diff --git a/src/main/java/net/floodlightcontroller/core/INetMapTopologyService.java b/src/main/java/net/floodlightcontroller/core/INetMapTopologyService.java
index ecf217e..f217c25 100644
--- a/src/main/java/net/floodlightcontroller/core/INetMapTopologyService.java
+++ b/src/main/java/net/floodlightcontroller/core/INetMapTopologyService.java
@@ -1,6 +1,7 @@
 package net.floodlightcontroller.core;
 
 import java.util.List;
+import java.util.Map;
 
 import net.floodlightcontroller.core.module.IFloodlightService;
 import net.floodlightcontroller.core.INetMapTopologyObjects.IDeviceObject;
@@ -47,7 +48,7 @@
 
 	    /**
 	     * Fetch the Switch and Ports info from the Titan Graph
-	     * and store it locally for fast access during the shortest path
+	     * and return it for fast access during the shortest path
 	     * computation.
 	     *
 	     * After fetching the state, method @ref getTopoShortestPath()
@@ -63,14 +64,17 @@
 	     * method @ref dropShortestPathTopo() should be used to release
 	     * the internal state that is not needed anymore:
 	     *
-	     *       prepareShortestPathTopo();
+	     *       Map<Long, ?> shortestPathTopo;
+	     *       shortestPathTopo = prepareShortestPathTopo();
 	     *       for (int i = 0; i < 10000; i++) {
-	     *           dataPath = getTopoShortestPath(...);
+	     *           dataPath = getTopoShortestPath(shortestPathTopo, ...);
 	     *           ...
 	     *        }
-	     *        dropShortestPathTopo();
+	     *        dropShortestPathTopo(shortestPathTopo);
+	     *
+	     * @return the Shortest Path info handler stored in a map.
 	     */
-	    void prepareShortestPathTopo();
+	    Map<Long, ?> prepareShortestPathTopo();
 
 	    /**
 	     * Release the state that was populated by
@@ -78,8 +82,10 @@
 	     *
 	     * See the documentation for method @ref prepareShortestPathTopo()
 	     * for additional information and usage.
+	     *
+	     * @shortestPathTopo the Shortest Path info handler to release.
 	     */
-	    void dropShortestPathTopo();
+	    void dropShortestPathTopo(Map<Long, ?> shortestPathTopo);
 
 	    /**
 	     * Get the shortest path from a source to a destination by
@@ -89,12 +95,15 @@
 	     * See the documentation for method @ref prepareShortestPathTopo()
 	     * for additional information and usage.
 	     *
+	     * @paran shortestPathTopoHandler the Shortest Path info handler
+	     * to use.
 	     * @param src the source in the shortest path computation.
 	     * @param dest the destination in the shortest path computation.
 	     * @return the data path with the computed shortest path if
 	     * found, otherwise null.
 	     */
-	    DataPath getTopoShortestPath(SwitchPort src, SwitchPort dest);
+	    DataPath getTopoShortestPath(Map<Long, ?> shortestPathTopo,
+					 SwitchPort src, SwitchPort dest);
 
 	    /**
 	     * Test whether a route exists from a source to a destination.
diff --git a/src/main/java/net/floodlightcontroller/flowcache/FlowManager.java b/src/main/java/net/floodlightcontroller/flowcache/FlowManager.java
index 57c136c..1020eab 100644
--- a/src/main/java/net/floodlightcontroller/flowcache/FlowManager.java
+++ b/src/main/java/net/floodlightcontroller/flowcache/FlowManager.java
@@ -98,6 +98,7 @@
     private LinkedList<FlowPath> measurementStoredPaths = new LinkedList<FlowPath>();
     private long measurementStartTimeProcessingPaths = 0;
     private long measurementEndTimeProcessingPaths = 0;
+    Map<Long, ?> measurementShortestPathTopo = null;
 
     /** The logger. */
     private static Logger log = LoggerFactory.getLogger(FlowManager.class);
@@ -277,7 +278,8 @@
 		// Fetch and recompute the Shortest Path for those
 		// Flow Paths this controller is responsible for.
 		//
-		topoRouteService.prepareShortestPathTopo();
+		Map<Long, ?> shortestPathTopo =
+		    topoRouteService.prepareShortestPathTopo();
 		Iterable<IFlowPath> allFlowPaths = conn.utils().getAllFlowPaths(conn);
 		for (IFlowPath flowPathObj : allFlowPaths) {
 		    counterAllFlowPaths++;
@@ -352,7 +354,8 @@
 		    // to avoid closing the transaction.
 		    //
 		    DataPath dataPath =
-			topoRouteService.getTopoShortestPath(srcSwitchPort,
+			topoRouteService.getTopoShortestPath(shortestPathTopo,
+							     srcSwitchPort,
 							     dstSwitchPort);
 		    if (dataPath == null) {
 			// We need the DataPath to compare the paths
@@ -377,7 +380,7 @@
 		    conn.utils().removeFlowPath(conn, flowPathObj);
 		}
 
