diff --git a/apps/bgprouter/src/main/java/org/onosproject/bgprouter/BgpRouter.java b/apps/bgprouter/src/main/java/org/onosproject/bgprouter/BgpRouter.java
index a17046f..b50681e 100644
--- a/apps/bgprouter/src/main/java/org/onosproject/bgprouter/BgpRouter.java
+++ b/apps/bgprouter/src/main/java/org/onosproject/bgprouter/BgpRouter.java
@@ -15,11 +15,14 @@
  */
 package org.onosproject.bgprouter;
 
-import com.google.common.collect.ConcurrentHashMultiset;
-import com.google.common.collect.HashMultimap;
-import com.google.common.collect.Maps;
-import com.google.common.collect.Multimap;
-import com.google.common.collect.Multiset;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
@@ -30,6 +33,7 @@
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
+import org.onlab.util.KryoNamespace;
 import org.onosproject.config.NetworkConfigService;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.core.CoreService;
@@ -47,12 +51,12 @@
 import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.group.DefaultGroupBucket;
 import org.onosproject.net.group.DefaultGroupDescription;
+import org.onosproject.net.group.DefaultGroupKey;
 import org.onosproject.net.group.Group;
 import org.onosproject.net.group.GroupBucket;
 import org.onosproject.net.group.GroupBuckets;
 import org.onosproject.net.group.GroupDescription;
 import org.onosproject.net.group.GroupEvent;
-import org.onosproject.net.group.GroupKey;
 import org.onosproject.net.group.GroupListener;
 import org.onosproject.net.group.GroupService;
 import org.onosproject.net.host.InterfaceIpAddress;
@@ -67,13 +71,11 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-import java.util.stream.Collectors;
+import com.google.common.collect.ConcurrentHashMultiset;
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Multiset;
 
 /**
  * BgpRouter component.
@@ -126,7 +128,7 @@
     private final Map<IpAddress, NextHop> nextHops = Maps.newHashMap();
 
     // Stores FIB updates that are waiting for groups to be set up
-    private final Multimap<GroupKey, FibEntry> pendingUpdates = HashMultimap.create();
+    private final Multimap<NextHopGroupKey, FibEntry> pendingUpdates = HashMultimap.create();
 
     // Device id of data-plane switch - should be learned from config
     private DeviceId deviceId;
@@ -143,6 +145,11 @@
 
     private InternalTableHandler provisionStaticTables = new InternalTableHandler();
 
+    private KryoNamespace.Builder appKryo = new KryoNamespace.Builder()
+                    .register(IpAddress.Version.class)
+                    .register(IpAddress.class)
+                    .register(NextHopGroupKey.class);
+
     @Activate
     protected void activate() {
         appId = coreService.registerApplication(BGP_ROUTER_APP);
@@ -210,7 +217,9 @@
             Group group;
             synchronized (pendingUpdates) {
                 NextHop nextHop = nextHops.get(entry.nextHopIp());
-                group = groupService.getGroup(deviceId, nextHop.group());
+                group = groupService.getGroup(deviceId,
+                                              new DefaultGroupKey(
+                                              appKryo.build().serialize(nextHop.group())));
 
                 if (group == null) {
                     log.debug("Adding pending flow {}", update.entry());
@@ -309,7 +318,7 @@
                                                   GroupDescription.Type.INDIRECT,
                                                   new GroupBuckets(Collections
                                                                            .singletonList(bucket)),
-                                                  groupKey,
+                                                  new DefaultGroupKey(appKryo.build().serialize(groupKey)),
                                                   appId);
 
             groupService.addGroup(groupDescription);
@@ -329,7 +338,10 @@
             return null;
         }
 
-        Group group = groupService.getGroup(deviceId, nextHop.group());
+        Group group = groupService.getGroup(deviceId,
+                                            new DefaultGroupKey(appKryo.
+                                                                build().
+                                                                serialize(nextHop.group())));
 
         // FIXME disabling group deletes for now until we verify the logic is OK
         /*if (nextHopsCount.remove(nextHopIp, 1) <= 1) {
@@ -339,7 +351,9 @@
 
             nextHops.remove(nextHopIp);
 
-            groupService.removeGroup(deviceId, nextHop.group(), appId);
+            groupService.removeGroup(deviceId,
+                                     new DefaultGroupKey(appKryo.build().serialize(nextHop.group())),
+                                     appId);
         }*/
 
         return group;
@@ -699,8 +713,10 @@
                     event.type() == GroupEvent.Type.GROUP_UPDATED) {
                 synchronized (pendingUpdates) {
 
