diff --git a/hyracks-api/.classpath b/hyracks-api/.classpath
new file mode 100644
index 0000000..1f3c1ff
--- /dev/null
+++ b/hyracks-api/.classpath
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" output="target/classes" path="src/main/java"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.6"/>
+	<classpathentry kind="con" path="org.maven.ide.eclipse.MAVEN2_CLASSPATH_CONTAINER"/>
+	<classpathentry kind="output" path="target/classes"/>
+</classpath>
diff --git a/hyracks-api/.project b/hyracks-api/.project
new file mode 100644
index 0000000..4ae9e54
--- /dev/null
+++ b/hyracks-api/.project
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>hyracks-api</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.maven.ide.eclipse.maven2Builder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.maven.ide.eclipse.maven2Nature</nature>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>
diff --git a/hyracks-api/.settings/org.eclipse.jdt.core.prefs b/hyracks-api/.settings/org.eclipse.jdt.core.prefs
new file mode 100644
index 0000000..a0e106b
--- /dev/null
+++ b/hyracks-api/.settings/org.eclipse.jdt.core.prefs
@@ -0,0 +1,6 @@
+#Thu Jul 29 01:10:06 PDT 2010
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.6
+org.eclipse.jdt.core.compiler.compliance=1.6
+org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning
+org.eclipse.jdt.core.compiler.source=1.6
diff --git a/hyracks-api/.settings/org.maven.ide.eclipse.prefs b/hyracks-api/.settings/org.maven.ide.eclipse.prefs
new file mode 100644
index 0000000..930b4a1
--- /dev/null
+++ b/hyracks-api/.settings/org.maven.ide.eclipse.prefs
@@ -0,0 +1,9 @@
+#Thu Jul 29 01:10:05 PDT 2010
+activeProfiles=
+eclipse.preferences.version=1
+fullBuildGoals=process-test-resources
+includeModules=false
+resolveWorkspaceProjects=true
+resourceFilterGoals=process-resources resources\:testResources
+skipCompilerPlugin=true
+version=1
diff --git a/hyracks-api/pom.xml b/hyracks-api/pom.xml
new file mode 100644
index 0000000..9bec30c
--- /dev/null
+++ b/hyracks-api/pom.xml
@@ -0,0 +1,28 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>edu.uci.ics.hyracks</groupId>
+  <artifactId>hyracks-api</artifactId>
+  <version>0.1.0</version>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>2.0.2</version>
+        <configuration>
+          <source>1.6</source>
+          <target>1.6</target>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+  <dependencies>
+  	<dependency>
+  		<groupId>org.json</groupId>
+  		<artifactId>json</artifactId>
+  		<version>20090211</version>
+  		<type>jar</type>
+  		<scope>compile</scope>
+  	</dependency>
+  </dependencies>
+</project>
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/AbstractHyracksConnection.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/AbstractHyracksConnection.java
new file mode 100644
index 0000000..2bb44e0
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/AbstractHyracksConnection.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.api.client;
+
+import java.net.InetAddress;
+import java.util.EnumSet;
+import java.util.Map;
+import java.util.UUID;
+
+import edu.uci.ics.hyracks.api.job.JobFlag;
+import edu.uci.ics.hyracks.api.job.JobSpecification;
+import edu.uci.ics.hyracks.api.job.JobStatus;
+import edu.uci.ics.hyracks.api.job.statistics.JobStatistics;
+
+abstract class AbstractHyracksConnection implements IHyracksClientConnection {
+    private IHyracksClientInterface hci;
+
+    public AbstractHyracksConnection(IHyracksClientInterface hci) {
+        this.hci = hci;
+    }
+
+    @Override
+    public void createApplication(String appName) throws Exception {
+        hci.createApplication(appName);
+    }
+
+    @Override
+    public void startApplication(String appName) throws Exception {
+        hci.startApplication(appName);
+    }
+
+    @Override
+    public void destroyApplication(String appName) throws Exception {
+        hci.destroyApplication(appName);
+    }
+
+    @Override
+    public UUID createJob(JobSpecification jobSpec) throws Exception {
+        return hci.createJob(jobSpec);
+    }
+
+    @Override
+    public UUID createJob(JobSpecification jobSpec, EnumSet<JobFlag> jobFlags) throws Exception {
+        return hci.createJob(jobSpec, jobFlags);
+    }
+
+    @Override
+    public JobStatus getJobStatus(UUID jobId) throws Exception {
+        return hci.getJobStatus(jobId);
+    }
+
+    @Override
+    public void start(UUID jobId) throws Exception {
+        hci.start(jobId);
+    }
+
+    @Override
+    public JobStatistics waitForCompletion(UUID jobId) throws Exception {
+        return hci.waitForCompletion(jobId);
+    }
+
+    @Override
+    public Map<String, InetAddress[]> getRegistry() throws Exception {
+        return hci.getRegistry();
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/HyracksLocalConnection.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/HyracksLocalConnection.java
new file mode 100644
index 0000000..df1ff2b
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/HyracksLocalConnection.java
@@ -0,0 +1,21 @@
+/*
+ * 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.client;
+
+public final class HyracksLocalConnection extends AbstractHyracksConnection {
+    public HyracksLocalConnection(IHyracksClientInterface hci) {
+        super(hci);
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/HyracksRMIConnection.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/HyracksRMIConnection.java
new file mode 100644
index 0000000..18c354b
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/HyracksRMIConnection.java
@@ -0,0 +1,31 @@
+/*
+ * 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.client;
+
+import java.rmi.NotBoundException;
+import java.rmi.RemoteException;
+import java.rmi.registry.LocateRegistry;
+import java.rmi.registry.Registry;
+
+public final class HyracksRMIConnection extends AbstractHyracksConnection {
+    public HyracksRMIConnection(String host, int port) throws RemoteException, NotBoundException {
+        super(lookupHCI(host, port));
+    }
+
+    private static IHyracksClientInterface lookupHCI(String host, int port) throws RemoteException, NotBoundException {
+        Registry registry = LocateRegistry.getRegistry(host, port);
+        return (IHyracksClientInterface) registry.lookup(IHyracksClientInterface.class.getName());
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/IHyracksClientConnection.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/IHyracksClientConnection.java
new file mode 100644
index 0000000..ef11fd0
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/IHyracksClientConnection.java
@@ -0,0 +1,45 @@
+/*
+ * 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.client;
+
+import java.net.InetAddress;
+import java.util.EnumSet;
+import java.util.Map;
+import java.util.UUID;
+
+import edu.uci.ics.hyracks.api.job.JobFlag;
+import edu.uci.ics.hyracks.api.job.JobSpecification;
+import edu.uci.ics.hyracks.api.job.JobStatus;
+import edu.uci.ics.hyracks.api.job.statistics.JobStatistics;
+
+public interface IHyracksClientConnection {
+    public void createApplication(String appName) throws Exception;
+
+    public void startApplication(String appName) throws Exception;
+
+    public void destroyApplication(String appName) throws Exception;
+
+    public UUID createJob(JobSpecification jobSpec) throws Exception;
+
+    public UUID createJob(JobSpecification jobSpec, EnumSet<JobFlag> jobFlags) throws Exception;
+
+    public JobStatus getJobStatus(UUID jobId) throws Exception;
+
+    public void start(UUID jobId) throws Exception;
+
+    public JobStatistics waitForCompletion(UUID jobId) throws Exception;
+
