diff --git a/src/main/java/net/onrc/onos/graph/DBOperation.java b/src/main/java/net/onrc/onos/graph/DBOperation.java
index b39771e..730f727 100644
--- a/src/main/java/net/onrc/onos/graph/DBOperation.java
+++ b/src/main/java/net/onrc/onos/graph/DBOperation.java
@@ -422,10 +422,21 @@
 	}
 
 	@Override
-	public void setFlowProperties(IFlowEntry flowEntry, Map<String, Object> map) {
+	public void setVertexProperties(Vertex vertex, Map<String, Object> map) {
 		log.debug("setProperties start: size {}", map.size());
-		RamCloudVertex v = (RamCloudVertex) flowEntry.asVertex();
+		RamCloudVertex v = (RamCloudVertex) vertex;
 		v.setProperties(map);
 		log.debug("setProperties end: size {}, id {}", map.size(), v.getId());
 	}
+
+	public String toString() {
+		StringBuilder sb = new StringBuilder();
+		for(ISwitchObject sw: getAllSwitches()) {
+			sb.append("sw: " + sw.getDPID() + "\n");
+			for(IPortObject port: sw.getPorts()) {
+				sb.append("  port: " + port.getPortId() + "\n");
+			}
+		}
+		return sb.toString();
+	}
 }
diff --git a/src/main/java/net/onrc/onos/graph/IDBOperation.java b/src/main/java/net/onrc/onos/graph/IDBOperation.java
index a2c6044..cb67bf8 100644
--- a/src/main/java/net/onrc/onos/graph/IDBOperation.java
+++ b/src/main/java/net/onrc/onos/graph/IDBOperation.java
@@ -2,6 +2,8 @@
 
 import java.util.Map;
 
+import com.tinkerpop.blueprints.Vertex;
+
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IDeviceObject;
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IFlowEntry;
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IFlowPath;
@@ -42,7 +44,7 @@
 	public Iterable<IFlowEntry> getAllFlowEntries();
 	public void removeFlowEntry(IFlowEntry flowEntry);
 
-	public void setFlowProperties(IFlowEntry flowEntry, Map<String, Object> map);
+	public void setVertexProperties(Vertex vertex, Map<String, Object> map);
 
 	public IDBConnection getDBConnection();	
 	public void commit();
diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEntryProperty.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEntryProperty.java
index e59ab93..7b17aaa 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEntryProperty.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEntryProperty.java
@@ -145,6 +145,6 @@
      * @param dbhandler
      */
     public void commitProperties() {
-        dbhandler.setFlowProperties(flowEntry ,map);
+        dbhandler.setVertexProperties(flowEntry.asVertex() ,map);
     }
 }