+                    NextHopGroupKey nhGroupKey =
+                            appKryo.build().deserialize(group.appCookie().key());
                     Map<FibEntry, Group> entriesToInstall =
-                            pendingUpdates.removeAll(group.appCookie())
+                            pendingUpdates.removeAll(nhGroupKey)
                                     .stream()
                                     .collect(Collectors
                                                      .toMap(e -> e, e -> group));
diff --git a/apps/bgprouter/src/main/java/org/onosproject/bgprouter/NextHop.java b/apps/bgprouter/src/main/java/org/onosproject/bgprouter/NextHop.java
index cc045bc..88ce1a3 100644
--- a/apps/bgprouter/src/main/java/org/onosproject/bgprouter/NextHop.java
+++ b/apps/bgprouter/src/main/java/org/onosproject/bgprouter/NextHop.java
@@ -15,12 +15,12 @@
  */
 package org.onosproject.bgprouter;
 
-import com.google.common.base.MoreObjects;
+import java.util.Objects;
+
 import org.onlab.packet.IpAddress;
 import org.onlab.packet.MacAddress;
-import org.onosproject.net.group.GroupKey;
 
-import java.util.Objects;
+import com.google.common.base.MoreObjects;
 
 /**
  * Represents a next hop for routing, whose MAC address has already been resolved.
@@ -29,7 +29,7 @@
 
     private final IpAddress ip;
     private final MacAddress mac;
-    private final GroupKey group;
+    private final NextHopGroupKey group;
 
     /**
      * Creates a new next hop.
@@ -38,7 +38,7 @@
      * @param mac next hop's MAC address
      * @param group next hop's group
      */
-    public NextHop(IpAddress ip, MacAddress mac, GroupKey group) {
+    public NextHop(IpAddress ip, MacAddress mac, NextHopGroupKey group) {
         this.ip = ip;
         this.mac = mac;
         this.group = group;
@@ -67,7 +67,7 @@
      *
      * @return group
      */
-    public GroupKey group() {
+    public NextHopGroupKey group() {
         return group;
     }
 
diff --git a/apps/bgprouter/src/main/java/org/onosproject/bgprouter/NextHopGroupKey.java b/apps/bgprouter/src/main/java/org/onosproject/bgprouter/NextHopGroupKey.java
index ae281e3..82a45a0 100644
--- a/apps/bgprouter/src/main/java/org/onosproject/bgprouter/NextHopGroupKey.java
+++ b/apps/bgprouter/src/main/java/org/onosproject/bgprouter/NextHopGroupKey.java
@@ -15,18 +15,18 @@
  */
 package org.onosproject.bgprouter;
 
-import com.google.common.base.MoreObjects;
-import org.onlab.packet.IpAddress;
-import org.onosproject.net.group.GroupKey;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 import java.util.Objects;
 
-import static com.google.common.base.Preconditions.checkNotNull;
+import org.onlab.packet.IpAddress;
+
+import com.google.common.base.MoreObjects;
 
 /**
  * Identifier for a next hop group.
  */
-public class NextHopGroupKey implements GroupKey {
+public class NextHopGroupKey {
 
     private final IpAddress address;
 
diff --git a/apps/grouphandler/pom.xml b/apps/grouphandler/pom.xml
index a245b9f..17aa23c 100644
--- a/apps/grouphandler/pom.xml
+++ b/apps/grouphandler/pom.xml
@@ -22,7 +22,7 @@
     <parent>
         <groupId>org.onosproject</groupId>
         <artifactId>onos-apps</artifactId>
-        <version>1.1.0-SNAPSHOT</version>
+        <version>1.2.0-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
 
diff --git a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultEdgeGroupHandler.java b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultEdgeGroupHandler.java
index 8da4acd..7523a64 100644
--- a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultEdgeGroupHandler.java
+++ b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultEdgeGroupHandler.java
@@ -124,16 +124,23 @@
             tBuilder.setOutput(newNeighborLink.src().port())
                     .setEthDst(deviceConfig.getDeviceMac(
                           newNeighborLink.dst().deviceId()))
-                    .setEthSrc(nodeMacAddr)
-                    .pushMpls()
-                    .setMpls(MplsLabel.mplsLabel(ns.getEdgeLabel()));
+                    .setEthSrc(nodeMacAddr);
+            if (ns.getEdgeLabel() != NeighborSet.NO_EDGE_LABEL) {
+                tBuilder.pushMpls()
+                        .setMpls(MplsLabel.
+                                 mplsLabel(ns.getEdgeLabel()));
+            }
             GroupBucket updatedBucket = DefaultGroupBucket.
                     createSelectGroupBucket(tBuilder.build());
             GroupBuckets updatedBuckets = new GroupBuckets(
                                         Arrays.asList(updatedBucket));
             log.debug("newPortToExistingNeighborAtEdgeRouter: "
                     + "groupService.addBucketsToGroup for neighborset{}", ns);
-            groupService.addBucketsToGroup(deviceId, ns, updatedBuckets, ns, appId);
+            groupService.addBucketsToGroup(deviceId,
+                                           getGroupKey(ns),
+                                           updatedBuckets,
+                                           getGroupKey(ns),
+                                           appId);
         }
     }
 
diff --git a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultGroupHandler.java b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultGroupHandler.java
index 755fac2..ec9e42f 100644
--- a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultGroupHandler.java
+++ b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultGroupHandler.java
@@ -18,6 +18,7 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 import static org.slf4j.LoggerFactory.getLogger;
 
