSelectionKey() {
-        return key;
-    }
-
-    @Override
-    public UUID getJobId() {
-        return jobId;
-    }
-
-    public void setJobId(UUID jobId) {
-        this.jobId = jobId;
-    }
-
-    @Override
-    public UUID getStageId() {
-        return stageId;
-    }
-
-    public void setStageId(UUID stageId) {
-        this.stageId = stageId;
-    }
-
-    public void abort() {
-        aborted = true;
-    }
-
-    @Override
-    public boolean aborted() {
-        return aborted;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/ConnectionManager.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/ConnectionManager.java
deleted file mode 100644
index 658f229..0000000
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/ConnectionManager.java
+++ /dev/null
@@ -1,400 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.nc.comm;
-
-import java.io.IOException;
-import java.net.InetAddress;
-import java.net.InetSocketAddress;
-import java.net.ServerSocket;
-import java.nio.ByteBuffer;
-import java.nio.channels.AsynchronousCloseException;
-import java.nio.channels.SelectionKey;
-import java.nio.channels.Selector;
-import java.nio.channels.ServerSocketChannel;
-import java.nio.channels.SocketChannel;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import edu.uci.ics.hyracks.api.comm.FrameConstants;
-import edu.uci.ics.hyracks.api.comm.FrameHelper;
-import edu.uci.ics.hyracks.api.comm.IConnectionEntry;
-import edu.uci.ics.hyracks.api.comm.IDataReceiveListener;
-import edu.uci.ics.hyracks.api.comm.IDataReceiveListenerFactory;
-import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.comm.NetworkAddress;
-import edu.uci.ics.hyracks.api.context.IHyracksRootContext;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-
-public class ConnectionManager {
-    private static final Logger LOGGER = Logger.getLogger(ConnectionManager.class.getName());
-
-    private static final int INITIAL_MESSAGE_LEN = 20;
-
-    private NetworkAddress networkAddress;
-
-    private ServerSocketChannel serverSocketChannel;
-
-    private final IHyracksRootContext ctx;
-
-    private final Map<UUID, IDataReceiveListenerFactory> pendingConnectionReceivers;
-
-    private final ConnectionListenerThread connectionListenerThread;
-
-    private final DataListenerThread dataListenerThread;
-
-    private final IDataReceiveListener initialDataReceiveListener;
-
-    private final Set<IConnectionEntry> connections;
-
-    private volatile boolean stopped;
-
-    private ByteBuffer emptyFrame;
-
-    public ConnectionManager(IHyracksRootContext ctx, InetAddress address) throws IOException {
-        this.ctx = ctx;
-        serverSocketChannel = ServerSocketChannel.open();
-        ServerSocket serverSocket = serverSocketChannel.socket();
-        serverSocket.bind(new InetSocketAddress(address, 0));
-
-        networkAddress = new NetworkAddress(serverSocket.getInetAddress(), serverSocket.getLocalPort());
-
-        if (LOGGER.isLoggable(Level.INFO)) {
-            LOGGER.info("Connection manager listening on " + serverSocket.getInetAddress() + ":"
-                    + serverSocket.getLocalPort());
-        }
-
-        pendingConnectionReceivers = new HashMap<UUID, IDataReceiveListenerFactory>();
-        dataListenerThread = new DataListenerThread();
-        connectionListenerThread = new ConnectionListenerThread();
-        initialDataReceiveListener = new InitialDataReceiveListener();
-        emptyFrame = ctx.allocateFrame();
-        emptyFrame.putInt(FrameHelper.getTupleCountOffset(ctx.getFrameSize()), 0);
-        connections = new HashSet<IConnectionEntry>();
-    }
-
-    public synchronized void dumpStats() {
-        if (LOGGER.isLoggable(Level.INFO)) {
-            LOGGER.info("Number of pendingConnectionReceivers: " + pendingConnectionReceivers.size());
-            LOGGER.info("Number of selectable keys: " + dataListenerThread.selector.keys().size());
-        }
-    }
-
-    public NetworkAddress getNetworkAddress() {
-        return networkAddress;
-    }
-
-    public void start() {
-        stopped = false;
-        connectionListenerThread.start();
-        dataListenerThread.start();
-    }
-
-    public void stop() {
-        try {
-            stopped = true;
-            serverSocketChannel.close();
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    public IFrameWriter connect(NetworkAddress address, UUID id, int senderId) throws HyracksDataException {
-        try {
-            SocketChannel channel = SocketChannel
-                    .open(new InetSocketAddress(address.getIpAddress(), address.getPort()));
-            byte[] initialFrame = new byte[INITIAL_MESSAGE_LEN];
-            ByteBuffer buffer = ByteBuffer.wrap(initialFrame);
-            buffer.clear();
-            buffer.putLong(id.getMostSignificantBits());
-            buffer.putLong(id.getLeastSignificantBits());
-            buffer.putInt(senderId);
-            buffer.flip();
-            int bytesWritten = 0;
-            while (bytesWritten < INITIAL_MESSAGE_LEN) {
-                int n = channel.write(buffer);
-                if (n < 0) {
-                    throw new HyracksDataException("Stream closed prematurely");
-                }
-                bytesWritten += n;
-            }
-            if (LOGGER.isLoggable(Level.FINE)) {
-                LOGGER.fine("Send Initial message: " + id + ":" + senderId);
-            }
-            buffer.clear();
-            buffer.limit(FrameConstants.SIZE_LEN);
-            int bytesRead = 0;
-            while (bytesRead < FrameConstants.SIZE_LEN) {
-                int n = channel.read(buffer);
-                if (n < 0) {
-                    throw new HyracksDataException("Stream closed prematurely");
-                }
-                bytesRead += n;
-            }
-            buffer.flip();
-            int frameLen = buffer.getInt();
-            if (frameLen != FrameConstants.SIZE_LEN) {
-                throw new IllegalStateException("Received illegal framelen = " + frameLen);
-            }
-            if (LOGGER.isLoggable(Level.FINE)) {
-                LOGGER.fine("Got Ack message: " + id + ":" + senderId);
-            }
-            return new NetworkFrameWriter(channel);
-        } catch (IOException e) {
-            throw new HyracksDataException(e);
-        }
-    }
-
-    public synchronized void acceptConnection(UUID id, IDataReceiveListenerFactory receiver) {
-        if (LOGGER.isLoggable(Level.FINE)) {
-            LOGGER.info("Connection manager accepting " + id);
-        }
-        pendingConnectionReceivers.put(id, receiver);
-    }
-
-    public synchronized void unacceptConnection(UUID id) {
-        if (LOGGER.isLoggable(Level.FINE)) {
-            LOGGER.info("Connection manager unaccepting " + id);
-        }
-        pendingConnectionReceivers.remove(id);
-    }
-
-    public synchronized void abortConnections(UUID jobId, UUID stageId) {
-        List<IConnectionEntry> abortConnections = new ArrayList<IConnectionEntry>();
-        synchronized (this) {
-            for (IConnectionEntry ce : connections) {
-                if (ce.getJobId().equals(jobId) && ce.getStageId().equals(stageId)) {
-                    abortConnections.add(ce);
-                }
-            }
-        }
-        dataListenerThread.addPendingAbortConnections(abortConnections);
-    }
-
-    private final class NetworkFrameWriter implements IFrameWriter {
-        private SocketChannel channel;
-
-        NetworkFrameWriter(SocketChannel channel) {
-            this.channel = channel;
-        }
-
-        @Override
-        public void close() throws HyracksDataException {
-            try {
-                synchronized (emptyFrame) {
-                    emptyFrame.position(0);
-                    emptyFrame.limit(emptyFrame.capacity());
-                    channel.write(emptyFrame);
-                }
-                channel.close();
-            } catch (IOException e) {
-                throw new HyracksDataException(e);
-            }
-        }
-
-        @Override
-        public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
-            try {
-                if (LOGGER.isLoggable(Level.FINER)) {
-                    int frameLen = buffer.getInt(buffer.position());
-                    LOGGER.finer("ConnectionManager.NetworkFrameWriter: frameLen = " + frameLen);
-                }
-                while (buffer.remaining() > 0) {
-                    channel.write(buffer);
-                }
-            } catch (IOException e) {
-                throw new HyracksDataException(e);
-            }
-        }
-
-        @Override
-        public void open() throws HyracksDataException {
-        }
-
-        @Override
-        public void flush() {
-        }
-    }
-
-    private final class ConnectionListenerThread extends Thread {
-        public ConnectionListenerThread() {
-            super("Hyracks Connection Listener Thread");
-        }
-
-        @Override
-        public void run() {
-            while (!stopped) {
-                try {
-                    SocketChannel sc = serverSocketChannel.accept();
-                    dataListenerThread.addSocketChannel(sc);
-                } catch (AsynchronousCloseException e) {
-                    // do nothing
-                } catch (IOException e) {
-                    e.printStackTrace();
-                }
-            }
-        }
-    }
-
-    private final class DataListenerThread extends Thread {
-        private Selector selector;
-
-        private List<SocketChannel> pendingNewSockets;
-        private List<IConnectionEntry> pendingAbortConnections;
-
-        public DataListenerThread() {
-            super("Hyracks Data Listener Thread");
-            try {
-                selector = Selector.open();
-            } catch (IOException e) {
-                throw new RuntimeException(e);
-            }
-            pendingNewSockets = new ArrayList<SocketChannel>();
-            pendingAbortConnections = new ArrayList<IConnectionEntry>();
-        }
-
-        synchronized void addSocketChannel(SocketChannel sc) throws IOException {
-            pendingNewSockets.add(sc);
-            selector.wakeup();
-        }
-
-        synchronized void addPendingAbortConnections(List<IConnectionEntry> abortConnections) {
-            pendingAbortConnections.addAll(abortConnections);
-            selector.wakeup();
-        }
-
-        @Override
-        public void run() {
-            while (!stopped) {
-                try {
-                    if (LOGGER.isLoggable(Level.FINE)) {
-                        LOGGER.fine("Starting Select");
-                    }
-                    int n = selector.select();
-                    synchronized (this) {
-                        if (!pendingNewSockets.isEmpty()) {
-                            for (SocketChannel sc : pendingNewSockets) {
-                                sc.configureBlocking(false);
-                                SelectionKey scKey = sc.register(selector, SelectionKey.OP_READ);
-                                ConnectionEntry entry = new ConnectionEntry(ctx, sc, scKey);
-                                entry.setDataReceiveListener(initialDataReceiveListener);
-                                scKey.attach(entry);
-                                if (LOGGER.isLoggable(Level.FINE)) {
-                                    LOGGER.fine("Woke up selector");
-                                }
-                            }
-                            pendingNewSockets.clear();
-                        }
-                        if (!pendingAbortConnections.isEmpty()) {
-                            for (IConnectionEntry ce : pendingAbortConnections) {
-                                SelectionKey key = ce.getSelectionKey();
-                                ((ConnectionEntry) ce).abort();
-                                ((ConnectionEntry) ce).dispatch(key);
-                                key.cancel();
-                                ce.close();
-                                synchronized (ConnectionManager.this) {
-                                    connections.remove(ce);
-                                }
-                            }
-                            pendingAbortConnections.clear();
-                        }
-                        if (LOGGER.isLoggable(Level.FINE)) {
-                            LOGGER.fine("Selector: " + n);
-                        }
-                        if (n > 0) {
-                            for (Iterator<SelectionKey> i = selector.selectedKeys().iterator(); i.hasNext();) {
-                                SelectionKey key = i.next();
-                                i.remove();
-                                ConnectionEntry entry = (ConnectionEntry) key.attachment();
-                                boolean close = false;
-                                try {
-                                    close = entry.dispatch(key);
-                                } catch (IOException e) {
-                                    e.printStackTrace();
-                                    close = true;
-                                }
-                                if (close) {
-                                    key.cancel();
-                                    entry.close();
-                                    synchronized (ConnectionManager.this) {
-                                        connections.remove(entry);
-                                    }
-                                }
-                            }
-                        }
-                    }
-                } catch (Exception e) {
-                    e.printStackTrace();
-                }
-            }
-        }
-    }
-
-    private class InitialDataReceiveListener implements IDataReceiveListener {
-        @Override
-        public void dataReceived(IConnectionEntry entry) throws IOException {
-            ConnectionEntry ce = (ConnectionEntry) entry;
-            ByteBuffer buffer = ce.getReadBuffer();
-            buffer.flip();
-            IDataReceiveListener newListener = null;
-            if (buffer.remaining() >= INITIAL_MESSAGE_LEN) {
-                long msb = buffer.getLong();
-                long lsb = buffer.getLong();
-                UUID endpointID = new UUID(msb, lsb);
-                int senderId = buffer.getInt();
-                if (LOGGER.isLoggable(Level.FINE)) {
-                    LOGGER.fine("Initial Frame received: " + endpointID + ":" + senderId);
-                }
-                IDataReceiveListenerFactory connectionReceiver;
-                synchronized (ConnectionManager.this) {
-                    connectionReceiver = pendingConnectionReceivers.get(endpointID);
-                    if (connectionReceiver == null) {
-                        ce.close();
-                        return;
-                    }
-                }
-
-                newListener = connectionReceiver.getDataReceiveListener(endpointID, ce, senderId);
-                ce.setDataReceiveListener(newListener);
-                ce.setJobId(connectionReceiver.getJobId());
-                ce.setStageId(connectionReceiver.getStageId());
-                synchronized (ConnectionManager.this) {
-                    connections.add(ce);
-                }
-                byte[] ack = new byte[4];
-                ByteBuffer ackBuffer = ByteBuffer.wrap(ack);
-                ackBuffer.clear();
-                ackBuffer.putInt(FrameConstants.SIZE_LEN);
-                ackBuffer.flip();
-                ce.write(ackBuffer);
-            }
-            buffer.compact();
-            if (newListener != null && buffer.remaining() > 0) {
-                newListener.dataReceived(ce);
-            }
-        }
-
-        @Override
-        public void eos(IConnectionEntry entry) {
-        }
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/DemuxDataReceiveListenerFactory.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/DemuxDataReceiveListenerFactory.java
deleted file mode 100644
index cb6e936..0000000
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/DemuxDataReceiveListenerFactory.java
+++ /dev/null
@@ -1,157 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.nc.comm;
-
-import java.io.IOException;
-import java.nio.ByteBuffer;
-import java.nio.channels.SelectionKey;
-import java.util.Arrays;
-import java.util.BitSet;
-import java.util.UUID;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
-import edu.uci.ics.hyracks.api.comm.IConnectionEntry;
-import edu.uci.ics.hyracks.api.comm.IDataReceiveListener;
-import edu.uci.ics.hyracks.api.comm.IDataReceiveListenerFactory;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-
-public class DemuxDataReceiveListenerFactory implements IDataReceiveListenerFactory, IConnectionDemultiplexer,
-        IDataReceiveListener {
-    private static final Logger LOGGER = Logger.getLogger(DemuxDataReceiveListenerFactory.class.getName());
-
-    private final BitSet readyBits;
-    private final int frameSize;
-    private IConnectionEntry senders[];
-    private int openSenderCount;
-    private final UUID jobId;
-    private final int attempt;
-    private final UUID stageId;
-    private final ConnectorDescriptorId cdId;
-
-    public DemuxDataReceiveListenerFactory(IHyracksStageletContext ctx, UUID jobId, int attempt, UUID stageId,
-            ConnectorDescriptorId cdId) {
-        frameSize = ctx.getFrameSize();
-        this.jobId = jobId;
-        this.attempt = attempt;
-        this.stageId = stageId;
-        this.cdId = cdId;
-        readyBits = new BitSet();
-        senders = null;
-        openSenderCount = 0;
-    }
-
-    @Override
-    public IDataReceiveListener getDataReceiveListener(UUID endpointUUID, IConnectionEntry entry, int senderIndex) {
-        entry.attach(senderIndex);
-        addSender(senderIndex, entry);
-        return this;
-    }
-
-    @Override
-    public synchronized void dataReceived(IConnectionEntry entry) throws IOException {
-        int senderIndex = (Integer) entry.getAttachment();
-        ByteBuffer buffer = entry.getReadBuffer();
-        buffer.flip();
-        int dataLen = buffer.remaining();
-        if (dataLen >= frameSize || entry.aborted()) {
-            if (LOGGER.isLoggable(Level.FINEST)) {
-                LOGGER.finest("NonDeterministicDataReceiveListener: frame received: sender = " + senderIndex);
-            }
-            SelectionKey key = entry.getSelectionKey();
-            if (key.isValid()) {
-                int ops = key.interestOps();
-                key.interestOps(ops & ~SelectionKey.OP_READ);
-            }
-            readyBits.set(senderIndex);
-            notifyAll();
-            return;
-        }
-        buffer.compact();
-    }
-
-    @Override
-    public void eos(IConnectionEntry entry) {
-    }
-
-    private synchronized void addSender(int senderIndex, IConnectionEntry entry) {
-        readyBits.clear(senderIndex);
-        if (senders == null) {
-            senders = new IConnectionEntry[senderIndex + 1];
-        } else if (senders.length <= senderIndex) {
-            senders = Arrays.copyOf(senders, senderIndex + 1);
-        }
-        senders[senderIndex] = entry;
-        ++openSenderCount;
-    }
-
-    @Override
-    public synchronized IConnectionEntry findNextReadyEntry(int lastReadSender) {
-        while (openSenderCount > 0 && readyBits.isEmpty()) {
-            try {
-                wait();
-            } catch (InterruptedException e) {
-            }
-        }
-        lastReadSender = readyBits.nextSetBit(lastReadSender);
-        if (lastReadSender < 0) {
-            lastReadSender = readyBits.nextSetBit(0);
-        }
-        return senders[lastReadSender];
-    }
-
-    @Override
-    public synchronized void unreadyEntry(int index) {
-        readyBits.clear(index);
-        IConnectionEntry entry = senders[index];
-        SelectionKey key = entry.getSelectionKey();
-        if (key.isValid()) {
-            int ops = key.interestOps();
-            key.interestOps(ops | SelectionKey.OP_READ);
-            key.selector().wakeup();
-        }
-    }
-
-    @Override
-    public synchronized int closeEntry(int index) throws HyracksDataException {
-        IConnectionEntry entry = senders[index];
-        SelectionKey key = entry.getSelectionKey();
-        key.cancel();
-        try {
-            entry.close();
-        } catch (IOException e) {
-            throw new HyracksDataException(e);
-        }
-        return --openSenderCount;
-    }
-
-    @Override
-    public synchronized int getSenderCount() {
-        return senders.length;
-    }
-
-    @Override
-    public UUID getJobId() {
-        return jobId;
-    }
-
-    @Override
-    public UUID getStageId() {
-        return stageId;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/Sender.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/Sender.java
deleted file mode 100644
index 8f4c846..0000000
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/comm/Sender.java
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.nc.comm;
-
-import java.util.UUID;
-
-import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.comm.ISender;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
-
-public class Sender implements ISender {
-    private final IHyracksStageletContext ctx;
-
-    private final UUID jobId;
-
-    private final int attempt;
-
-    private final UUID stageId;
-
-    private final ConnectorDescriptorId cdId;
-
-    private final int senderIndex;
-
-    public Sender(IHyracksStageletContext ctx, UUID jobId, int attempt, UUID stageId, ConnectorDescriptorId cdId,
-            int senderIndex) {
-        this.ctx = ctx;
-        this.jobId = jobId;
-        this.attempt = attempt;
-        this.stageId = stageId;
-        this.cdId = cdId;
-        this.senderIndex = senderIndex;
-    }
-
-    @Override
-    public IFrameWriter createSenderWriter(int receiverIndex) {
-        return null;
-    }
-
-    public UUID getJobId() {
-        return jobId;
-    }
-
-    public int getAttempt() {
-        return attempt;
-    }
-
-    public UUID getStageId() {
-        return stageId;
-    }
-
-    public ConnectorDescriptorId getConnectorDescriptorId() {
-        return cdId;
-    }
-
-    public int getSenderIndex() {
-        return senderIndex;
-    }
-}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/io/ManagedWorkspaceFileFactory.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/io/WorkspaceFileFactory.java
similarity index 75%
rename from hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/io/ManagedWorkspaceFileFactory.java
rename to hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/io/WorkspaceFileFactory.java
index c6be844..16421ab 100644
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/io/ManagedWorkspaceFileFactory.java
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/io/WorkspaceFileFactory.java
@@ -20,24 +20,29 @@
 import edu.uci.ics.hyracks.api.resources.IDeallocatable;
 import edu.uci.ics.hyracks.api.resources.IDeallocatableRegistry;
 
-public final class ManagedWorkspaceFileFactory implements IWorkspaceFileFactory {
+public final class WorkspaceFileFactory implements IWorkspaceFileFactory {
     private final IDeallocatableRegistry registry;
     private final IOManager ioManager;
 
-    public ManagedWorkspaceFileFactory(IDeallocatableRegistry registry, IOManager ioManager) {
+    public WorkspaceFileFactory(IDeallocatableRegistry registry, IOManager ioManager) {
         this.registry = registry;
         this.ioManager = ioManager;
     }
 