+    public Map<String, InetAddress[]> getRegistry() throws Exception;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/IHyracksClientInterface.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/IHyracksClientInterface.java
new file mode 100644
index 0000000..229299f
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/client/IHyracksClientInterface.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.client;
+
+import java.net.InetAddress;
+import java.rmi.Remote;
+import java.util.EnumSet;
+import java.util.Map;
+import java.util.UUID;
+
+import edu.uci.ics.hyracks.api.job.JobFlag;
+import edu.uci.ics.hyracks.api.job.JobSpecification;
+import edu.uci.ics.hyracks.api.job.JobStatus;
+import edu.uci.ics.hyracks.api.job.statistics.JobStatistics;
+
+public interface IHyracksClientInterface extends Remote {
+    public void createApplication(String appName) throws Exception;
+
+    public void startApplication(String appName) throws Exception;
+
+    public void destroyApplication(String appName) throws Exception;
+
+    public UUID createJob(JobSpecification jobSpec) throws Exception;
+
+    public UUID createJob(JobSpecification jobSpec, EnumSet<JobFlag> jobFlags) throws Exception;
+
+    public JobStatus getJobStatus(UUID jobId) throws Exception;
+
+    public void start(UUID jobId) throws Exception;
+
+    public JobStatistics waitForCompletion(UUID jobId) throws Exception;
+
+    public Map<String, InetAddress[]> getRegistry() throws Exception;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IConnectionDemultiplexer.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IConnectionDemultiplexer.java
new file mode 100644
index 0000000..0587722
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IConnectionDemultiplexer.java
@@ -0,0 +1,27 @@
+/*
+ * 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.exceptions.HyracksDataException;
+
+public interface IConnectionDemultiplexer {
+    public int getSenderCount();
+
+    public IConnectionEntry findNextReadyEntry(int lastReadSender);
+
+    public void unreadyEntry(int index);
+
+    public int closeEntry(int index) throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IConnectionEntry.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IConnectionEntry.java
new file mode 100644
index 0000000..9e3cbbe
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IConnectionEntry.java
@@ -0,0 +1,48 @@
+/*
+ * 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;
+import java.nio.ByteBuffer;
+import java.nio.channels.SelectionKey;
+import java.util.UUID;
+
+public interface IConnectionEntry {
+    ByteBuffer getReadBuffer();
+
+    SelectionKey getSelectionKey();
+
+    void setDataReceiveListener(IDataReceiveListener listener);
+
+    void attach(Object attachment);
+
+    Object getAttachment();
+
+    void close() throws IOException;
+
+    void write(ByteBuffer buffer);
+
+    UUID getJobId();
+
+    UUID getStageId();
+
+    void setJobId(UUID jobId);
+
+    void setStageId(UUID stageId);
+
+    boolean aborted();
+
+    void abort();
+}
\ 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
new file mode 100644
index 0000000..463e4e1
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IDataReceiveListener.java
@@ -0,0 +1,23 @@
+/*
+ * 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
new file mode 100644
index 0000000..7e74aee
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IDataReceiveListenerFactory.java
@@ -0,0 +1,25 @@
+/*
+ * 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/IFrameReader.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IFrameReader.java
new file mode 100644
index 0000000..0188578
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IFrameReader.java
@@ -0,0 +1,27 @@
+/*
+ * 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.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface IFrameReader {
+    public void open() throws HyracksDataException;
+
+    public boolean nextFrame(ByteBuffer buffer) throws HyracksDataException;
+
+    public void close() throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IFrameTupleAccessor.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IFrameTupleAccessor.java
new file mode 100644
index 0000000..88b8768
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IFrameTupleAccessor.java
@@ -0,0 +1,21 @@
+package edu.uci.ics.hyracks.api.comm;
+
+import java.nio.ByteBuffer;
+
+public interface IFrameTupleAccessor {
+    public int getFieldSlotsLength();
+
+    public int getFieldEndOffset(int tupleIndex, int fIdx);
+
+    public int getFieldStartOffset(int tupleIndex, int fIdx);
+
+    public int getTupleEndOffset(int tupleIndex);
+
+    public int getTupleStartOffset(int tupleIndex);
+
+    public int getTupleCount();
+
+    public ByteBuffer getBuffer();
+
+    public void reset(ByteBuffer buffer);
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IFrameWriter.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IFrameWriter.java
new file mode 100644
index 0000000..eccd6cb
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/comm/IFrameWriter.java
@@ -0,0 +1,27 @@
+/*
+ * 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.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface IFrameWriter {
+    public void open() throws HyracksDataException;
+
+    public void nextFrame(ByteBuffer buffer) throws HyracksDataException;
+
+    public void close() throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/AbsoluteLocationConstraint.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/AbsoluteLocationConstraint.java
new file mode 100644
index 0000000..bbd4b4f
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/AbsoluteLocationConstraint.java
@@ -0,0 +1,45 @@
+/*
+ * 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;
+
+public class AbsoluteLocationConstraint extends LocationConstraint {
+    private static final long serialVersionUID = 1L;
+
+    private String nodeId;
+
+    public AbsoluteLocationConstraint() {
+    }
+
+    public AbsoluteLocationConstraint(String nodeId) {
+        this.nodeId = nodeId;
+    }
+
+    @Override
+    public LocationConstraintType getConstraintType() {
+        return LocationConstraintType.ABSOLUTE;
+    }
+
+    public String getLocationId() {
+        return nodeId;
+    }
+
+    public void setLocationId(String nodeId) {
+        this.nodeId = nodeId;
+    }
+
+    public String toString() {
+        return getConstraintType() + ":" + nodeId;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/ChoiceLocationConstraint.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/ChoiceLocationConstraint.java
new file mode 100644
index 0000000..edfb1c5
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/ChoiceLocationConstraint.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.api.constraints;
+
+public class ChoiceLocationConstraint extends LocationConstraint {
+    private static final long serialVersionUID = 1L;
+
+    private LocationConstraint[] choices;
+
+    public ChoiceLocationConstraint(LocationConstraint... choices) {
+        this.choices = choices;
+    }
+
+    public LocationConstraint[] getChoices() {
+        return choices;
+    }
+
+    @Override
+    public LocationConstraintType getConstraintType() {
+        return LocationConstraintType.CHOICE;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/ExplicitPartitionConstraint.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/ExplicitPartitionConstraint.java
new file mode 100644
index 0000000..16b7b24
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/ExplicitPartitionConstraint.java
@@ -0,0 +1,41 @@
+/*
+ * 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.util.Arrays;
+
+public class ExplicitPartitionConstraint extends PartitionConstraint {
+    private static final long serialVersionUID = 1L;
+
+    private final LocationConstraint[] locationConstraints;
+
