diff --git a/src/main/java/net/onrc/onos/ofcontroller/core/internal/DeviceStorageImpl.java b/src/main/java/net/onrc/onos/ofcontroller/core/internal/DeviceStorageImpl.java
index 6130218..f469911 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/core/internal/DeviceStorageImpl.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/core/internal/DeviceStorageImpl.java
@@ -7,7 +7,6 @@
 
 import net.floodlightcontroller.devicemanager.IDevice;
 import net.floodlightcontroller.devicemanager.SwitchPort;
-import net.floodlightcontroller.packet.IPv4;
 import net.onrc.onos.graph.DBOperation;
 import net.onrc.onos.graph.GraphDBManager;
 import net.onrc.onos.ofcontroller.core.IDeviceStorage;
@@ -30,15 +29,13 @@
  * @author Pankaj
  */
 public class DeviceStorageImpl implements IDeviceStorage {
+	protected final static Logger log = LoggerFactory.getLogger(DeviceStorageImpl.class);
 
 	private DBOperation ope;
-	protected final static Logger log = LoggerFactory.getLogger(SwitchStorageImpl.class);
-	/**
-	* *
-	* Initialize function. Before you use this class, please call this method
-	*
-	* @param conf configuration file for Cassandra DB
-	*/
+	/***
+	 * Initialize function. Before you use this class, please call this method
+	 * @param conf configuration file for Cassandra DB
+	 */
 	@Override
 	public void init(final String dbStore, final String conf) {
 		try {
@@ -49,34 +46,29 @@
 		}
 	}
 
-	/**
-	* *
-	* Finalize/close function. After you use this class, please call this
-	* method. It will close the DB connection.
-	*/
+	/***
+	 * Finalize/close function. After you use this class, please call this method.
+	 * It will close the DB connection.
+	 */
 	@Override
 	public void close() {
 		ope.close();
 	}
 
-	/**
-	* *
-	* Finalize/close function. After you use this class, please call this
-	* method. It will close the DB connection. This is for Java garbage
-	* collection.
-	*/
+	/***
+	 * Finalize/close function. After you use this class, please call this method.
+	 * It will close the DB connection. This is for Java garbage collection.
+	 */
 	@Override
 	public void finalize() {
 		close();
 	}
 
-	/**
-	* *
-	* This function is for adding the device into the DB.
-	*
-	* @param device The device you want to add into the DB.
-	* @return IDeviceObject which was added in the DB.
-	*/
+	/***
+	 * This function is for adding the device into the DB.
+	 * @param device The device you want to add into the DB.
+	 * @return IDeviceObject which was added in the DB.
+	 */
 	@Override
 	public IDeviceObject addDevice(IDevice device) {
 		IDeviceObject obj = null;
@@ -91,20 +83,20 @@
 	            	obj = ope.newDevice();
 	                log.debug("Adding device {}: creating new device", device.getMACAddressString());
 	            }
-	 			
+
 	            if (obj == null) {
 	            	return null;
 	            }
-	            
+
 	            changeDeviceAttachments(device, obj);
-		        
+
 	            changeDeviceIpv4Addresses(device, obj);
-	            
+
 	 			obj.setMACAddress(device.getMACAddressString());
 	 			obj.setType("device");
 	 			obj.setState("ACTIVE");
 	 			ope.commit();
-	 			
+
 	 			break;
 	 			//log.debug("Adding device {}",device.getMACAddressString());
 			} catch (TitanException e) {
@@ -113,16 +105,14 @@
 				obj = null;
 			}
 		}
- 		
-		return obj;		
+
+		return obj;
 	}
-	/**
-	* *
-	* This function is for updating the Device properties.
-	*
-	* @param device The device you want to add into the DB.
-	* @return IDeviceObject which was added in the DB.
-	*/
+	/***
+	 * This function is for updating the Device properties.
+	 * @param device The device you want to add into the DB.
+	 * @return IDeviceObject which was added in the DB.
+	 */
 	@Override
 	public IDeviceObject updateDevice(IDevice device) {
 		return addDevice(device);
@@ -135,12 +125,13 @@
 	@Override
 	public void removeDevice(IDevice device) {
 		IDeviceObject dev;
-		
+
 		if ((dev = ope.searchDevice(device.getMACAddressString())) != null) {
 			removeDevice(dev);
 		}
 	}
-	
+
+	@Override
 	public void removeDevice(IDeviceObject deviceObject) {
 		String deviceMac = deviceObject.getMACAddress();
 