-		topoRouteService.dropShortestPathTopo();
+		topoRouteService.dropShortestPathTopo(shortestPathTopo);
 
 		conn.endTx(Transaction.COMMIT);
 
@@ -1891,13 +1894,14 @@
 	// Prepare the Shortest Path computation if the first Flow Path
 	//
 	if (measurementStoredPaths.isEmpty())
-	    topoRouteService.prepareShortestPathTopo();
+	    measurementShortestPathTopo = topoRouteService.prepareShortestPathTopo();
 
 	//
 	// Compute the Shortest Path
 	//
 	DataPath dataPath =
-	    topoRouteService.getTopoShortestPath(flowPath.dataPath().srcPort(),
+	    topoRouteService.getTopoShortestPath(measurementShortestPathTopo,
+						 flowPath.dataPath().srcPort(),
 						 flowPath.dataPath().dstPort());
 	if (dataPath == null) {
 	    // We need the DataPath to populate the Network MAP
@@ -2030,7 +2034,7 @@
     @Override
     public boolean measurementClearAllPaths() {
 	measurementStoredPaths.clear();
-	topoRouteService.dropShortestPathTopo();
+	topoRouteService.dropShortestPathTopo(measurementShortestPathTopo);
 	measurementStartTimeProcessingPaths = 0;
 	measurementEndTimeProcessingPaths = 0;
 
diff --git a/src/main/java/net/floodlightcontroller/routing/TopoRouteService.java b/src/main/java/net/floodlightcontroller/routing/TopoRouteService.java
index 95a3b19..1e002aa 100644
--- a/src/main/java/net/floodlightcontroller/routing/TopoRouteService.java
+++ b/src/main/java/net/floodlightcontroller/routing/TopoRouteService.java
@@ -101,14 +101,6 @@
     
     GraphDBConnection conn;
 
-    //
-    // Topology state for storing (on demand) Switch and Ports info for
-    // fast access during the shortest path computation.
-    // It is explicitly populated by method @ref prepareShortestPathTopo().
-    // See the documentation for that method for details.
-    //
-    HashMap<Long, Node> shortestPathTopo;
-
     @Override
     public Collection<Class<? extends IFloodlightService>> getModuleServices() {
         Collection<Class<? extends IFloodlightService>> l = 
@@ -168,7 +160,7 @@
 
     /**
      * Fetch the Switch and Ports info from the Titan Graph
-     * and store it locally for fast access during the shortest path
+     * and return it for fast access during the shortest path
      * computation.
      *
      * After fetching the state, method @ref getTopoShortestPath()
@@ -184,16 +176,18 @@
      * method @ref dropShortestPathTopo() should be used to release
      * the internal state that is not needed anymore:
      *
-     *       prepareShortestPathTopo();
+     *       Map<Long, ?> shortestPathTopo;
+     *       shortestPathTopo = prepareShortestPathTopo();
      *       for (int i = 0; i < 10000; i++) {
-     *           dataPath = getTopoShortestPath(...);
+     *           dataPath = getTopoShortestPath(shortestPathTopo, ...);
      *           ...
      *        }
-     *        dropShortestPathTopo();
+     *        dropShortestPathTopo(shortestPathTopo);
+     *
+     * @return the Shortest Path info handler stored in a map.
      */
-    
-    public void prepareShortestPathTopo() {
-	shortestPathTopo = new HashMap<Long, Node>();
+    public Map<Long, ?> prepareShortestPathTopo() {
+	Map<Long, Node> shortestPathTopo = new HashMap<Long, Node>();
 
 	//
 	// Fetch the relevant info from the Switch and Port vertices
@@ -260,6 +254,8 @@
 	    }
 	}
 	conn.endTx(Transaction.COMMIT);
+
+	return shortestPathTopo;
     }
 
     /**
@@ -268,9 +264,10 @@
      *
      * See the documentation for method @ref prepareShortestPathTopo()
      * for additional information and usage.
+     *
+     * @shortestPathTopo the Shortest Path info handler to release.
      */
-  
-    public void dropShortestPathTopo() {
+    public void dropShortestPathTopo(Map<Long, ?> shortestPathTopo) {
 	shortestPathTopo = null;
     }
 
@@ -282,13 +279,17 @@
      * See the documentation for method @ref prepareShortestPathTopo()
      * for additional information and usage.
      *
+     * @param shortestPathTopoHandler the Shortest Path info handler
+     * to use.
      * @param src the source in the shortest path computation.
      * @param dest the destination in the shortest path computation.
      * @return the data path with the computed shortest path if
      * found, otherwise null.
      */
-  
-    public DataPath getTopoShortestPath(SwitchPort src, SwitchPort dest) {
+    public DataPath getTopoShortestPath(Map<Long, ?> shortestPathTopoHandler,
+					SwitchPort src, SwitchPort dest) {
+	@SuppressWarnings("unchecked")
+	Map<Long, Node> shortestPathTopo = (Map)shortestPathTopoHandler;
 	DataPath result_data_path = new DataPath();
 
 	// Initialize the source and destination in the data path to return