+    public ExplicitPartitionConstraint(LocationConstraint[] locationConstraints) {
+        this.locationConstraints = locationConstraints;
+    }
+
+    public LocationConstraint[] getLocationConstraints() {
+        return locationConstraints;
+    }
+
+    @Override
+    public String toString() {
+        return Arrays.deepToString(locationConstraints);
+    }
+
+    @Override
+    public PartitionConstraintType getPartitionConstraintType() {
+        return PartitionConstraintType.EXPLICIT;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/LocationConstraint.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/LocationConstraint.java
new file mode 100644
index 0000000..1228b90
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/LocationConstraint.java
@@ -0,0 +1,28 @@
+/*
+ * 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;
+
+public abstract class LocationConstraint implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    public enum LocationConstraintType {
+        ABSOLUTE,
+        CHOICE
+    }
+
+    public abstract LocationConstraintType getConstraintType();
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/PartitionConstraint.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/PartitionConstraint.java
new file mode 100644
index 0000000..82a6f7b
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/PartitionConstraint.java
@@ -0,0 +1,28 @@
+/*
+ * 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;
+
+public abstract class PartitionConstraint implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    public abstract PartitionConstraintType getPartitionConstraintType();
+
+    public enum PartitionConstraintType {
+        EXPLICIT,
+        COUNT
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/PartitionCountConstraint.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/PartitionCountConstraint.java
new file mode 100644
index 0000000..b49d880
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/constraints/PartitionCountConstraint.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.api.constraints;
+
+public class PartitionCountConstraint extends PartitionConstraint {
+    private static final long serialVersionUID = 1L;
+
+    private final int count;
+
+    public PartitionCountConstraint(int count) {
+        this.count = count;
+    }
+
+    public int getCount() {
+        return count;
+    }
+
+    @Override
+    public PartitionConstraintType getPartitionConstraintType() {
+        return PartitionConstraintType.COUNT;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksContext.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksContext.java
new file mode 100644
index 0000000..8173785
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/context/IHyracksContext.java
@@ -0,0 +1,23 @@
+/*
+ * 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.context;
+
+import edu.uci.ics.hyracks.api.resources.IResourceManager;
+
+public interface IHyracksContext {
+    public IResourceManager getResourceManager();
+
+    public int getFrameSize();
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/ActivityNodeId.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/ActivityNodeId.java
new file mode 100644
index 0000000..12f76fe
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/ActivityNodeId.java
@@ -0,0 +1,58 @@
+/*
+ * 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;
+import java.util.UUID;
+
+public final class ActivityNodeId implements Serializable {
+    private static final long serialVersionUID = 1L;
+    private final OperatorDescriptorId odId;
+    private final UUID id;
+
+    public ActivityNodeId(OperatorDescriptorId odId, UUID id) {
+        this.odId = odId;
+        this.id = id;
+    }
+
+    public OperatorDescriptorId getOperatorDescriptorId() {
+        return odId;
+    }
+
+    public UUID getLocalId() {
+        return id;
+    }
+
+    @Override
+    public int hashCode() {
+        return odId.hashCode() + id.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof ActivityNodeId)) {
+            return false;
+        }
+        ActivityNodeId other = (ActivityNodeId) o;
+        return other.odId.equals(odId) && other.id.equals(id);
+    }
+
+    public String toString() {
+        return "ANID:" + id;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/ConnectorDescriptorId.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/ConnectorDescriptorId.java
new file mode 100644
index 0000000..86d8118
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/ConnectorDescriptorId.java
@@ -0,0 +1,54 @@
+/*
+ * 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;
+import java.util.UUID;
+
+public final class ConnectorDescriptorId implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private UUID id;
+
+    public ConnectorDescriptorId(UUID id) {
+        this.id = id;
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    @Override
+    public int hashCode() {
+        return id.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof ConnectorDescriptorId)) {
+            return false;
+        }
+        ConnectorDescriptorId other = (ConnectorDescriptorId) obj;
+        return id.equals(other.id);
+    }
+
+    @Override
+    public String toString() {
+        return "CDID:" + id;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/Direction.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/Direction.java
new file mode 100644
index 0000000..c884998
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/Direction.java
@@ -0,0 +1,20 @@
+/*
+ * 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;
+
+public enum Direction {
+    INPUT,
+    OUTPUT,
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IActivityGraphBuilder.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IActivityGraphBuilder.java
new file mode 100644
index 0000000..c6bc5e3
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IActivityGraphBuilder.java
@@ -0,0 +1,25 @@
+/*
+ * 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;
+
+public interface IActivityGraphBuilder {
+    public void addTask(IActivityNode task);
+
+    public void addBlockingEdge(IActivityNode blocker, IActivityNode blocked);
+
+    public void addSourceEdge(int operatorInputIndex, IActivityNode task, int taskInputIndex);
+
+    public void addTargetEdge(int operatorOutputIndex, IActivityNode task, int taskOutputIndex);
+}
\ 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
new file mode 100644
index 0000000..82d0e9e
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IActivityNode.java
@@ -0,0 +1,30 @@
+/*
+ * 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;
+
+import edu.uci.ics.hyracks.api.context.IHyracksContext;
+import edu.uci.ics.hyracks.api.dataflow.value.IRecordDescriptorProvider;
+import edu.uci.ics.hyracks.api.job.IOperatorEnvironment;
+
+public interface IActivityNode extends Serializable {
+    public ActivityNodeId getActivityNodeId();
+
+    public IOperatorDescriptor getOwner();
+
+    public IOperatorNodePushable createPushRuntime(IHyracksContext ctx, IOperatorEnvironment env,
+            IRecordDescriptorProvider recordDescProvider, int partition, int nPartitions);
+}
\ 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
new file mode 100644
index 0000000..25be8b3
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IConnectorDescriptor.java
@@ -0,0 +1,93 @@
+/*
+ * 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;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import edu.uci.ics.hyracks.api.comm.IConnectionDemultiplexer;
+import edu.uci.ics.hyracks.api.comm.IFrameReader;
+import edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.context.IHyracksContext;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+/**
+ * Connector that connects operators in a Job.
