use commit() and rollback() methods on IDBConnection instead of entTx() method.
diff --git a/src/main/java/net/onrc/onos/util/GraphDBConnection.java b/src/main/java/net/onrc/onos/util/GraphDBConnection.java
index e25a0c6..9a50f47 100644
--- a/src/main/java/net/onrc/onos/util/GraphDBConnection.java
+++ b/src/main/java/net/onrc/onos/util/GraphDBConnection.java
@@ -80,7 +80,6 @@
 	}
 
 	public FramedGraph<TitanGraph> getFramedGraph() {
-
 		if (isValid()) {
 			FramedGraph<TitanGraph> fg = new FramedGraph<TitanGraph>(graph);
 			return fg;
@@ -91,7 +90,6 @@
 	}
 
 	protected EventTransactionalGraph<TitanGraph> getEventGraph() {
-
 		if (isValid()) {
 			return eg;
 		} else {
@@ -106,65 +104,28 @@
 	}
 
 	public Boolean isValid() {
-
 		return (graph != null || graph.isOpen());
 	}
 
-	public void startTx() {
-
-	}
-
-	public void endTx(Transaction tx) {
+	public void commit() {
 		try {
-			switch (tx) {
-			case COMMIT:
-				graph.commit();
-			case ROLLBACK:
-				graph.rollback();
-			}
-		} catch (Exception e) {
-			// TODO Auto-generated catch block
+			graph.commit();
+		}
+		catch (Exception e) {
 			log.error("{}", e.toString());
 		}
 	}
 
-	public void endTx(TransactionHandle tr, Transaction tx) {
-		switch (tx) {
-		case COMMIT:
-			if (tr != null && tr.tr != null) {
-				tr.tr.commit();
-			} else {
-				graph.commit();
-			}
-		case ROLLBACK:
-			if (tr != null && tr.tr != null) {
-				tr.tr.rollback();
-			} else {
-				graph.rollback();
-			}
-		}
-	}
-
-	public void endTx(Transaction tx, GenerateEvent fire) {
-
+	public void rollback() {
 		try {
-			if (fire.equals(GenerateEvent.TRUE)) {
-				switch (tx) {
-				case COMMIT:
-					eg.commit();
-				case ROLLBACK:
-					eg.rollback();
-				}
-			} else {
-				endTx(tx);
-			}
-		} catch (Exception e) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
+			graph.rollback();
+		}
+		catch (Exception e) {
+			log.error("{}", e.toString());
 		}
 	}
 
 	public void close() {
-		endTx(Transaction.COMMIT);
+		commit();
 	}
 }
diff --git a/src/main/java/net/onrc/onos/util/GraphDBOperation.java b/src/main/java/net/onrc/onos/util/GraphDBOperation.java
index 5a70dbc..858a17e 100644
--- a/src/main/java/net/onrc/onos/util/GraphDBOperation.java
+++ b/src/main/java/net/onrc/onos/util/GraphDBOperation.java
@@ -12,16 +12,6 @@
 import net.onrc.onos.ofcontroller.util.FlowEntryId;
 import net.onrc.onos.ofcontroller.util.FlowId;
 
-//import net.floodlightcontroller.core.INetMapTopologyObjects.IDeviceObject;
-//import net.floodlightcontroller.core.INetMapTopologyObjects.IFlowEntry;
-//import net.floodlightcontroller.core.INetMapTopologyObjects.IFlowPath;
-//import net.floodlightcontroller.core.INetMapTopologyObjects.IPortObject;
-//import net.floodlightcontroller.core.INetMapTopologyObjects.ISwitchObject;
-//import net.floodlightcontroller.core.ISwitchStorage.SwitchState;
-//import net.floodlightcontroller.util.FlowEntryId;
-//import net.floodlightcontroller.util.FlowId;
-import net.onrc.onos.util.GraphDBConnection.Transaction;
-
 import com.thinkaurelius.titan.core.TitanGraph;
 import com.tinkerpop.blueprints.Vertex;
 import com.tinkerpop.frames.FramedGraph;
@@ -209,7 +199,6 @@
 
 	@Override
 	public IFlowPath getFlowPathByFlowEntry(IFlowEntry flowEntry) {
-		FramedGraph<TitanGraph> fg = conn.getFramedGraph();
 		GremlinPipeline<Vertex, IFlowPath> pipe = new GremlinPipeline<Vertex, IFlowPath>();
 		pipe.start(flowEntry.asVertex());
 		pipe.out("flow");
@@ -273,11 +262,11 @@
 	}
 	
 	public void commit() {
-		conn.endTx(Transaction.COMMIT);
+		conn.commit();
 	}
 	
 	public void rollback() {
-		conn.endTx(Transaction.ROLLBACK);
+		conn.rollback();
 	}
 
 	public void close() {
diff --git a/src/main/java/net/onrc/onos/util/IDBConnection.java b/src/main/java/net/onrc/onos/util/IDBConnection.java
index e599a5e..995ce39 100644
--- a/src/main/java/net/onrc/onos/util/IDBConnection.java
+++ b/src/main/java/net/onrc/onos/util/IDBConnection.java
@@ -1,9 +1,5 @@
 package net.onrc.onos.util;
 
-import net.onrc.onos.util.GraphDBConnection.GenerateEvent;
-import net.onrc.onos.util.GraphDBConnection.Transaction;
-import net.onrc.onos.util.GraphDBConnection.TransactionHandle;
-
 import com.thinkaurelius.titan.core.TitanGraph;
 import com.tinkerpop.frames.FramedGraph;
 
@@ -11,9 +7,7 @@
 	public FramedGraph<TitanGraph> getFramedGraph();
 	public void addEventListener(final LocalGraphChangedListener listener);
 	public Boolean isValid();
-	public void startTx();
-	public void endTx(Transaction tx);
-	public void endTx(TransactionHandle tr, Transaction tx);
-	public void endTx(Transaction tx, GenerateEvent fire);
+	public void commit();
+	public void rollback();
 	public void close();
 }