@@ -154,26 +145,23 @@
 			log.error("DeviceStorage:removeDevice mac:{} failed", deviceMac);
 		}
 	}
-	
+
 	public void removeDeviceImpl(IDeviceObject deviceObject) {
 		for (IIpv4Address ipv4AddressVertex : deviceObject.getIpv4Addresses()) {
 			ope.removeIpv4Address(ipv4AddressVertex);
 		}
-		
+
 		ope.removeDevice(deviceObject);
 	}
-    /**
-     * *
-     * This function is for getting the Device from the DB by Mac address of the
-     * device.
-     *
-     * @param mac The device mac address you want to get from the DB.
-     * @return IDeviceObject you want to get.
-     */
-    @Override
-    public IDeviceObject getDeviceByMac(String mac) {
-        return ope.searchDevice(mac);
-    }
+	/***
+	 * This function is for getting the Device from the DB by Mac address of the device.
+	 * @param mac The device mac address you want to get from the DB.
+	 * @return IDeviceObject you want to get.
+	 */
+	@Override
+	public IDeviceObject getDeviceByMac(String mac) {
+	    return ope.searchDevice(mac);
+	}
 
 	/***
 	 * This function is for getting the Device from the DB by IP address of the device.
@@ -195,12 +183,10 @@
 		}
 	}
 
-	/**
-	* *
-	* This function is for changing the Device attachment point.
-	*
-	* @param device The device you want change the attachment point
-	*/
+	/***
+	 * This function is for changing the Device attachment point.
+	 * @param device The device you want change the attachment point
+	 */
 	@Override
 	public void changeDeviceAttachments(IDevice device) {
 		IDeviceObject obj = null;
@@ -218,7 +204,7 @@
 			log.error(":addDevice mac:{} failed", device.getMACAddressString());
 		}
 	}
-	
+
 	/***
 	 * This function is for changing the Device attachment point.
 	 * @param device The new device you want change the attachment point
@@ -232,7 +218,7 @@
 			//Check if there is the port
 			IPortObject port = ope.searchPort(HexString.toHexString(ap.getSwitchDPID()),
 					(short) ap.getPort());
-			log.debug("New Switch Port is {},{}", 
+			log.debug("New Switch Port is {},{}",
 					HexString.toHexString(ap.getSwitchDPID()), (short) ap.getPort());
 
 			if (port != null){
@@ -242,18 +228,18 @@
 					attachedPorts.remove(port);
 				} else {
 					log.debug("Adding device {}: attaching to port", device.getMACAddressString());
-					port.setDevice(obj);  
+					port.setDevice(obj);
 				}
 
 				log.debug("port number is {}", port.getNumber());
 				log.debug("port desc is {}", port.getDesc());
 			}
-		}      		 
+		}
 
 		for (IPortObject port: attachedPorts) {
 			log.debug("Detaching the device {}: detaching from port", device.getMACAddressString());
 			port.removeDevice(obj);
-			
+
 			if (!obj.getAttachedPorts().iterator().hasNext()) {
 				// XXX If there are no more ports attached to the device,
 				// delete it. Otherwise we have a situation where the
@@ -285,7 +271,7 @@
 			log.error(":changeDeviceIPv4Address mac:{} failed due to exception {}", device.getMACAddressString(), e);
 		}
 	}
-	
+
 	private void changeDeviceIpv4Addresses(IDevice device, IDeviceObject deviceObject) {
 		List<String> dbIpv4Addresses = new ArrayList<String>();
 		List<Integer> intDbIpv4Addresses = new ArrayList<Integer>();
@@ -293,33 +279,33 @@
 			dbIpv4Addresses.add(InetAddresses.fromInteger(ipv4Vertex.getIpv4Address()).getHostAddress());
 			intDbIpv4Addresses.add(ipv4Vertex.getIpv4Address());
 		}
-		
+
 		List<String> memIpv4Addresses = new ArrayList<String>();
 		for (int addr : device.getIPv4Addresses()) {
 			memIpv4Addresses.add(InetAddresses.fromInteger(addr).getHostAddress());
 		}
-		
+
 		log.debug("Device IP addresses {}, database IP addresses {}",
 				memIpv4Addresses, dbIpv4Addresses);
-		
+
 		for (int ipv4Address : device.getIPv4Addresses()) {
 			//if (deviceObject.getIpv4Address(ipv4Address) == null) {
 			if (!intDbIpv4Addresses.contains(ipv4Address)) {
 				IIpv4Address dbIpv4Address = ope.ensureIpv4Address(ipv4Address);
-				
+
 				/*
 				IDeviceObject oldDevice = dbIpv4Address.getDevice();
 				if (oldDevice != null) {
 					oldDevice.removeIpv4Address(dbIpv4Address);
 				}
 				*/
-				
-				log.debug("Adding IP address {}", 
+
+				log.debug("Adding IP address {}",
 						InetAddresses.fromInteger(ipv4Address).getHostAddress());
 				deviceObject.addIpv4Address(dbIpv4Address);
 			}
 		}
-			
+
 		List<Integer> deviceIpv4Addresses = Arrays.asList(device.getIPv4Addresses());
 		for (IIpv4Address dbIpv4Address : deviceObject.getIpv4Addresses()) {
 			if (!deviceIpv4Addresses.contains(dbIpv4Address.getIpv4Address())) {
@@ -330,17 +316,17 @@
 			}
 		}
 	}
-	
+
 	/**
 	 * Takes an {@link OnosDevice} and adds it into the database. There is no
-	 * checking of the database data and removing old data - an 
+	 * checking of the database data and removing old data - an
 	 * {@link OnosDevice} basically corresponds to a packet we've just seen,
 	 * and we need to add that information into the database.
 	 */
 	@Override
 	public void addOnosDevice(OnosDevice onosDevice) {
 		String macAddress = HexString.toHexString(onosDevice.getMacAddress().toBytes());
-		
+
 		//if the switch port we try to attach a new device already has a link, then stop adding device
 		IPortObject portObject1 = ope.searchPort(HexString.toHexString(
 				onosDevice.getSwitchDPID()), onosDevice.getSwitchPort());
@@ -352,19 +338,19 @@
 			}
 			return;
 		}
-		
+
 		log.debug("addOnosDevice: {}", onosDevice);
 