+ * 
+ * @author vinayakb
+ */
+public interface IConnectorDescriptor extends Serializable {
+    /**
+     * Gets the id of the connector.
+     * 
+     * @return
+     */
+    public ConnectorDescriptorId getConnectorId();
+
+    /**
+     * Factory method to create the send side writer that writes into this connector.
+     * 
+     * @param ctx
+     *            Context
+     * @param recordDesc
+     *            Record Descriptor
+     * @param edwFactory
+     *            Endpoint writer factory.
+     * @param index
+     *            ordinal index of the data producer partition.
+     * @param nProducerPartitions
+     *            Number of partitions of the producing operator.
+     * @param nConsumerPartitions
+     *            Number of partitions of the consuming operator.
+     * @return data writer.
+     * @throws Exception
+     */
+    public IFrameWriter createSendSideWriter(IHyracksContext ctx, RecordDescriptor recordDesc,
+            IEndpointDataWriterFactory edwFactory, int index, int nProducerPartitions, int nConsumerPartitions)
+            throws HyracksDataException;
+
+    /**
+     * Factory metod to create the receive side reader that reads data from this connector.
+     * 
+     * @param ctx
+     *            Context
+     * @param recordDesc
+     *            Job plan
+     * @param demux
+     *            Connection Demultiplexer
+     * @param index
+     *            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
+     * @throws HyracksDataException
+     */
+    public IFrameReader createReceiveSideReader(IHyracksContext ctx, RecordDescriptor recordDesc,
+            IConnectionDemultiplexer demux, int index, int nProducerPartitions, int nConsumerPartitions)
+            throws HyracksDataException;
+
+    /**
+     * Translate this connector descriptor to JSON.
+     * 
+     * @return
+     * @throws JSONException
+     */
+    public JSONObject toJSON() throws JSONException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IDataReader.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IDataReader.java
new file mode 100644
index 0000000..b5f45cb
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IDataReader.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.api.dataflow;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+/**
+ * Provides data to a consumer.
+ * 
+ * @author vinayakb
+ */
+public interface IDataReader<T> {
+    /**
+     * Reads one data item.
+     * 
+     * @return data. <code>null</code> indicates end of stream.
+     * @throws Exception
+     */
+    public T readData() throws HyracksDataException;
+
+    /**
+     * Closes this reader.
+     * 
+     * @throws Exception
+     */
+    public void close() throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IDataWriter.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IDataWriter.java
new file mode 100644
index 0000000..128576c
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IDataWriter.java
@@ -0,0 +1,40 @@
+/*
+ * 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 edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+/**
+ * Accepts data from data producers.
+ * 
+ * @author vinayakb
+ */
+public interface IDataWriter<T> {
+    /**
+     * Pushes data to the acceptor.
+     * 
+     * @param data
+     *            - Data pushed to the acceptor. <code>null</code> indicates the end of stream.
+     * @throws HyracksDataException
+     */
+    public void writeData(T data) throws HyracksDataException;
+
+    /**
+     * Closes this writer.
+     * 
+     * @throws Exception
+     */
+    public void close() throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IEndpointDataWriterFactory.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IEndpointDataWriterFactory.java
new file mode 100644
index 0000000..45c589a
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IEndpointDataWriterFactory.java
@@ -0,0 +1,22 @@
+/*
+ * 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 edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface IEndpointDataWriterFactory {
+    public IFrameWriter createFrameWriter(int index) throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOpenableDataReader.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOpenableDataReader.java
new file mode 100644
index 0000000..d0b6474
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOpenableDataReader.java
@@ -0,0 +1,21 @@
+/*
+ * 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 edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface IOpenableDataReader<T> extends IDataReader<T> {
+    public void open() throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOpenableDataWriter.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOpenableDataWriter.java
new file mode 100644
index 0000000..b2b15c6
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOpenableDataWriter.java
@@ -0,0 +1,21 @@
+/*
+ * 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 edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface IOpenableDataWriter<T> extends IDataWriter<T> {
+    public void open() throws HyracksDataException;
+}
\ No newline at end of file
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
new file mode 100644
index 0000000..ad51370
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorDescriptor.java
@@ -0,0 +1,86 @@
+/*
+ * 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;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import edu.uci.ics.hyracks.api.constraints.PartitionConstraint;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+
+/**
+ * Descriptor for operators in Hyracks.
+ * 
+ * @author vinayakb
+ */
+public interface IOperatorDescriptor extends Serializable {
+    /**
+     * Returns the id of the operator.
+     * 
+     * @return operator id
+     */
+    public OperatorDescriptorId getOperatorId();
+
+    /**
+     * Returns the number of inputs into this operator.
+     * 
+     * @return Number of inputs.
+     */
+    public int getInputArity();
+
+    /**
+     * Returns the number of outputs out of this operator.
+     * 
+     * @return Number of outputs.
+     */
+    public int getOutputArity();
+
+    /**
+     * Returns the partition constraint requested for scheduling this operator. This value is set as part of Job creation by the client.
+     * 
+     * @return the partition constraint.
+     */
+    public PartitionConstraint getPartitionConstraint();
+
+    /**
+     * Sets the partition constraint.
+     * 
+     * @param partitionConstraint
+     *            - partition constraint.
+     */
+    public void setPartitionConstraint(PartitionConstraint partitionConstraint);
+
+    /**
+     * Gets the output record descriptor
+     * 
+     * @return Array of RecordDescriptor, one per output.
+     */
+    public RecordDescriptor[] getOutputRecordDescriptors();
+
+    /**
+     * Contributes the activity graph that describes the behavior of this operator.
+     * 
+     * @param builder
+     *            - graph builder
+     */
+    public void contributeTaskGraph(IActivityGraphBuilder builder);
+
+    /**
+     * Translates this operator descriptor to JSON.