     @Override
-    public FileReference createWorkspaceFile(String prefix) throws HyracksDataException {
+    public FileReference createManagedWorkspaceFile(String prefix) throws HyracksDataException {
         final FileReference fRef = ioManager.createWorkspaceFile(prefix);
         registry.registerDeallocatable(new IDeallocatable() {
             @Override
             public void deallocate() {
-                fRef.getFile().delete();
+                fRef.delete();
             }
         });
         return fRef;
     }
+
+    @Override
+    public FileReference createUnmanagedWorkspaceFile(String prefix) throws HyracksDataException {
+        return ioManager.createWorkspaceFile(prefix);
+    }
 }
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/ConnectionManager.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/ConnectionManager.java
new file mode 100644
index 0000000..fbddabd
--- /dev/null
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/ConnectionManager.java
@@ -0,0 +1,265 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.nc.net;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+import java.net.SocketAddress;
+import java.nio.ByteBuffer;
+import java.nio.channels.AsynchronousCloseException;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.Selector;
+import java.nio.channels.ServerSocketChannel;
+import java.nio.channels.SocketChannel;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.UUID;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import edu.uci.ics.hyracks.api.comm.NetworkAddress;
+import edu.uci.ics.hyracks.api.context.IHyracksRootContext;
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+import edu.uci.ics.hyracks.control.nc.partitions.IPartitionRequestListener;
+
+public class ConnectionManager {
+    private static final Logger LOGGER = Logger.getLogger(ConnectionManager.class.getName());
+
+    private static final int INITIAL_MESSAGE_SIZE = 40;
+
+    private final IHyracksRootContext ctx;
+
+    private IPartitionRequestListener partitionRequestListener;
+
+    private final ServerSocketChannel serverChannel;
+
+    private volatile boolean stopped;
+
+    private final ConnectionListenerThread connectionListener;
+
+    private final DataListenerThread dataListener;
+
+    private final NetworkAddress networkAddress;
+
+    public ConnectionManager(IHyracksRootContext ctx, InetAddress inetAddress) throws IOException {
+        this.ctx = ctx;
+        serverChannel = ServerSocketChannel.open();
+        ServerSocket serverSocket = serverChannel.socket();
+        serverSocket.bind(new InetSocketAddress(inetAddress, 0));
+        stopped = false;
+        connectionListener = new ConnectionListenerThread();
+        dataListener = new DataListenerThread();
+        networkAddress = new NetworkAddress(serverSocket.getInetAddress(), serverSocket.getLocalPort());
+
+    }
+
+    public void setPartitionRequestListener(IPartitionRequestListener partitionRequestListener) {
+        this.partitionRequestListener = partitionRequestListener;
+    }
+
+    public void start() {
+        connectionListener.start();
+        dataListener.start();
+    }
+
+    public void stop() {
+        try {
+            stopped = true;
+            serverChannel.close();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void connect(INetworkChannel channel) throws IOException {
+        dataListener.addOutgoingConnection(channel);
+    }
+
+    private final class ConnectionListenerThread extends Thread {
+        public ConnectionListenerThread() {
+            super("Hyracks NC Connection Listener");
+        }
+
+        @Override
+        public void run() {
+            while (!stopped) {
+                try {
+                    SocketChannel sc = serverChannel.accept();
+                    dataListener.addIncomingConnection(sc);
+                } catch (AsynchronousCloseException e) {
+                    // do nothing
+                    e.printStackTrace();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+    }
+
+    private final class DataListenerThread extends Thread {
+        private Selector selector;
+
+        private final List<SocketChannel> pendingIncomingConnections;
+        private final List<SocketChannel> pendingNegotiations;
+        private final List<INetworkChannel> pendingOutgoingConnections;
+        private final List<INetworkChannel> pendingAbortConnections;
+
+        public DataListenerThread() {
+            super("Hyracks Data Listener Thread");
+            try {
+                selector = Selector.open();
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+            pendingIncomingConnections = new ArrayList<SocketChannel>();
+            pendingNegotiations = new ArrayList<SocketChannel>();
+            pendingOutgoingConnections = new ArrayList<INetworkChannel>();
+            pendingAbortConnections = new ArrayList<INetworkChannel>();
+        }
+
+        synchronized void addIncomingConnection(SocketChannel sc) throws IOException {
+            pendingIncomingConnections.add(sc);
+            selector.wakeup();
+        }
+
+        synchronized void addOutgoingConnection(INetworkChannel channel) throws IOException {
+            pendingOutgoingConnections.add(channel);
+            selector.wakeup();
+        }
+
+        synchronized void addPendingAbortConnections(List<INetworkChannel> abortConnections) {
+            pendingAbortConnections.addAll(abortConnections);
+            selector.wakeup();
+        }
+
+        @Override
+        public void run() {
+            while (!stopped) {
+                try {
+                    if (LOGGER.isLoggable(Level.FINE)) {
+                        LOGGER.fine("Starting Select");
+                    }
+                    int n = selector.select();
+                    synchronized (this) {
+                        if (!pendingIncomingConnections.isEmpty()) {
+                            for (SocketChannel sc : pendingIncomingConnections) {
+                                sc.configureBlocking(false);
+                                SelectionKey scKey = sc.register(selector, SelectionKey.OP_READ);
+                                ByteBuffer buffer = ByteBuffer.allocate(INITIAL_MESSAGE_SIZE);
+                                scKey.attach(buffer);
+                                pendingNegotiations.add(sc);
+                            }
+                            pendingIncomingConnections.clear();
+                        }
+                        if (!pendingOutgoingConnections.isEmpty()) {
+                            for (INetworkChannel nc : pendingOutgoingConnections) {
+                                SocketAddress rAddr = nc.getRemoteAddress();
+                                SocketChannel sc = SocketChannel.open();
+                                sc.configureBlocking(false);
+                                int interestOps = SelectionKey.OP_READ;
+                                if (!sc.connect(rAddr)) {
+                                    interestOps |= SelectionKey.OP_CONNECT;
+                                }
+                                SelectionKey scKey = sc.register(selector, interestOps);
+                                scKey.attach(nc);
+                                nc.setSelectionKey(scKey);
+                            }
+                            pendingOutgoingConnections.clear();
+                        }
+                        if (!pendingAbortConnections.isEmpty()) {
+                            for (INetworkChannel nc : pendingAbortConnections) {
+                                SelectionKey key = nc.getSelectionKey();
+                                nc.abort();
+                                nc.dispatchNetworkEvent();
+                                key.cancel();
+                            }
+                            pendingAbortConnections.clear();
+                        }
+                        if (LOGGER.isLoggable(Level.FINE)) {
+                            LOGGER.fine("Selector: " + n);
+                        }
+                        if (n > 0) {
+                            for (Iterator<SelectionKey> i = selector.selectedKeys().iterator(); i.hasNext();) {
+                                SelectionKey key = i.next();
+                                i.remove();
+                                SocketChannel sc = (SocketChannel) key.channel();
+                                if (pendingNegotiations.contains(sc)) {
+                                    if (key.isReadable()) {
+                                        ByteBuffer buffer = (ByteBuffer) key.attachment();
+                                        sc.read(buffer);
+                                        buffer.flip();
+                                        if (buffer.remaining() >= INITIAL_MESSAGE_SIZE) {
+                                            PartitionId pid = readInitialMessage(buffer);
+                                            key.interestOps(0);
+                                            NetworkOutputChannel channel = new NetworkOutputChannel(ctx, 5);
+                                            channel.setSelectionKey(key);
+                                            key.attach(channel);
+                                            try {
+                                                partitionRequestListener.registerPartitionRequest(pid, channel);
+                                            } catch (HyracksException e) {
+                                                key.cancel();
+                                                sc.close();
+                                            }
+                                        } else {
+                                            buffer.compact();
+                                        }
+                                    }
+                                } else {
+                                    INetworkChannel channel = (INetworkChannel) key.attachment();
+                                    boolean close = false;
+                                    try {
+                                        close = channel.dispatchNetworkEvent();
+                                    } catch (IOException e) {
+                                        e.printStackTrace();
+                                        close = true;
+                                    }
+                                    if (close) {
+                                        key.cancel();
+                                        sc.close();
+                                    }
+                                }
+                            }
+                        }
+                    }
+                } catch (Exception e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+
+        private PartitionId readInitialMessage(ByteBuffer buffer) {
+            UUID jobId = readUUID(buffer);
+            ConnectorDescriptorId cdid = new ConnectorDescriptorId(readUUID(buffer));
+            int senderIndex = buffer.getInt();
+            int receiverIndex = buffer.getInt();
+            return new PartitionId(jobId, cdid, senderIndex, receiverIndex);
+        }
+
+        private UUID readUUID(ByteBuffer buffer) {
+            long msb = buffer.getLong();
+            long lsb = buffer.getLong();
+            return new UUID(msb, lsb);
+        }
+    }
+
+    public NetworkAddress getNetworkAddress() {
+        return networkAddress;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/INetworkChannel.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/INetworkChannel.java
new file mode 100644
index 0000000..98215ee
--- /dev/null
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/INetworkChannel.java
@@ -0,0 +1,17 @@
+package edu.uci.ics.hyracks.control.nc.net;
+
+import java.io.IOException;
+import java.net.SocketAddress;
+import java.nio.channels.SelectionKey;
+
+public interface INetworkChannel {
+    public boolean dispatchNetworkEvent() throws IOException;
+
+    public void setSelectionKey(SelectionKey key);
+
+    public SelectionKey getSelectionKey();
+
+    public SocketAddress getRemoteAddress();
+
+    public void abort();
+}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/NetworkInputChannel.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/NetworkInputChannel.java
new file mode 100644
index 0000000..24a6412
--- /dev/null
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/NetworkInputChannel.java
@@ -0,0 +1,188 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.nc.net;
+
+import java.io.IOException;
+import java.net.SocketAddress;
+import java.nio.ByteBuffer;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.SocketChannel;
+import java.util.ArrayDeque;
+import java.util.Queue;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import edu.uci.ics.hyracks.api.channels.IInputChannel;
+import edu.uci.ics.hyracks.api.channels.IInputChannelMonitor;
+import edu.uci.ics.hyracks.api.context.IHyracksRootContext;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+
+public class NetworkInputChannel implements IInputChannel, INetworkChannel {
+    private static final Logger LOGGER = Logger.getLogger(NetworkInputChannel.class.getName());
+
+    private final ConnectionManager connectionManager;
+
+    private final SocketAddress remoteAddress;
+
+    private final PartitionId partitionId;
+
+    private final Queue<ByteBuffer> emptyQueue;
+
+    private final Queue<ByteBuffer> fullQueue;
+
+    private SocketChannel socketChannel;
+
+    private SelectionKey key;
+
+    private ByteBuffer currentBuffer;
+
+    private boolean eos;
+
+    private boolean aborted;
+
+    private IInputChannelMonitor monitor;
+
+    private Object attachment;
+
+    public NetworkInputChannel(IHyracksRootContext ctx, ConnectionManager connectionManager,
+            SocketAddress remoteAddress, PartitionId partitionId, int nBuffers) {
+        this.connectionManager = connectionManager;
+        this.remoteAddress = remoteAddress;
+        this.partitionId = partitionId;
+        this.emptyQueue = new ArrayDeque<ByteBuffer>(nBuffers);
+        for (int i = 0; i < nBuffers; ++i) {
+            emptyQueue.add(ctx.allocateFrame());
+        }
+        fullQueue = new ArrayDeque<ByteBuffer>(nBuffers);
+        aborted = false;
+        eos = false;
+    }
+
+    @Override
+    public void registerMonitor(IInputChannelMonitor monitor) throws HyracksException {
+        this.monitor = monitor;
+    }
+
+    @Override
+    public void setAttachment(Object attachment) {
+        this.attachment = attachment;
+    }
+
+    @Override
+    public Object getAttachment() {
+        return attachment;
+    }
+
+    @Override
+    public synchronized ByteBuffer getNextBuffer() {
+        return fullQueue.poll();
+    }
+
+    @Override
+    public synchronized void recycleBuffer(ByteBuffer buffer) {
+        emptyQueue.add(buffer);
+        if (!eos && !aborted) {
+            int ops = key.interestOps();
+            if ((ops & SelectionKey.OP_READ) == 0) {
+                key.interestOps(ops | SelectionKey.OP_READ);
+            }
+        }
+    }
+
+    @Override
+    public void open() throws HyracksDataException {
+        currentBuffer = emptyQueue.poll();
+        try {
+            connectionManager.connect(this);
+        } catch (IOException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    @Override
+    public void close() throws HyracksDataException {
+
+    }
+
+    @Override
+    public synchronized boolean dispatchNetworkEvent() throws IOException {
+        if (aborted) {
+            eos = true;
+            monitor.notifyEndOfStream(this);
+            return true;
+        }
+        if (key.isReadable()) {
+            if (LOGGER.isLoggable(Level.FINER)) {
+                LOGGER.finer("Before read: " + currentBuffer.position() + " " + currentBuffer.limit());
+            }
+            int bytesRead = socketChannel.read(currentBuffer);
+            if (bytesRead < 0) {
+                eos = true;
+                monitor.notifyEndOfStream(this);
+                return true;
+            }
+            if (LOGGER.isLoggable(Level.FINER)) {
+                LOGGER.finer("After read: " + currentBuffer.position() + " " + currentBuffer.limit());
+            }
+            currentBuffer.flip();
+            int dataLen = currentBuffer.remaining();
+            if (dataLen >= currentBuffer.capacity() || aborted()) {
+                if (LOGGER.isLoggable(Level.FINEST)) {
+                    LOGGER.finest("NetworkInputChannel: frame received: sender = " + partitionId.getSenderIndex());
+                }
+                fullQueue.add(currentBuffer);
+                currentBuffer = emptyQueue.poll();
+                if (currentBuffer == null && key.isValid()) {
+                    int ops = key.interestOps();
+                    key.interestOps(ops & ~SelectionKey.OP_READ);
+                }
+                monitor.notifyDataAvailability(this, 1);
+                return false;
+            }
+            currentBuffer.compact();
+        }
+        return false;
+    }
+
+    @Override
+    public void setSelectionKey(SelectionKey key) {
+        this.key = key;
+        socketChannel = (SocketChannel) key.channel();
+    }
+
+    @Override
+    public SocketAddress getRemoteAddress() {
+        return remoteAddress;
+    }
+
+    @Override
+    public SelectionKey getSelectionKey() {
+        return key;
+    }
+
+    public PartitionId getPartitionId() {
+        return partitionId;
+    }
+
+    public void abort() {
+        aborted = true;
+    }
+
+    public boolean aborted() {
+        return aborted;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/NetworkOutputChannel.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/NetworkOutputChannel.java
new file mode 100644
index 0000000..eb1ec89
--- /dev/null
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/net/NetworkOutputChannel.java
@@ -0,0 +1,167 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.nc.net;
+
+import java.io.IOException;
+import java.net.SocketAddress;
+import java.nio.ByteBuffer;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.SocketChannel;
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+import edu.uci.ics.hyracks.api.comm.FrameHelper;
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.context.IHyracksRootContext;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public class NetworkOutputChannel implements INetworkChannel, IFrameWriter {
+    private final IHyracksRootContext ctx;
+
+    private final Queue<ByteBuffer> emptyQueue;
+
+    private final Queue<ByteBuffer> fullQueue;
+
+    private SelectionKey key;
+
+    private boolean aborted;
+
+    private boolean eos;
+
+    private boolean eosSent;
+
+    private ByteBuffer currentBuffer;
+
+    public NetworkOutputChannel(IHyracksRootContext ctx, int nBuffers) {
+        this.ctx = ctx;
+        emptyQueue = new ArrayDeque<ByteBuffer>(nBuffers);
+        for (int i = 0; i < nBuffers; ++i) {
+            emptyQueue.add(ctx.allocateFrame());
+        }
+        fullQueue = new ArrayDeque<ByteBuffer>(nBuffers);
+    }
+
+    @Override
+    public synchronized boolean dispatchNetworkEvent() throws IOException {
+        if (aborted) {
+            eos = true;
+            return true;
+        } else if (key.isWritable()) {
+            while (true) {
+                if (currentBuffer == null) {
+                    if (eosSent) {
+                        return true;
+                    }
+                    currentBuffer = fullQueue.poll();
+                    if (currentBuffer == null) {
+                        if (eos) {
+                            currentBuffer = emptyQueue.poll();
+                            currentBuffer.clear();
+                            currentBuffer.putInt(FrameHelper.getTupleCountOffset(ctx.getFrameSize()), 0);
+                            eosSent = true;
+                        } else {
+                            key.interestOps(key.interestOps() & ~SelectionKey.OP_WRITE);
+                            return false;
+                        }
+                    }
+                }
+                int bytesWritten = ((SocketChannel) key.channel()).write(currentBuffer);
+                if (bytesWritten < 0) {
+                    eos = true;
+                    return true;
+                }
+                if (currentBuffer.remaining() == 0) {
+                    emptyQueue.add(currentBuffer);
+                    notifyAll();
+                    currentBuffer = null;
+                    if (eosSent) {
+                        return true;
+                    }
+                } else {
+                    return false;
+                }
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public void setSelectionKey(SelectionKey key) {
+        this.key = key;
+    }
+
+    @Override
+    public SelectionKey getSelectionKey() {
+        return key;
+    }
+
+    @Override
+    public SocketAddress getRemoteAddress() {
+        return ((SocketChannel) key.channel()).socket().getRemoteSocketAddress();
+    }
+
+    @Override
+    public synchronized void abort() {
+        aborted = true;
+    }
+
+    @Override
+    public void open() throws HyracksDataException {
+        currentBuffer = null;
+    }
+
+    @Override
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        ByteBuffer destBuffer = null;
+        synchronized (this) {
+            if (aborted) {
+                throw new HyracksDataException("Connection has been aborted");
+            }
+            while (true) {
+                destBuffer = emptyQueue.poll();
+                if (destBuffer != null) {
+                    break;
+                }
+                try {
+                    wait();
+                } catch (InterruptedException e) {
+                    throw new HyracksDataException(e);
+                }
+            }
+        }
+        buffer.position(0);
+        buffer.limit(destBuffer.capacity());
+        destBuffer.clear();
+        destBuffer.put(buffer);
+        destBuffer.flip();
+        synchronized (this) {
+            fullQueue.add(destBuffer);
+        }
+        int interestOps = key.interestOps();
+        if ((interestOps & SelectionKey.OP_WRITE) == 0) {
+            key.interestOps(interestOps | SelectionKey.OP_WRITE);
+        }
+    }
+
+    @Override
+    public void flush() throws HyracksDataException {
+
+    }
+
+    @Override
+    public synchronized void close() throws HyracksDataException {
+        eos = true;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IScheduler.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/IPartitionRequestListener.java
similarity index 63%
copy from hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IScheduler.java
copy to hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/IPartitionRequestListener.java
index 3893a2d..20ed49c 100644
--- a/hyracks-control-cc/src/main/java/edu/uci/ics/hyracks/control/cc/scheduler/IScheduler.java
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/IPartitionRequestListener.java
@@ -12,16 +12,12 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.hyracks.control.cc.scheduler;
+package edu.uci.ics.hyracks.control.nc.partitions;
 
-import java.util.Set;
-
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
-import edu.uci.ics.hyracks.control.cc.job.JobAttempt;
-import edu.uci.ics.hyracks.control.cc.job.JobStageAttempt;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
 
-public interface IScheduler {
-    public IJobAttemptSchedulerState createJobAttemptState(JobAttempt ja);
-
-    public void schedule(Set<JobStageAttempt> runnableStageAttempts) throws HyracksException;
+public interface IPartitionRequestListener {
+    public void registerPartitionRequest(PartitionId partitionId, IFrameWriter writer) throws HyracksException;
 }
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/MaterializedPartition.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/MaterializedPartition.java
new file mode 100644
index 0000000..6833cbe
--- /dev/null
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/MaterializedPartition.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.nc.partitions;
+
+import java.nio.ByteBuffer;
+import java.util.concurrent.Executor;
+
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.context.IHyracksRootContext;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.FileHandle;
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.api.io.IIOManager;
+import edu.uci.ics.hyracks.api.partitions.IPartition;
+import edu.uci.ics.hyracks.control.nc.io.IOManager;
+
+public class MaterializedPartition implements IPartition {
+    private final IHyracksRootContext ctx;
+
+    private final FileReference partitionFile;
+
+    private final Executor executor;
+
+    private final IOManager ioManager;
+
+    public MaterializedPartition(IHyracksRootContext ctx, FileReference partitionFile, Executor executor,
+            IOManager ioManager) {
+        this.ctx = ctx;
+        this.partitionFile = partitionFile;
+        this.executor = executor;
+        this.ioManager = ioManager;
+    }
+
+    @Override
+    public void deallocate() {
+        partitionFile.delete();
+    }
+
+    @Override
+    public void writeTo(final IFrameWriter writer) {
+        executor.execute(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    FileHandle fh = ioManager.open(partitionFile, IIOManager.FileReadWriteMode.READ_ONLY,
+                            IIOManager.FileSyncMode.METADATA_ASYNC_DATA_ASYNC);
+                    writer.open();
+                    try {
+                        long offset = 0;
+                        ByteBuffer buffer = ctx.allocateFrame();
+                        while (true) {
+                            buffer.clear();
+                            long size = ioManager.syncRead(fh, offset, buffer);
+                            if (size < 0) {
+                                break;
+                            } else if (size < buffer.capacity()) {
+                                throw new HyracksDataException("Premature end of file");
+                            }
+                            buffer.flip();
+                            writer.nextFrame(buffer);
+                        }
+                    } finally {
+                        writer.close();
+                    }
+                } catch (HyracksDataException e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        });
+    }
+
+    @Override
+    public boolean isReusable() {
+        return true;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/PartitionManager.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/PartitionManager.java
new file mode 100644
index 0000000..27afb8c
--- /dev/null
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/PartitionManager.java
@@ -0,0 +1,82 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.nc.partitions;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.UUID;
+
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.comm.NetworkAddress;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.partitions.IPartition;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+import edu.uci.ics.hyracks.control.nc.NodeControllerService;
+
+public class PartitionManager implements IPartitionRequestListener {
+    private final NetworkAddress dataPort;
+
+    private final NodeControllerService ncs;
+
+    private final Map<PartitionId, IPartition> partitionMap;
+
+    public PartitionManager(NodeControllerService ncs, NetworkAddress dataPort) {
+        this.dataPort = dataPort;
+        this.ncs = ncs;
+        partitionMap = new HashMap<PartitionId, IPartition>();
+    }
+
+    public void registerPartition(PartitionId pid, IPartition partition) throws HyracksDataException {
+        synchronized (this) {
+            partitionMap.put(pid, partition);
+        }
+        try {
+            ncs.getClusterController().registerPartitionProvider(pid, dataPort);
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    public synchronized IPartition getPartition(PartitionId pid) {
+        return partitionMap.get(pid);
+    }
+
+    public synchronized void unregisterPartitions(UUID jobId) {
+        for (Iterator<Map.Entry<PartitionId, IPartition>> i = partitionMap.entrySet().iterator(); i.hasNext();) {
+            Map.Entry<PartitionId, IPartition> e = i.next();
+            PartitionId pid = e.getKey();
+            if (jobId.equals(pid.getJobId())) {
+                e.getValue().deallocate();
+                i.remove();
+            }
+        }
+    }
+
+    @Override
+    public synchronized void registerPartitionRequest(PartitionId partitionId, IFrameWriter writer)
+            throws HyracksException {
+        IPartition partition = partitionMap.get(partitionId);
+        if (partition != null) {
+            partition.writeTo(writer);
+            if (!partition.isReusable()) {
+                partitionMap.remove(partitionId);
+            }
+        } else {
+            throw new HyracksException("Request for unknown partition " + partitionId);
+        }
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/PipelinedPartition.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/PipelinedPartition.java
new file mode 100644
index 0000000..c667ef4
--- /dev/null
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/partitions/PipelinedPartition.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.nc.partitions;
+
+import java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.partitions.IPartition;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+
+public class PipelinedPartition implements IFrameWriter, IPartition {
+    private final PartitionManager manager;
+
+    private final PartitionId pid;
+
+    private IFrameWriter delegate;
+
+    public PipelinedPartition(PartitionManager manager, PartitionId pid) {
+        this.manager = manager;
+        this.pid = pid;
+    }
+
+    @Override
+    public boolean isReusable() {
+        return false;
+    }
+
+    @Override
+    public void deallocate() {
+        // do nothing
+    }
+
+    @Override
+    public synchronized void writeTo(IFrameWriter writer) {
+        delegate = writer;
+        notifyAll();
+    }
+
+    @Override
+    public synchronized void open() throws HyracksDataException {
+        manager.registerPartition(pid, this);
+        while (delegate == null) {
+            try {
+                wait();
+            } catch (InterruptedException e) {
+                throw new HyracksDataException(e);
+            }
+        }
+        delegate.open();
+    }
+
+    @Override
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        delegate.nextFrame(buffer);
+    }
+
+    @Override
+    public void flush() throws HyracksDataException {
+        delegate.flush();
+    }
+
+    @Override
+    public void close() throws HyracksDataException {
+        delegate.close();
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/profiling/ConnectorReceiverProfilingFrameReader.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/profiling/ConnectorReceiverProfilingFrameReader.java
new file mode 100644
index 0000000..96fcf75
--- /dev/null
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/profiling/ConnectorReceiverProfilingFrameReader.java
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.nc.profiling;
+
+import java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.comm.IFrameReader;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.job.profiling.counters.ICounter;
+
+public class ConnectorReceiverProfilingFrameReader implements IFrameReader {
+    private final IFrameReader reader;
+    private final ICounter openCounter;
+    private final ICounter closeCounter;
+    private final ICounter frameCounter;
+
+    public ConnectorReceiverProfilingFrameReader(IHyracksTaskContext ctx, IFrameReader reader,
+            ConnectorDescriptorId cdId, int receiverIndex) {
+        this.reader = reader;
+        this.openCounter = ctx.getCounterContext().getCounter(cdId + ".receiver." + receiverIndex + ".open", true);
+        this.closeCounter = ctx.getCounterContext().getCounter(cdId + ".receiver." + receiverIndex + ".close", true);
+        this.frameCounter = ctx.getCounterContext()
+                .getCounter(cdId + ".receiver." + receiverIndex + ".nextFrame", true);
+    }
+
+    @Override
+    public void open() throws HyracksDataException {
+        reader.open();
+        openCounter.update(1);
+    }
+
+    @Override
+    public boolean nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        boolean status = reader.nextFrame(buffer);
+        if (status) {
+            frameCounter.update(1);
+        }
+        return status;
+    }
+
+    @Override
+    public void close() throws HyracksDataException {
+        reader.close();
+        closeCounter.update(1);
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/profiling/ConnectorSenderProfilingFrameWriter.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/profiling/ConnectorSenderProfilingFrameWriter.java
new file mode 100644
index 0000000..c64e187
--- /dev/null
+++ b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/profiling/ConnectorSenderProfilingFrameWriter.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.control.nc.profiling;
+
+import java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.job.profiling.counters.ICounter;
+
+public class ConnectorSenderProfilingFrameWriter implements IFrameWriter {
+    private final IFrameWriter writer;
+    private final ICounter openCounter;
+    private final ICounter closeCounter;
+    private final ICounter frameCounter;
+
+    public ConnectorSenderProfilingFrameWriter(IHyracksTaskContext ctx, IFrameWriter writer,
+            ConnectorDescriptorId cdId, int senderIndex, int receiverIndex) {
+        this.writer = writer;
+        this.openCounter = ctx.getCounterContext().getCounter(
+                cdId + ".sender." + senderIndex + "." + receiverIndex + ".open", true);
+        this.closeCounter = ctx.getCounterContext().getCounter(
+                cdId + ".sender." + senderIndex + "." + receiverIndex + ".close", true);
+        this.frameCounter = ctx.getCounterContext().getCounter(
+                cdId + ".sender." + senderIndex + "." + receiverIndex + ".nextFrame", true);
+    }
+
+    @Override
+    public void open() throws HyracksDataException {
+        writer.open();
+        openCounter.update(1);
+    }
+
+    @Override
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        frameCounter.update(1);
+        writer.nextFrame(buffer);
+    }
+
+    @Override
+    public void close() throws HyracksDataException {
+        closeCounter.update(1);
+        writer.close();
+    }
+
+    @Override
+    public void flush() throws HyracksDataException {
+        writer.flush();
+    }
+}
\ No newline at end of file
diff --git a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/runtime/OperatorRunnable.java b/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/runtime/OperatorRunnable.java
deleted file mode 100644
index eca7fd0..0000000
--- a/hyracks-control-nc/src/main/java/edu/uci/ics/hyracks/control/nc/runtime/OperatorRunnable.java
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.control.nc.runtime;
-
-import java.nio.ByteBuffer;
-
-import edu.uci.ics.hyracks.api.comm.IFrameReader;
-import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
-import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-
-public class OperatorRunnable implements Runnable {
-    private final IOperatorNodePushable opNode;
-    private IFrameReader reader;
-    private ByteBuffer buffer;
-    private volatile boolean abort;
-
-    public OperatorRunnable(IHyracksStageletContext ctx, IOperatorNodePushable opNode) {
-        this.opNode = opNode;
-        buffer = ctx.allocateFrame();
-    }
-
-    public void setFrameWriter(int index, IFrameWriter writer, RecordDescriptor recordDesc) {
-        opNode.setOutputFrameWriter(index, writer, recordDesc);
-    }
-
-    public void setFrameReader(IFrameReader reader) {
-        this.reader = reader;
-    }
-
-    public void abort() {
-        abort = true;
-    }
-
-    @Override
-    public void run() {
-        try {
-            opNode.initialize();
-            if (reader != null) {
-                IFrameWriter writer = opNode.getInputFrameWriter(0);
-                writer.open();
-                reader.open();
-                while (readFrame()) {
-                    if (abort) {
-                        break;
-                    }
-                    buffer.flip();
-                    writer.nextFrame(buffer);
-                    buffer.compact();
-                }
-                reader.close();
-                writer.close();
-            }
-            opNode.deinitialize();
-        } catch (Exception e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    protected boolean readFrame() throws HyracksDataException {
-        return reader.nextFrame(buffer);
-    }
-
-    @Override
-    public String toString() {
-        return "OperatorRunnable[" + opNode.getDisplayName() + "]";
-    }
-}
\ No newline at end of file
diff --git a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/AbstractPartitionCollector.java b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/AbstractPartitionCollector.java
new file mode 100644
index 0000000..4326a9f
--- /dev/null
+++ b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/AbstractPartitionCollector.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.dataflow.common.comm;
+
+import java.util.UUID;
+
+import edu.uci.ics.hyracks.api.comm.IPartitionCollector;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+
+public abstract class AbstractPartitionCollector implements IPartitionCollector {
+    protected final IHyracksTaskContext stageletContext;
+
+    protected final ConnectorDescriptorId connectorId;
+
+    protected final int receiverIndex;
+
+    public AbstractPartitionCollector(IHyracksTaskContext ctx, ConnectorDescriptorId connectorId, int receiverIndex) {
+        this.stageletContext = ctx;
+        this.connectorId = connectorId;
+        this.receiverIndex = receiverIndex;
+    }
+
+    @Override
+    public UUID getJobId() {
+        return stageletContext.getJobletContext().getJobId();
+    }
+
+    @Override
+    public ConnectorDescriptorId getConnectorId() {
+        return connectorId;
+    }
+
+    @Override
+    public int getReceiverIndex() {
+        return receiverIndex;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/NonDeterministicFrameReader.java b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/NonDeterministicFrameReader.java
deleted file mode 100644
index 49d3db7..0000000
--- a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/NonDeterministicFrameReader.java
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.dataflow.common.comm;
-
-import java.nio.ByteBuffer;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import edu.uci.ics.hyracks.api.comm.FrameHelper;
-import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
-import edu.uci.ics.hyracks.api.comm.IConnectionEntry;
-import edu.uci.ics.hyracks.api.comm.IFrameReader;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-
-public class NonDeterministicFrameReader implements IFrameReader {
-    private static final Logger LOGGER = Logger.getLogger(NonDeterministicFrameReader.class.getName());
-
-    private final IHyracksStageletContext ctx;
-    private final IConnectionDemultiplexer demux;
-    private int lastReadSender;
-    private boolean eos;
-
-    public NonDeterministicFrameReader(IHyracksStageletContext ctx, IConnectionDemultiplexer demux) {
-        this.ctx = ctx;
-        this.demux = demux;
-    }
-
-    @Override
-    public void open() throws HyracksDataException {
-        lastReadSender = 0;
-        eos = false;
-    }
-
-    @Override
-    public void close() throws HyracksDataException {
-    }
-
-    @Override
-    public boolean nextFrame(ByteBuffer buffer) throws HyracksDataException {
-        if (eos) {
-            return false;
-        }
-        while (true) {
-            IConnectionEntry entry = demux.findNextReadyEntry(lastReadSender);
-            if (entry.aborted()) {
-                eos = true;
-                return false;
-            }
-            lastReadSender = (Integer) entry.getAttachment();
-            ByteBuffer netBuffer = entry.getReadBuffer();
-            int tupleCount = netBuffer.getInt(FrameHelper.getTupleCountOffset(ctx.getFrameSize()));
-            if (LOGGER.isLoggable(Level.FINER)) {
-                LOGGER.finer("Frame Tuple Count: " + tupleCount);
-            }
-            if (tupleCount == 0) {
-                if (LOGGER.isLoggable(Level.FINE)) {
-                    LOGGER.fine("Empty Frame received: Closing " + lastReadSender);
-                }
-                int openEntries = demux.closeEntry(lastReadSender);
-                if (openEntries == 0) {
-                    eos = true;
-                    return false;
-                }
-                netBuffer.clear();
-                demux.unreadyEntry(lastReadSender);
-            } else {
-                buffer.clear();
-                buffer.put(netBuffer);
-                netBuffer.clear();
-                demux.unreadyEntry(lastReadSender);
-                return true;
-            }
-        }
-    }
-}
\ No newline at end of file
diff --git a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/NonDeterministicPartitionCollector.java b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/NonDeterministicPartitionCollector.java
new file mode 100644
index 0000000..fb6a883
--- /dev/null
+++ b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/NonDeterministicPartitionCollector.java
@@ -0,0 +1,181 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.dataflow.common.comm;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.BitSet;
+import java.util.Collection;
+
+import edu.uci.ics.hyracks.api.channels.IInputChannel;
+import edu.uci.ics.hyracks.api.channels.IInputChannelMonitor;
+import edu.uci.ics.hyracks.api.comm.IFrameReader;
+import edu.uci.ics.hyracks.api.comm.PartitionChannel;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+import edu.uci.ics.hyracks.dataflow.common.comm.util.FrameUtils;
+
+public class NonDeterministicPartitionCollector extends AbstractPartitionCollector {
+    private final FrameReader reader;
+
+    private final BitSet expectedPartitions;
+
+    private IInputChannel[] channels;
+
+    private BitSet frameAvailability;
+
+    private int[] availableFrameCounts;
+
+    private BitSet eosSenders;
+
+    private BitSet closedSenders;
+
+    private int lastReadSender;
+
+    public NonDeterministicPartitionCollector(IHyracksTaskContext ctx, ConnectorDescriptorId connectorId,
+            int receiverIndex, BitSet expectedPartitions) {
+        super(ctx, connectorId, receiverIndex);
+        this.expectedPartitions = expectedPartitions;
+        int nSenders = expectedPartitions.size();
+        reader = new FrameReader();
+        channels = new IInputChannel[nSenders];
+        eosSenders = new BitSet(nSenders);
+        closedSenders = new BitSet(nSenders);
+        closedSenders.or(expectedPartitions);
+        closedSenders.flip(0, nSenders);
+        frameAvailability = new BitSet(nSenders);
+        availableFrameCounts = new int[nSenders];
+    }
+
+    @Override
+    public void open() throws HyracksException {
+        lastReadSender = 0;
+    }
+
+    @Override
+    public synchronized void addPartitions(Collection<PartitionChannel> partitions) throws HyracksException {
+        for (PartitionChannel pc : partitions) {
+            PartitionId pid = pc.getPartitionId();
+            IInputChannel channel = pc.getInputChannel();
+            channel.setAttachment(pid);
+            channel.registerMonitor(reader);
+            channels[pid.getSenderIndex()] = channel;
+            channel.open();
+        }
+    }
+
+    @Override
+    public IFrameReader getReader() throws HyracksException {
+        return reader;
+    }
+
+    @Override
+    public void close() throws HyracksException {
+    }
+
+    private final class FrameReader implements IFrameReader, IInputChannelMonitor {
+        @Override
+        public void open() throws HyracksDataException {
+        }
+
+        @Override
+        public boolean nextFrame(ByteBuffer buffer) throws HyracksDataException {
+            synchronized (NonDeterministicPartitionCollector.this) {
+                while (true) {
+                    switch (lastReadSender) {
+                        default:
+                            lastReadSender = frameAvailability.nextSetBit(lastReadSender);
+                            if (lastReadSender >= 0) {
+                                break;
+                            }
+                        case 0:
+                            lastReadSender = frameAvailability.nextSetBit(0);
+                    }
+                    if (lastReadSender >= 0) {
+                        assert availableFrameCounts[lastReadSender] > 0;
+                        if (--availableFrameCounts[lastReadSender] == 0) {
+                            frameAvailability.clear(lastReadSender);
+                        }
+                        ByteBuffer srcFrame = channels[lastReadSender].getNextBuffer();
+                        FrameUtils.copy(srcFrame, buffer);
+                        channels[lastReadSender].recycleBuffer(srcFrame);
+                        return true;
+                    }
+                    for (int i = eosSenders.nextSetBit(0); i >= 0; i = eosSenders.nextSetBit(i)) {
+                        channels[i].close();
+                        eosSenders.clear(i);
+                        closedSenders.set(i);
+                    }
+                    if (closedSenders.nextClearBit(0) < 0) {
+                        return false;
+                    }
+                    try {
+                        NonDeterministicPartitionCollector.this.wait();
+                    } catch (InterruptedException e) {
+                        e.printStackTrace();
+                    }
+                }
+            }
+        }
+
+        @Override
+        public void close() throws HyracksDataException {
+            synchronized (NonDeterministicPartitionCollector.this) {
+                for (int i = closedSenders.nextClearBit(0); i >= 0; i = closedSenders.nextClearBit(i)) {
+                    if (channels[i] != null) {
+                        channels[i].close();
+                    }
+                }
+            }
+        }
+
+        @Override
+        public void notifyDataAvailability(IInputChannel channel, int nFrames) {
+            synchronized (NonDeterministicPartitionCollector.this) {
+                PartitionId pid = (PartitionId) channel.getAttachment();
+                int senderIndex = pid.getSenderIndex();
+                availableFrameCounts[senderIndex] += nFrames;
+                frameAvailability.set(senderIndex);
+                NonDeterministicPartitionCollector.this.notifyAll();
+            }
+        }
+
+        @Override
+        public void notifyEndOfStream(IInputChannel channel) {
+            synchronized (NonDeterministicPartitionCollector.this) {
+                PartitionId pid = (PartitionId) channel.getAttachment();
+                int senderIndex = pid.getSenderIndex();
+                eosSenders.set(senderIndex);
+                NonDeterministicPartitionCollector.this.notifyAll();
+            }
+        }
+    }
+
+    @Override
+    public Collection<PartitionId> getRequiredPartitionIds() throws HyracksException {
+        Collection<PartitionId> c = new ArrayList<PartitionId>(expectedPartitions.cardinality());
+        for (int i = expectedPartitions.nextSetBit(0); i >= 0; i = expectedPartitions.nextSetBit(i)) {
+            c.add(new PartitionId(getJobId(), getConnectorId(), i, getReceiverIndex()));
+        }
+        return c;
+    }
+
+    @Override
+    public void abort() {
+    }
+}
\ No newline at end of file
diff --git a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/SortMergeFrameReader.java b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/SortMergeFrameReader.java
deleted file mode 100644
index 7be9b08..0000000
--- a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/SortMergeFrameReader.java
+++ /dev/null
@@ -1,214 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.dataflow.common.comm;
-
-import java.nio.ByteBuffer;
-import java.util.Comparator;
-import java.util.PriorityQueue;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import edu.uci.ics.hyracks.api.comm.FrameHelper;
-import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
-import edu.uci.ics.hyracks.api.comm.IConnectionEntry;
-import edu.uci.ics.hyracks.api.comm.IFrameReader;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
-import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.io.FileHandle;
-import edu.uci.ics.hyracks.api.io.FileReference;
-import edu.uci.ics.hyracks.api.io.IIOManager;
-import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
-import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
-import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTuplePairComparator;
-
-public class SortMergeFrameReader implements IFrameReader {
-    private static final Logger LOGGER = Logger.getLogger(SortMergeFrameReader.class.getName());
-
-    private final IHyracksStageletContext ctx;
-    private final IConnectionDemultiplexer demux;
-    private final FrameTuplePairComparator tpc;
-    private final FrameTupleAppender appender;
-    private final RecordDescriptor recordDescriptor;
-    private Run[] runs;
-    private ByteBuffer[] frames;
-    private PriorityQueue<Integer> pQueue;
-    private int lastReadSender;
-    private boolean first;
-
-    public SortMergeFrameReader(IHyracksStageletContext ctx, IConnectionDemultiplexer demux, int[] sortFields,
-            IBinaryComparator[] comparators, RecordDescriptor recordDescriptor) {
-        this.ctx = ctx;
-        this.demux = demux;
-        tpc = new FrameTuplePairComparator(sortFields, sortFields, comparators);
-        appender = new FrameTupleAppender(ctx.getFrameSize());
-        this.recordDescriptor = recordDescriptor;
-    }
-
-    @Override
-    public void open() throws HyracksDataException {
-        int nSenders = demux.getSenderCount();
-        runs = new Run[nSenders];
-        frames = new ByteBuffer[nSenders];
-        for (int i = 0; i < runs.length; ++i) {
-            runs[i] = new Run(i);
-            frames[i] = ctx.allocateFrame();
-        }
-        pQueue = new PriorityQueue<Integer>(nSenders, new Comparator<Integer>() {
-            @Override
-            public int compare(Integer o1, Integer o2) {
-                int i1 = o1.intValue();
-                int i2 = o2.intValue();
-                Run r1 = runs[i1];
-                Run r2 = runs[i2];
-
-                int c = tpc.compare(r1.accessor, r1.tIndex, r2.accessor, r2.tIndex);
-                return c == 0 ? (i1 < i2 ? -1 : 1) : c;
-            }
-        });
-        lastReadSender = 0;
-        first = true;
-    }
-
-    @Override
-    public void close() throws HyracksDataException {
-        for (Run r : runs) {
-            r.close();
-        }
-    }
-
-    @Override
-    public boolean nextFrame(ByteBuffer buffer) throws HyracksDataException {
-        buffer.clear();
-        buffer.position(buffer.capacity());
-        appender.reset(buffer, true);
-        if (first) {
-            for (int i = 0; i < runs.length; ++i) {
-                if (runs[i].next()) {
-                    pQueue.add(Integer.valueOf(i));
-                }
-            }
-        }
-        first = false;
-        while (true) {
-            if (pQueue.isEmpty()) {
-                return appender.getTupleCount() > 0;
-            }
-            Integer top = pQueue.peek();
-            Run run = runs[top.intValue()];
-            if (!appender.append(run.accessor, run.tIndex)) {
-                return true;
-            }
-            pQueue.remove();
-            if (run.next()) {
-                pQueue.add(top);
-            }
-        }
-    }
-
-    private class Run {
-        private final int runId;
-        private final FileReference fRef;
-        private final FileHandle fHandle;
-        private final ByteBuffer frame;
-        private final FrameTupleAccessor accessor;
-        private int tIndex;
-        private long readFP;
-        private long writeFP;
-        private boolean eof;
-
-        public Run(int runId) throws HyracksDataException {
-            this.runId = runId;
-            fRef = ctx.createWorkspaceFile(SortMergeFrameReader.class.getName());
-            fHandle = ctx.getIOManager().open(fRef, IIOManager.FileReadWriteMode.READ_WRITE,
-                    IIOManager.FileSyncMode.METADATA_ASYNC_DATA_ASYNC);
-            frame = ctx.allocateFrame();
-            accessor = new FrameTupleAccessor(ctx.getFrameSize(), recordDescriptor);
-            readFP = 0;
-            writeFP = 0;
-            eof = false;
-        }
-
-        public void close() throws HyracksDataException {
-            ctx.getIOManager().close(fHandle);
-        }
-
-        private void write(ByteBuffer frame) throws HyracksDataException {
-            int sz = ctx.getIOManager().syncWrite(fHandle, writeFP, frame);
-            writeFP += sz;
-        }
-
-        private boolean next() throws HyracksDataException {
-            ++tIndex;
-            while (readFP == 0 || tIndex >= accessor.getTupleCount()) {
-                if (!read(frame)) {
-                    return false;
-                }
-                accessor.reset(frame);
-                tIndex = 0;
-            }
-            return true;
-        }
-
-        private boolean read(ByteBuffer frame) throws HyracksDataException {
-            frame.clear();
-            while (!eof && readFP >= writeFP) {
-                spoolRuns(runId);
-            }
-            if (eof && readFP >= writeFP) {
-                return false;
-            }
-            int sz = ctx.getIOManager().syncRead(fHandle, readFP, frame);
-            readFP += sz;
-            return true;
-        }
-
-        private void eof() {
-            eof = true;
-        }
-    }
-
-    private void spoolRuns(int interestingRun) throws HyracksDataException {
-        while (true) {
-            IConnectionEntry entry = demux.findNextReadyEntry(lastReadSender);
-            lastReadSender = (Integer) entry.getAttachment();
-            ByteBuffer netBuffer = entry.getReadBuffer();
-            int tupleCount = netBuffer.getInt(FrameHelper.getTupleCountOffset(ctx.getFrameSize()));
-            if (LOGGER.isLoggable(Level.FINER)) {
-                LOGGER.finer("Frame Tuple Count: " + tupleCount);
-            }
-            if (tupleCount == 0) {
-                if (LOGGER.isLoggable(Level.FINE)) {
-                    LOGGER.fine("Empty Frame received: Closing " + lastReadSender);
-                }
-                int openEntries = demux.closeEntry(lastReadSender);
-                runs[lastReadSender].eof();
-                netBuffer.clear();
-                demux.unreadyEntry(lastReadSender);
-                if (openEntries == 0) {
-                    return;
-                }
-            } else {
-                runs[lastReadSender].write(netBuffer);
-                netBuffer.clear();
-                demux.unreadyEntry(lastReadSender);
-            }
-            if (lastReadSender == interestingRun) {
-                return;
-            }
-        }
-    }
-}
\ No newline at end of file
diff --git a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/SortMergePartitionCollector.java b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/SortMergePartitionCollector.java
new file mode 100644
index 0000000..0977002
--- /dev/null
+++ b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/SortMergePartitionCollector.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.dataflow.common.comm;
+
+import java.util.Collection;
+
+import edu.uci.ics.hyracks.api.channels.IInputChannel;
+import edu.uci.ics.hyracks.api.comm.IFrameReader;
+import edu.uci.ics.hyracks.api.comm.PartitionChannel;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksException;
+import edu.uci.ics.hyracks.api.partitions.PartitionId;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
+import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTuplePairComparator;
+
+public class SortMergePartitionCollector extends AbstractPartitionCollector {
+    private final FrameTuplePairComparator tpc;
+
+    private final FrameTupleAppender appender;
+
+    private final RecordDescriptor recordDescriptor;
+
+    private final int maxFramesLimit;
+
+    private IInputChannel[] channels;
+
+    public SortMergePartitionCollector(IHyracksTaskContext ctx, ConnectorDescriptorId connectorId, int receiverIndex,
+            int[] sortFields, IBinaryComparator[] comparators, RecordDescriptor recordDescriptor, int maxFramesLimit,
+            int nSenders) {
+        super(ctx, connectorId, receiverIndex);
+        tpc = new FrameTuplePairComparator(sortFields, sortFields, comparators);
+        appender = new FrameTupleAppender(ctx.getFrameSize());
+        this.recordDescriptor = recordDescriptor;
+        this.maxFramesLimit = maxFramesLimit;
+        channels = new IInputChannel[nSenders];
+    }
+
+    @Override
+    public void open() throws HyracksException {
+    }
+
+    @Override
+    public void addPartitions(Collection<PartitionChannel> partitions) throws HyracksException {
+
+    }
+
+    @Override
+    public IFrameReader getReader() throws HyracksException {
+        return null;
+    }
+
+    @Override
+    public void close() throws HyracksException {
+
+    }
+
+    @Override
+    public Collection<PartitionId> getRequiredPartitionIds() throws HyracksException {
+        return null;
+    }
+
+    @Override
+    public void abort() {
+
+    }
+}
\ No newline at end of file
diff --git a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/FrameDeserializingDataReader.java b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/FrameDeserializingDataReader.java
index d2a3c53..f4862d8 100644
--- a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/FrameDeserializingDataReader.java
+++ b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/FrameDeserializingDataReader.java
@@ -17,7 +17,7 @@
 import java.nio.ByteBuffer;
 