 		try {
 			IDeviceObject device = ope.searchDevice(macAddress);
-			
+
 			if (device == null) {
 				device = ope.newDevice();
 				device.setType("device");
 				device.setState("ACTIVE");
 				device.setMACAddress(macAddress);
 			}
-			
+
 			// Check if the device has the IP address, add it if it doesn't
 			if (onosDevice.getIpv4Address() != null) {
 				boolean hasIpAddress = false;
@@ -374,7 +360,7 @@
 						break;
 					}
 				}
-				
+
 				if (!hasIpAddress) {
 					IIpv4Address ipv4Address = ope.ensureIpv4Address(onosDevice.getIpv4Address().intValue());
 					IDeviceObject oldDevice = ipv4Address.getDevice();
@@ -384,7 +370,7 @@
 					device.addIpv4Address(ipv4Address);
 				}
 			}
-			
+
 			// Check if the device has the attachment point, add it if not
 			// TODO single attachment point for now, extend to multiple later
 			String switchDpid = HexString.toHexString(onosDevice.getSwitchDPID());
@@ -403,7 +389,7 @@
 					}
 				}
 			}
-			
+
 			/*
 			for (IPortObject portObject : device.getAttachedPorts()) {
 				ISwitchObject switchObject = portObject.getSwitch();
@@ -414,14 +400,14 @@
 				}
 			}
 			*/
-			
+
 			if (!hasAttachmentPoint) {
 				IPortObject portObject = ope.searchPort(switchDpid, onosDevice.getSwitchPort());
 				if (portObject != null) {
 					portObject.setDevice(device);
 				}
 			}
-			
+
 			ope.commit();
 		}
 		catch (TitanException e) {
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 05c5ecb..b944a01 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowDatabaseOperation.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowDatabaseOperation.java
@@ -17,6 +17,8 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.tinkerpop.blueprints.impls.ramcloud.PerfMon;
+
 /**
  * Class for performing Flow-related operations on the Database.
  */
@@ -50,7 +52,9 @@
 	long accTimeAddFlowEntries = 0;
 	int numNewFlowEntries = 0;
 	LinkedList<long[]> flowEntryTimes = new LinkedList<>();
+	PerfMon pm = PerfMon.getInstance();
 
+	pm.addflowpath_start();
 	try {
 	    if ( measureONOSFlowTimeProp ) {
 		startAddFlow = System.nanoTime();
@@ -260,6 +264,7 @@
 	if ( measureONOSFlowTimeProp ) {
 		endSettingFlowPathProps = System.nanoTime();
 	}
+	pm.addflowpath_end();
 	// Flow edges:
 	//   HeadFE
 
@@ -268,10 +273,13 @@
 	// Flow Entries:
 	// flowPath.dataPath().flowEntries()
 	//
+	pm.addflowentry_start();
 	for (FlowEntry flowEntry : flowPath.dataPath().flowEntries()) {
 	    if (flowEntry.flowEntryUserState() == FlowEntryUserState.FE_USER_DELETE)
 		continue;	// Skip: all Flow Entries were deleted earlier
 
+	    pm.addflowentry_incr();
+
 	    long startAddFlowEntry = 0, endAddFlowEntry;
 	    if( measureONOSFlowTimeProp ) {
 		startAddFlowEntry = System.nanoTime();
@@ -288,6 +296,7 @@
 		return false;
 	    }
 	}
+	pm.addflowentry_end();
 	dbHandler.commit();