+     */
+    public JSONObject toJSON() throws JSONException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorNodePullable.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorNodePullable.java
new file mode 100644
index 0000000..1fa039f
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorNodePullable.java
@@ -0,0 +1,19 @@
+/*
+ * 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;
+
+public interface IOperatorNodePullable extends IOpenableDataReader<Object[]> {
+    public void setDataReader(int index, IOpenableDataWriter<Object[]> writer);
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorNodePushable.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorNodePushable.java
new file mode 100644
index 0000000..f019b13
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/IOperatorNodePushable.java
@@ -0,0 +1,22 @@
+/*
+ * 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 edu.uci.ics.hyracks.api.comm.IFrameWriter;
+import edu.uci.ics.hyracks.api.dataflow.value.RecordDescriptor;
+
+public interface IOperatorNodePushable extends IFrameWriter {
+    public void setFrameWriter(int index, IFrameWriter writer, RecordDescriptor recordDesc);
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/OperatorDescriptorId.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/OperatorDescriptorId.java
new file mode 100644
index 0000000..bbf3cf5
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/OperatorDescriptorId.java
@@ -0,0 +1,53 @@
+/*
+ * 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;
+import java.util.UUID;
+
+public final class OperatorDescriptorId implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private final UUID id;
+
+    public OperatorDescriptorId(UUID id) {
+        this.id = id;
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    @Override
+    public int hashCode() {
+        return id.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == this) {
+            return true;
+        }
+        if (!(o instanceof OperatorDescriptorId)) {
+            return false;
+        }
+        return ((OperatorDescriptorId) o).id.equals(id);
+    }
+
+    @Override
+    public String toString() {
+        return "ODID:" + id;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/OperatorInstanceId.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/OperatorInstanceId.java
new file mode 100644
index 0000000..f6ee39b
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/OperatorInstanceId.java
@@ -0,0 +1,65 @@
+/*
+ * 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 OperatorInstanceId implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private OperatorDescriptorId odId;
+    private int partition;
+
+    public OperatorInstanceId(OperatorDescriptorId odId, int partition) {
+        this.odId = odId;
+        this.partition = partition;
+    }
+
+    public OperatorDescriptorId getOperatorId() {
+        return odId;
+    }
+
+    public int getPartition() {
+        return partition;
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((odId == null) ? 0 : odId.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;
+        OperatorInstanceId other = (OperatorInstanceId) obj;
+        if (odId == null) {
+            if (other.odId != null)
+                return false;
+        } else if (!odId.equals(other.odId))
+            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/dataflow/PortInstanceId.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/PortInstanceId.java
new file mode 100644
index 0000000..844266d
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/PortInstanceId.java
@@ -0,0 +1,91 @@
+/*
+ * 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 PortInstanceId implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private OperatorDescriptorId odId;
+    private Direction direction;
+    private int portIndex;
+    private int partition;
+
+    public PortInstanceId(OperatorDescriptorId odId, Direction direction, int portIndex, int partition) {
+        this.odId = odId;
+        this.direction = direction;
+        this.portIndex = portIndex;
+        this.partition = partition;
+    }
+
+    public OperatorDescriptorId getOperatorId() {
+        return odId;
+    }
+
+    public Direction getDirection() {
+        return direction;
+    }
+
+    public int getPortIndex() {
+        return portIndex;
+    }
+
+    public int getPartition() {
+        return partition;
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((direction == null) ? 0 : direction.hashCode());
+        result = prime * result + ((odId == null) ? 0 : odId.hashCode());
+        result = prime * result + partition;
+        result = prime * result + portIndex;
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        PortInstanceId other = (PortInstanceId) obj;
+        if (direction == null) {
+            if (other.direction != null)
+                return false;
+        } else if (!direction.equals(other.direction))
+            return false;
+        if (odId == null) {
+            if (other.odId != null)
+                return false;
+        } else if (!odId.equals(other.odId))
+            return false;
+        if (partition != other.partition)
+            return false;
+        if (portIndex != other.portIndex)
+            return false;
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        return odId + ":" + direction + ":" + partition + ":" + portIndex;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryComparator.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryComparator.java
new file mode 100644
index 0000000..767684d
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryComparator.java
@@ -0,0 +1,19 @@
+/*
+ * 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.value;
+
+public interface IBinaryComparator {
+    public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2);
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryComparatorFactory.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryComparatorFactory.java
new file mode 100644
index 0000000..9976818
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryComparatorFactory.java
@@ -0,0 +1,21 @@
+/*
+ * 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.value;
+
+import java.io.Serializable;
+
+public interface IBinaryComparatorFactory extends Serializable {
+    public IBinaryComparator createBinaryComparator();
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryHashFunction.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryHashFunction.java
new file mode 100644
index 0000000..a995703
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryHashFunction.java
@@ -0,0 +1,19 @@
+/*
+ * 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.value;
+
+public interface IBinaryHashFunction {
+    int hash(byte[] bytes, int offset, int length);
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryHashFunctionFactory.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryHashFunctionFactory.java
new file mode 100644
index 0000000..a064d5f
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IBinaryHashFunctionFactory.java
@@ -0,0 +1,21 @@
+/*
+ * 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.value;
+
+import java.io.Serializable;
+
+public interface IBinaryHashFunctionFactory extends Serializable {
+    public IBinaryHashFunction createBinaryHashFunction();
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IComparator.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IComparator.java
new file mode 100644
index 0000000..2d24496
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IComparator.java
@@ -0,0 +1,19 @@
+/*
+ * 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.value;
+
+public interface IComparator<T> {
+    public int compare(T o1, T o2);
+}
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IComparatorFactory.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IComparatorFactory.java
new file mode 100644
index 0000000..ef9161f
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IComparatorFactory.java
@@ -0,0 +1,21 @@
+/*
+ * 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.value;
+
+import java.io.Serializable;
+
+public interface IComparatorFactory<T> extends Serializable {
+    public IComparator<T> createComparator();
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IHashFunction.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IHashFunction.java
new file mode 100644
index 0000000..9124fca
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IHashFunction.java
@@ -0,0 +1,21 @@
+/*
+ * 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.value;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface IHashFunction<T> {
+    public int hash(T o) throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IHashFunctionFactory.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IHashFunctionFactory.java
new file mode 100644
index 0000000..b67a96c
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IHashFunctionFactory.java
@@ -0,0 +1,21 @@
+/*
+ * 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.value;
+
+import java.io.Serializable;
+
+public interface IHashFunctionFactory<T> extends Serializable {
+    public IHashFunction<T> createHashFunction();
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IRecordDescriptorProvider.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IRecordDescriptorProvider.java
new file mode 100644
index 0000000..96d43a7
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/IRecordDescriptorProvider.java
@@ -0,0 +1,23 @@
+/*
+ * 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.value;
+
+import edu.uci.ics.hyracks.api.dataflow.OperatorDescriptorId;
+
+public interface IRecordDescriptorProvider {
+    public RecordDescriptor getInputRecordDescriptor(OperatorDescriptorId opId, int inputIndex);
+
+    public RecordDescriptor getOutputRecordDescriptor(OperatorDescriptorId opId, int outputIndex);
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/ISerializerDeserializer.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/ISerializerDeserializer.java
new file mode 100644
index 0000000..33ba602
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/ISerializerDeserializer.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.dataflow.value;
+
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.Serializable;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface ISerializerDeserializer<T> extends Serializable {
+    /**
+     * Deserialization method.
