diff --git a/src/main/java/net/onrc/onos/graph/DBOperation.java b/src/main/java/net/onrc/onos/graph/DBOperation.java
index db3dad7..eae323f 100644
--- a/src/main/java/net/onrc/onos/graph/DBOperation.java
+++ b/src/main/java/net/onrc/onos/graph/DBOperation.java
@@ -13,9 +13,11 @@
 import java.util.Iterator;
 import java.util.List;
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects;
+import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IBaseObject;
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IDeviceObject;
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IFlowEntry;
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IFlowPath;
+import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IIpv4Address;
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IPortObject;
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.ISwitchObject;
 import net.onrc.onos.ofcontroller.core.ISwitchStorage;
@@ -182,5 +184,47 @@
         }
         return flowEntry;
     }
+    
+    	
+	public IIpv4Address newIpv4Address() {
+		return newVertex("ipv4Address", IIpv4Address.class);
+	}
+	private <T extends IBaseObject> T newVertex(String type, Class<T> vertexType) {
+		FramedGraph<TitanGraph> fg = conn.getFramedGraph();
+		T newVertex = fg.addVertex(null, vertexType);
+		if (newVertex != null) {
+			newVertex.setType(type);
+		}
+		return newVertex;
+	}
+	
+	public IIpv4Address searchIpv4Address(int intIpv4Address) {
+		return searchForVertex("ipv4_address", intIpv4Address, IIpv4Address.class);
+	}
+	
+	
+	public IIpv4Address ensureIpv4Address(int intIpv4Address) {
+		IIpv4Address ipv4Vertex = searchIpv4Address(intIpv4Address);
+		if (ipv4Vertex == null) {
+			ipv4Vertex = newIpv4Address();
+			ipv4Vertex.setIpv4Address(intIpv4Address);
+		}
+		return ipv4Vertex;
+	}	
+
+	
+	private <T> T searchForVertex(String propertyName, Object propertyValue, Class<T> vertexType) {
+		if (conn.getFramedGraph() != null) {
+			Iterator<T> it = conn.getFramedGraph().getVertices(propertyName, propertyValue, vertexType).iterator();
+			if (it.hasNext()) {
+				return it.next();
+			}
+		}
+		return null;
+	}
+
+	public void removeIpv4Address(IIpv4Address ipv4Address) {
+		conn.getFramedGraph().removeVertex(ipv4Address.asVertex());
+	}
 
 }
diff --git a/src/main/java/net/onrc/onos/graph/TitanDBOperation.java b/src/main/java/net/onrc/onos/graph/TitanDBOperation.java
index 26289bd..66221f3 100644
--- a/src/main/java/net/onrc/onos/graph/TitanDBOperation.java
+++ b/src/main/java/net/onrc/onos/graph/TitanDBOperation.java
@@ -10,6 +10,7 @@
 import com.tinkerpop.frames.structures.FramedVertexIterable;
 import com.tinkerpop.gremlin.java.GremlinPipeline;
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.*;
 import net.onrc.onos.ofcontroller.core.ISwitchStorage;
@@ -82,8 +83,17 @@
             fg.removeVertex(dev.asVertex());
         }
     }
-
-
+	
+	/**
+         * Create and return a flow path object.
+         */
+        public IFlowPath newFlowPath() {
+                FramedGraph<TitanGraph> fg = conn.getFramedGraph();
+                IFlowPath flowPath = fg.addVertex(null, IFlowPath.class);
+                if (flowPath != null) flowPath.setType("flow");
+                return flowPath;
+        }
+	
     @Override
     public IFlowPath searchFlowPath(FlowId flowId) {
         FramedGraph<TitanGraph> fg = conn.getFramedGraph();
diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowDatabaseOperation.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowDatabaseOperation.java
index 73c4e51..4e67bf5 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowDatabaseOperation.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowDatabaseOperation.java
@@ -10,6 +10,7 @@
 import java.util.concurrent.ConcurrentLinkedQueue;
 
 import net.floodlightcontroller.util.MACAddress;
+import net.onrc.onos.graph.DBOperation;
 
 import net.onrc.onos.graph.GraphDBOperation;
 
@@ -38,7 +39,7 @@
      * @return true on success, otherwise false.
      */
     static boolean addFlow(FlowManager flowManager,
-			   GraphDBOperation dbHandler,
+			   DBOperation dbHandler,
 			   FlowPath flowPath, FlowId flowId) {
 	IFlowPath flowObj = null;
 	boolean found = false;
@@ -180,7 +181,7 @@
      * @return the added Flow Entry object on success, otherwise null.
      */
     static IFlowEntry addFlowEntry(FlowManager flowManager,
-				   GraphDBOperation dbHandler,
+				   DBOperation dbHandler,
 				   IFlowPath flowObj,
 				   FlowEntry flowEntry) {
 	// Flow edges
@@ -333,7 +334,7 @@
      * @param flowEntry the Flow Entry to delete.
      * @return true on success, otherwise false.
      */
-    static boolean deleteFlowEntry(GraphDBOperation dbHandler,
+    static boolean deleteFlowEntry(DBOperation dbHandler,
 				   IFlowPath flowObj,
 				   FlowEntry flowEntry) {
 	IFlowEntry flowEntryObj = null;
@@ -369,7 +370,7 @@
      * @param dbHandler the Graph Database handler to use.
      * @return true on success, otherwise false.
      */
-    static boolean deleteAllFlows(GraphDBOperation dbHandler) {
+    static boolean deleteAllFlows(DBOperation dbHandler) {
 	List<FlowId> allFlowIds = new LinkedList<FlowId>();
 