 import edu.uci.ics.hyracks.api.comm.IFrameReader;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOpenableDataReader;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
@@ -33,7 +33,7 @@
 
     private final FrameDeserializer frameDeserializer;
 
-    public FrameDeserializingDataReader(IHyracksStageletContext ctx, IFrameReader frameReader,
+    public FrameDeserializingDataReader(IHyracksTaskContext ctx, IFrameReader frameReader,
             RecordDescriptor recordDescriptor) {
         buffer = ctx.allocateFrame();
         this.frameReader = frameReader;
diff --git a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/SerializingDataWriter.java b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/SerializingDataWriter.java
index 9edd3bf..7c7979b 100644
--- a/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/SerializingDataWriter.java
+++ b/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/SerializingDataWriter.java
@@ -19,7 +19,7 @@
 import java.util.logging.Logger;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOpenableDataWriter;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
@@ -39,8 +39,7 @@
 
     private boolean open;
 
-    public SerializingDataWriter(IHyracksStageletContext ctx, RecordDescriptor recordDescriptor,
-            IFrameWriter frameWriter) {
+    public SerializingDataWriter(IHyracksTaskContext ctx, RecordDescriptor recordDescriptor, IFrameWriter frameWriter) {
         buffer = ctx.allocateFrame();
         tb = new ArrayTupleBuilder(recordDescriptor.getFields().length);
         this.recordDescriptor = recordDescriptor;
diff --git a/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopMapperOperatorDescriptor.java b/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopMapperOperatorDescriptor.java
index c3167cb..ca37f37 100644
--- a/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopMapperOperatorDescriptor.java
+++ b/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopMapperOperatorDescriptor.java
@@ -34,7 +34,7 @@
 import org.apache.hadoop.mapreduce.TaskAttemptID;
 import org.apache.hadoop.util.ReflectionUtils;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOpenableDataWriter;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
@@ -350,7 +350,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) throws HyracksDataException {
 
         JobConf conf = getJobConf();
@@ -391,7 +391,7 @@
         }
     }
 
-    private IOperatorNodePushable createSelfReadingMapper(final IHyracksStageletContext ctx, IOperatorEnvironment env,
+    private IOperatorNodePushable createSelfReadingMapper(final IHyracksTaskContext ctx, IOperatorEnvironment env,
             final RecordDescriptor recordDescriptor, final int partition) {
         return new AbstractUnaryOutputSourceOperatorNodePushable() {
             @Override
diff --git a/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopReadOperatorDescriptor.java b/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopReadOperatorDescriptor.java
index 915d09b..52f0c8a 100644
--- a/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopReadOperatorDescriptor.java
+++ b/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopReadOperatorDescriptor.java
@@ -32,7 +32,7 @@
 import org.apache.hadoop.util.ReflectionUtils;
 
 import edu.uci.ics.hyracks.api.constraints.PartitionConstraintHelper;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -143,7 +143,7 @@
 
     @SuppressWarnings("deprecation")
     @Override
-    public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, IOperatorEnvironment env,
             final IRecordDescriptorProvider recordDescProvider, final int partition, int nPartitions)
             throws HyracksDataException {
         return new AbstractUnaryOutputSourceOperatorNodePushable() {
diff --git a/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopReducerOperatorDescriptor.java b/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopReducerOperatorDescriptor.java
index 2d44c79..0e05997 100644
--- a/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopReducerOperatorDescriptor.java
+++ b/hyracks-dataflow-hadoop/src/main/java/edu/uci/ics/hyracks/dataflow/hadoop/HadoopReducerOperatorDescriptor.java
@@ -34,7 +34,7 @@
 import org.apache.hadoop.util.Progress;
 import org.apache.hadoop.util.ReflectionUtils;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IDataReader;
 import edu.uci.ics.hyracks.api.dataflow.IDataWriter;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
@@ -335,7 +335,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         try {
             if (this.comparatorFactory == null) {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/aggregators/MultiAggregatorFactory.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/aggregators/MultiAggregatorFactory.java
index 957c453..dc89abe 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/aggregators/MultiAggregatorFactory.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/aggregators/MultiAggregatorFactory.java
@@ -17,7 +17,7 @@
 import java.io.DataOutput;
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
@@ -36,7 +36,7 @@
     }
 
     @Override
-    public ISpillableAccumulatingAggregator createSpillableAggregator(IHyracksStageletContext ctx,
+    public ISpillableAccumulatingAggregator createSpillableAggregator(IHyracksTaskContext ctx,
             RecordDescriptor inRecordDesc, final RecordDescriptor outRecordDescriptor) {
         final ISpillableFieldValueResultingAggregator aggregators[] = new ISpillableFieldValueResultingAggregator[aFactories.length];
         for (int i = 0; i < aFactories.length; ++i) {
@@ -122,7 +122,7 @@
     }
 
     @Override
-    public IAccumulatingAggregator createAggregator(IHyracksStageletContext ctx, RecordDescriptor inRecordDesc,
+    public IAccumulatingAggregator createAggregator(IHyracksTaskContext ctx, RecordDescriptor inRecordDesc,
             RecordDescriptor outRecordDescriptor) throws HyracksDataException {
         final IFieldValueResultingAggregator aggregators[] = new IFieldValueResultingAggregator[aFactories.length];
         for (int i = 0; i < aFactories.length; ++i) {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractConnectorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractConnectorDescriptor.java
index 0eebd93..19965b9 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractConnectorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractConnectorDescriptor.java
@@ -19,10 +19,10 @@
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import edu.uci.ics.hyracks.api.constraints.IConstraintExpressionAcceptor;
+import edu.uci.ics.hyracks.api.constraints.IConstraintAcceptor;
 import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
 import edu.uci.ics.hyracks.api.dataflow.IConnectorDescriptor;
-import edu.uci.ics.hyracks.api.job.JobPlan;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
 
 public abstract class AbstractConnectorDescriptor implements IConnectorDescriptor {
@@ -50,7 +50,7 @@
     }
 
     @Override
-    public void contributeSchedulingConstraints(IConstraintExpressionAcceptor constraintAcceptor, JobPlan plan) {
+    public void contributeSchedulingConstraints(IConstraintAcceptor constraintAcceptor, JobActivityGraph plan) {
         // do nothing
     }
 }
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractMToNConnectorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractMToNConnectorDescriptor.java
new file mode 100644
index 0000000..aa550ae
--- /dev/null
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractMToNConnectorDescriptor.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.dataflow.std.base;
+
+import java.util.BitSet;
+
+import edu.uci.ics.hyracks.api.job.JobSpecification;
+
+public abstract class AbstractMToNConnectorDescriptor extends AbstractConnectorDescriptor {
+    private static final long serialVersionUID = 1L;
+
+    public AbstractMToNConnectorDescriptor(JobSpecification spec) {
+        super(spec);
+    }
+
+    @Override
+    public void indicateTargetPartitions(int nProducerPartitions, int nConsumerPartitions, int producerIndex,
+            BitSet targetBitmap) {
+        targetBitmap.clear();
+        targetBitmap.set(0, nConsumerPartitions);
+    }
+}
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractOperatorDescriptor.java
index 7e97975..8b16068 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/base/AbstractOperatorDescriptor.java
@@ -19,11 +19,11 @@
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import edu.uci.ics.hyracks.api.constraints.IConstraintExpressionAcceptor;
+import edu.uci.ics.hyracks.api.constraints.IConstraintAcceptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
-import edu.uci.ics.hyracks.api.job.JobPlan;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
 
 public abstract class AbstractOperatorDescriptor implements IOperatorDescriptor {
@@ -68,7 +68,7 @@
     }
 
     @Override
-    public void contributeSchedulingConstraints(IConstraintExpressionAcceptor constraintAcceptor, JobPlan plan) {
+    public void contributeSchedulingConstraints(IConstraintAcceptor constraintAcceptor, JobActivityGraph plan) {
         // do nothing
     }
 