+     * 
+     * @param in
+     *            - Stream to read instance from.
+     * @return A new instance of T with data.
+     */
+    public T deserialize(DataInput in) throws HyracksDataException;
+
+    /**
+     * Serialization method.
+     * 
+     * @param instance
+     *            - the instance to serialize.
+     * @param out
+     *            - Stream to write data to.
+     */
+    public void serialize(T instance, DataOutput out) throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/ITuplePartitionComputer.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/ITuplePartitionComputer.java
new file mode 100644
index 0000000..baf9d5c
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/ITuplePartitionComputer.java
@@ -0,0 +1,22 @@
+/*
+ * 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.value;
+
+import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+
+public interface ITuplePartitionComputer {
+    public int partition(IFrameTupleAccessor accessor, int tIndex, int nParts) throws HyracksDataException;
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/ITuplePartitionComputerFactory.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/ITuplePartitionComputerFactory.java
new file mode 100644
index 0000000..eb2bbe8
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/ITuplePartitionComputerFactory.java
@@ -0,0 +1,21 @@
+/*
+ * 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.value;
+
+import java.io.Serializable;
+
+public interface ITuplePartitionComputerFactory extends Serializable {
+    public ITuplePartitionComputer createPartitioner();
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/RecordDescriptor.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/RecordDescriptor.java
new file mode 100644
index 0000000..20dc034
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/dataflow/value/RecordDescriptor.java
@@ -0,0 +1,32 @@
+/*
+ * 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.value;
+
+import java.io.Serializable;
+
+@SuppressWarnings("unchecked")
+public final class RecordDescriptor implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private final ISerializerDeserializer[] fields;
+
+    public RecordDescriptor(ISerializerDeserializer[] fields) {
+        this.fields = fields;
+    }
+
+    public ISerializerDeserializer[] getFields() {
+        return fields;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/exceptions/HyracksDataException.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/exceptions/HyracksDataException.java
new file mode 100644
index 0000000..1bdfe4b
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/exceptions/HyracksDataException.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.exceptions;
+
+import java.io.IOException;
+
+public class HyracksDataException extends IOException {
+    private static final long serialVersionUID = 1L;
+
+    public HyracksDataException() {
+    }
+
+    public HyracksDataException(String message) {
+        super(message);
+    }
+
+    public HyracksDataException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public HyracksDataException(Throwable cause) {
+        super(cause);
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/IOperatorEnvironment.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/IOperatorEnvironment.java
new file mode 100644
index 0000000..b41cb35
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/IOperatorEnvironment.java
@@ -0,0 +1,21 @@
+/*
+ * 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;
+
+public interface IOperatorEnvironment {
+    public void set(String name, Object value);
+
+    public Object get(String name);
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobFlag.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobFlag.java
new file mode 100644
index 0000000..9219ec3
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobFlag.java
@@ -0,0 +1,19 @@
+/*
+ * 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;
+
+public enum JobFlag {
+    COLLECT_FRAME_COUNTS
+}
\ 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
new file mode 100644
index 0000000..27bbdc8
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobSpecification.java
@@ -0,0 +1,228 @@
+/*
+ * 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.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import edu.uci.ics.hyracks.api.dataflow.ConnectorDescriptorId;
+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 JobSpecification implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private final List<OperatorDescriptorId> roots;
+
+    private final Map<OperatorDescriptorId, IOperatorDescriptor> opMap;
+
+    private final Map<ConnectorDescriptorId, IConnectorDescriptor> connMap;
+
+    private final Map<OperatorDescriptorId, List<IConnectorDescriptor>> opInputMap;
+
+    private final Map<OperatorDescriptorId, List<IConnectorDescriptor>> opOutputMap;
+
+    private final Map<ConnectorDescriptorId, Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>>> connectorOpMap;
+
+    public JobSpecification() {
+        roots = new ArrayList<OperatorDescriptorId>();
+        opMap = new HashMap<OperatorDescriptorId, IOperatorDescriptor>();
+        connMap = new HashMap<ConnectorDescriptorId, IConnectorDescriptor>();
+        opInputMap = new HashMap<OperatorDescriptorId, List<IConnectorDescriptor>>();
+        opOutputMap = new HashMap<OperatorDescriptorId, List<IConnectorDescriptor>>();
+        connectorOpMap = new HashMap<ConnectorDescriptorId, Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>>>();
+    }
+
+    public void addRoot(IOperatorDescriptor op) {
+        roots.add(op.getOperatorId());
+    }
+
+    public void connect(IConnectorDescriptor conn, IOperatorDescriptor producerOp, int producerPort,
+            IOperatorDescriptor consumerOp, int consumerPort) {
+        insertIntoIndexedMap(opInputMap, consumerOp.getOperatorId(), consumerPort, conn);
+        insertIntoIndexedMap(opOutputMap, producerOp.getOperatorId(), producerPort, conn);
+        connectorOpMap.put(conn.getConnectorId(),
+                new Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>>(
+                        new Pair<IOperatorDescriptor, Integer>(producerOp, producerPort),
+                        new Pair<IOperatorDescriptor, Integer>(consumerOp, consumerPort)));
+    }
+
+    private <T> void extend(List<T> list, int index) {
+        int n = list.size();
+        for (int i = n; i <= index; ++i) {
+            list.add(null);
+        }
+    }
+
+    public Map<ConnectorDescriptorId, IConnectorDescriptor> getConnectorMap() {
+        return connMap;
+    }
+
+    public Map<ConnectorDescriptorId, Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>>> getConnectorOperatorMap() {
+        return connectorOpMap;
+    }
+
+    public RecordDescriptor getConnectorRecordDescriptor(IConnectorDescriptor conn) {
+        Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>> connInfo = connectorOpMap.get(conn
+                .getConnectorId());
+        return connInfo.first.first.getOutputRecordDescriptors()[connInfo.first.second];
+    }
+
+    public IOperatorDescriptor getConsumer(IConnectorDescriptor conn) {
+        Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>> connInfo = connectorOpMap.get(conn
+                .getConnectorId());
+        return connInfo.second.first;
+    }
+
+    public int getConsumerInputIndex(IConnectorDescriptor conn) {
+        Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>> connInfo = connectorOpMap.get(conn