 	// Get all Flow IDs
@@ -399,7 +400,7 @@
      * @param flowId the Flow ID of the flow to delete.
      * @return true on success, otherwise false.
      */
-    static boolean deleteFlow(GraphDBOperation dbHandler, FlowId flowId) {
+    static boolean deleteFlow(DBOperation dbHandler, FlowId flowId) {
 	IFlowPath flowObj = null;
 	try {
 	    flowObj = dbHandler.searchFlowPath(flowId);
@@ -436,7 +437,7 @@
      * @param flowId the Flow ID of the flow to get.
      * @return the Flow Path if found, otherwise null.
      */
-    static FlowPath getFlow(GraphDBOperation dbHandler, FlowId flowId) {
+    static FlowPath getFlow(DBOperation dbHandler, FlowId flowId) {
 	IFlowPath flowObj = null;
 	try {
 	    flowObj = dbHandler.searchFlowPath(flowId);
@@ -466,7 +467,7 @@
      * @param dbHandler the Graph Database handler to use.
      * @return the Flow Paths if found, otherwise null.
      */
-    static ArrayList<FlowPath> getAllFlows(GraphDBOperation dbHandler) {
+    static ArrayList<FlowPath> getAllFlows(DBOperation dbHandler) {
 	Iterable<IFlowPath> flowPathsObj = null;
 	ArrayList<FlowPath> flowPaths = new ArrayList<FlowPath>();
 
@@ -506,7 +507,7 @@
      * @param dataPathEndpoints the data path endpoints of the flow to get.
      * @return the Flow Paths if found, otherwise null.
      */
-    static ArrayList<FlowPath> getAllFlows(GraphDBOperation dbHandler,
+    static ArrayList<FlowPath> getAllFlows(DBOperation dbHandler,
 					   CallerId installerId,
 					   DataPathEndpoints dataPathEndpoints) {
 	//
@@ -549,7 +550,7 @@
      * @param dataPathEndpoints the data path endpoints of the flows to get.
      * @return the Flow Paths if found, otherwise null.
      */
-    static ArrayList<FlowPath> getAllFlows(GraphDBOperation dbHandler,
+    static ArrayList<FlowPath> getAllFlows(DBOperation dbHandler,
 					   DataPathEndpoints dataPathEndpoints) {
 	//
 	// TODO: The implementation below is not optimal:
@@ -590,7 +591,7 @@
      * @param maxFlows the maximum number of flows to be returned.
      * @return the Flow Paths if found, otherwise null.
      */
-    static ArrayList<IFlowPath> getAllFlowsSummary(GraphDBOperation dbHandler,
+    static ArrayList<IFlowPath> getAllFlowsSummary(DBOperation dbHandler,
 						   FlowId flowId,
 						   int maxFlows) {
 	//
@@ -630,7 +631,7 @@
      * @param dbHandler the Graph Database handler to use.
      * @return all Flows information, without the associated Flow Entries.
      */
-    static ArrayList<IFlowPath> getAllFlowsWithoutFlowEntries(GraphDBOperation dbHandler) {
+    static ArrayList<IFlowPath> getAllFlowsWithoutFlowEntries(DBOperation dbHandler) {
     	Iterable<IFlowPath> flowPathsObj = null;
     	ArrayList<IFlowPath> flowPathsObjArray = new ArrayList<IFlowPath>();
 
diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
index db1e588..68450c2 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowManager.java
@@ -42,8 +42,8 @@
 public class FlowManager implements IFloodlightModule, IFlowService, INetMapStorage {
     // flag to use FlowPusher instead of FlowSwitchOperation/MessageDamper
     private final static boolean enableFlowPusher = false;
-
-    protected DBOperation op;
+    protected DBOperation dbHandlerApi;
+    protected DBOperation dbHandlerInner;
 
     protected volatile IFloodlightProviderService floodlightProvider;
     protected volatile IDatagridService datagridService;
@@ -82,8 +82,9 @@
      */
     @Override
     public void init(final String dbStore, final String conf) {
-    	op = GraphDBManager.getDBOperation(dbStore, conf);
-	topoRouteService = new TopoRouteService(dbStore, conf);
+	dbHandlerApi = GraphDBManager.getDBOperation(dbStore, conf);
+	dbHandlerInner = GraphDBManager.getDBOperation(dbStore, conf);
+	
     }
 