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNHashPartitioningConnectorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNHashPartitioningConnectorDescriptor.java
deleted file mode 100644
index 882ee16..0000000
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNHashPartitioningConnectorDescriptor.java
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.dataflow.std.connectors;
-
-import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
-import edu.uci.ics.hyracks.api.comm.IEndpointDataWriterFactory;
-import edu.uci.ics.hyracks.api.comm.IFrameReader;
-import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.dataflow.value.ITuplePartitionComputerFactory;
-import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.job.JobSpecification;
-import edu.uci.ics.hyracks.dataflow.common.comm.NonDeterministicFrameReader;
-import edu.uci.ics.hyracks.dataflow.std.base.AbstractConnectorDescriptor;
-
-public class MToNHashPartitioningConnectorDescriptor extends AbstractConnectorDescriptor {
-    private static final long serialVersionUID = 1L;
-    private ITuplePartitionComputerFactory tpcf;
-
-    public MToNHashPartitioningConnectorDescriptor(JobSpecification spec, ITuplePartitionComputerFactory tpcf) {
-        super(spec);
-        this.tpcf = tpcf;
-    }
-
-    @Override
-    public IFrameWriter createSendSideWriter(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IEndpointDataWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
-            throws HyracksDataException {
-        final HashDataWriter hashWriter = new HashDataWriter(ctx, nConsumerPartitions, edwFactory, recordDesc,
-                tpcf.createPartitioner());
-        return hashWriter;
-    }
-
-    @Override
-    public IFrameReader createReceiveSideReader(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IConnectionDemultiplexer demux, int index, int nProducerPartitions, int nConsumerPartitions)
-            throws HyracksDataException {
-        return new NonDeterministicFrameReader(ctx, demux);
-    }
-}
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNHashPartitioningMergingConnectorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNHashPartitioningMergingConnectorDescriptor.java
deleted file mode 100644
index 5e73e23..0000000
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNHashPartitioningMergingConnectorDescriptor.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.dataflow.std.connectors;
-
-import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
-import edu.uci.ics.hyracks.api.comm.IEndpointDataWriterFactory;
-import edu.uci.ics.hyracks.api.comm.IFrameReader;
-import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
-import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
-import edu.uci.ics.hyracks.api.dataflow.value.ITuplePartitionComputerFactory;
-import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.job.JobSpecification;
-import edu.uci.ics.hyracks.dataflow.common.comm.SortMergeFrameReader;
-import edu.uci.ics.hyracks.dataflow.std.base.AbstractConnectorDescriptor;
-
-public class MToNHashPartitioningMergingConnectorDescriptor extends AbstractConnectorDescriptor {
-    private static final long serialVersionUID = 1L;
-
-    private final ITuplePartitionComputerFactory tpcf;
-    private final int[] sortFields;
-    private final IBinaryComparatorFactory[] comparatorFactories;
-
-    public MToNHashPartitioningMergingConnectorDescriptor(JobSpecification spec, ITuplePartitionComputerFactory tpcf,
-            int[] sortFields, IBinaryComparatorFactory[] comparatorFactories) {
-        super(spec);
-        this.tpcf = tpcf;
-        this.sortFields = sortFields;
-        this.comparatorFactories = comparatorFactories;
-    }
-
-    @Override
-    public IFrameWriter createSendSideWriter(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IEndpointDataWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
-            throws HyracksDataException {
-        final HashDataWriter hashWriter = new HashDataWriter(ctx, nConsumerPartitions, edwFactory, recordDesc,
-                tpcf.createPartitioner());
-        return hashWriter;
-    }
-
-    @Override
-    public IFrameReader createReceiveSideReader(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IConnectionDemultiplexer demux, int index, int nProducerPartitions, int nConsumerPartitions)
-            throws HyracksDataException {
-        IBinaryComparator[] comparators = new IBinaryComparator[comparatorFactories.length];
-        for (int i = 0; i < comparatorFactories.length; ++i) {
-            comparators[i] = comparatorFactories[i].createBinaryComparator();
-        }
-        return new SortMergeFrameReader(ctx, demux, sortFields, comparators, recordDesc);
-    }
-}
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNPartitioningConnectorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNPartitioningConnectorDescriptor.java
new file mode 100644
index 0000000..6037393
--- /dev/null
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNPartitioningConnectorDescriptor.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.dataflow.std.connectors;
+
+import java.util.BitSet;
+
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.comm.IPartitionCollector;
+import edu.uci.ics.hyracks.api.comm.IPartitionWriterFactory;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.value.ITuplePartitionComputerFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.job.JobSpecification;
+import edu.uci.ics.hyracks.dataflow.common.comm.NonDeterministicPartitionCollector;
+import edu.uci.ics.hyracks.dataflow.std.base.AbstractMToNConnectorDescriptor;
+
+public class MToNPartitioningConnectorDescriptor extends AbstractMToNConnectorDescriptor {
+    private static final long serialVersionUID = 1L;
+    private ITuplePartitionComputerFactory tpcf;
+
+    public MToNPartitioningConnectorDescriptor(JobSpecification spec, ITuplePartitionComputerFactory tpcf) {
+        super(spec);
+        this.tpcf = tpcf;
+    }
+
+    @Override
+    public IFrameWriter createPartitioner(IHyracksTaskContext ctx, RecordDescriptor recordDesc,
+            IPartitionWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
+            throws HyracksDataException {
+        final PartitionDataWriter hashWriter = new PartitionDataWriter(ctx, nConsumerPartitions, edwFactory,
+                recordDesc, tpcf.createPartitioner());
+        return hashWriter;
+    }
+
+    @Override
+    public IPartitionCollector createPartitionCollector(IHyracksTaskContext ctx, RecordDescriptor recordDesc,
+            int index, int nProducerPartitions, int nConsumerPartitions) throws HyracksDataException {
+        BitSet expectedPartitions = new BitSet(nProducerPartitions);
+        expectedPartitions.set(0, nProducerPartitions);
+        return new NonDeterministicPartitionCollector(ctx, getConnectorId(), index, expectedPartitions);
+    }
+}
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNPartitioningMergingConnectorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNPartitioningMergingConnectorDescriptor.java
new file mode 100644
index 0000000..a8bcfa5
--- /dev/null
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNPartitioningMergingConnectorDescriptor.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.dataflow.std.connectors;
+
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.comm.IPartitionCollector;
+import edu.uci.ics.hyracks.api.comm.IPartitionWriterFactory;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.ITuplePartitionComputerFactory;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.job.JobSpecification;
+import edu.uci.ics.hyracks.dataflow.common.comm.SortMergePartitionCollector;
+import edu.uci.ics.hyracks.dataflow.std.base.AbstractMToNConnectorDescriptor;
+
+public class MToNPartitioningMergingConnectorDescriptor extends AbstractMToNConnectorDescriptor {
+    private static final long serialVersionUID = 1L;
+
+    private final ITuplePartitionComputerFactory tpcf;
+    private final int[] sortFields;
+    private final IBinaryComparatorFactory[] comparatorFactories;
+
+    public MToNPartitioningMergingConnectorDescriptor(JobSpecification spec, ITuplePartitionComputerFactory tpcf,
+            int[] sortFields, IBinaryComparatorFactory[] comparatorFactories) {
+        super(spec);
+        this.tpcf = tpcf;
+        this.sortFields = sortFields;
+        this.comparatorFactories = comparatorFactories;
+    }
+
+    @Override
+    public IFrameWriter createPartitioner(IHyracksTaskContext ctx, RecordDescriptor recordDesc,
+            IPartitionWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
+            throws HyracksDataException {
+        final PartitionDataWriter hashWriter = new PartitionDataWriter(ctx, nConsumerPartitions, edwFactory,
+                recordDesc, tpcf.createPartitioner());
+        return hashWriter;
+    }
+
+    @Override
+    public IPartitionCollector createPartitionCollector(IHyracksTaskContext ctx, RecordDescriptor recordDesc,
+            int index, int nProducerPartitions, int nConsumerPartitions) throws HyracksDataException {
+        IBinaryComparator[] comparators = new IBinaryComparator[comparatorFactories.length];
+        for (int i = 0; i < comparatorFactories.length; ++i) {
+            comparators[i] = comparatorFactories[i].createBinaryComparator();
+        }
+        return new SortMergePartitionCollector(ctx, getConnectorId(), index, sortFields, comparators, recordDesc,
+                nProducerPartitions, nProducerPartitions);
+    }
+}
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNRangePartitioningConnectorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNRangePartitioningConnectorDescriptor.java
deleted file mode 100644
index e085f29..0000000
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNRangePartitioningConnectorDescriptor.java
+++ /dev/null
@@ -1,144 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package edu.uci.ics.hyracks.dataflow.std.connectors;
-
-import java.io.IOException;
-import java.nio.ByteBuffer;
-
-import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
-import edu.uci.ics.hyracks.api.comm.IEndpointDataWriterFactory;
-import edu.uci.ics.hyracks.api.comm.IFrameReader;
-import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
-import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.job.JobSpecification;
-import edu.uci.ics.hyracks.dataflow.common.comm.NonDeterministicFrameReader;
-import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
-import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
-import edu.uci.ics.hyracks.dataflow.std.base.AbstractConnectorDescriptor;
-
-public class MToNRangePartitioningConnectorDescriptor extends AbstractConnectorDescriptor {
-    private static final long serialVersionUID = 1L;
-
-    private class RangeDataWriter implements IFrameWriter {
-        private final IFrameWriter[] epWriters;
-        private final FrameTupleAppender[] appenders;
-        private final FrameTupleAccessor tupleAccessor;
-
-        public RangeDataWriter(IHyracksStageletContext ctx, int consumerPartitionCount, IFrameWriter[] epWriters,
-                FrameTupleAppender[] appenders, RecordDescriptor recordDescriptor) {
-            this.epWriters = epWriters;
-            this.appenders = appenders;
-            tupleAccessor = new FrameTupleAccessor(ctx.getFrameSize(), recordDescriptor);
-        }
-
-        @Override
-        public void close() throws HyracksDataException {
-            for (int i = 0; i < epWriters.length; ++i) {
-                if (appenders[i].getTupleCount() > 0) {
-                    flushFrame(appenders[i].getBuffer(), epWriters[i]);
-                }
-                epWriters[i].close();
-            }
-        }
-
-        private void flushFrame(ByteBuffer buffer, IFrameWriter frameWriter) throws HyracksDataException {
-            buffer.position(0);
-            buffer.limit(buffer.capacity());
-            frameWriter.nextFrame(buffer);
-        }
-
-        @Override
-        public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
-            if (true) {
-                throw new UnsupportedOperationException();
-            }
-            tupleAccessor.reset(buffer);
-            int slotLength = tupleAccessor.getFieldSlotsLength();
-            int tupleCount = tupleAccessor.getTupleCount();
-            for (int i = 0; i < tupleCount; ++i) {
-                int startOffset = tupleAccessor.getTupleStartOffset(i);
-                int fStart = tupleAccessor.getFieldStartOffset(i, partitioningField);
-                int fEnd = tupleAccessor.getFieldEndOffset(i, partitioningField);
-                int h = 0;
-                FrameTupleAppender appender = appenders[h];
-                if (!appender.append(tupleAccessor, i)) {
-                    ByteBuffer appenderBuffer = appender.getBuffer();
-                    flushFrame(appenderBuffer, epWriters[h]);
-                    appender.reset(appenderBuffer, true);
-                }
-            }
-        }
-
-        @Override
-        public void open() throws HyracksDataException {
-            for (int i = 0; i < epWriters.length; ++i) {
-                epWriters[i].open();
-                appenders[i].reset(appenders[i].getBuffer(), true);
-            }
-        }
-
-        @Override
-        public void flush() throws HyracksDataException {
-            for (int i = 0; i < appenders.length; ++i) {
-                FrameTupleAppender appender = appenders[i];
-                if (appender.getTupleCount() > 0) {
-                    ByteBuffer buffer = appender.getBuffer();
-                    IFrameWriter frameWriter = epWriters[i];
-                    flushFrame(buffer, frameWriter);
-                    epWriters[i].flush();
-                    appender.reset(buffer, true);
-                }
-            }
-        }
-    }
-
-    private final int partitioningField;
-    private final Object[] splitVector;
-
-    public MToNRangePartitioningConnectorDescriptor(JobSpecification spec, int partitioningField, Object[] splitVector) {
-        super(spec);
-        this.partitioningField = partitioningField;
-        this.splitVector = splitVector;
-    }
-
-    @Override
-    public IFrameWriter createSendSideWriter(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IEndpointDataWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
-            throws HyracksDataException {
-        final IFrameWriter[] epWriters = new IFrameWriter[nConsumerPartitions];
-        final FrameTupleAppender[] appenders = new FrameTupleAppender[nConsumerPartitions];
-        for (int i = 0; i < nConsumerPartitions; ++i) {
-            try {
-                epWriters[i] = edwFactory.createFrameWriter(i);
-                appenders[i] = new FrameTupleAppender(ctx.getFrameSize());
-                appenders[i].reset(ctx.allocateFrame(), true);
-            } catch (IOException e) {
-                throw new HyracksDataException(e);
-            }
-        }
-        final RangeDataWriter rangeWriter = new RangeDataWriter(ctx, nConsumerPartitions, epWriters, appenders,
-                recordDesc);
-        return rangeWriter;
-    }
-
-    @Override
-    public IFrameReader createReceiveSideReader(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IConnectionDemultiplexer demux, int index, int nProducerPartitions, int nConsumerPartitions)
-            throws HyracksDataException {
-        return new NonDeterministicFrameReader(ctx, demux);
-    }
-}
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNReplicatingConnectorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNReplicatingConnectorDescriptor.java
index deb8d8d..957734c 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNReplicatingConnectorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/MToNReplicatingConnectorDescriptor.java
@@ -15,19 +15,19 @@
 package edu.uci.ics.hyracks.dataflow.std.connectors;
 
 import java.nio.ByteBuffer;
+import java.util.BitSet;
 
-import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
-import edu.uci.ics.hyracks.api.comm.IEndpointDataWriterFactory;
-import edu.uci.ics.hyracks.api.comm.IFrameReader;
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.comm.IPartitionCollector;
+import edu.uci.ics.hyracks.api.comm.IPartitionWriterFactory;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
-import edu.uci.ics.hyracks.dataflow.common.comm.NonDeterministicFrameReader;
-import edu.uci.ics.hyracks.dataflow.std.base.AbstractConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.common.comm.NonDeterministicPartitionCollector;
+import edu.uci.ics.hyracks.dataflow.std.base.AbstractMToNConnectorDescriptor;
 
-public class MToNReplicatingConnectorDescriptor extends AbstractConnectorDescriptor {
+public class MToNReplicatingConnectorDescriptor extends AbstractMToNConnectorDescriptor {
     public MToNReplicatingConnectorDescriptor(JobSpecification spec) {
         super(spec);
     }
@@ -35,8 +35,8 @@
     private static final long serialVersionUID = 1L;
 
     @Override
-    public IFrameWriter createSendSideWriter(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IEndpointDataWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
+    public IFrameWriter createPartitioner(IHyracksTaskContext ctx, RecordDescriptor recordDesc,
+            IPartitionWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
             throws HyracksDataException {
         final IFrameWriter[] epWriters = new IFrameWriter[nConsumerPartitions];
         for (int i = 0; i < nConsumerPartitions; ++i) {
@@ -78,9 +78,10 @@
     }
 
     @Override
-    public IFrameReader createReceiveSideReader(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IConnectionDemultiplexer demux, int index, int nProducerPartitions, int nConsumerPartitions)
-            throws HyracksDataException {
-        return new NonDeterministicFrameReader(ctx, demux);
+    public IPartitionCollector createPartitionCollector(IHyracksTaskContext ctx, RecordDescriptor recordDesc,
+            int index, int nProducerPartitions, int nConsumerPartitions) throws HyracksDataException {
+        BitSet expectedPartitions = new BitSet(nProducerPartitions);
+        expectedPartitions.set(0, nProducerPartitions);
+        return new NonDeterministicPartitionCollector(ctx, getConnectorId(), index, expectedPartitions);
     }
 }
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/OneToOneConnectorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/OneToOneConnectorDescriptor.java
index 640ce35..a15a64f 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/OneToOneConnectorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/OneToOneConnectorDescriptor.java
@@ -14,20 +14,21 @@
  */
 package edu.uci.ics.hyracks.dataflow.std.connectors;
 
-import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
-import edu.uci.ics.hyracks.api.comm.IEndpointDataWriterFactory;
-import edu.uci.ics.hyracks.api.comm.IFrameReader;
+import java.util.BitSet;
+
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.constraints.IConstraintExpressionAcceptor;
+import edu.uci.ics.hyracks.api.comm.IPartitionCollector;
+import edu.uci.ics.hyracks.api.comm.IPartitionWriterFactory;
+import edu.uci.ics.hyracks.api.constraints.Constraint;
+import edu.uci.ics.hyracks.api.constraints.IConstraintAcceptor;
 import edu.uci.ics.hyracks.api.constraints.expressions.PartitionCountExpression;
-import edu.uci.ics.hyracks.api.constraints.expressions.RelationalExpression;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.job.JobPlan;
+import edu.uci.ics.hyracks.api.job.JobActivityGraph;
 import edu.uci.ics.hyracks.api.job.JobSpecification;
-import edu.uci.ics.hyracks.dataflow.common.comm.NonDeterministicFrameReader;
+import edu.uci.ics.hyracks.dataflow.common.comm.NonDeterministicPartitionCollector;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractConnectorDescriptor;
 
 public class OneToOneConnectorDescriptor extends AbstractConnectorDescriptor {
@@ -38,27 +39,34 @@
     }
 
     @Override
-    public IFrameWriter createSendSideWriter(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IEndpointDataWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
+    public IFrameWriter createPartitioner(IHyracksTaskContext ctx, RecordDescriptor recordDesc,
+            IPartitionWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
             throws HyracksDataException {
         return edwFactory.createFrameWriter(index);
     }
 
     @Override
-    public IFrameReader createReceiveSideReader(IHyracksStageletContext ctx, RecordDescriptor recordDesc,
-            IConnectionDemultiplexer demux, int index, int nProducerPartitions, int nConsumerPartitions)
-            throws HyracksDataException {
-        return new NonDeterministicFrameReader(ctx, demux);
+    public IPartitionCollector createPartitionCollector(IHyracksTaskContext ctx, RecordDescriptor recordDesc,
+            int index, int nProducerPartitions, int nConsumerPartitions) throws HyracksDataException {
+        BitSet expectedPartitions = new BitSet(nProducerPartitions);
+        expectedPartitions.set(index);
+        return new NonDeterministicPartitionCollector(ctx, getConnectorId(), index, expectedPartitions);
     }
 
     @Override
-    public void contributeSchedulingConstraints(IConstraintExpressionAcceptor constraintAcceptor, JobPlan plan) {
+    public void contributeSchedulingConstraints(IConstraintAcceptor constraintAcceptor, JobActivityGraph plan) {
         JobSpecification jobSpec = plan.getJobSpecification();
         IOperatorDescriptor consumer = jobSpec.getConsumer(this);
         IOperatorDescriptor producer = jobSpec.getProducer(this);
 
-        constraintAcceptor.addConstraintExpression(new RelationalExpression(new PartitionCountExpression(consumer
-                .getOperatorId()), new PartitionCountExpression(producer.getOperatorId()),
-                RelationalExpression.Operator.EQUAL));
+        constraintAcceptor.addConstraint(new Constraint(new PartitionCountExpression(consumer.getOperatorId()),
+                new PartitionCountExpression(producer.getOperatorId())));
+    }
+
+    @Override
+    public void indicateTargetPartitions(int nProducerPartitions, int nConsumerPartitions, int producerIndex,
+            BitSet targetBitmap) {
+        targetBitmap.clear();
+        targetBitmap.set(producerIndex);
     }
 }
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/HashDataWriter.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/PartitionDataWriter.java
similarity index 78%
rename from hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/HashDataWriter.java
rename to hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/PartitionDataWriter.java
index 2f1c8e7..7054535 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/HashDataWriter.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/connectors/PartitionDataWriter.java
@@ -17,31 +17,30 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.comm.IEndpointDataWriterFactory;
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.comm.IPartitionWriterFactory;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.ITuplePartitionComputer;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
 
-public class HashDataWriter implements IFrameWriter {
+public class PartitionDataWriter implements IFrameWriter {
     private final int consumerPartitionCount;
-    private final IFrameWriter[] epWriters;
+    private final IFrameWriter[] pWriters;
     private final FrameTupleAppender[] appenders;
     private final FrameTupleAccessor tupleAccessor;
     private final ITuplePartitionComputer tpc;
 
-    public HashDataWriter(IHyracksStageletContext ctx, int consumerPartitionCount,
-            IEndpointDataWriterFactory edwFactory, RecordDescriptor recordDescriptor, ITuplePartitionComputer tpc)
-            throws HyracksDataException {
+    public PartitionDataWriter(IHyracksTaskContext ctx, int consumerPartitionCount, IPartitionWriterFactory pwFactory,
+            RecordDescriptor recordDescriptor, ITuplePartitionComputer tpc) throws HyracksDataException {
         this.consumerPartitionCount = consumerPartitionCount;
-        epWriters = new IFrameWriter[consumerPartitionCount];
+        pWriters = new IFrameWriter[consumerPartitionCount];
         appenders = new FrameTupleAppender[consumerPartitionCount];
         for (int i = 0; i < consumerPartitionCount; ++i) {
             try {
-                epWriters[i] = edwFactory.createFrameWriter(i);
+                pWriters[i] = pwFactory.createFrameWriter(i);
                 appenders[i] = new FrameTupleAppender(ctx.getFrameSize());
                 appenders[i].reset(ctx.allocateFrame(), true);
             } catch (IOException e) {
@@ -54,11 +53,11 @@
 
     @Override
     public void close() throws HyracksDataException {
-        for (int i = 0; i < epWriters.length; ++i) {
+        for (int i = 0; i < pWriters.length; ++i) {
             if (appenders[i].getTupleCount() > 0) {
-                flushFrame(appenders[i].getBuffer(), epWriters[i]);
+                flushFrame(appenders[i].getBuffer(), pWriters[i]);
             }
-            epWriters[i].close();
+            pWriters[i].close();
         }
     }
 
@@ -70,8 +69,8 @@
 
     @Override
     public void open() throws HyracksDataException {
-        for (int i = 0; i < epWriters.length; ++i) {
-            epWriters[i].open();
+        for (int i = 0; i < pWriters.length; ++i) {
+            pWriters[i].open();
             appenders[i].reset(appenders[i].getBuffer(), true);
         }
     }
@@ -85,7 +84,7 @@
             FrameTupleAppender appender = appenders[h];
             if (!appender.append(tupleAccessor, i)) {
                 ByteBuffer appenderBuffer = appender.getBuffer();
-                flushFrame(appenderBuffer, epWriters[h]);
+                flushFrame(appenderBuffer, pWriters[h]);
                 appender.reset(appenderBuffer, true);
                 if (!appender.append(tupleAccessor, i)) {
                     throw new IllegalStateException();
@@ -100,9 +99,9 @@
             FrameTupleAppender appender = appenders[i];
             if (appender.getTupleCount() > 0) {
                 ByteBuffer buffer = appender.getBuffer();
-                IFrameWriter frameWriter = epWriters[i];
+                IFrameWriter frameWriter = pWriters[i];
                 flushFrame(buffer, frameWriter);
-                epWriters[i].flush();
+                pWriters[i].flush();
                 appender.reset(buffer, true);
             }
         }
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/AbstractDeserializedFileScanOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/AbstractDeserializedFileScanOperatorDescriptor.java
index b2265dd..03438d3 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/AbstractDeserializedFileScanOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/AbstractDeserializedFileScanOperatorDescriptor.java
@@ -16,7 +16,7 @@
 
 import java.io.File;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOpenableDataWriter;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
@@ -100,7 +100,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         return new DeserializedOperatorNodePushable(ctx, new DeserializedFileScanOperator(partition), null);
     }
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/AbstractFileWriteOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/AbstractFileWriteOperatorDescriptor.java
index 8e4199b..ae1a722 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/AbstractFileWriteOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/AbstractFileWriteOperatorDescriptor.java
@@ -14,7 +14,7 @@
  */
 package edu.uci.ics.hyracks.dataflow.std.file;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOpenableDataWriter;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
@@ -85,7 +85,7 @@
     protected abstract IRecordWriter createRecordWriter(FileSplit fileSplit, int index) throws Exception;
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         return new DeserializedOperatorNodePushable(ctx, new FileWriteOperator(partition),
                 recordDescProvider.getInputRecordDescriptor(getOperatorId(), 0));
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/DelimitedDataTupleParserFactory.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/DelimitedDataTupleParserFactory.java
index 954d64a..0096576 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/DelimitedDataTupleParserFactory.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/DelimitedDataTupleParserFactory.java
@@ -23,7 +23,7 @@
 import java.util.Arrays;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
@@ -42,7 +42,7 @@
     }
 
     @Override
-    public ITupleParser createTupleParser(final IHyracksStageletContext ctx) {
+    public ITupleParser createTupleParser(final IHyracksTaskContext ctx) {
         return new ITupleParser() {
             @Override
             public void parse(InputStream in, IFrameWriter writer) throws HyracksDataException {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/FileScanOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/FileScanOperatorDescriptor.java
index 7cbb2ed..1d580b1 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/FileScanOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/FileScanOperatorDescriptor.java
@@ -19,7 +19,7 @@
 import java.io.FileNotFoundException;
 import java.io.InputStream;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -45,7 +45,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         final FileSplit split = fileSplitProvider.getFileSplits()[partition];
         final ITupleParser tp = tupleParserFactory.createTupleParser(ctx);
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/FrameFileWriterOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/FrameFileWriterOperatorDescriptor.java
index 1628984..21e197d 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/FrameFileWriterOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/FrameFileWriterOperatorDescriptor.java
@@ -20,7 +20,7 @@
 import java.io.OutputStream;
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
@@ -40,7 +40,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, final int partition, int nPartitions) {
         final FileSplit[] splits = fileSplitProvider.getFileSplits();
         return new AbstractUnaryInputSinkOperatorNodePushable() {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/ITupleParserFactory.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/ITupleParserFactory.java
index a11dae0..eb051f5 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/ITupleParserFactory.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/ITupleParserFactory.java
@@ -16,8 +16,8 @@
 
 import java.io.Serializable;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 
 public interface ITupleParserFactory extends Serializable {
-    public ITupleParser createTupleParser(IHyracksStageletContext ctx);
+    public ITupleParser createTupleParser(IHyracksTaskContext ctx);
 }
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/PlainFileWriterOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/PlainFileWriterOperatorDescriptor.java
index 530207d..cd320dd 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/PlainFileWriterOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/file/PlainFileWriterOperatorDescriptor.java
@@ -20,7 +20,7 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -61,9 +61,9 @@
      * @see edu.uci.ics.hyracks.api.dataflow.IActivityNode#createPushRuntime(edu.uci.ics.hyracks.api.context.IHyracksContext, edu.uci.ics.hyracks.api.job.IOperatorEnvironment, edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider, int, int)
      */
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, final int partition, int nPartitions)
-    throws HyracksDataException {
+            throws HyracksDataException {
         // Output files
         final FileSplit[] splits = fileSplitProvider.getFileSplits();
         // Frame accessor
@@ -95,7 +95,7 @@
                     frameTupleAccessor.reset(buffer);
                     for (int tIndex = 0; tIndex < frameTupleAccessor.getTupleCount(); tIndex++) {
                         int start = frameTupleAccessor.getTupleStartOffset(tIndex)
-                        + frameTupleAccessor.getFieldSlotsLength();
+                                + frameTupleAccessor.getFieldSlotsLength();
                         bbis.setByteBuffer(buffer, start);
                         Object[] record = new Object[recordDescriptor.getFields().length];
                         for (int i = 0; i < record.length; ++i) {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/ExternalHashGroupOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/ExternalHashGroupOperatorDescriptor.java
index b13b087..4257083 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/ExternalHashGroupOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/ExternalHashGroupOperatorDescriptor.java
@@ -24,7 +24,7 @@
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
@@ -198,15 +198,14 @@
         private static final long serialVersionUID = 1L;
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, final IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                final IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             // Create the in-memory hash table
             final SpillableGroupingHashTable gTable = new SpillableGroupingHashTable(ctx, keyFields,
                     comparatorFactories, tpcf, aggregatorFactory, recordDescProvider.getInputRecordDescriptor(
                             getOperatorId(), 0), recordDescriptors[0],
-                            // Always take one frame for the input records
-                            framesLimit - 1, tableSize);
+                    // Always take one frame for the input records
+                    framesLimit - 1, tableSize);
             // Create the tuple accessor
             final FrameTupleAccessor accessor = new FrameTupleAccessor(ctx.getFrameSize(),
                     recordDescProvider.getInputRecordDescriptor(getOperatorId(), 0));
@@ -255,7 +254,7 @@
                             flushFramesToRun();
                             if (!gTable.insert(accessor, i))
                                 throw new HyracksDataException(
-                                "Failed to insert a new buffer into the aggregate operator!");
+                                        "Failed to insert a new buffer into the aggregate operator!");
                         }
                     }
 
@@ -280,7 +279,7 @@
                     gTable.sortFrames();
                     FileReference runFile;
                     try {
-                        runFile = ctx.getJobletContext().createWorkspaceFile(
+                        runFile = ctx.getJobletContext().createManagedWorkspaceFile(
                                 ExternalHashGroupOperatorDescriptor.class.getSimpleName());
                     } catch (IOException e) {
                         throw new HyracksDataException(e);
@@ -319,9 +318,8 @@
         private static final long serialVersionUID = 1L;
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             final IBinaryComparator[] comparators = new IBinaryComparator[comparatorFactories.length];
             for (int i = 0; i < comparatorFactories.length; ++i) {
                 comparators[i] = comparatorFactories[i].createBinaryComparator();
@@ -400,7 +398,7 @@
                  * @throws IOException
                  */
                 private void doPass(LinkedList<RunFileReader> runs, int passCount) throws HyracksDataException,
-                IOException {
+                        IOException {
                     FileReference newRun = null;
                     IFrameWriter writer = this.writer;
                     boolean finalPass = false;
@@ -424,7 +422,7 @@
                         }
                     } else {
                         // Otherwise, a new run file will be created
-                        newRun = ctx.getJobletContext().createWorkspaceFile(
+                        newRun = ctx.getJobletContext().createManagedWorkspaceFile(
                                 ExternalHashGroupOperatorDescriptor.class.getSimpleName());
                         writer = new RunFileWriter(newRun, ctx.getIOManager());
                         writer.open();
@@ -610,7 +608,7 @@
                  * @throws HyracksDataException
                  */
                 private void closeRun(int index, RunFileReader[] runCursors, IFrameTupleAccessor[] tupleAccessor)
-                throws HyracksDataException {
+                        throws HyracksDataException {
                     runCursors[index].close();
                     runCursors[index] = null;
                     tupleAccessor[index] = null;
@@ -673,10 +671,10 @@
                     for (int f = 0; f < keyFields.length; ++f) {
                         int fIdx = keyFields[f];
                         int s1 = fta1.getTupleStartOffset(j1) + fta1.getFieldSlotsLength()
-                        + fta1.getFieldStartOffset(j1, fIdx);
+                                + fta1.getFieldStartOffset(j1, fIdx);
                         int l1 = fta1.getFieldEndOffset(j1, fIdx) - fta1.getFieldStartOffset(j1, fIdx);
                         int s2 = fta2.getTupleStartOffset(j2) + fta2.getFieldSlotsLength()
-                        + fta2.getFieldStartOffset(j2, fIdx);
+                                + fta2.getFieldStartOffset(j2, fIdx);
                         int l2 = fta2.getFieldEndOffset(j2, fIdx) - fta2.getFieldStartOffset(j2, fIdx);
                         int c = comparators[f].compare(b1, s1, l1, b2, s2, l2);
                         if (c != 0) {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/GroupingHashTable.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/GroupingHashTable.java
index 07a5b81..5733c11 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/GroupingHashTable.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/GroupingHashTable.java
@@ -20,7 +20,7 @@
 import java.util.List;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
@@ -60,7 +60,7 @@
     }
 
     private static final int INIT_ACCUMULATORS_SIZE = 8;
-    private final IHyracksStageletContext ctx;
+    private final IHyracksTaskContext ctx;
     private final FrameTupleAppender appender;
     private final List<ByteBuffer> buffers;
     private final Link[] table;
@@ -79,7 +79,7 @@
 
     private final FrameTupleAccessor storedKeysAccessor;
 
-    GroupingHashTable(IHyracksStageletContext ctx, int[] fields, IBinaryComparatorFactory[] comparatorFactories,
+    GroupingHashTable(IHyracksTaskContext ctx, int[] fields, IBinaryComparatorFactory[] comparatorFactories,
             ITuplePartitionComputerFactory tpcf, IAccumulatingAggregatorFactory aggregatorFactory,
             RecordDescriptor inRecordDescriptor, RecordDescriptor outRecordDescriptor, int tableSize) {
         this.ctx = ctx;
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/HashGroupOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/HashGroupOperatorDescriptor.java
index 50d467c..8d92c54 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/HashGroupOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/HashGroupOperatorDescriptor.java
@@ -16,7 +16,7 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
@@ -73,9 +73,8 @@
         private static final long serialVersionUID = 1L;
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, final IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                final IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             final FrameTupleAccessor accessor = new FrameTupleAccessor(ctx.getFrameSize(),
                     recordDescProvider.getInputRecordDescriptor(getOperatorId(), 0));
             return new AbstractUnaryInputSinkOperatorNodePushable() {
@@ -118,7 +117,7 @@
         private static final long serialVersionUID = 1L;
 
