diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/GlobalAggregator.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/GlobalAggregator.java
new file mode 100644
index 0000000..9920b4c
--- /dev/null
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/GlobalAggregator.java
@@ -0,0 +1,30 @@
+package edu.uci.ics.pregelix.api.graph;
+
+import java.io.IOException;
+
+import org.apache.hadoop.io.Writable;
+import org.apache.hadoop.io.WritableComparable;
+
+@SuppressWarnings("rawtypes")
+public interface GlobalAggregator<I extends WritableComparable, V extends Writable, E extends Writable, M extends Writable, T extends Writable> {
+	/**
+	 * initialize combiner
+	 */
+	public void init();
+
+	/**
+	 * step call
+	 * 
+	 * @param vertexIndex
+	 * @param msg
+	 * @throws IOException
+	 */
+	public void step(Vertex<I, V, E, M> v) throws IOException;
+
+	/**
+	 * finish aggregate
+	 * 
+	 * @return the final aggregate value
+	 */
+	public T finish();
+}
diff --git a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/DataflowUtils.java b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/DataflowUtils.java
index d6606c6..aa389e2 100644
--- a/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/DataflowUtils.java
+++ b/pregelix/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/util/DataflowUtils.java
@@ -23,8 +23,8 @@
 import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptorFactory;
 import edu.uci.ics.pregelix.core.hadoop.config.ConfigurationFactory;
 import edu.uci.ics.pregelix.core.runtime.touchpoint.WritableRecordDescriptorFactory;
+import edu.uci.ics.pregelix.dataflow.std.base.IAggregateFunctionFactory;
 import edu.uci.ics.pregelix.dataflow.std.base.IRecordDescriptorFactory;
-import edu.uci.ics.pregelix.runtime.base.IAggregateFunctionFactory;
 import edu.uci.ics.pregelix.runtime.simpleagg.AccumulatingAggregatorFactory;
 import edu.uci.ics.pregelix.runtime.simpleagg.AggregationFunctionFactory;
 
@@ -75,7 +75,7 @@
         IAggregateFunctionFactory aggFuncFactory = new AggregationFunctionFactory(new ConfigurationFactory(conf),
                 isFinal);
         IAggregatorDescriptorFactory aggregatorFactory = new AccumulatingAggregatorFactory(
-                new IAggregateFunctionFactory[] { aggFuncFactory }, new int[] { 0 }, new int[] {});
+                new IAggregateFunctionFactory[] { aggFuncFactory });
         return aggregatorFactory;
     }
 }
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/base/IAggregateFunction.java b/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunction.java
similarity index 95%
rename from pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/base/IAggregateFunction.java
rename to pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunction.java
index 4cd8f52..c05e9b9 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/base/IAggregateFunction.java
+++ b/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunction.java
@@ -12,7 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.pregelix.runtime.base;
+package edu.uci.ics.pregelix.dataflow.std.base;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/base/IAggregateFunctionFactory.java b/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunctionFactory.java
similarity index 94%
rename from pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/base/IAggregateFunctionFactory.java
rename to pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunctionFactory.java
index b8f70b6..4be0bed 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/base/IAggregateFunctionFactory.java
+++ b/pregelix/pregelix-dataflow-std-base/src/main/java/edu/uci/ics/pregelix/dataflow/std/base/IAggregateFunctionFactory.java
@@ -12,7 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package edu.uci.ics.pregelix.runtime.base;
+package edu.uci.ics.pregelix.dataflow.std.base;
 
 import java.io.Serializable;
 
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AccumulatingAggregatorFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AccumulatingAggregatorFactory.java
index 659100a..8f63b6e 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AccumulatingAggregatorFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AccumulatingAggregatorFactory.java
@@ -26,15 +26,15 @@
 import edu.uci.ics.hyracks.dataflow.std.group.AggregateState;
 import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptor;
 import edu.uci.ics.hyracks.dataflow.std.group.IAggregatorDescriptorFactory;
-import edu.uci.ics.pregelix.runtime.base.IAggregateFunction;
-import edu.uci.ics.pregelix.runtime.base.IAggregateFunctionFactory;
+import edu.uci.ics.pregelix.dataflow.std.base.IAggregateFunction;
+import edu.uci.ics.pregelix.dataflow.std.base.IAggregateFunctionFactory;
 
 public class AccumulatingAggregatorFactory implements IAggregatorDescriptorFactory {
 
     private static final long serialVersionUID = 1L;
     private IAggregateFunctionFactory[] aggFactories;
 
-    public AccumulatingAggregatorFactory(IAggregateFunctionFactory[] aggFactories, int[] keys, int[] fdColumns) {
+    public AccumulatingAggregatorFactory(IAggregateFunctionFactory[] aggFactories) {
         this.aggFactories = aggFactories;
     }
 
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunction.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunction.java
index d6352ed..e4697ab 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunction.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunction.java
@@ -34,7 +34,7 @@
 import edu.uci.ics.pregelix.api.graph.VertexCombiner;
 import edu.uci.ics.pregelix.api.util.BspUtils;
 import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
-import edu.uci.ics.pregelix.runtime.base.IAggregateFunction;
+import edu.uci.ics.pregelix.dataflow.std.base.IAggregateFunction;
 
 @SuppressWarnings({ "rawtypes", "unchecked" })
 public class AggregationFunction implements IAggregateFunction {
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunctionFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunctionFactory.java
index e45ece0..b6402ef 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunctionFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/simpleagg/AggregationFunctionFactory.java
@@ -20,8 +20,8 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
 import edu.uci.ics.pregelix.dataflow.base.IConfigurationFactory;
-import edu.uci.ics.pregelix.runtime.base.IAggregateFunction;
-import edu.uci.ics.pregelix.runtime.base.IAggregateFunctionFactory;
+import edu.uci.ics.pregelix.dataflow.std.base.IAggregateFunction;
+import edu.uci.ics.pregelix.dataflow.std.base.IAggregateFunctionFactory;
 
 public class AggregationFunctionFactory implements IAggregateFunctionFactory {
     private static final long serialVersionUID = 1L;