+                .getConnectorId());
+        return connInfo.second.second;
+    }
+
+    public IConnectorDescriptor getInputConnectorDescriptor(IOperatorDescriptor op, int inputIndex) {
+        return getInputConnectorDescriptor(op.getOperatorId(), inputIndex);
+    }
+
+    public IConnectorDescriptor getInputConnectorDescriptor(OperatorDescriptorId odId, int inputIndex) {
+        return opInputMap.get(odId).get(inputIndex);
+    }
+
+    public Map<OperatorDescriptorId, List<IConnectorDescriptor>> getOperatorInputMap() {
+        return opInputMap;
+    }
+
+    public RecordDescriptor getOperatorInputRecordDescriptor(OperatorDescriptorId odId, int inputIndex) {
+        return getConnectorRecordDescriptor(getInputConnectorDescriptor(odId, inputIndex));
+    }
+
+    public Map<OperatorDescriptorId, IOperatorDescriptor> getOperatorMap() {
+        return opMap;
+    }
+
+    public Map<OperatorDescriptorId, List<IConnectorDescriptor>> getOperatorOutputMap() {
+        return opOutputMap;
+    }
+
+    public RecordDescriptor getOperatorOutputRecordDescriptor(OperatorDescriptorId odId, int outputIndex) {
+        return getConnectorRecordDescriptor(getOutputConnectorDescriptor(odId, outputIndex));
+    }
+
+    public IConnectorDescriptor getOutputConnectorDescriptor(IOperatorDescriptor op, int outputIndex) {
+        return getOutputConnectorDescriptor(op.getOperatorId(), outputIndex);
+    }
+
+    public IConnectorDescriptor getOutputConnectorDescriptor(OperatorDescriptorId odId, int outputIndex) {
+        return opOutputMap.get(odId).get(outputIndex);
+    }
+
+    public IOperatorDescriptor getProducer(IConnectorDescriptor conn) {
+        Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>> connInfo = connectorOpMap.get(conn
+                .getConnectorId());
+        return connInfo.first.first;
+    }
+
+    public int getProducerOutputIndex(IConnectorDescriptor conn) {
+        Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>> connInfo = connectorOpMap.get(conn
+                .getConnectorId());
+        return connInfo.first.second;
+    }
+
+    public List<OperatorDescriptorId> getRoots() {
+        return roots;
+    }
+
+    private <K, V> void insertIntoIndexedMap(Map<K, List<V>> map, K key, int index, V value) {
+        List<V> vList = map.get(key);
+        if (vList == null) {
+            vList = new ArrayList<V>();
+            map.put(key, vList);
+        }
+        extend(vList, index);
+        vList.set(index, value);
+    }
+
+    public String toString() {
+        StringBuilder buffer = new StringBuilder();
+
+        for (Map.Entry<OperatorDescriptorId, IOperatorDescriptor> e : opMap.entrySet()) {
+            buffer.append(e.getKey().getId()).append(" : ").append(e.getValue().toString()).append("\n");
+            IOperatorDescriptor op = e.getValue();
+            buffer.append("   Partition Constraint: ").append(op.getPartitionConstraint()).append("\n");
+            List<IConnectorDescriptor> inputs = opInputMap.get(e.getKey());
+            if (inputs != null && !inputs.isEmpty()) {
+                buffer.append("   Inputs:\n");
+                for (IConnectorDescriptor c : inputs) {
+                    buffer.append("      ").append(c.getConnectorId().getId()).append(" : ").append(c.toString())
+                            .append("\n");
+                }
+            }
+            List<IConnectorDescriptor> outputs = opOutputMap.get(e.getKey());
+            if (outputs != null && !outputs.isEmpty()) {
+                buffer.append("   Outputs:\n");
+                for (IConnectorDescriptor c : outputs) {
+                    buffer.append("      ").append(c.getConnectorId().getId()).append(" : ").append(c.toString())
+                            .append("\n");
+                }
+            }
+        }
+
+        return buffer.toString();
+    }
+
+    public JSONObject toJSON() throws JSONException {
+        JSONObject jjob = new JSONObject();
+
+        jjob.put("type", "job");
+
+        JSONArray jopArray = new JSONArray();
+        for (Map.Entry<OperatorDescriptorId, IOperatorDescriptor> e : opMap.entrySet()) {
+            jopArray.put(e.getValue().toJSON());
+        }
+        jjob.put("operators", jopArray);
+
+        JSONArray jcArray = new JSONArray();
+        for (Map.Entry<ConnectorDescriptorId, IConnectorDescriptor> e : connMap.entrySet()) {
+            jcArray.put(e.getValue().toJSON());
+        }
+        jjob.put("connectors", jcArray);
+
+        JSONArray jconnectionsArray = new JSONArray();
+        for (Map.Entry<ConnectorDescriptorId, Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>>> e : connectorOpMap
+                .entrySet()) {
+            JSONObject conn = new JSONObject();
+            conn.put("type", "connection");
+            conn.put("connector-id", e.getValue().toString());
+            conn.put("in-operator-id", e.getValue().first.first.getOperatorId().toString());
+            conn.put("in-operator-port", e.getValue().first.second.intValue());
+            conn.put("out-operator-id", e.getValue().second.first.getOperatorId().toString());
+            conn.put("out-operator-port", e.getValue().second.second.intValue());
+            jconnectionsArray.put(conn);
+        }
+        jjob.put("connections", jconnectionsArray);
+
+        return jjob;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobStatus.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobStatus.java
new file mode 100644
index 0000000..977f41a
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/JobStatus.java
@@ -0,0 +1,21 @@
+/*
+ * 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;
+
+public enum JobStatus {
+    INITIALIZED,
+    RUNNING,
+    TERMINATED,
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/statistics/JobStatistics.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/statistics/JobStatistics.java
new file mode 100644
index 0000000..8784b46
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/statistics/JobStatistics.java
@@ -0,0 +1,91 @@
+/*
+ * 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.statistics;
+
+import java.io.Serializable;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+
+public class JobStatistics implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private Date startTime;
+
+    private Date endTime;
+
+    private List<StageStatistics> stages;
+
+    public JobStatistics() {
+        stages = new ArrayList<StageStatistics>();
+    }
+
+    public void setStartTime(Date startTime) {
+        this.startTime = startTime;
+    }
+
+    public Date getStartTime() {
+        return startTime;
+    }
+
+    public void setEndTime(Date endTime) {
+        this.endTime = endTime;
+    }
+
+    public Date getEndTime() {
+        return endTime;
+    }
+
+    public void addStageStatistics(StageStatistics stageStatistics) {
+        stages.add(stageStatistics);
+    }
+
+    public List<StageStatistics> getStages() {
+        return stages;
+    }
+
+    @Override
+    public String toString() {
+        DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
+        StringBuilder buffer = new StringBuilder();
+
+        buffer.append("{\n");
+        indent(buffer, 1).append("startTime: '").append(startTime == null ? null : df.format(startTime)).append("',\n");
+        indent(buffer, 1).append("endTime: '").append(endTime == null ? null : df.format(endTime)).append("',\n");