         @Override
-        public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, final IOperatorEnvironment env,
+        public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, final IOperatorEnvironment env,
                 IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             return new AbstractUnaryOutputSourceOperatorNodePushable() {
                 @Override
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/IAccumulatingAggregatorFactory.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/IAccumulatingAggregatorFactory.java
index 3fc7d79..5cf94d2 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/IAccumulatingAggregatorFactory.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/IAccumulatingAggregatorFactory.java
@@ -16,14 +16,14 @@
 
 import java.io.Serializable;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 
 public interface IAccumulatingAggregatorFactory extends Serializable {
-    IAccumulatingAggregator createAggregator(IHyracksStageletContext ctx, RecordDescriptor inRecordDesc,
+    IAccumulatingAggregator createAggregator(IHyracksTaskContext ctx, RecordDescriptor inRecordDesc,
             RecordDescriptor outRecordDescriptor) throws HyracksDataException;
 
-    ISpillableAccumulatingAggregator createSpillableAggregator(IHyracksStageletContext ctx,
-            RecordDescriptor inRecordDesc, RecordDescriptor outRecordDescriptor) throws HyracksDataException;
+    ISpillableAccumulatingAggregator createSpillableAggregator(IHyracksTaskContext ctx, RecordDescriptor inRecordDesc,
+            RecordDescriptor outRecordDescriptor) throws HyracksDataException;
 }
\ No newline at end of file
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/PreclusteredGroupOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/PreclusteredGroupOperatorDescriptor.java
index ea86d19..b5568e6 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/PreclusteredGroupOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/PreclusteredGroupOperatorDescriptor.java
@@ -16,7 +16,7 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
@@ -48,7 +48,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) throws HyracksDataException {
         final IBinaryComparator[] comparators = new IBinaryComparator[comparatorFactories.length];
         for (int i = 0; i < comparatorFactories.length; ++i) {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/PreclusteredGroupWriter.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/PreclusteredGroupWriter.java
index 8817113..60a1dc3 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/PreclusteredGroupWriter.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/PreclusteredGroupWriter.java
@@ -17,7 +17,7 @@
 import java.nio.ByteBuffer;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
@@ -37,7 +37,7 @@
     private final FrameTupleAppender appender;
     private boolean first;
 
-    public PreclusteredGroupWriter(IHyracksStageletContext ctx, int[] groupFields, IBinaryComparator[] comparators,
+    public PreclusteredGroupWriter(IHyracksTaskContext ctx, int[] groupFields, IBinaryComparator[] comparators,
             IAccumulatingAggregator aggregator, RecordDescriptor inRecordDesc, IFrameWriter writer) {
         this.groupFields = groupFields;
         this.comparators = comparators;
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/SpillableGroupingHashTable.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/SpillableGroupingHashTable.java
index b3b9f24..4104c5f 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/SpillableGroupingHashTable.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/group/SpillableGroupingHashTable.java
@@ -20,7 +20,7 @@
 import java.util.List;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
@@ -43,7 +43,7 @@
     /**
      * Context.
      */
-    private final IHyracksStageletContext ctx;
+    private final IHyracksTaskContext ctx;
 
     /**
      * Columns for group-by
@@ -164,7 +164,7 @@
      * @param tableSize
      *            The size of the table, which specified the number of partitions of the table.
      */
-    public SpillableGroupingHashTable(IHyracksStageletContext ctx, int[] fields,
+    public SpillableGroupingHashTable(IHyracksTaskContext ctx, int[] fields,
             IBinaryComparatorFactory[] comparatorFactories, ITuplePartitionComputerFactory tpcf,
             IAccumulatingAggregatorFactory aggregatorFactory, RecordDescriptor inRecordDescriptor,
             RecordDescriptor outputRecordDescriptor, int framesLimit, int tableSize) {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/GraceHashJoinOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/GraceHashJoinOperatorDescriptor.java
index bff101e..1e77547 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/GraceHashJoinOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/GraceHashJoinOperatorDescriptor.java
@@ -16,7 +16,7 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
@@ -108,9 +108,8 @@
         }
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, final IRecordDescriptorProvider recordDescProvider, int partition,
-                final int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                final IRecordDescriptorProvider recordDescProvider, int partition, final int nPartitions) {
             final IBinaryComparator[] comparators = new IBinaryComparator[comparatorFactories.length];
             for (int i = 0; i < comparatorFactories.length; ++i) {
                 comparators[i] = comparatorFactories[i].createBinaryComparator();
@@ -151,7 +150,7 @@
                 private void write(int i, ByteBuffer head) throws HyracksDataException {
                     RunFileWriter writer = fWriters[i];
                     if (writer == null) {
-                        FileReference file = ctx.getJobletContext().createWorkspaceFile(partitionsKey);
+                        FileReference file = ctx.getJobletContext().createManagedWorkspaceFile(partitionsKey);
                         writer = new RunFileWriter(file, ctx.getIOManager());
                         writer.open();
                         fWriters[i] = writer;
@@ -208,9 +207,8 @@
         private static final long serialVersionUID = 1L;
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, final IRecordDescriptorProvider recordDescProvider, int partition,
-                final int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                final IRecordDescriptorProvider recordDescProvider, int partition, final int nPartitions) {
             final IBinaryComparator[] comparators = new IBinaryComparator[comparatorFactories.length];
             for (int i = 0; i < comparatorFactories.length; ++i) {
                 comparators[i] = comparatorFactories[i].createBinaryComparator();
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/HybridHashJoinOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/HybridHashJoinOperatorDescriptor.java
index d7c1086..faa7afb 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/HybridHashJoinOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/HybridHashJoinOperatorDescriptor.java
@@ -16,7 +16,7 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
@@ -118,9 +118,8 @@
         }
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                final int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, final int nPartitions) {
             final RecordDescriptor rd0 = recordDescProvider.getInputRecordDescriptor(getOperatorId(), 0);
             final RecordDescriptor rd1 = recordDescProvider.getInputRecordDescriptor(getOperatorId(), 1);
             final IBinaryComparator[] comparators = new IBinaryComparator[comparatorFactories.length];
@@ -279,7 +278,7 @@
                 private void write(int i, ByteBuffer head) throws HyracksDataException {
                     RunFileWriter writer = fWriters[i];
                     if (writer == null) {
-                        FileReference file = ctx.getJobletContext().createWorkspaceFile(relationName);
+                        FileReference file = ctx.getJobletContext().createManagedWorkspaceFile(relationName);
                         writer = new RunFileWriter(file, ctx.getIOManager());
                         writer.open();
                         fWriters[i] = writer;
@@ -306,9 +305,8 @@
         }
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                final int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, final int nPartitions) {
             final RecordDescriptor rd0 = recordDescProvider.getInputRecordDescriptor(getOperatorId(), 0);
             final RecordDescriptor rd1 = recordDescProvider.getInputRecordDescriptor(getOperatorId(), 1);
             final IBinaryComparator[] comparators = new IBinaryComparator[comparatorFactories.length];
@@ -484,7 +482,7 @@
                 private void write(int i, ByteBuffer head) throws HyracksDataException {
                     RunFileWriter writer = sWriters[i];
                     if (writer == null) {
-                        FileReference file = ctx.createWorkspaceFile(largeRelation);
+                        FileReference file = ctx.createManagedWorkspaceFile(largeRelation);
                         writer = new RunFileWriter(file, ctx.getIOManager());
                         writer.open();
                         sWriters[i] = writer;
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoin.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoin.java
index 4d98c6a..a49c21a 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoin.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoin.java
@@ -20,7 +20,7 @@
 import java.util.List;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.ITuplePartitionComputer;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
@@ -38,7 +38,7 @@
     private final FrameTuplePairComparator tpComparator;
     private final ByteBuffer outBuffer;
 
-    public InMemoryHashJoin(IHyracksStageletContext ctx, int tableSize, FrameTupleAccessor accessor0,
+    public InMemoryHashJoin(IHyracksTaskContext ctx, int tableSize, FrameTupleAccessor accessor0,
             ITuplePartitionComputer tpc0, FrameTupleAccessor accessor1, ITuplePartitionComputer tpc1,
             FrameTuplePairComparator comparator) {
         table = new Link[tableSize];
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoinOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoinOperatorDescriptor.java
index 74f0146..6f46932 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoinOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/join/InMemoryHashJoinOperatorDescriptor.java
@@ -16,7 +16,7 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
@@ -79,9 +79,8 @@
         private static final long serialVersionUID = 1L;
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             final RecordDescriptor rd0 = recordDescProvider.getInputRecordDescriptor(getOperatorId(), 0);
             final RecordDescriptor rd1 = recordDescProvider.getInputRecordDescriptor(getOperatorId(), 1);
             final IBinaryComparator[] comparators = new IBinaryComparator[comparatorFactories.length];
@@ -131,9 +130,8 @@
         private static final long serialVersionUID = 1L;
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             IOperatorNodePushable op = new AbstractUnaryInputUnaryOutputOperatorNodePushable() {
                 private InMemoryHashJoin joiner;
 
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/map/DeserializedMapperOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/map/DeserializedMapperOperatorDescriptor.java
index 37b5165..a142c94 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/map/DeserializedMapperOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/map/DeserializedMapperOperatorDescriptor.java
@@ -14,7 +14,7 @@
  */
 package edu.uci.ics.hyracks.dataflow.std.map;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOpenableDataWriter;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
@@ -69,7 +69,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         return new DeserializedOperatorNodePushable(ctx, new MapperOperator(),
                 recordDescProvider.getInputRecordDescriptor(getOperatorId(), 0));
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/ConstantTupleSourceOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/ConstantTupleSourceOperatorDescriptor.java
index 4ec6393..48e53b5 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/ConstantTupleSourceOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/ConstantTupleSourceOperatorDescriptor.java
@@ -14,7 +14,7 @@
  */
 package edu.uci.ics.hyracks.dataflow.std.misc;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -41,7 +41,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) throws HyracksDataException {
         return new ConstantTupleSourceOperatorNodePushable(ctx, fieldSlots, tupleData, tupleSize);
     }
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/ConstantTupleSourceOperatorNodePushable.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/ConstantTupleSourceOperatorNodePushable.java
index 8784d4a..cf46c0c 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/ConstantTupleSourceOperatorNodePushable.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/ConstantTupleSourceOperatorNodePushable.java
@@ -17,20 +17,20 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
 import edu.uci.ics.hyracks.dataflow.common.comm.util.FrameUtils;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractUnaryOutputSourceOperatorNodePushable;
 
 public class ConstantTupleSourceOperatorNodePushable extends AbstractUnaryOutputSourceOperatorNodePushable {
-    private IHyracksStageletContext ctx;
+    private IHyracksTaskContext ctx;
 
     private int[] fieldSlots;
     private byte[] tupleData;
     private int tupleSize;
 
-    public ConstantTupleSourceOperatorNodePushable(IHyracksStageletContext ctx, int[] fieldSlots, byte[] tupleData,
+    public ConstantTupleSourceOperatorNodePushable(IHyracksTaskContext ctx, int[] fieldSlots, byte[] tupleData,
             int tupleSize) {
         super();
         this.fieldSlots = fieldSlots;
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/MaterializingOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/MaterializingOperatorDescriptor.java
index 23c6385..f4fb240 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/MaterializingOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/MaterializingOperatorDescriptor.java
@@ -16,7 +16,7 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
@@ -60,15 +60,14 @@
         private static final long serialVersionUID = 1L;
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             return new AbstractUnaryInputSinkOperatorNodePushable() {
                 private RunFileWriter out;
 
                 @Override
                 public void open() throws HyracksDataException {
-                    FileReference file = ctx.getJobletContext().createWorkspaceFile(
+                    FileReference file = ctx.getJobletContext().createManagedWorkspaceFile(
                             MaterializingOperatorDescriptor.class.getSimpleName());
                     out = new RunFileWriter(file, ctx.getIOManager());
                     out.open();
@@ -101,9 +100,8 @@
         private static final long serialVersionUID = 1L;
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             return new AbstractUnaryOutputSourceOperatorNodePushable() {
                 @Override
                 public void initialize() throws HyracksDataException {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/NullSinkOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/NullSinkOperatorDescriptor.java
index 4bc4a7f..5a4ea37 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/NullSinkOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/NullSinkOperatorDescriptor.java
@@ -16,7 +16,7 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
@@ -33,7 +33,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         return new AbstractUnaryInputSinkOperatorNodePushable() {
             @Override
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/PrinterOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/PrinterOperatorDescriptor.java
index 7f097e0..fb02cec 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/PrinterOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/PrinterOperatorDescriptor.java
@@ -14,7 +14,7 @@
  */
 package edu.uci.ics.hyracks.dataflow.std.misc;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOpenableDataWriter;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
@@ -57,7 +57,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         return new DeserializedOperatorNodePushable(ctx, new PrinterOperator(),
                 recordDescProvider.getInputRecordDescriptor(getOperatorId(), 0));
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/SplitVectorOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/SplitVectorOperatorDescriptor.java
index 5b1acd5..a12e49e 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/SplitVectorOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/misc/SplitVectorOperatorDescriptor.java
@@ -17,7 +17,7 @@
 import java.util.ArrayList;
 import java.util.List;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
 import edu.uci.ics.hyracks.api.dataflow.IOpenableDataWriter;
@@ -48,7 +48,7 @@
         }
 
         @Override
-        public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, final IOperatorEnvironment env,
+        public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, final IOperatorEnvironment env,
                 IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             IOpenableDataWriterOperator op = new IOpenableDataWriterOperator() {
                 private ArrayList<Object[]> buffer;
@@ -88,7 +88,7 @@
         }
 
         @Override
-        public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, final IOperatorEnvironment env,
+        public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, final IOperatorEnvironment env,
                 IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             IOpenableDataWriterOperator op = new IOpenableDataWriterOperator() {
                 private IOpenableDataWriter<Object[]> writer;
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortOperatorDescriptor.java
index fd1d96e..c860b2b 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortOperatorDescriptor.java
@@ -17,7 +17,7 @@
 import java.nio.ByteBuffer;
 import java.util.List;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
@@ -86,9 +86,8 @@
         }
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             final ExternalSortRunGenerator runGen = new ExternalSortRunGenerator(ctx, sortFields,
                     firstKeyNormalizerFactory, comparatorFactories, recordDescriptors[0], framesLimit);
             IOperatorNodePushable op = new AbstractUnaryInputSinkOperatorNodePushable() {
@@ -127,9 +126,8 @@
         }
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             IOperatorNodePushable op = new AbstractUnaryOutputSourceOperatorNodePushable() {
                 @Override
                 public void initialize() throws HyracksDataException {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortRunGenerator.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortRunGenerator.java
index 50b968a..742a5f9 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortRunGenerator.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortRunGenerator.java
@@ -19,7 +19,7 @@
 import java.util.List;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.INormalizedKeyComputerFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -29,12 +29,12 @@
 import edu.uci.ics.hyracks.dataflow.common.io.RunFileWriter;
 
 public class ExternalSortRunGenerator implements IFrameWriter {
-    private final IHyracksStageletContext ctx;
+    private final IHyracksTaskContext ctx;
     private final FrameSorter frameSorter;
     private final List<RunFileReader> runs;
     private final int maxSortFrames;
 
-    public ExternalSortRunGenerator(IHyracksStageletContext ctx, int[] sortFields,
+    public ExternalSortRunGenerator(IHyracksTaskContext ctx, int[] sortFields,
             INormalizedKeyComputerFactory firstKeyNormalizerFactory, IBinaryComparatorFactory[] comparatorFactories,
             RecordDescriptor recordDesc, int framesLimit) {
         this.ctx = ctx;
@@ -70,7 +70,8 @@
 
     private void flushFramesToRun() throws HyracksDataException {
         frameSorter.sortFrames();
-        FileReference file = ctx.getJobletContext().createWorkspaceFile(ExternalSortRunGenerator.class.getSimpleName());
+        FileReference file = ctx.getJobletContext().createManagedWorkspaceFile(
+                ExternalSortRunGenerator.class.getSimpleName());
         RunFileWriter writer = new RunFileWriter(file, ctx.getIOManager());
         writer.open();
         try {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortRunMerger.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortRunMerger.java
index 19f3b7c..096adaa 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortRunMerger.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/ExternalSortRunMerger.java
@@ -21,7 +21,7 @@
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -36,7 +36,7 @@
 import edu.uci.ics.hyracks.dataflow.std.util.ReferencedPriorityQueue;
 
 public class ExternalSortRunMerger {
-    private final IHyracksStageletContext ctx;
+    private final IHyracksTaskContext ctx;
     private final FrameSorter frameSorter;
     private final List<RunFileReader> runs;
     private final int[] sortFields;
@@ -48,7 +48,7 @@
     private ByteBuffer outFrame;
     private FrameTupleAppender outFrameAppender;
 
-    public ExternalSortRunMerger(IHyracksStageletContext ctx, FrameSorter frameSorter, List<RunFileReader> runs,
+    public ExternalSortRunMerger(IHyracksTaskContext ctx, FrameSorter frameSorter, List<RunFileReader> runs,
             int[] sortFields, IBinaryComparatorFactory[] comparatorFactories, RecordDescriptor recordDesc,
             int framesLimit, IFrameWriter writer) {
         this.ctx = ctx;
@@ -116,7 +116,7 @@
                 inFrames.remove(i);
             }
         } else {
-            newRun = ctx.createWorkspaceFile(ExternalSortRunMerger.class.getSimpleName());
+            newRun = ctx.createManagedWorkspaceFile(ExternalSortRunMerger.class.getSimpleName());
             writer = new RunFileWriter(newRun, ctx.getIOManager());
             writer.open();
         }
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/InMemorySortOperatorDescriptor.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/InMemorySortOperatorDescriptor.java
index 3d41e18..afa27ba 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/InMemorySortOperatorDescriptor.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/sort/InMemorySortOperatorDescriptor.java
@@ -16,7 +16,7 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IActivityGraphBuilder;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorDescriptor;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
@@ -78,9 +78,8 @@
         }
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             final FrameSorter frameSorter = new FrameSorter(ctx, sortFields, firstKeyNormalizerFactory,
                     comparatorFactories, recordDescriptors[0]);
             IOperatorNodePushable op = new AbstractUnaryInputSinkOperatorNodePushable() {
@@ -117,9 +116,8 @@
         }
 
         @Override
-        public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx,
-                final IOperatorEnvironment env, IRecordDescriptorProvider recordDescProvider, int partition,
-                int nPartitions) {
+        public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
+                IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
             IOperatorNodePushable op = new AbstractUnaryOutputSourceOperatorNodePushable() {
                 @Override
                 public void initialize() throws HyracksDataException {
diff --git a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/util/DeserializedOperatorNodePushable.java b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/util/DeserializedOperatorNodePushable.java
index 6660a60..b2c6feb 100644
--- a/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/util/DeserializedOperatorNodePushable.java
+++ b/hyracks-dataflow-std/src/main/java/edu/uci/ics/hyracks/dataflow/std/util/DeserializedOperatorNodePushable.java
@@ -17,7 +17,7 @@
 import java.nio.ByteBuffer;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameDeserializer;
@@ -26,13 +26,13 @@
 import edu.uci.ics.hyracks.dataflow.std.base.IOpenableDataWriterOperator;
 
 public final class DeserializedOperatorNodePushable extends AbstractUnaryInputOperatorNodePushable {
-    private final IHyracksStageletContext ctx;
+    private final IHyracksTaskContext ctx;
 
     private final IOpenableDataWriterOperator delegate;
 
     private final FrameDeserializer deserializer;
 
-    public DeserializedOperatorNodePushable(IHyracksStageletContext ctx, IOpenableDataWriterOperator delegate,
+    public DeserializedOperatorNodePushable(IHyracksTaskContext ctx, IOpenableDataWriterOperator delegate,
             RecordDescriptor inRecordDesc) {
         this.ctx = ctx;
         this.delegate = delegate;
diff --git a/hyracks-examples/btree-example/btreeclient/src/main/java/edu/uci/ics/hyracks/examples/btree/client/InsertPipelineExample.java b/hyracks-examples/btree-example/btreeclient/src/main/java/edu/uci/ics/hyracks/examples/btree/client/InsertPipelineExample.java
index b5468ad..80f0d97 100644
--- a/hyracks-examples/btree-example/btreeclient/src/main/java/edu/uci/ics/hyracks/examples/btree/client/InsertPipelineExample.java
+++ b/hyracks-examples/btree-example/btreeclient/src/main/java/edu/uci/ics/hyracks/examples/btree/client/InsertPipelineExample.java
@@ -37,7 +37,7 @@
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.UTF8StringSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.data.partition.FieldHashPartitionComputerFactory;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
 import edu.uci.ics.hyracks.dataflow.std.misc.NullSinkOperatorDescriptor;
@@ -198,7 +198,7 @@
         // ops
         IBinaryHashFunctionFactory[] hashFactories = new IBinaryHashFunctionFactory[1];
         hashFactories[0] = UTF8StringBinaryHashFunctionFactory.INSTANCE;
-        IConnectorDescriptor hashConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor hashConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 }, hashFactories));
 
         // connect the ops
diff --git a/hyracks-examples/btree-example/btreeclient/src/main/java/edu/uci/ics/hyracks/examples/btree/client/PrimaryIndexBulkLoadExample.java b/hyracks-examples/btree-example/btreeclient/src/main/java/edu/uci/ics/hyracks/examples/btree/client/PrimaryIndexBulkLoadExample.java
index 204bdf5..bf3e04c 100644
--- a/hyracks-examples/btree-example/btreeclient/src/main/java/edu/uci/ics/hyracks/examples/btree/client/PrimaryIndexBulkLoadExample.java
+++ b/hyracks-examples/btree-example/btreeclient/src/main/java/edu/uci/ics/hyracks/examples/btree/client/PrimaryIndexBulkLoadExample.java
@@ -35,7 +35,7 @@
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.UTF8StringSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.data.partition.FieldHashPartitionComputerFactory;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
 import edu.uci.ics.hyracks.dataflow.std.sort.ExternalSortOperatorDescriptor;
@@ -164,7 +164,7 @@
         // ops
         IBinaryHashFunctionFactory[] hashFactories = new IBinaryHashFunctionFactory[1];
         hashFactories[0] = UTF8StringBinaryHashFunctionFactory.INSTANCE;
-        IConnectorDescriptor hashConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor hashConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 }, hashFactories));
 
         spec.connect(hashConn, dataGen, 0, sorter, 0);
diff --git a/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/BTreeRegistryProvider.java b/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/BTreeRegistryProvider.java
index 57b10a3..b618c82 100644
--- a/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/BTreeRegistryProvider.java
+++ b/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/BTreeRegistryProvider.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.examples.btree.helper;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.BTreeRegistry;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.IBTreeRegistryProvider;
 
@@ -28,7 +28,7 @@
     }
 
     @Override
-    public BTreeRegistry getBTreeRegistry(IHyracksStageletContext ctx) {
+    public BTreeRegistry getBTreeRegistry(IHyracksTaskContext ctx) {
         return RuntimeContext.get(ctx).getBTreeRegistry();
     }
 }
\ No newline at end of file
diff --git a/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/DataGenOperatorDescriptor.java b/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/DataGenOperatorDescriptor.java
index 0c72503..357760a 100644
--- a/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/DataGenOperatorDescriptor.java
+++ b/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/DataGenOperatorDescriptor.java
@@ -20,7 +20,7 @@
 import java.util.HashSet;
 import java.util.Random;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -59,7 +59,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
 
         final ByteBuffer outputFrame = ctx.allocateFrame();
diff --git a/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/RuntimeContext.java b/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/RuntimeContext.java
index 9f99468..62ce19d 100644
--- a/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/RuntimeContext.java
+++ b/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/RuntimeContext.java
@@ -16,7 +16,7 @@
 package edu.uci.ics.hyracks.examples.btree.helper;
 
 import edu.uci.ics.hyracks.api.application.INCApplicationContext;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.BTreeRegistry;
 import edu.uci.ics.hyracks.storage.common.buffercache.BufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.ClockPageReplacementStrategy;
@@ -57,7 +57,7 @@
         return btreeRegistry;
     }
     
-    public static RuntimeContext get(IHyracksStageletContext ctx) {
+    public static RuntimeContext get(IHyracksTaskContext ctx) {
         return (RuntimeContext) ctx.getJobletContext().getApplicationContext().getApplicationObject();
     }
 }
\ No newline at end of file
diff --git a/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/StorageManagerInterface.java b/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/StorageManagerInterface.java
index e1e47af..4c6363b 100644
--- a/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/StorageManagerInterface.java
+++ b/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/StorageManagerInterface.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.examples.btree.helper;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
@@ -29,12 +29,12 @@
     }
 
     @Override
-    public IBufferCache getBufferCache(IHyracksStageletContext ctx) {
+    public IBufferCache getBufferCache(IHyracksTaskContext ctx) {
         return RuntimeContext.get(ctx).getBufferCache();
     }
 
     @Override
-    public IFileMapProvider getFileMapProvider(IHyracksStageletContext ctx) {
+    public IFileMapProvider getFileMapProvider(IHyracksTaskContext ctx) {
         return RuntimeContext.get(ctx).getFileMapManager();
     }
 }
\ No newline at end of file
diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/comm/SerializationDeserializationTest.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/comm/SerializationDeserializationTest.java
index 9aac876..99204d8 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/comm/SerializationDeserializationTest.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/comm/SerializationDeserializationTest.java
@@ -19,16 +19,12 @@
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.UUID;
 
 import org.junit.Test;
 
-import edu.uci.ics.hyracks.api.application.INCApplicationContext;
 import edu.uci.ics.hyracks.api.comm.IFrameReader;
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksJobletContext;
-import edu.uci.ics.hyracks.api.context.IHyracksRootContext;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IDataWriter;
 import edu.uci.ics.hyracks.api.dataflow.IOpenableDataReader;
 import edu.uci.ics.hyracks.api.dataflow.IOpenableDataWriter;
@@ -40,25 +36,19 @@
 import edu.uci.ics.hyracks.dataflow.common.comm.io.SerializingDataWriter;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
 import edu.uci.ics.hyracks.dataflow.common.data.marshalling.UTF8StringSerializerDeserializer;
-import edu.uci.ics.hyracks.test.support.TestJobletContext;
-import edu.uci.ics.hyracks.test.support.TestNCApplicationContext;
-import edu.uci.ics.hyracks.test.support.TestRootContext;
-import edu.uci.ics.hyracks.test.support.TestStageletContext;
+import edu.uci.ics.hyracks.test.support.TestUtils;
 
 public class SerializationDeserializationTest {
     private static final String DBLP_FILE = "data/dblp.txt";
 
     private static class SerDeserRunner {
-        private final IHyracksStageletContext ctx;
+        private final IHyracksTaskContext ctx;
         private static final int FRAME_SIZE = 32768;
         private RecordDescriptor rDes;
         private List<ByteBuffer> buffers;
 
         public SerDeserRunner(RecordDescriptor rDes) throws HyracksException {
-            IHyracksRootContext rootCtx = new TestRootContext(FRAME_SIZE);
-            INCApplicationContext appCtx = new TestNCApplicationContext(rootCtx);
-            IHyracksJobletContext jobletCtx = new TestJobletContext(appCtx, UUID.randomUUID(), 0);
-            ctx = new TestStageletContext(jobletCtx, UUID.randomUUID());
+            ctx = TestUtils.create(FRAME_SIZE);
             this.rDes = rDes;
             buffers = new ArrayList<ByteBuffer>();
         }
diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/CountOfCountsTest.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/CountOfCountsTest.java
index 8468b54..0a0df60 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/CountOfCountsTest.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/CountOfCountsTest.java
@@ -37,7 +37,7 @@
 import edu.uci.ics.hyracks.dataflow.std.aggregators.CountAggregatorFactory;
 import edu.uci.ics.hyracks.dataflow.std.aggregators.IFieldValueResultingAggregatorFactory;
 import edu.uci.ics.hyracks.dataflow.std.aggregators.MultiAggregatorFactory;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.MToNReplicatingConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.ConstantFileSplitProvider;
@@ -95,7 +95,7 @@
         PrinterOperatorDescriptor printer = new PrinterOperatorDescriptor(spec);
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, printer, NC1_ID);
 