     /**
diff --git a/src/main/java/net/onrc/onos/ofcontroller/forwarding/Forwarding.java b/src/main/java/net/onrc/onos/ofcontroller/forwarding/Forwarding.java
index 686bee0..e5144ab 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/forwarding/Forwarding.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/forwarding/Forwarding.java
@@ -57,9 +57,9 @@
 		floodlightProvider.addOFMessageListener(OFType.PACKET_IN, this);
 		
 		deviceStorage = new DeviceStorageImpl();
-		deviceStorage.init("");
+		deviceStorage.init("","");
 		topologyService = new TopologyManager();
-		topologyService.init("");
+		topologyService.init("","");
 	}
 	
 	public void startUp() {
diff --git a/src/main/java/net/onrc/onos/ofcontroller/proxyarp/BgpProxyArpManager.java b/src/main/java/net/onrc/onos/ofcontroller/proxyarp/BgpProxyArpManager.java
index 801e414..3dba4f8 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/proxyarp/BgpProxyArpManager.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/proxyarp/BgpProxyArpManager.java
@@ -143,7 +143,7 @@
 		floodlightProvider.addOFMessageListener(OFType.PACKET_IN, this);
 		
 		deviceStorage = new DeviceStorageImpl();
-		deviceStorage.init("");
+		deviceStorage.init("","");
 		
 		Timer arpTimer = new Timer("arp-processing");
 		arpTimer.scheduleAtFixedRate(new TimerTask() {
diff --git a/src/main/java/net/onrc/onos/ofcontroller/proxyarp/ProxyArpManager.java b/src/main/java/net/onrc/onos/ofcontroller/proxyarp/ProxyArpManager.java
index 85fd618..ec8065c 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/proxyarp/ProxyArpManager.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/proxyarp/ProxyArpManager.java
@@ -160,7 +160,7 @@
 		datagrid.registerArpEventHandler(this);
 		
 		deviceStorage = new DeviceStorageImpl();
-		deviceStorage.init("");
+		deviceStorage.init("","");
 		
 		Timer arpTimer = new Timer("arp-processing");
 		arpTimer.scheduleAtFixedRate(new TimerTask() {
diff --git a/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java b/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java
index dbf9ada..c914bbe 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java
@@ -13,6 +13,7 @@
 
 import com.tinkerpop.blueprints.Direction;
 import com.tinkerpop.blueprints.Vertex;
+import net.onrc.onos.graph.DBOperation;
 
 /**
  * A class for storing Node and Link information for fast computation
@@ -376,7 +377,7 @@
      *
      * @param dbHandler the Graph Database handler to use.
      */
-    public void readFromDatabase(GraphDBOperation dbHandler) {
+    public void readFromDatabase(DBOperation dbHandler) {
 	//
 	// Fetch the relevant info from the Switch and Port vertices
 	// from the Titan Graph.
diff --git a/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java b/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java
index c0e04f2..dae0cf4 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java
@@ -12,6 +12,8 @@
 import net.floodlightcontroller.core.module.IFloodlightService;
 
 import net.onrc.onos.datagrid.IDatagridService;
+import net.onrc.onos.graph.DBOperation;
+import net.onrc.onos.graph.GraphDBManager;
 import net.onrc.onos.graph.GraphDBOperation;
 import net.onrc.onos.ofcontroller.floodlightlistener.INetworkGraphService;
 import net.onrc.onos.ofcontroller.util.DataPath;
@@ -34,7 +36,7 @@
     private final static Logger log = LoggerFactory.getLogger(TopologyManager.class);
     protected IFloodlightProviderService floodlightProvider;
 
-    protected GraphDBOperation dbHandler;
+    protected DBOperation dbHandler;
 
 
     /**
@@ -50,7 +52,7 @@
      * the initialization.
      */
     public TopologyManager(String config) {
-	this.init(config);
+	this.init("",config);
     }
 
     /**
@@ -59,19 +61,19 @@
      * @param dbHandler the database operation handler to use for the
      * initialization.
      */
-    public TopologyManager(GraphDBOperation dbHandler) {
+    public TopologyManager(DBOperation dbHandler) {
 	this.dbHandler = dbHandler;
     }
 
     /**
      * Init the module.
-     *
+     * @param 
      * @param config the database configuration file to use for
      * the initialization.
      */
-    public void init(String config) {
+    public void init(final String dbStore, String config) {
 	try {
-	    dbHandler = new GraphDBOperation(config);
+	    dbHandler = GraphDBManager.getDBOperation(dbStore, config);
 	} catch (Exception e) {
 	    log.error(e.getMessage());
 	}
@@ -147,7 +149,7 @@
 	floodlightProvider = context.getServiceImpl(IFloodlightProviderService.class);
 
 	String conf = "";
-	this.init(conf);
+	this.init("",conf);
     }
 
     /**