+        indent(buffer, 1).append("stages: [\n");
+        boolean first = true;
+        for (StageStatistics ss : stages) {
+            if (!first) {
+                buffer.append(",\n");
+            }
+            first = false;
+            ss.toString(buffer, 2);
+        }
+        buffer.append("\n");
+        indent(buffer, 1).append("]\n");
+        buffer.append("}");
+
+        return buffer.toString();
+    }
+
+    static StringBuilder indent(StringBuilder buffer, int level) {
+        for (int i = 0; i < level; ++i) {
+            buffer.append(" ");
+        }
+        return buffer;
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/statistics/StageStatistics.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/statistics/StageStatistics.java
new file mode 100644
index 0000000..6cc437b
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/statistics/StageStatistics.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.api.job.statistics;
+
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+public class StageStatistics implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private UUID stageId;
+
+    private Map<String, StageletStatistics> stageletMap;
+
+    public StageStatistics() {
+        stageletMap = new HashMap<String, StageletStatistics>();
+    }
+
+    public void setStageId(UUID stageId) {
+        this.stageId = stageId;
+    }
+
+    public UUID getStageId() {
+        return stageId;
+    }
+
+    public void addStageletStatistics(StageletStatistics ss) {
+        stageletMap.put(ss.getNodeId(), ss);
+    }
+
+    public Map<String, StageletStatistics> getStageletStatistics() {
+        return stageletMap;
+    }
+
+    public void toString(StringBuilder buffer, int level) {
+        JobStatistics.indent(buffer, level).append("{\n");
+        JobStatistics.indent(buffer, level + 1).append("stageId: '").append(stageId).append("',\n");
+        JobStatistics.indent(buffer, level + 1).append("stagelets: {\n");
+        boolean first = true;
+        for (Map.Entry<String, StageletStatistics> e : stageletMap.entrySet()) {
+            if (!first) {
+                buffer.append(",\n");
+            }
+            first = false;
+            JobStatistics.indent(buffer, level + 2).append(e.getKey()).append(": ");
+            e.getValue().toString(buffer, level + 3);
+        }
+        buffer.append("\n");
+        JobStatistics.indent(buffer, level + 1).append("}\n");
+        JobStatistics.indent(buffer, level).append("}");
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/statistics/StageletStatistics.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/statistics/StageletStatistics.java
new file mode 100644
index 0000000..66fb871
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/job/statistics/StageletStatistics.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.api.job.statistics;
+
+import java.io.Serializable;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Collections;
+import java.util.Date;
+import java.util.Map;
+import java.util.TreeMap;
+
+public class StageletStatistics implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private String nodeId;
+
+    private Date startTime;
+
+    private Date endTime;
+
+    private Map<String, String> statisticsMap;
+
+    public StageletStatistics() {
+        statisticsMap = Collections.synchronizedMap(new TreeMap<String, String>());
+    }
+
+    public void setNodeId(String nodeId) {
+        this.nodeId = nodeId;
+    }
+
+    public String getNodeId() {
+        return nodeId;
+    }
+
+    public void setStartTime(Date startTime) {
+        this.startTime = startTime;
+    }
+
+    public Date getStartTime() {
+        return startTime;
+    }
+
+    public void setEndTime(Date endTime) {
+        this.endTime = endTime;
+    }
+
+    public Date getEndTime() {
+        return endTime;
+    }
+
+    public Map<String, String> getStatisticsMap() {
+        return statisticsMap;
+    }
+
+    public void toString(StringBuilder buffer, int level) {
+        DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
+        buffer.append("{\n");
+        JobStatistics.indent(buffer, level + 1).append("nodeId: '").append(nodeId).append("',\n");
+        JobStatistics.indent(buffer, level + 1).append("startTime: '").append(df.format(startTime)).append("',\n");
+        JobStatistics.indent(buffer, level + 1).append("endTime: '").append(df.format(endTime)).append("',\n");
+        JobStatistics.indent(buffer, level + 1).append("statistics: {\n");
+        boolean first = true;
+        for (Map.Entry<String, String> e : statisticsMap.entrySet()) {
+            if (!first) {
+                buffer.append(",\n");
+            }
+            first = false;
+            JobStatistics.indent(buffer, level + 2).append(e.getKey()).append(": '").append(e.getValue()).append("'");
+        }
+        buffer.append("\n");
+        JobStatistics.indent(buffer, level + 1).append("}\n");
+        JobStatistics.indent(buffer, level).append("}");
+    }
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/IResource.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/IResource.java
new file mode 100644
index 0000000..2d76c26
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/IResource.java
@@ -0,0 +1,20 @@
+/*
+ * 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.resources;
+
+import java.io.Serializable;
+
+public interface IResource extends Serializable {
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/IResourceManager.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/IResourceManager.java
new file mode 100644
index 0000000..495db70
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/IResourceManager.java
@@ -0,0 +1,27 @@
+/*
+ * 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.resources;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+public interface IResourceManager {
+
+    public ByteBuffer allocateFrame();
+
+    public File createFile(String prefix, String suffix) throws IOException;
+
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/ISpaceSharedResource.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/ISpaceSharedResource.java
new file mode 100644
index 0000000..3a6f930
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/ISpaceSharedResource.java
@@ -0,0 +1,19 @@
+/*
+ * 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.resources;
+
+public interface ISpaceSharedResource {
+
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/ITimeSharedResource.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/ITimeSharedResource.java
new file mode 100644
index 0000000..1fb0465
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/resources/ITimeSharedResource.java
@@ -0,0 +1,18 @@
+/*
+ * 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.resources;
+
+public interface ITimeSharedResource {
+}
\ No newline at end of file
diff --git a/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/util/Pair.java b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/util/Pair.java
new file mode 100644
index 0000000..2364d74
--- /dev/null
+++ b/hyracks-api/src/main/java/edu/uci/ics/hyracks/api/util/Pair.java
@@ -0,0 +1,29 @@
+/*
+ * 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.util;
+
+import java.io.Serializable;
+
+public final class Pair<F, S> implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    public F first;
+    public S second;
+
+    public Pair(F first, S second) {
+        this.first = first;
+        this.second = second;
+    }
+}