-        IConnectorDescriptor conn1 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn1 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn1, csvScanner, 0, sorter, 0);
@@ -103,7 +103,7 @@
         IConnectorDescriptor conn2 = new OneToOneConnectorDescriptor(spec);
         spec.connect(conn2, sorter, 0, group, 0);
 
-        IConnectorDescriptor conn3 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn3 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 1 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn3, group, 0, sorter2, 0);
@@ -162,7 +162,7 @@
         PrinterOperatorDescriptor printer = new PrinterOperatorDescriptor(spec);
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, printer, NC1_ID);
 
-        IConnectorDescriptor conn1 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn1 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn1, csvScanner, 0, sorter, 0);
@@ -170,7 +170,7 @@
         IConnectorDescriptor conn2 = new OneToOneConnectorDescriptor(spec);
         spec.connect(conn2, sorter, 0, group, 0);
 
-        IConnectorDescriptor conn3 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn3 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 1 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn3, group, 0, sorter2, 0);
@@ -229,7 +229,7 @@
         PrinterOperatorDescriptor printer = new PrinterOperatorDescriptor(spec);
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, printer, NC1_ID);
 
-        IConnectorDescriptor conn1 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn1 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn1, csvScanner, 0, sorter, 0);
@@ -237,7 +237,7 @@
         IConnectorDescriptor conn2 = new OneToOneConnectorDescriptor(spec);
         spec.connect(conn2, sorter, 0, group, 0);
 
-        IConnectorDescriptor conn3 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn3 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 1 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn3, group, 0, sorter2, 0);
diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/ScanPrintTest.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/ScanPrintTest.java
index f0974d9..d343232 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/ScanPrintTest.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/ScanPrintTest.java
@@ -33,7 +33,7 @@
 import edu.uci.ics.hyracks.dataflow.common.data.parsers.IntegerParserFactory;
 import edu.uci.ics.hyracks.dataflow.common.data.parsers.UTF8StringParserFactory;
 import edu.uci.ics.hyracks.dataflow.common.data.partition.FieldHashPartitionComputerFactory;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.ConstantFileSplitProvider;
 import edu.uci.ics.hyracks.dataflow.std.file.DelimitedDataTupleParserFactory;
@@ -96,7 +96,7 @@
         PrinterOperatorDescriptor printer = new PrinterOperatorDescriptor(spec);
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, printer, NC1_ID);
 
-        IConnectorDescriptor conn1 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn1 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn1, ordScanner, 0, printer, 0);
@@ -130,7 +130,7 @@
         PrinterOperatorDescriptor printer = new PrinterOperatorDescriptor(spec);
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, printer, NC1_ID);
 
-        IConnectorDescriptor conn1 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn1 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { IntegerBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn1, ordScanner, 0, printer, 0);
diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/SortMergeTest.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/SortMergeTest.java
index b0c33ae..1b6ff14 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/SortMergeTest.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/SortMergeTest.java
@@ -31,7 +31,7 @@
 import edu.uci.ics.hyracks.dataflow.common.data.parsers.IValueParserFactory;
 import edu.uci.ics.hyracks.dataflow.common.data.parsers.UTF8StringParserFactory;
 import edu.uci.ics.hyracks.dataflow.common.data.partition.FieldHashPartitionComputerFactory;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningMergingConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningMergingConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.ConstantFileSplitProvider;
 import edu.uci.ics.hyracks.dataflow.std.file.DelimitedDataTupleParserFactory;
@@ -75,7 +75,7 @@
 
         spec.connect(new OneToOneConnectorDescriptor(spec), ordScanner, 0, sorter, 0);
 
-        spec.connect(new MToNHashPartitioningMergingConnectorDescriptor(spec, new FieldHashPartitionComputerFactory(
+        spec.connect(new MToNPartitioningMergingConnectorDescriptor(spec, new FieldHashPartitionComputerFactory(
                 new int[] { 1 }, new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }),
                 new int[] { 1 }, new IBinaryComparatorFactory[] { UTF8StringBinaryComparatorFactory.INSTANCE }),
                 sorter, 0, printer, 0);
@@ -116,7 +116,7 @@
 
         spec.connect(new OneToOneConnectorDescriptor(spec), ordScanner, 0, sorter, 0);
 
-        spec.connect(new MToNHashPartitioningMergingConnectorDescriptor(spec, new FieldHashPartitionComputerFactory(
+        spec.connect(new MToNPartitioningMergingConnectorDescriptor(spec, new FieldHashPartitionComputerFactory(
                 new int[] { 1, 0 }, new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE,
                         UTF8StringBinaryHashFunctionFactory.INSTANCE }), new int[] { 1, 0 },
                 new IBinaryComparatorFactory[] { UTF8StringBinaryComparatorFactory.INSTANCE,
diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/TPCHCustomerOrderHashJoinTest.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/TPCHCustomerOrderHashJoinTest.java
index 4958a35..c0d0211 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/TPCHCustomerOrderHashJoinTest.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/integration/TPCHCustomerOrderHashJoinTest.java
@@ -33,7 +33,7 @@
 import edu.uci.ics.hyracks.dataflow.common.data.parsers.IValueParserFactory;
 import edu.uci.ics.hyracks.dataflow.common.data.parsers.UTF8StringParserFactory;
 import edu.uci.ics.hyracks.dataflow.common.data.partition.FieldHashPartitionComputerFactory;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.MToNReplicatingConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.ConstantFileSplitProvider;
@@ -334,12 +334,12 @@
                 : new NullSinkOperatorDescriptor(spec);
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, printer, NC1_ID);
 
-        IConnectorDescriptor ordJoinConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor ordJoinConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 1 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(ordJoinConn, ordScanner, 0, join, 0);
 
-        IConnectorDescriptor custJoinConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor custJoinConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(custJoinConn, custScanner, 0, join, 1);
@@ -413,12 +413,12 @@
                 : new NullSinkOperatorDescriptor(spec);
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, printer, NC1_ID);
 
-        IConnectorDescriptor ordJoinConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor ordJoinConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 1 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(ordJoinConn, ordScanner, 0, join, 0);
 
-        IConnectorDescriptor custJoinConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor custJoinConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(custJoinConn, custScanner, 0, join, 1);
@@ -492,12 +492,12 @@
                 : new NullSinkOperatorDescriptor(spec);
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, printer, NC1_ID);
 
-        IConnectorDescriptor ordJoinConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor ordJoinConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 1 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(ordJoinConn, ordScanner, 0, join, 0);
 
-        IConnectorDescriptor custJoinConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor custJoinConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(custJoinConn, custScanner, 0, join, 1);
@@ -570,12 +570,12 @@
                 : new NullSinkOperatorDescriptor(spec);
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, printer, NC1_ID);
 
-        IConnectorDescriptor ordJoinConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor ordJoinConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 1 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(ordJoinConn, ordScanner, 0, join, 0);
 
-        IConnectorDescriptor custJoinConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor custJoinConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(custJoinConn, custScanner, 0, join, 1);
@@ -654,12 +654,12 @@
                 : new NullSinkOperatorDescriptor(spec);
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, printer, NC1_ID);
 
-        IConnectorDescriptor ordPartConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor ordPartConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 1 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(ordPartConn, ordScanner, 0, ordMat, 0);
 
-        IConnectorDescriptor custPartConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor custPartConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(custPartConn, custScanner, 0, custMat, 0);
diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/spillable/ExternalAggregateTest.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/spillable/ExternalAggregateTest.java
index 694f183..f1942f1 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/spillable/ExternalAggregateTest.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/spillable/ExternalAggregateTest.java
@@ -43,7 +43,7 @@
 import edu.uci.ics.hyracks.dataflow.std.aggregators.MinMaxAggregatorFactory;
 import edu.uci.ics.hyracks.dataflow.std.aggregators.MultiAggregatorFactory;
 import edu.uci.ics.hyracks.dataflow.std.aggregators.SumAggregatorFactory;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.ConstantFileSplitProvider;
 import edu.uci.ics.hyracks.dataflow.std.file.DelimitedDataTupleParserFactory;
@@ -112,7 +112,7 @@
 
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, grouper, NC2_ID, NC1_ID);
 
-        IConnectorDescriptor conn1 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn1 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(keys,
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn1, csvScanner, 0, grouper, 0);
@@ -168,7 +168,7 @@
 
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, grouper, NC2_ID, NC1_ID);
 
-        IConnectorDescriptor conn1 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn1 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(keys,
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn1, csvScanner, 0, grouper, 0);
@@ -232,7 +232,7 @@
 
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, grouper, NC1_ID);
 
-        IConnectorDescriptor conn1 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn1 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(keys,
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn1, ordScanner, 0, grouper, 0);
@@ -300,7 +300,7 @@
 
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, grouper, NC1_ID);
 
-        IConnectorDescriptor conn1 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn1 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(keys, new IBinaryHashFunctionFactory[] {
                         UTF8StringBinaryHashFunctionFactory.INSTANCE, UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn1, ordScanner, 0, grouper, 0);
@@ -368,7 +368,7 @@
 
         PartitionConstraintHelper.addAbsoluteLocationConstraint(spec, grouper, NC1_ID);
 
-        IConnectorDescriptor conn1 = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor conn1 = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(keys, new IBinaryHashFunctionFactory[] {
                         IntegerBinaryHashFunctionFactory.INSTANCE, IntegerBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(conn1, ordScanner, 0, grouper, 0);
diff --git a/hyracks-examples/text-example/textclient/src/main/java/edu/uci/ics/hyracks/examples/text/client/ExternalGroupClient.java b/hyracks-examples/text-example/textclient/src/main/java/edu/uci/ics/hyracks/examples/text/client/ExternalGroupClient.java
index 8d22bca..235d966 100644
--- a/hyracks-examples/text-example/textclient/src/main/java/edu/uci/ics/hyracks/examples/text/client/ExternalGroupClient.java
+++ b/hyracks-examples/text-example/textclient/src/main/java/edu/uci/ics/hyracks/examples/text/client/ExternalGroupClient.java
@@ -46,7 +46,7 @@
 import edu.uci.ics.hyracks.dataflow.std.aggregators.MultiAggregatorFactory;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractSingleActivityOperatorDescriptor;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.ConstantFileSplitProvider;
 import edu.uci.ics.hyracks.dataflow.std.file.DelimitedDataTupleParserFactory;
@@ -207,7 +207,7 @@
                 createPartitionConstraint(spec, grouper, outSplits);
 
                 // Connect scanner with the grouper
-                IConnectorDescriptor scanGroupConn = new MToNHashPartitioningConnectorDescriptor(spec,
+                IConnectorDescriptor scanGroupConn = new MToNPartitioningConnectorDescriptor(spec,
                         new FieldHashPartitionComputerFactory(keys, new IBinaryHashFunctionFactory[] {
                         // IntegerBinaryHashFunctionFactory.INSTANCE,
                                 IntegerBinaryHashFunctionFactory.INSTANCE }));
@@ -221,7 +221,7 @@
                 createPartitionConstraint(spec, sorter, inSplits);
 
                 // Connect scan operator with the sorter
-                IConnectorDescriptor scanSortConn = new MToNHashPartitioningConnectorDescriptor(spec,
+                IConnectorDescriptor scanSortConn = new MToNPartitioningConnectorDescriptor(spec,
                         new FieldHashPartitionComputerFactory(keys, new IBinaryHashFunctionFactory[] {
                         // IntegerBinaryHashFunctionFactory.INSTANCE,
                                 IntegerBinaryHashFunctionFactory.INSTANCE }));
@@ -251,7 +251,7 @@
                 createPartitionConstraint(spec, grouper, outSplits);
 
                 // Connect scanner with the grouper
-                IConnectorDescriptor scanConn = new MToNHashPartitioningConnectorDescriptor(spec,
+                IConnectorDescriptor scanConn = new MToNPartitioningConnectorDescriptor(spec,
                         new FieldHashPartitionComputerFactory(keys, new IBinaryHashFunctionFactory[] {
                         // IntegerBinaryHashFunctionFactory.INSTANCE,
                                 IntegerBinaryHashFunctionFactory.INSTANCE }));
@@ -270,7 +270,7 @@
                 createPartitionConstraint(spec, grouper, outSplits);
 
                 // Connect scanner with the grouper
-                IConnectorDescriptor scanGroupConnDef = new MToNHashPartitioningConnectorDescriptor(spec,
+                IConnectorDescriptor scanGroupConnDef = new MToNPartitioningConnectorDescriptor(spec,
                         new FieldHashPartitionComputerFactory(keys, new IBinaryHashFunctionFactory[] {
                         // IntegerBinaryHashFunctionFactory.INSTANCE,
                                 IntegerBinaryHashFunctionFactory.INSTANCE }));
diff --git a/hyracks-examples/text-example/textclient/src/main/java/edu/uci/ics/hyracks/examples/text/client/WordCountMain.java b/hyracks-examples/text-example/textclient/src/main/java/edu/uci/ics/hyracks/examples/text/client/WordCountMain.java
index 4f20774..ace8a83 100644
--- a/hyracks-examples/text-example/textclient/src/main/java/edu/uci/ics/hyracks/examples/text/client/WordCountMain.java
+++ b/hyracks-examples/text-example/textclient/src/main/java/edu/uci/ics/hyracks/examples/text/client/WordCountMain.java
@@ -40,7 +40,7 @@
 import edu.uci.ics.hyracks.dataflow.std.aggregators.CountAggregatorFactory;
 import edu.uci.ics.hyracks.dataflow.std.aggregators.IFieldValueResultingAggregatorFactory;
 import edu.uci.ics.hyracks.dataflow.std.aggregators.MultiAggregatorFactory;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.ConstantFileSplitProvider;
 import edu.uci.ics.hyracks.dataflow.std.file.FileScanOperatorDescriptor;
@@ -137,7 +137,7 @@
                             new IFieldValueResultingAggregatorFactory[] { new CountAggregatorFactory() }),
                     groupResultDesc, htSize);
             createPartitionConstraint(spec, gBy, outSplits);
-            IConnectorDescriptor scanGroupConn = new MToNHashPartitioningConnectorDescriptor(spec,
+            IConnectorDescriptor scanGroupConn = new MToNPartitioningConnectorDescriptor(spec,
                     new FieldHashPartitionComputerFactory(keys,
                             new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
             spec.connect(scanGroupConn, wordScanner, 0, gBy, 0);
@@ -149,7 +149,7 @@
                             new UTF8StringNormalizedKeyComputerFactory(), cfs, wordDesc);
             createPartitionConstraint(spec, sorter, outSplits);
 
-            IConnectorDescriptor scanSortConn = new MToNHashPartitioningConnectorDescriptor(spec,
+            IConnectorDescriptor scanSortConn = new MToNPartitioningConnectorDescriptor(spec,
                     new FieldHashPartitionComputerFactory(keys,
                             new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
             spec.connect(scanSortConn, wordScanner, 0, sorter, 0);
diff --git a/hyracks-examples/text-example/texthelper/src/main/java/edu/uci/ics/hyracks/examples/text/WordTupleParserFactory.java b/hyracks-examples/text-example/texthelper/src/main/java/edu/uci/ics/hyracks/examples/text/WordTupleParserFactory.java
index 65b9011..13a2c80 100644
--- a/hyracks-examples/text-example/texthelper/src/main/java/edu/uci/ics/hyracks/examples/text/WordTupleParserFactory.java
+++ b/hyracks-examples/text-example/texthelper/src/main/java/edu/uci/ics/hyracks/examples/text/WordTupleParserFactory.java
@@ -9,7 +9,7 @@
 import java.util.Arrays;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
@@ -23,7 +23,7 @@
     private static final long serialVersionUID = 1L;
 
     @Override
-    public ITupleParser createTupleParser(final IHyracksStageletContext ctx) {
+    public ITupleParser createTupleParser(final IHyracksTaskContext ctx) {
         return new ITupleParser() {
             @Override
             public void parse(InputStream in, IFrameWriter writer) throws HyracksDataException {
diff --git a/hyracks-examples/tpch-example/tpchclient/src/main/java/edu/uci/ics/hyracks/examples/tpch/client/Main.java b/hyracks-examples/tpch-example/tpchclient/src/main/java/edu/uci/ics/hyracks/examples/tpch/client/Main.java
index b1a1224..d476a9d 100644
--- a/hyracks-examples/tpch-example/tpchclient/src/main/java/edu/uci/ics/hyracks/examples/tpch/client/Main.java
+++ b/hyracks-examples/tpch-example/tpchclient/src/main/java/edu/uci/ics/hyracks/examples/tpch/client/Main.java
@@ -43,7 +43,7 @@
 import edu.uci.ics.hyracks.dataflow.std.aggregators.CountAggregatorFactory;
 import edu.uci.ics.hyracks.dataflow.std.aggregators.IFieldValueResultingAggregatorFactory;
 import edu.uci.ics.hyracks.dataflow.std.aggregators.MultiAggregatorFactory;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.file.ConstantFileSplitProvider;
 import edu.uci.ics.hyracks.dataflow.std.file.DelimitedDataTupleParserFactory;
@@ -184,17 +184,17 @@
         FrameFileWriterOperatorDescriptor writer = new FrameFileWriterOperatorDescriptor(spec, outSplitProvider);
         createPartitionConstraint(spec, writer, resultSplits);
 
-        IConnectorDescriptor ordJoinConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor ordJoinConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 1 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(ordJoinConn, ordScanner, 0, join, 1);
 
-        IConnectorDescriptor custJoinConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor custJoinConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 0 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(custJoinConn, custScanner, 0, join, 0);
 
-        IConnectorDescriptor joinGroupConn = new MToNHashPartitioningConnectorDescriptor(spec,
+        IConnectorDescriptor joinGroupConn = new MToNPartitioningConnectorDescriptor(spec,
                 new FieldHashPartitionComputerFactory(new int[] { 6 },
                         new IBinaryHashFunctionFactory[] { UTF8StringBinaryHashFunctionFactory.INSTANCE }));
         spec.connect(joinGroupConn, join, 0, gby, 0);
diff --git a/hyracks-hadoop-compat/src/main/java/edu/uci/ics/hyracks/hadoop/compat/util/HadoopAdapter.java b/hyracks-hadoop-compat/src/main/java/edu/uci/ics/hyracks/hadoop/compat/util/HadoopAdapter.java
index d0df7f1..4c91906 100644
--- a/hyracks-hadoop-compat/src/main/java/edu/uci/ics/hyracks/hadoop/compat/util/HadoopAdapter.java
+++ b/hyracks-hadoop-compat/src/main/java/edu/uci/ics/hyracks/hadoop/compat/util/HadoopAdapter.java
@@ -40,7 +40,7 @@
 import edu.uci.ics.hyracks.dataflow.hadoop.util.ClasspathBasedHadoopClassFactory;
 import edu.uci.ics.hyracks.dataflow.hadoop.util.DatatypeHelper;
 import edu.uci.ics.hyracks.dataflow.hadoop.util.IHadoopClassFactory;
-import edu.uci.ics.hyracks.dataflow.std.connectors.MToNHashPartitioningConnectorDescriptor;
+import edu.uci.ics.hyracks.dataflow.std.connectors.MToNPartitioningConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.connectors.OneToOneConnectorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.sort.ExternalSortOperatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.sort.InMemorySortOperatorDescriptor;
@@ -328,13 +328,13 @@
         return externalSortOp;
     }
     
-    public static MToNHashPartitioningConnectorDescriptor getMtoNHashPartitioningConnector(JobConf conf,
+    public static MToNPartitioningConnectorDescriptor getMtoNHashPartitioningConnector(JobConf conf,
             JobSpecification spec) {
 
         Class mapOutputKeyClass = conf.getMapOutputKeyClass();
         Class mapOutputValueClass = conf.getMapOutputValueClass();
 
-        MToNHashPartitioningConnectorDescriptor connectorDescriptor = null;
+        MToNPartitioningConnectorDescriptor connectorDescriptor = null;
         ITuplePartitionComputerFactory factory = null;
         conf.getMapOutputKeyClass();
         if (conf.getPartitionerClass() != null && !conf.getPartitionerClass().getName().startsWith("org.apache.hadoop")) {
@@ -349,7 +349,7 @@
                     .createSerializerDeserializer(mapOutputKeyClass);
             factory = new HadoopHashTuplePartitionComputerFactory(mapOutputKeySerializerDerserializer);
         }
-        connectorDescriptor = new MToNHashPartitioningConnectorDescriptor(spec, factory);
+        connectorDescriptor = new MToNPartitioningConnectorDescriptor(spec, factory);
         return connectorDescriptor;
     }
 
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorDescriptor.java
index a4c4b61..48740ed 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorDescriptor.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.storage.am.btree.dataflow;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
@@ -45,7 +45,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         return new BTreeBulkLoadOperatorNodePushable(this, ctx, partition, fieldPermutation, fillFactor,
                 recordDescProvider);
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorNodePushable.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorNodePushable.java
index 6e13ed7..11456e9 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorNodePushable.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeBulkLoadOperatorNodePushable.java
@@ -16,7 +16,7 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
@@ -26,70 +26,62 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.MetaDataFrame;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 
-public class BTreeBulkLoadOperatorNodePushable extends
-		AbstractUnaryInputSinkOperatorNodePushable {
-	private float fillFactor;
-	private final BTreeOpHelper btreeOpHelper;
-	private FrameTupleAccessor accessor;
-	private BTree.BulkLoadContext bulkLoadCtx;
+public class BTreeBulkLoadOperatorNodePushable extends AbstractUnaryInputSinkOperatorNodePushable {
+    private float fillFactor;
+    private final BTreeOpHelper btreeOpHelper;
+    private FrameTupleAccessor accessor;
+    private BTree.BulkLoadContext bulkLoadCtx;
 
-	private IRecordDescriptorProvider recordDescProvider;
+    private IRecordDescriptorProvider recordDescProvider;
 
-	private PermutingFrameTupleReference tuple = new PermutingFrameTupleReference();
+    private PermutingFrameTupleReference tuple = new PermutingFrameTupleReference();
 
-	public BTreeBulkLoadOperatorNodePushable(
-			AbstractBTreeOperatorDescriptor opDesc,
-			IHyracksStageletContext ctx, int partition, int[] fieldPermutation,
-			float fillFactor, IRecordDescriptorProvider recordDescProvider) {
-		btreeOpHelper = new BTreeOpHelper(opDesc, ctx, partition,
-				BTreeOpHelper.BTreeMode.CREATE_BTREE);
-		this.fillFactor = fillFactor;
-		this.recordDescProvider = recordDescProvider;
-		tuple.setFieldPermutation(fieldPermutation);
-	}
+    public BTreeBulkLoadOperatorNodePushable(AbstractBTreeOperatorDescriptor opDesc, IHyracksTaskContext ctx,
+            int partition, int[] fieldPermutation, float fillFactor, IRecordDescriptorProvider recordDescProvider) {
+        btreeOpHelper = new BTreeOpHelper(opDesc, ctx, partition, BTreeOpHelper.BTreeMode.CREATE_BTREE);
+        this.fillFactor = fillFactor;
+        this.recordDescProvider = recordDescProvider;
+        tuple.setFieldPermutation(fieldPermutation);
+    }
 
-	@Override
-	public void open() throws HyracksDataException {
-		AbstractBTreeOperatorDescriptor opDesc = btreeOpHelper
-				.getOperatorDescriptor();
-		RecordDescriptor recDesc = recordDescProvider.getInputRecordDescriptor(
-				opDesc.getOperatorId(), 0);
-		accessor = new FrameTupleAccessor(btreeOpHelper
-				.getHyracksStageletContext().getFrameSize(), recDesc);
-		IBTreeMetaDataFrame metaFrame = new MetaDataFrame();
-		try {
-			btreeOpHelper.init();
-			btreeOpHelper.getBTree().open(btreeOpHelper.getBTreeFileId());
-			bulkLoadCtx = btreeOpHelper.getBTree().beginBulkLoad(fillFactor,
-					btreeOpHelper.getLeafFrame(),
-					btreeOpHelper.getInteriorFrame(), metaFrame);
-		} catch (Exception e) {
-			// cleanup in case of failure
-			btreeOpHelper.deinit();
-			throw new HyracksDataException(e);
-		}
-	}
+    @Override
+    public void open() throws HyracksDataException {
+        AbstractBTreeOperatorDescriptor opDesc = btreeOpHelper.getOperatorDescriptor();
+        RecordDescriptor recDesc = recordDescProvider.getInputRecordDescriptor(opDesc.getOperatorId(), 0);
+        accessor = new FrameTupleAccessor(btreeOpHelper.getHyracksStageletContext().getFrameSize(), recDesc);
+        IBTreeMetaDataFrame metaFrame = new MetaDataFrame();
+        try {
+            btreeOpHelper.init();
+            btreeOpHelper.getBTree().open(btreeOpHelper.getBTreeFileId());
+            bulkLoadCtx = btreeOpHelper.getBTree().beginBulkLoad(fillFactor, btreeOpHelper.getLeafFrame(),
+                    btreeOpHelper.getInteriorFrame(), metaFrame);
+        } catch (Exception e) {
+            // cleanup in case of failure
+            btreeOpHelper.deinit();
+            throw new HyracksDataException(e);
+        }
+    }
 
-	@Override
-	public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
-		accessor.reset(buffer);
-		int tupleCount = accessor.getTupleCount();
-		for (int i = 0; i < tupleCount; i++) {
-			tuple.reset(accessor, i);
-			btreeOpHelper.getBTree().bulkLoadAddTuple(bulkLoadCtx, tuple);
-		}
-	}
+    @Override
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        accessor.reset(buffer);
+        int tupleCount = accessor.getTupleCount();
+        for (int i = 0; i < tupleCount; i++) {
+            tuple.reset(accessor, i);
+            btreeOpHelper.getBTree().bulkLoadAddTuple(bulkLoadCtx, tuple);
+        }
+    }
 
-	@Override
-	public void close() throws HyracksDataException {
-		try {
-			btreeOpHelper.getBTree().endBulkLoad(bulkLoadCtx);
-		} finally {
-			btreeOpHelper.deinit();
-		}
-	}
+    @Override
+    public void close() throws HyracksDataException {
+        try {
+            btreeOpHelper.getBTree().endBulkLoad(bulkLoadCtx);
+        } finally {
+            btreeOpHelper.deinit();
+        }
+    }
 
-	@Override
-	public void flush() throws HyracksDataException {
-	}
+    @Override
+    public void flush() throws HyracksDataException {
+    }
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorDescriptor.java
index 17fbf97..af23ad6 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorDescriptor.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.storage.am.btree.dataflow;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
@@ -40,7 +40,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         return new BTreeDiskOrderScanOperatorNodePushable(this, ctx, partition);
     }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorNodePushable.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorNodePushable.java
index c362183..5d9748c 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorNodePushable.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDiskOrderScanOperatorNodePushable.java
@@ -17,7 +17,7 @@
 import java.io.DataOutput;
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
@@ -33,7 +33,7 @@
 public class BTreeDiskOrderScanOperatorNodePushable extends AbstractUnaryOutputSourceOperatorNodePushable {
     private final BTreeOpHelper btreeOpHelper;
 
-    public BTreeDiskOrderScanOperatorNodePushable(AbstractBTreeOperatorDescriptor opDesc, IHyracksStageletContext ctx,
+    public BTreeDiskOrderScanOperatorNodePushable(AbstractBTreeOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
         btreeOpHelper = new BTreeOpHelper(opDesc, ctx, partition, BTreeOpHelper.BTreeMode.OPEN_BTREE);
     }
@@ -46,55 +46,55 @@
         IBTreeMetaDataFrame metaFrame = new MetaDataFrame();
 
         try {
-        
-        	btreeOpHelper.init();
-        	
-        	try {
-        		btreeOpHelper.getBTree().diskOrderScan(cursor, cursorFrame, metaFrame);
 
-        		MultiComparator cmp = btreeOpHelper.getBTree().getMultiComparator();
-        		ByteBuffer frame = btreeOpHelper.getHyracksStageletContext().allocateFrame();
-        		FrameTupleAppender appender = new FrameTupleAppender(btreeOpHelper.getHyracksStageletContext().getFrameSize());
-        		appender.reset(frame, true);
-        		ArrayTupleBuilder tb = new ArrayTupleBuilder(cmp.getFieldCount());
-        		DataOutput dos = tb.getDataOutput();
+            btreeOpHelper.init();
 
-        		while (cursor.hasNext()) {
-        			tb.reset();
-        			cursor.next();
+            try {
+                btreeOpHelper.getBTree().diskOrderScan(cursor, cursorFrame, metaFrame);
 
-        			ITupleReference frameTuple = cursor.getTuple();
-        			for (int i = 0; i < frameTuple.getFieldCount(); i++) {
-        				dos.write(frameTuple.getFieldData(i), frameTuple.getFieldStart(i), frameTuple.getFieldLength(i));
-        				tb.addFieldEndOffset();
-        			}
+                MultiComparator cmp = btreeOpHelper.getBTree().getMultiComparator();
+                ByteBuffer frame = btreeOpHelper.getHyracksStageletContext().allocateFrame();
+                FrameTupleAppender appender = new FrameTupleAppender(btreeOpHelper.getHyracksStageletContext()
+                        .getFrameSize());
+                appender.reset(frame, true);
+                ArrayTupleBuilder tb = new ArrayTupleBuilder(cmp.getFieldCount());
+                DataOutput dos = tb.getDataOutput();
 
-        			if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
-        				FrameUtils.flushFrame(frame, writer);
-        				appender.reset(frame, true);
-        				if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
-        					throw new IllegalStateException();
-        				}
-        			}
-        		}
+                while (cursor.hasNext()) {
+                    tb.reset();
+                    cursor.next();
 
-        		if (appender.getTupleCount() > 0) {
-        			FrameUtils.flushFrame(frame, writer);
-        		}
-        	}
-        	finally {
-        		cursor.close();
-        		writer.close();
-        	}
+                    ITupleReference frameTuple = cursor.getTuple();
+                    for (int i = 0; i < frameTuple.getFieldCount(); i++) {
+                        dos.write(frameTuple.getFieldData(i), frameTuple.getFieldStart(i), frameTuple.getFieldLength(i));
+                        tb.addFieldEndOffset();
+                    }
 
-        } catch(Exception e) {
-        	deinitialize();
-        	throw new HyracksDataException(e);
+                    if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
+                        FrameUtils.flushFrame(frame, writer);
+                        appender.reset(frame, true);
+                        if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
+                            throw new IllegalStateException();
+                        }
+                    }
+                }
+
+                if (appender.getTupleCount() > 0) {
+                    FrameUtils.flushFrame(frame, writer);
+                }
+            } finally {
+                cursor.close();
+                writer.close();
+            }
+
+        } catch (Exception e) {
+            deinitialize();
+            throw new HyracksDataException(e);
         }
     }
 
     @Override
     public void deinitialize() throws HyracksDataException {
-    	btreeOpHelper.deinit();
+        btreeOpHelper.deinit();
     }
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorDescriptor.java
index 970d44a..efbb257 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorDescriptor.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.storage.am.btree.dataflow;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.job.IOperatorEnvironment;
@@ -41,8 +41,9 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
-        return new BTreeDropOperatorNodePushable(ctx, storageManager, btreeRegistryProvider, fileSplitProvider, partition);
+        return new BTreeDropOperatorNodePushable(ctx, storageManager, btreeRegistryProvider, fileSplitProvider,
+                partition);
     }
 }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorNodePushable.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorNodePushable.java
index c087fdd..6bea88c 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorNodePushable.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeDropOperatorNodePushable.java
@@ -19,7 +19,7 @@
 import java.util.logging.Logger;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
@@ -30,15 +30,15 @@
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
 public class BTreeDropOperatorNodePushable extends AbstractOperatorNodePushable {
-	private static final Logger LOGGER = Logger.getLogger(BTreeDropOperatorNodePushable.class.getName());
-	
-	private final IHyracksStageletContext ctx;
+    private static final Logger LOGGER = Logger.getLogger(BTreeDropOperatorNodePushable.class.getName());
+
+    private final IHyracksTaskContext ctx;
     private IBTreeRegistryProvider btreeRegistryProvider;
     private IStorageManagerInterface storageManager;
     private IFileSplitProvider fileSplitProvider;
     private int partition;
 
-    public BTreeDropOperatorNodePushable(IHyracksStageletContext ctx, IStorageManagerInterface storageManager,
+    public BTreeDropOperatorNodePushable(IHyracksTaskContext ctx, IStorageManagerInterface storageManager,
             IBTreeRegistryProvider btreeRegistryProvider, IFileSplitProvider fileSplitProvider, int partition) {
         this.ctx = ctx;
         this.storageManager = storageManager;
@@ -63,39 +63,40 @@
 
     @Override
     public void initialize() throws HyracksDataException {
-    	try {
+        try {
 
-    		BTreeRegistry btreeRegistry = btreeRegistryProvider.getBTreeRegistry(ctx);
-    		IBufferCache bufferCache = storageManager.getBufferCache(ctx);
-    		IFileMapProvider fileMapProvider = storageManager.getFileMapProvider(ctx);
+            BTreeRegistry btreeRegistry = btreeRegistryProvider.getBTreeRegistry(ctx);
+            IBufferCache bufferCache = storageManager.getBufferCache(ctx);
+            IFileMapProvider fileMapProvider = storageManager.getFileMapProvider(ctx);
 
-    		FileReference f = fileSplitProvider.getFileSplits()[partition].getLocalFile();
+            FileReference f = fileSplitProvider.getFileSplits()[partition].getLocalFile();
 
-    		boolean fileIsMapped = fileMapProvider.isMapped(f);
-    		if (!fileIsMapped) {    			    			
-    			throw new HyracksDataException("Cannot drop B-Tree with name " + f.toString() + ". No file mapping exists.");
-    		}
+            boolean fileIsMapped = fileMapProvider.isMapped(f);
+            if (!fileIsMapped) {
+                throw new HyracksDataException("Cannot drop B-Tree with name " + f.toString()
+                        + ". No file mapping exists.");
+            }
 
-    		int btreeFileId = fileMapProvider.lookupFileId(f);
+            int btreeFileId = fileMapProvider.lookupFileId(f);
 
-    		// unregister btree instance
-    		btreeRegistry.lock();
-    		try {
-    			btreeRegistry.unregister(btreeFileId);
-    		} finally {
-    			btreeRegistry.unlock();
-    		}
+            // unregister btree instance
+            btreeRegistry.lock();
+            try {
+                btreeRegistry.unregister(btreeFileId);
+            } finally {
+                btreeRegistry.unlock();
+            }
 
-    		// remove name to id mapping
-    		bufferCache.deleteFile(btreeFileId);
-    	}
-    	// TODO: for the time being we don't throw,
-		// with proper exception handling (no hanging job problem) we should throw
-    	catch (Exception e) {
-    		if (LOGGER.isLoggable(Level.WARNING)) {
+            // remove name to id mapping
+            bufferCache.deleteFile(btreeFileId);
+        }
+        // TODO: for the time being we don't throw,
+        // with proper exception handling (no hanging job problem) we should throw
+        catch (Exception e) {
+            if (LOGGER.isLoggable(Level.WARNING)) {
                 LOGGER.warning("BTRee Drop Operator Failed Due To Exception: " + e.getMessage());
             }
-    	}
+        }
     }
 
     @Override
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeFileEnlistmentOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeFileEnlistmentOperatorDescriptor.java
index c105274..9939c6f 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeFileEnlistmentOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeFileEnlistmentOperatorDescriptor.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.storage.am.btree.dataflow;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
@@ -47,7 +47,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int partitions) throws HyracksDataException {
         return new BTreeFileEnlistmentOperatorNodePushable(this, ctx, partition);
     }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeFileEnlistmentOperatorNodePushable.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeFileEnlistmentOperatorNodePushable.java
index 023cd40..6099095 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeFileEnlistmentOperatorNodePushable.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeFileEnlistmentOperatorNodePushable.java
@@ -16,7 +16,7 @@
 package edu.uci.ics.hyracks.storage.am.btree.dataflow;
 
 import edu.uci.ics.hyracks.api.comm.IFrameWriter;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.std.base.AbstractOperatorNodePushable;
@@ -25,7 +25,7 @@
 
     private final BTreeOpHelper btreeOpHelper;
 
-    public BTreeFileEnlistmentOperatorNodePushable(AbstractBTreeOperatorDescriptor opDesc, IHyracksStageletContext ctx,
+    public BTreeFileEnlistmentOperatorNodePushable(AbstractBTreeOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
         btreeOpHelper = new BTreeOpHelper(opDesc, ctx, partition, BTreeOpHelper.BTreeMode.ENLIST_BTREE);
     }
@@ -47,10 +47,9 @@
     @Override
     public void initialize() throws HyracksDataException {
         try {
-        	btreeOpHelper.init();
-        }
-        finally {
-        	btreeOpHelper.deinit();
+            btreeOpHelper.init();
+        } finally {
+            btreeOpHelper.deinit();
         }
     }
 
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorDescriptor.java
index 7d50fff..bcae5e1 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorDescriptor.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.storage.am.btree.dataflow;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
@@ -49,7 +49,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         return new BTreeInsertUpdateDeleteOperatorNodePushable(this, ctx, partition, fieldPermutation,
                 recordDescProvider, op);
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorNodePushable.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorNodePushable.java
index acb7d0f..ec6da88 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorNodePushable.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeInsertUpdateDeleteOperatorNodePushable.java
@@ -16,7 +16,7 @@
 
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
@@ -37,9 +37,8 @@
     private ByteBuffer writeBuffer;
     private BTreeOpContext opCtx;
 
-    public BTreeInsertUpdateDeleteOperatorNodePushable(AbstractBTreeOperatorDescriptor opDesc,
-            IHyracksStageletContext ctx, int partition, int[] fieldPermutation,
-            IRecordDescriptorProvider recordDescProvider, BTreeOp op) {
+    public BTreeInsertUpdateDeleteOperatorNodePushable(AbstractBTreeOperatorDescriptor opDesc, IHyracksTaskContext ctx,
+            int partition, int[] fieldPermutation, IRecordDescriptorProvider recordDescProvider, BTreeOp op) {
         btreeOpHelper = new BTreeOpHelper(opDesc, ctx, partition, BTreeOpHelper.BTreeMode.OPEN_BTREE);
         this.recordDescProvider = recordDescProvider;
         this.op = op;
@@ -48,20 +47,20 @@
 
     @Override
     public void open() throws HyracksDataException {
-    	AbstractBTreeOperatorDescriptor opDesc = btreeOpHelper.getOperatorDescriptor();
-    	RecordDescriptor inputRecDesc = recordDescProvider.getInputRecordDescriptor(opDesc.getOperatorId(), 0);
-    	accessor = new FrameTupleAccessor(btreeOpHelper.getHyracksStageletContext().getFrameSize(), inputRecDesc);
-    	writeBuffer = btreeOpHelper.getHyracksStageletContext().allocateFrame();
-    	try {
-    		btreeOpHelper.init();
-    		btreeOpHelper.getBTree().open(btreeOpHelper.getBTreeFileId());
-    		opCtx = btreeOpHelper.getBTree().createOpContext(op, btreeOpHelper.getLeafFrame(),
-    				btreeOpHelper.getInteriorFrame(), new MetaDataFrame());
-    	} catch(Exception e) {
-    		// cleanup in case of failure
-    		btreeOpHelper.deinit();
-    		throw new HyracksDataException(e);
-    	}
+        AbstractBTreeOperatorDescriptor opDesc = btreeOpHelper.getOperatorDescriptor();
+        RecordDescriptor inputRecDesc = recordDescProvider.getInputRecordDescriptor(opDesc.getOperatorId(), 0);
+        accessor = new FrameTupleAccessor(btreeOpHelper.getHyracksStageletContext().getFrameSize(), inputRecDesc);
+        writeBuffer = btreeOpHelper.getHyracksStageletContext().allocateFrame();
+        try {
+            btreeOpHelper.init();
+            btreeOpHelper.getBTree().open(btreeOpHelper.getBTreeFileId());
+            opCtx = btreeOpHelper.getBTree().createOpContext(op, btreeOpHelper.getLeafFrame(),
+                    btreeOpHelper.getInteriorFrame(), new MetaDataFrame());
+        } catch (Exception e) {
+            // cleanup in case of failure
+            btreeOpHelper.deinit();
+            throw new HyracksDataException(e);
+        }
     }
 
     @Override
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeOpHelper.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeOpHelper.java
index 880cc25..528b8cf 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeOpHelper.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeOpHelper.java
@@ -14,7 +14,7 @@
  */
 package edu.uci.ics.hyracks.storage.am.btree.dataflow;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
@@ -29,31 +29,32 @@
 
 final class BTreeOpHelper {
 
-	public enum BTreeMode {
-		OPEN_BTREE, CREATE_BTREE, ENLIST_BTREE
-	}
-	
-	private IBTreeInteriorFrame interiorFrame;
-	private IBTreeLeafFrame leafFrame;
+    public enum BTreeMode {
+        OPEN_BTREE,
+        CREATE_BTREE,
+        ENLIST_BTREE
+    }
 
-	private BTree btree;
-	private int btreeFileId = -1;
-	private int partition;
+    private IBTreeInteriorFrame interiorFrame;
+    private IBTreeLeafFrame leafFrame;
+
+    private BTree btree;
+    private int btreeFileId = -1;
+    private int partition;
 
     private AbstractBTreeOperatorDescriptor opDesc;
-    private IHyracksStageletContext ctx;
+    private IHyracksTaskContext ctx;
 
-	private BTreeMode mode;
+    private BTreeMode mode;
 
-    BTreeOpHelper(AbstractBTreeOperatorDescriptor opDesc, final IHyracksStageletContext ctx, int partition,
-            BTreeMode mode) {
+    BTreeOpHelper(AbstractBTreeOperatorDescriptor opDesc, final IHyracksTaskContext ctx, int partition, BTreeMode mode) {
         this.opDesc = opDesc;
         this.ctx = ctx;
         this.mode = mode;
         this.partition = partition;
     }
 
-	void init() throws HyracksDataException {
+    void init() throws HyracksDataException {
         IBufferCache bufferCache = opDesc.getStorageManager().getBufferCache(ctx);
         IFileMapProvider fileMapProvider = opDesc.getStorageManager().getFileMapProvider(ctx);
         IFileSplitProvider fileSplitProvider = opDesc.getFileSplitProvider();
@@ -61,72 +62,67 @@
         FileReference f = fileSplitProvider.getFileSplits()[partition].getLocalFile();
         boolean fileIsMapped = fileMapProvider.isMapped(f);
 
-		switch (mode) {
-		
-		case OPEN_BTREE: {
-			if (!fileIsMapped) {
-				throw new HyracksDataException(
-						"Trying to open btree from unmapped file " + f.toString());
-			}
-		}
-		break;
+        switch (mode) {
 
-		case CREATE_BTREE:
-		case ENLIST_BTREE: {
-			if (!fileIsMapped) {
-				bufferCache.createFile(f);
-			}
-		}
-		break;
-		
-		}
+            case OPEN_BTREE: {
+                if (!fileIsMapped) {
+                    throw new HyracksDataException("Trying to open btree from unmapped file " + f.toString());
+                }
+            }
+                break;
+
+            case CREATE_BTREE:
+            case ENLIST_BTREE: {
+                if (!fileIsMapped) {
+                    bufferCache.createFile(f);
+                }
+            }
+                break;
+
+        }
 
         btreeFileId = fileMapProvider.lookupFileId(f);
         bufferCache.openFile(btreeFileId);
 
-		interiorFrame = opDesc.getInteriorFactory().getFrame();
-		leafFrame = opDesc.getLeafFactory().getFrame();
+        interiorFrame = opDesc.getInteriorFactory().getFrame();
+        leafFrame = opDesc.getLeafFactory().getFrame();
 
         BTreeRegistry btreeRegistry = opDesc.getBtreeRegistryProvider().getBTreeRegistry(ctx);
         btree = btreeRegistry.get(btreeFileId);
         if (btree == null) {
 
-			// create new btree and register it
-			btreeRegistry.lock();
-			try {
-				// check if btree has already been registered by another thread
-				btree = btreeRegistry.get(btreeFileId);
-				if (btree == null) {
-					// this thread should create and register the btree
+            // create new btree and register it
+            btreeRegistry.lock();
+            try {
+                // check if btree has already been registered by another thread
+                btree = btreeRegistry.get(btreeFileId);
+                if (btree == null) {
+                    // this thread should create and register the btree
 
-					IBinaryComparator[] comparators = new IBinaryComparator[opDesc
-							.getComparatorFactories().length];
-					for (int i = 0; i < opDesc.getComparatorFactories().length; i++) {
-						comparators[i] = opDesc.getComparatorFactories()[i]
-								.createBinaryComparator();
-					}
+                    IBinaryComparator[] comparators = new IBinaryComparator[opDesc.getComparatorFactories().length];
+                    for (int i = 0; i < opDesc.getComparatorFactories().length; i++) {
+                        comparators[i] = opDesc.getComparatorFactories()[i].createBinaryComparator();
+                    }
 
-					MultiComparator cmp = new MultiComparator(opDesc
-							.getTypeTraits(), comparators);
+                    MultiComparator cmp = new MultiComparator(opDesc.getTypeTraits(), comparators);
 
-					btree = new BTree(bufferCache, opDesc.getInteriorFactory(),
-							opDesc.getLeafFactory(), cmp);
-					if (mode == BTreeMode.CREATE_BTREE) {
-						MetaDataFrame metaFrame = new MetaDataFrame();
-						try {
-							btree.create(btreeFileId, leafFrame, metaFrame);
-							btree.open(btreeFileId);
-						} catch (Exception e) {
-							throw new HyracksDataException(e);
-						}
-					}
-					btreeRegistry.register(btreeFileId, btree);
-				}
-			} finally {
-				btreeRegistry.unlock();
-			}
-		}
-	}
+                    btree = new BTree(bufferCache, opDesc.getInteriorFactory(), opDesc.getLeafFactory(), cmp);
+                    if (mode == BTreeMode.CREATE_BTREE) {
+                        MetaDataFrame metaFrame = new MetaDataFrame();
+                        try {
+                            btree.create(btreeFileId, leafFrame, metaFrame);
+                            btree.open(btreeFileId);
+                        } catch (Exception e) {
+                            throw new HyracksDataException(e);
+                        }
+                    }
+                    btreeRegistry.register(btreeFileId, btree);
+                }
+            } finally {
+                btreeRegistry.unlock();
+            }
+        }
+    }
 
     public void deinit() throws HyracksDataException {
         if (btreeFileId != -1) {
@@ -135,27 +131,27 @@
         }
     }
 
-	public BTree getBTree() {
-		return btree;
-	}
+    public BTree getBTree() {
+        return btree;
+    }
 
-    public IHyracksStageletContext getHyracksStageletContext() {
+    public IHyracksTaskContext getHyracksStageletContext() {
         return ctx;
     }
 
-	public AbstractBTreeOperatorDescriptor getOperatorDescriptor() {
-		return opDesc;
-	}
+    public AbstractBTreeOperatorDescriptor getOperatorDescriptor() {
+        return opDesc;
+    }
 
-	public IBTreeLeafFrame getLeafFrame() {
-		return leafFrame;
-	}
+    public IBTreeLeafFrame getLeafFrame() {
+        return leafFrame;
+    }
 
-	public IBTreeInteriorFrame getInteriorFrame() {
-		return interiorFrame;
-	}
+    public IBTreeInteriorFrame getInteriorFrame() {
+        return interiorFrame;
+    }
 
-	public int getBTreeFileId() {
-		return btreeFileId;
-	}
+    public int getBTreeFileId() {
+        return btreeFileId;
+    }
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorDescriptor.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorDescriptor.java
index 21f37a3..efb616b 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorDescriptor.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorDescriptor.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.storage.am.btree.dataflow;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
@@ -55,7 +55,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(final IHyracksStageletContext ctx, final IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(final IHyracksTaskContext ctx, final IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) {
         return new BTreeSearchOperatorNodePushable(this, ctx, partition, recordDescProvider, isForward, lowKeyFields,
                 highKeyFields, lowKeyInclusive, highKeyInclusive);
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorNodePushable.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorNodePushable.java
index 415f169..819dea6 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorNodePushable.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/BTreeSearchOperatorNodePushable.java
@@ -17,7 +17,7 @@
 import java.io.DataOutput;
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -37,194 +37,172 @@
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangeSearchCursor;
 
-public class BTreeSearchOperatorNodePushable extends
-		AbstractUnaryInputUnaryOutputOperatorNodePushable {
-	private BTreeOpHelper btreeOpHelper;
-	private FrameTupleAccessor accessor;
+public class BTreeSearchOperatorNodePushable extends AbstractUnaryInputUnaryOutputOperatorNodePushable {
+    private BTreeOpHelper btreeOpHelper;
+    private FrameTupleAccessor accessor;
 
-	private ByteBuffer writeBuffer;
-	private FrameTupleAppender appender;
-	private ArrayTupleBuilder tb;
-	private DataOutput dos;
+    private ByteBuffer writeBuffer;
+    private FrameTupleAppender appender;
+    private ArrayTupleBuilder tb;
+    private DataOutput dos;
 
-	private BTree btree;
-	private boolean isForward;
-	private PermutingFrameTupleReference lowKey;
-	private PermutingFrameTupleReference highKey;
-	private boolean lowKeyInclusive;
-	private boolean highKeyInclusive;
-	private RangePredicate rangePred;
-	private MultiComparator lowKeySearchCmp;
-	private MultiComparator highKeySearchCmp;
-	private IBTreeCursor cursor;
-	private IBTreeLeafFrame cursorFrame;
-	private BTreeOpContext opCtx;
+    private BTree btree;
+    private boolean isForward;
+    private PermutingFrameTupleReference lowKey;
+    private PermutingFrameTupleReference highKey;
+    private boolean lowKeyInclusive;
+    private boolean highKeyInclusive;
+    private RangePredicate rangePred;
+    private MultiComparator lowKeySearchCmp;
+    private MultiComparator highKeySearchCmp;
+    private IBTreeCursor cursor;
+    private IBTreeLeafFrame cursorFrame;
+    private BTreeOpContext opCtx;
 
-	private RecordDescriptor recDesc;
+    private RecordDescriptor recDesc;
 
-	public BTreeSearchOperatorNodePushable(
-			AbstractBTreeOperatorDescriptor opDesc,
-			IHyracksStageletContext ctx, int partition,
-			IRecordDescriptorProvider recordDescProvider, boolean isForward,
-			int[] lowKeyFields, int[] highKeyFields, boolean lowKeyInclusive,
-			boolean highKeyInclusive) {
-		btreeOpHelper = new BTreeOpHelper(opDesc, ctx, partition,
-				BTreeOpHelper.BTreeMode.OPEN_BTREE);
-		this.isForward = isForward;
-		this.lowKeyInclusive = lowKeyInclusive;
-		this.highKeyInclusive = highKeyInclusive;
-		this.recDesc = recordDescProvider.getInputRecordDescriptor(opDesc
-				.getOperatorId(), 0);
-		if (lowKeyFields != null && lowKeyFields.length > 0) {
-			lowKey = new PermutingFrameTupleReference();
-			lowKey.setFieldPermutation(lowKeyFields);
-		}
-		if (highKeyFields != null && highKeyFields.length > 0) {
-			highKey = new PermutingFrameTupleReference();
-			highKey.setFieldPermutation(highKeyFields);
-		}
-	}
+    public BTreeSearchOperatorNodePushable(AbstractBTreeOperatorDescriptor opDesc, IHyracksTaskContext ctx,
+            int partition, IRecordDescriptorProvider recordDescProvider, boolean isForward, int[] lowKeyFields,
+            int[] highKeyFields, boolean lowKeyInclusive, boolean highKeyInclusive) {
+        btreeOpHelper = new BTreeOpHelper(opDesc, ctx, partition, BTreeOpHelper.BTreeMode.OPEN_BTREE);
+        this.isForward = isForward;
+        this.lowKeyInclusive = lowKeyInclusive;
+        this.highKeyInclusive = highKeyInclusive;
+        this.recDesc = recordDescProvider.getInputRecordDescriptor(opDesc.getOperatorId(), 0);
+        if (lowKeyFields != null && lowKeyFields.length > 0) {
+            lowKey = new PermutingFrameTupleReference();
+            lowKey.setFieldPermutation(lowKeyFields);
+        }
+        if (highKeyFields != null && highKeyFields.length > 0) {
+            highKey = new PermutingFrameTupleReference();
+            highKey.setFieldPermutation(highKeyFields);
+        }
+    }
 
-	@Override
-	public void open() throws HyracksDataException {
-		AbstractBTreeOperatorDescriptor opDesc = btreeOpHelper
-				.getOperatorDescriptor();
-		accessor = new FrameTupleAccessor(btreeOpHelper
-				.getHyracksStageletContext().getFrameSize(), recDesc);
+    @Override
+    public void open() throws HyracksDataException {
+        AbstractBTreeOperatorDescriptor opDesc = btreeOpHelper.getOperatorDescriptor();
+        accessor = new FrameTupleAccessor(btreeOpHelper.getHyracksStageletContext().getFrameSize(), recDesc);
 
-		cursorFrame = opDesc.getLeafFactory().getFrame();
-		cursor = new RangeSearchCursor(cursorFrame);
+        cursorFrame = opDesc.getLeafFactory().getFrame();
+        cursor = new RangeSearchCursor(cursorFrame);
 
-		try {
+        try {
 
-			btreeOpHelper.init();
-			btree = btreeOpHelper.getBTree();
+            btreeOpHelper.init();
+            btree = btreeOpHelper.getBTree();
 
-			// construct range predicate
+            // construct range predicate
 
-			int lowKeySearchFields = btree.getMultiComparator()
-					.getComparators().length;
-			int highKeySearchFields = btree.getMultiComparator()
-					.getComparators().length;
-			if (lowKey != null)
-				lowKeySearchFields = lowKey.getFieldCount();
-			if (highKey != null)
-				highKeySearchFields = highKey.getFieldCount();
+            int lowKeySearchFields = btree.getMultiComparator().getComparators().length;
+            int highKeySearchFields = btree.getMultiComparator().getComparators().length;
+            if (lowKey != null)
+                lowKeySearchFields = lowKey.getFieldCount();
+            if (highKey != null)
+                highKeySearchFields = highKey.getFieldCount();
 
-			IBinaryComparator[] lowKeySearchComparators = new IBinaryComparator[lowKeySearchFields];
-			for (int i = 0; i < lowKeySearchFields; i++) {
-				lowKeySearchComparators[i] = btree.getMultiComparator()
-						.getComparators()[i];
-			}
-			lowKeySearchCmp = new MultiComparator(btree.getMultiComparator()
-					.getTypeTraits(), lowKeySearchComparators);
+            IBinaryComparator[] lowKeySearchComparators = new IBinaryComparator[lowKeySearchFields];
+            for (int i = 0; i < lowKeySearchFields; i++) {
+                lowKeySearchComparators[i] = btree.getMultiComparator().getComparators()[i];
+            }
+            lowKeySearchCmp = new MultiComparator(btree.getMultiComparator().getTypeTraits(), lowKeySearchComparators);
 
-			if (lowKeySearchFields == highKeySearchFields) {
-				highKeySearchCmp = lowKeySearchCmp;
-			} else {
-				IBinaryComparator[] highKeySearchComparators = new IBinaryComparator[highKeySearchFields];
-				for (int i = 0; i < highKeySearchFields; i++) {
-					highKeySearchComparators[i] = btree.getMultiComparator()
-							.getComparators()[i];
-				}
-				highKeySearchCmp = new MultiComparator(btree
-						.getMultiComparator().getTypeTraits(),
-						highKeySearchComparators);
+            if (lowKeySearchFields == highKeySearchFields) {
+                highKeySearchCmp = lowKeySearchCmp;
+            } else {
+                IBinaryComparator[] highKeySearchComparators = new IBinaryComparator[highKeySearchFields];
+                for (int i = 0; i < highKeySearchFields; i++) {
+                    highKeySearchComparators[i] = btree.getMultiComparator().getComparators()[i];
+                }
+                highKeySearchCmp = new MultiComparator(btree.getMultiComparator().getTypeTraits(),
+                        highKeySearchComparators);
 
-			}
+            }
 
-			rangePred = new RangePredicate(isForward, null, null,
-					lowKeyInclusive, highKeyInclusive, lowKeySearchCmp,
-					highKeySearchCmp);
+            rangePred = new RangePredicate(isForward, null, null, lowKeyInclusive, highKeyInclusive, lowKeySearchCmp,
+                    highKeySearchCmp);
 
-			accessor = new FrameTupleAccessor(btreeOpHelper
-					.getHyracksStageletContext().getFrameSize(), recDesc);
+            accessor = new FrameTupleAccessor(btreeOpHelper.getHyracksStageletContext().getFrameSize(), recDesc);
 
-			writeBuffer = btreeOpHelper.getHyracksStageletContext()
-					.allocateFrame();
-			tb = new ArrayTupleBuilder(btree.getMultiComparator()
-					.getFieldCount());
-			dos = tb.getDataOutput();
-			appender = new FrameTupleAppender(btreeOpHelper
-					.getHyracksStageletContext().getFrameSize());
-			appender.reset(writeBuffer, true);
+            writeBuffer = btreeOpHelper.getHyracksStageletContext().allocateFrame();
+            tb = new ArrayTupleBuilder(btree.getMultiComparator().getFieldCount());
+            dos = tb.getDataOutput();
+            appender = new FrameTupleAppender(btreeOpHelper.getHyracksStageletContext().getFrameSize());
+            appender.reset(writeBuffer, true);
 
-			opCtx = btree.createOpContext(BTreeOp.BTO_SEARCH, btreeOpHelper
-					.getLeafFrame(), btreeOpHelper.getInteriorFrame(), null);
+            opCtx = btree.createOpContext(BTreeOp.BTO_SEARCH, btreeOpHelper.getLeafFrame(),
+                    btreeOpHelper.getInteriorFrame(), null);
 
-		} catch (Exception e) {
-			btreeOpHelper.deinit();
-		}
-	}
+        } catch (Exception e) {
+            btreeOpHelper.deinit();
+        }
+    }
 
-	private void writeSearchResults() throws Exception {
-		while (cursor.hasNext()) {
-			tb.reset();
-			cursor.next();
+    private void writeSearchResults() throws Exception {
+        while (cursor.hasNext()) {
+            tb.reset();
+            cursor.next();
 
-			ITupleReference frameTuple = cursor.getTuple();
-			for (int i = 0; i < frameTuple.getFieldCount(); i++) {
-				dos.write(frameTuple.getFieldData(i), frameTuple
-						.getFieldStart(i), frameTuple.getFieldLength(i));
-				tb.addFieldEndOffset();
-			}
+            ITupleReference frameTuple = cursor.getTuple();
+            for (int i = 0; i < frameTuple.getFieldCount(); i++) {
+                dos.write(frameTuple.getFieldData(i), frameTuple.getFieldStart(i), frameTuple.getFieldLength(i));
+                tb.addFieldEndOffset();
+            }
 
-			if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0,
-					tb.getSize())) {
-				FrameUtils.flushFrame(writeBuffer, writer);
-				appender.reset(writeBuffer, true);
-				if (!appender.append(tb.getFieldEndOffsets(),
-						tb.getByteArray(), 0, tb.getSize())) {
-					throw new IllegalStateException();
-				}
-			}
-		}
-	}
+            if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
+                FrameUtils.flushFrame(writeBuffer, writer);
+                appender.reset(writeBuffer, true);
+                if (!appender.append(tb.getFieldEndOffsets(), tb.getByteArray(), 0, tb.getSize())) {
+                    throw new IllegalStateException();
+                }
+            }
+        }
+    }
 
-	@Override
-	public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
-		accessor.reset(buffer);
+    @Override
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
+        accessor.reset(buffer);
 
-		int tupleCount = accessor.getTupleCount();
-		try {
-			for (int i = 0; i < tupleCount; i++) {
-				if (lowKey != null)
-					lowKey.reset(accessor, i);
-				if (highKey != null)
-					highKey.reset(accessor, i);
-				rangePred.setLowKey(lowKey, lowKeyInclusive);
-				rangePred.setHighKey(highKey, highKeyInclusive);
+        int tupleCount = accessor.getTupleCount();
+        try {
+            for (int i = 0; i < tupleCount; i++) {
+                if (lowKey != null)
+                    lowKey.reset(accessor, i);
+                if (highKey != null)
+                    highKey.reset(accessor, i);
+                rangePred.setLowKey(lowKey, lowKeyInclusive);
+                rangePred.setHighKey(highKey, highKeyInclusive);
 
-				cursor.reset();
-				btree.search(cursor, rangePred, opCtx);
-				writeSearchResults();
-			}
-		} catch (Exception e) {
-			throw new HyracksDataException(e);
-		}
-	}
+                cursor.reset();
+                btree.search(cursor, rangePred, opCtx);
+                writeSearchResults();
+            }
+        } catch (Exception e) {
+            throw new HyracksDataException(e);
+        }
+    }
 
-	@Override
-	public void close() throws HyracksDataException {
-		try {
-			if (appender.getTupleCount() > 0) {
-				FrameUtils.flushFrame(writeBuffer, writer);
-			}
-			writer.close();
-			try {
-				cursor.close();
-			} catch (Exception e) {
-				throw new HyracksDataException(e);
-			}
-		} finally {
-			btreeOpHelper.deinit();
-		}
-	}
+    @Override
+    public void close() throws HyracksDataException {
+        try {
+            if (appender.getTupleCount() > 0) {
+                FrameUtils.flushFrame(writeBuffer, writer);
+            }
+            writer.close();
+            try {
+                cursor.close();
+            } catch (Exception e) {
+                throw new HyracksDataException(e);
+            }
+        } finally {
+            btreeOpHelper.deinit();
+        }
+    }
 
-	@Override
-	public void flush() throws HyracksDataException {
-		if (appender.getTupleCount() > 0) {
-			FrameUtils.flushFrame(writeBuffer, writer);
-		}
-	}
+    @Override
+    public void flush() throws HyracksDataException {
+        if (appender.getTupleCount() > 0) {
+            FrameUtils.flushFrame(writeBuffer, writer);
+        }
+    }
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/IBTreeRegistryProvider.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/IBTreeRegistryProvider.java
index 7b66d0a..caf8615 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/IBTreeRegistryProvider.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/dataflow/IBTreeRegistryProvider.java
@@ -17,8 +17,8 @@
 
 import java.io.Serializable;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 
 public interface IBTreeRegistryProvider extends Serializable {
-    public BTreeRegistry getBTreeRegistry(IHyracksStageletContext ctx);
+    public BTreeRegistry getBTreeRegistry(IHyracksTaskContext ctx);
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorDescriptor.java b/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorDescriptor.java
index 059a1e2..6e7e0d3 100644
--- a/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorDescriptor.java
+++ b/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorDescriptor.java
@@ -15,7 +15,7 @@
 
 package edu.uci.ics.hyracks.storage.am.invertedindex.dataflow;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.IOperatorNodePushable;
 import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -47,7 +47,7 @@
     }
 
     @Override
-    public IOperatorNodePushable createPushRuntime(IHyracksStageletContext ctx, IOperatorEnvironment env,
+    public IOperatorNodePushable createPushRuntime(IHyracksTaskContext ctx, IOperatorEnvironment env,
             IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions) throws HyracksDataException {
         return new BinaryTokenizerOperatorNodePushable(ctx, recordDescProvider.getInputRecordDescriptor(odId, 0),
                 recordDescriptors[0], tokenizerFactory.createBinaryTokenizer(), tokenFields, projFields);
diff --git a/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorNodePushable.java b/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorNodePushable.java
index 9dac535..c6f6e5b 100644
--- a/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorNodePushable.java
+++ b/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/dataflow/BinaryTokenizerOperatorNodePushable.java
@@ -19,7 +19,7 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
@@ -31,7 +31,7 @@
 
 public class BinaryTokenizerOperatorNodePushable extends AbstractUnaryInputUnaryOutputOperatorNodePushable {
 
-    private final IHyracksStageletContext ctx;
+    private final IHyracksTaskContext ctx;
     private final IBinaryTokenizer tokenizer;
     private final int[] tokenFields;
     private final int[] projFields;
@@ -44,7 +44,7 @@
     private FrameTupleAppender appender;
     private ByteBuffer writeBuffer;
 
-    public BinaryTokenizerOperatorNodePushable(IHyracksStageletContext ctx, RecordDescriptor inputRecDesc,
+    public BinaryTokenizerOperatorNodePushable(IHyracksTaskContext ctx, RecordDescriptor inputRecDesc,
             RecordDescriptor outputRecDesc, IBinaryTokenizer tokenizer, int[] tokenFields, int[] projFields) {
         this.ctx = ctx;
         this.tokenizer = tokenizer;
diff --git a/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/SimpleConjunctiveSearcher.java b/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/SimpleConjunctiveSearcher.java
index 6ad5a9c..f88439c 100644
--- a/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/SimpleConjunctiveSearcher.java
+++ b/hyracks-storage-am-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/invertedindex/impls/SimpleConjunctiveSearcher.java
@@ -21,7 +21,7 @@
 import java.util.ArrayList;
 import java.util.List;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
@@ -54,7 +54,7 @@
     private final IBinaryComparator[] valueCmps;
 
     private final BTree btree;
-    private final IHyracksStageletContext ctx;
+    private final IHyracksTaskContext ctx;
     private final ArrayTupleBuilder resultTupleBuilder;
     private final FrameTupleAppender resultTupleAppender;
     private final FrameTupleAccessor resultFrameAccessor;
@@ -73,7 +73,7 @@
 
     private final IBinaryTokenizer queryTokenizer;
 
-    public SimpleConjunctiveSearcher(IHyracksStageletContext ctx, BTree btree, RecordDescriptor btreeRecDesc,
+    public SimpleConjunctiveSearcher(IHyracksTaskContext ctx, BTree btree, RecordDescriptor btreeRecDesc,
             IBinaryTokenizer queryTokenizer, int numKeyFields, int numValueFields) {
         this.ctx = ctx;
         this.btree = btree;
diff --git a/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/IStorageManagerInterface.java b/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/IStorageManagerInterface.java
index f64af2e..562305e 100644
--- a/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/IStorageManagerInterface.java
+++ b/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/IStorageManagerInterface.java
@@ -16,12 +16,12 @@
 
 import java.io.Serializable;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
 public interface IStorageManagerInterface extends Serializable {
-    public IBufferCache getBufferCache(IHyracksStageletContext ctx);
+    public IBufferCache getBufferCache(IHyracksTaskContext ctx);
 
-    public IFileMapProvider getFileMapProvider(IHyracksStageletContext ctx);
+    public IFileMapProvider getFileMapProvider(IHyracksTaskContext ctx);
 }
\ No newline at end of file
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestBTreeRegistryProvider.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestBTreeRegistryProvider.java
index 3ab0427..864f916 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestBTreeRegistryProvider.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestBTreeRegistryProvider.java
@@ -14,7 +14,7 @@
  */
 package edu.uci.ics.hyracks.test.support;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.BTreeRegistry;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.IBTreeRegistryProvider;
 
@@ -22,7 +22,7 @@
     private static final long serialVersionUID = 1L;
 
     @Override
-    public BTreeRegistry getBTreeRegistry(IHyracksStageletContext ctx) {
+    public BTreeRegistry getBTreeRegistry(IHyracksTaskContext ctx) {
         return TestStorageManagerComponentHolder.getBTreeRegistry(ctx);
     }
 }
\ No newline at end of file
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestJobletContext.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestJobletContext.java
index 2fc43fc..620e1a5 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestJobletContext.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestJobletContext.java
@@ -26,19 +26,17 @@
 import edu.uci.ics.hyracks.api.job.profiling.counters.ICounterContext;
 import edu.uci.ics.hyracks.api.resources.IDeallocatable;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
-import edu.uci.ics.hyracks.control.nc.io.ManagedWorkspaceFileFactory;
+import edu.uci.ics.hyracks.control.nc.io.WorkspaceFileFactory;
 
 public class TestJobletContext implements IHyracksJobletContext {
     private final INCApplicationContext appContext;
     private UUID jobId;
-    private int attempt;
-    private ManagedWorkspaceFileFactory fileFactory;
+    private WorkspaceFileFactory fileFactory;
 
-    public TestJobletContext(INCApplicationContext appContext, UUID jobId, int attempt) throws HyracksException {
+    public TestJobletContext(INCApplicationContext appContext, UUID jobId) throws HyracksException {
         this.appContext = appContext;
         this.jobId = jobId;
-        this.attempt = attempt;
-        fileFactory = new ManagedWorkspaceFileFactory(this, (IOManager) getIOManager());
+        fileFactory = new WorkspaceFileFactory(this, (IOManager) getIOManager());
     }
 
     @Override
@@ -57,13 +55,18 @@
     }
 
     @Override
-    public FileReference createWorkspaceFile(String prefix) throws HyracksDataException {
-        return fileFactory.createWorkspaceFile(prefix);
+    public FileReference createManagedWorkspaceFile(String prefix) throws HyracksDataException {
+        return fileFactory.createManagedWorkspaceFile(prefix);
+    }
+
+    @Override
+    public FileReference createUnmanagedWorkspaceFile(String prefix) throws HyracksDataException {
+        return fileFactory.createUnmanagedWorkspaceFile(prefix);
     }
 
     @Override
     public ICounterContext getCounterContext() {
-        return new CounterContext(jobId + "." + attempt);
+        return new CounterContext(jobId.toString());
     }
 
     @Override
@@ -85,9 +88,4 @@
     public UUID getJobId() {
         return jobId;
     }
-
-    @Override
-    public int getAttempt() {
-        return attempt;
-    }
 }
\ No newline at end of file
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStorageManagerComponentHolder.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStorageManagerComponentHolder.java
index 5338d5e..25e6f3f 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStorageManagerComponentHolder.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStorageManagerComponentHolder.java
@@ -14,7 +14,7 @@
  */
 package edu.uci.ics.hyracks.test.support;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.btree.dataflow.BTreeRegistry;
 import edu.uci.ics.hyracks.storage.common.buffercache.BufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.ClockPageReplacementStrategy;
@@ -42,7 +42,7 @@
         btreeRegistry = null;
     }
 
-    public synchronized static IBufferCache getBufferCache(IHyracksStageletContext ctx) {
+    public synchronized static IBufferCache getBufferCache(IHyracksTaskContext ctx) {
         if (bufferCache == null) {
             ICacheMemoryAllocator allocator = new HeapBufferAllocator();
             IPageReplacementStrategy prs = new ClockPageReplacementStrategy();
@@ -53,14 +53,14 @@
         return bufferCache;
     }
 
-    public synchronized static IFileMapProvider getFileMapProvider(IHyracksStageletContext ctx) {
+    public synchronized static IFileMapProvider getFileMapProvider(IHyracksTaskContext ctx) {
         if (fileMapProvider == null) {
             fileMapProvider = new TransientFileMapManager();
         }
         return fileMapProvider;
     }
 
-    public synchronized static BTreeRegistry getBTreeRegistry(IHyracksStageletContext ctx) {
+    public synchronized static BTreeRegistry getBTreeRegistry(IHyracksTaskContext ctx) {
         if (btreeRegistry == null) {
             btreeRegistry = new BTreeRegistry();
         }
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStorageManagerInterface.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStorageManagerInterface.java
index e923cdd..4059ef0 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStorageManagerInterface.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStorageManagerInterface.java
@@ -14,7 +14,7 @@
  */
 package edu.uci.ics.hyracks.test.support;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.common.IStorageManagerInterface;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
@@ -23,12 +23,12 @@
     private static final long serialVersionUID = 1L;
 
     @Override
-    public IBufferCache getBufferCache(IHyracksStageletContext ctx) {
+    public IBufferCache getBufferCache(IHyracksTaskContext ctx) {
         return TestStorageManagerComponentHolder.getBufferCache(ctx);
     }
 
     @Override
-    public IFileMapProvider getFileMapProvider(IHyracksStageletContext ctx) {
+    public IFileMapProvider getFileMapProvider(IHyracksTaskContext ctx) {
         return TestStorageManagerComponentHolder.getFileMapProvider(ctx);
     }
 }
\ No newline at end of file
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStageletContext.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestTaskContext.java
similarity index 68%
rename from hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStageletContext.java
rename to hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestTaskContext.java
index 4d31326..589352a 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestStageletContext.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestTaskContext.java
@@ -15,10 +15,10 @@
 package edu.uci.ics.hyracks.test.support;
 
 import java.nio.ByteBuffer;
-import java.util.UUID;
 
 import edu.uci.ics.hyracks.api.context.IHyracksJobletContext;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.api.io.FileReference;
@@ -26,17 +26,17 @@
 import edu.uci.ics.hyracks.api.job.profiling.counters.ICounterContext;
 import edu.uci.ics.hyracks.api.resources.IDeallocatable;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
-import edu.uci.ics.hyracks.control.nc.io.ManagedWorkspaceFileFactory;
+import edu.uci.ics.hyracks.control.nc.io.WorkspaceFileFactory;
 
-public class TestStageletContext implements IHyracksStageletContext {
+public class TestTaskContext implements IHyracksTaskContext {
     private final IHyracksJobletContext jobletContext;
-    private UUID stageId;
-    private ManagedWorkspaceFileFactory fileFactory;
+    private final TaskAttemptId taskId;
+    private WorkspaceFileFactory fileFactory;
 
-    public TestStageletContext(IHyracksJobletContext jobletContext, UUID stageId) throws HyracksException {
+    public TestTaskContext(IHyracksJobletContext jobletContext, TaskAttemptId taskId) throws HyracksException {
         this.jobletContext = jobletContext;
-        this.stageId = stageId;
-        fileFactory = new ManagedWorkspaceFileFactory(this, (IOManager) getIOManager());
+        this.taskId = taskId;
+        fileFactory = new WorkspaceFileFactory(this, (IOManager) getIOManager());
     }
 
     @Override
@@ -55,8 +55,13 @@
     }
 
     @Override
-    public FileReference createWorkspaceFile(String prefix) throws HyracksDataException {
-        return fileFactory.createWorkspaceFile(prefix);
+    public FileReference createManagedWorkspaceFile(String prefix) throws HyracksDataException {
+        return fileFactory.createManagedWorkspaceFile(prefix);
+    }
+
+    @Override
+    public FileReference createUnmanagedWorkspaceFile(String prefix) throws HyracksDataException {
+        return fileFactory.createUnmanagedWorkspaceFile(prefix);
     }
 
     @Override
@@ -65,13 +70,8 @@
     }
 
     @Override
-    public UUID getStageId() {
-        return stageId;
-    }
-
-    @Override
     public ICounterContext getCounterContext() {
-        return new CounterContext(jobletContext.getJobId() + "." + jobletContext.getAttempt() + "." + stageId);
+        return new CounterContext(jobletContext.getJobId() + "." + taskId);
     }
 
     @Override
@@ -83,4 +83,9 @@
             }
         });
     }
+
+    @Override
+    public TaskAttemptId getTaskId() {
+        return taskId;
+    }
 }
\ No newline at end of file
diff --git a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestUtils.java b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestUtils.java
index 2edeaff..71c4a24 100644
--- a/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestUtils.java
+++ b/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestUtils.java
@@ -19,17 +19,23 @@
 import edu.uci.ics.hyracks.api.application.INCApplicationContext;
 import edu.uci.ics.hyracks.api.context.IHyracksJobletContext;
 import edu.uci.ics.hyracks.api.context.IHyracksRootContext;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.ActivityNodeId;
+import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
+import edu.uci.ics.hyracks.api.dataflow.TaskAttemptId;
+import edu.uci.ics.hyracks.api.dataflow.TaskId;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 
 public class TestUtils {
-    public static IHyracksStageletContext create(int frameSize) {
+    public static IHyracksTaskContext create(int frameSize) {
         try {
             IHyracksRootContext rootCtx = new TestRootContext(frameSize);
             INCApplicationContext appCtx = new TestNCApplicationContext(rootCtx);
-            IHyracksJobletContext jobletCtx = new TestJobletContext(appCtx, UUID.randomUUID(), 0);
-            IHyracksStageletContext stageletCtx = new TestStageletContext(jobletCtx, UUID.randomUUID());
-            return stageletCtx;
+            IHyracksJobletContext jobletCtx = new TestJobletContext(appCtx, UUID.randomUUID());
+            TaskAttemptId tid = new TaskAttemptId(new TaskId(new ActivityNodeId(new OperatorDescriptorId(
+                    UUID.randomUUID()), UUID.randomUUID()), 0), 0);
+            IHyracksTaskContext taskCtx = new TestTaskContext(jobletCtx, tid);
+            return taskCtx;
         } catch (HyracksException e) {
             throw new RuntimeException(e);
         }
diff --git a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeFieldPrefixNSMTest.java b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeFieldPrefixNSMTest.java
index e856296..8e3be9c 100644
--- a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeFieldPrefixNSMTest.java
+++ b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeFieldPrefixNSMTest.java
@@ -24,7 +24,7 @@
 import org.junit.Test;
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
@@ -59,7 +59,7 @@
 	private static final int PAGE_SIZE = 32768; // 32K
 	private static final int NUM_PAGES = 40;
 	private static final int HYRACKS_FRAME_SIZE = 128;
-	private IHyracksStageletContext ctx = TestUtils.create(HYRACKS_FRAME_SIZE);
+	private IHyracksTaskContext ctx = TestUtils.create(HYRACKS_FRAME_SIZE);
 	
 	public class BufferAllocator implements ICacheMemoryAllocator {
 		@Override
@@ -72,7 +72,7 @@
 		}
 	}
 
-	private ITupleReference createTuple(IHyracksStageletContext ctx, int f0,
+    private ITupleReference createTuple(IHyracksTaskContext ctx, int f0,
 			int f1, int f2, boolean print) throws HyracksDataException {
 		if (print)
 			System.out.println("CREATING: " + f0 + " " + f1 + " " + f2);
diff --git a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeTest.java b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeTest.java
index 2985601..f9f8b89 100644
--- a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeTest.java
+++ b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/BTreeTest.java
@@ -23,7 +23,7 @@
 import org.junit.Test;
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
@@ -71,7 +71,7 @@
 	private static final int PAGE_SIZE = 256;
 	private static final int NUM_PAGES = 10;
 	private static final int HYRACKS_FRAME_SIZE = 128;
-	private IHyracksStageletContext ctx = TestUtils.create(HYRACKS_FRAME_SIZE);
+    private IHyracksTaskContext ctx = TestUtils.create(HYRACKS_FRAME_SIZE);
 
 	public class BufferAllocator implements ICacheMemoryAllocator {
 		@Override
diff --git a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/RangeSearchCursorTest.java b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/RangeSearchCursorTest.java
index 12371be..26a52b1 100644
--- a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/RangeSearchCursorTest.java
+++ b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/RangeSearchCursorTest.java
@@ -30,7 +30,7 @@
 import org.junit.Test;
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
@@ -102,7 +102,7 @@
 	IBTreeInteriorFrame interiorFrame = interiorFrameFactory.getFrame();
 	IBTreeMetaDataFrame metaFrame = metaFrameFactory.getFrame();
 
-	IHyracksStageletContext ctx = TestUtils.create(HYRACKS_FRAME_SIZE);
+    IHyracksTaskContext ctx = TestUtils.create(HYRACKS_FRAME_SIZE);
 	ByteBuffer frame = ctx.allocateFrame();
 	FrameTupleAppender appender = new FrameTupleAppender(ctx.getFrameSize());
 
diff --git a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/StorageManagerTest.java b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/StorageManagerTest.java
index 430a33c..709dd41 100644
--- a/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/StorageManagerTest.java
+++ b/hyracks-tests/hyracks-storage-am-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/btree/StorageManagerTest.java
@@ -22,7 +22,7 @@
 
 import org.junit.Test;
 
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
@@ -36,7 +36,7 @@
 public class StorageManagerTest extends AbstractBTreeTest {
 	private static final int PAGE_SIZE = 256;
 	private static final int NUM_PAGES = 10;
-	private IHyracksStageletContext ctx = TestUtils.create(32768);
+    private IHyracksTaskContext ctx = TestUtils.create(32768);
 
 	public class PinnedLatchedPage {
 		public final ICachedPage page;
diff --git a/hyracks-tests/hyracks-storage-am-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchers/SimpleConjunctiveSearcherTest.java b/hyracks-tests/hyracks-storage-am-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchers/SimpleConjunctiveSearcherTest.java
index f61249b..88b801f 100644
--- a/hyracks-tests/hyracks-storage-am-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchers/SimpleConjunctiveSearcherTest.java
+++ b/hyracks-tests/hyracks-storage-am-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/invertedindex/searchers/SimpleConjunctiveSearcherTest.java
@@ -28,7 +28,7 @@
 import org.junit.Test;
 
 import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
-import edu.uci.ics.hyracks.api.context.IHyracksStageletContext;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTrait;
@@ -79,7 +79,7 @@
     private static final int PAGE_SIZE = 32768;
     private static final int NUM_PAGES = 10;
     private static final int HYRACKS_FRAME_SIZE = 32768;
-    private IHyracksStageletContext ctx = TestUtils.create(HYRACKS_FRAME_SIZE);
+    private IHyracksTaskContext ctx = TestUtils.create(HYRACKS_FRAME_SIZE);
 
     public class BufferAllocator implements ICacheMemoryAllocator {
         @Override
@@ -224,7 +224,7 @@
         RecordDescriptor resultRecDesc = new RecordDescriptor(resultSerde);
         FrameTupleAccessor resultAccessor = new FrameTupleAccessor(ctx.getFrameSize(), resultRecDesc);
         FrameTupleReference resultTuple = new FrameTupleReference();
-        
+
         SimpleConjunctiveSearcher searcher = new SimpleConjunctiveSearcher(ctx, btree, btreeRecDesc, queryTokenizer,
                 numKeyFields, numValueFields);
 
@@ -241,8 +241,8 @@
             for (int i = 0; i < resultAccessor.getTupleCount(); i++) {
                 resultTuple.reset(resultAccessor, i);
                 for (int j = 0; j < resultTuple.getFieldCount(); j++) {
-                    ByteArrayInputStream inStream = new ByteArrayInputStream(resultTuple.getFieldData(j), resultTuple
-                            .getFieldStart(j), resultTuple.getFieldLength(j));
+                    ByteArrayInputStream inStream = new ByteArrayInputStream(resultTuple.getFieldData(j),
+                            resultTuple.getFieldStart(j), resultTuple.getFieldLength(j));
                     DataInput dataIn = new DataInputStream(inStream);
                     Object o = resultSerde[j].deserialize(dataIn);
                     System.out.print(o + " ");