+import java.net.URI;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -27,6 +28,7 @@
 
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.MplsLabel;
+import org.onlab.util.KryoNamespace;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.Link;
@@ -35,6 +37,7 @@
 import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.group.DefaultGroupBucket;
 import org.onosproject.net.group.DefaultGroupDescription;
+import org.onosproject.net.group.DefaultGroupKey;
 import org.onosproject.net.group.Group;
 import org.onosproject.net.group.GroupBucket;
 import org.onosproject.net.group.GroupBuckets;
@@ -71,6 +74,16 @@
             new HashMap<PortNumber, DeviceId>();
 
     private GroupListener listener = new InternalGroupListener();
+    protected KryoNamespace.Builder kryo = new KryoNamespace.Builder()
+    .register(URI.class)
+    .register(HashSet.class)
+    .register(DeviceId.class)
+    .register(PortNumber.class)
+    .register(NeighborSet.class)
+    .register(PolicyGroupIdentifier.class)
+    .register(PolicyGroupParams.class)
+    .register(GroupBucketIdentifier.class)
+    .register(GroupBucketIdentifier.BucketOutputType.class);
 
     protected DefaultGroupHandler(DeviceId deviceId,
                                ApplicationId appId,
@@ -185,9 +198,11 @@
             tBuilder.setOutput(port)
                     .setEthDst(deviceConfig.getDeviceMac(
                          portDeviceMap.get(port)))
-                    .setEthSrc(nodeMacAddr)
-                    .pushMpls()
+                    .setEthSrc(nodeMacAddr);
+            if (ns.getEdgeLabel() != NeighborSet.NO_EDGE_LABEL) {
+                tBuilder.pushMpls()
                     .setMpls(MplsLabel.mplsLabel(ns.getEdgeLabel()));
+            }
             GroupBucket removeBucket = DefaultGroupBucket.
                     createSelectGroupBucket(tBuilder.build());
             GroupBuckets removeBuckets = new GroupBuckets(
@@ -196,9 +211,9 @@
                     + "groupService.removeBucketsFromGroup "
                     + "for neighborset{}", deviceId, ns);
             groupService.removeBucketsFromGroup(deviceId,
-                                                ns,
+                                                getGroupKey(ns),
                                                 removeBuckets,
-                                                ns,
+                                                getGroupKey(ns),
                                                 appId);
         }
 
@@ -331,9 +346,12 @@
                             DefaultTrafficTreatment.builder();
                     tBuilder.setOutput(sp)
                             .setEthDst(deviceConfig.getDeviceMac(d))
-                            .setEthSrc(nodeMacAddr)
-                            .pushMpls()
-                            .setMpls(MplsLabel.mplsLabel(ns.getEdgeLabel()));
+                            .setEthSrc(nodeMacAddr);
+                    if (ns.getEdgeLabel() != NeighborSet.NO_EDGE_LABEL) {
+                        tBuilder.pushMpls()
+                                .setMpls(MplsLabel.
+                                         mplsLabel(ns.getEdgeLabel()));
+                    }
                     buckets.add(DefaultGroupBucket.createSelectGroupBucket(
                                                                 tBuilder.build()));
                 }
@@ -343,7 +361,7 @@
                                       deviceId,
                                       Group.Type.SELECT,
                                       groupBuckets,
-                                      ns,
+                                      getGroupKey(ns),
                                       appId);
             log.debug("createGroupsFromNeighborsets: "
                     + "groupService.addGroup for neighborset{}", ns);
@@ -386,4 +404,8 @@
             handleGroupEvent(event);
         }
     }
+
+    protected GroupKey getGroupKey(Object obj) {
+        return new DefaultGroupKey(kryo.build().serialize(obj));
+    }
 }
diff --git a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultGroupHandlerApp.java b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultGroupHandlerApp.java
index 2bd2b4e..bb1a035 100644
--- a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultGroupHandlerApp.java
+++ b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultGroupHandlerApp.java
@@ -17,8 +17,10 @@
 
 import static org.slf4j.LoggerFactory.getLogger;
 
+import java.net.URI;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 
 import org.apache.felix.scr.annotations.Activate;
@@ -27,10 +29,13 @@
 import org.apache.felix.scr.annotations.Reference;
 import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.onlab.packet.MacAddress;
+import org.onlab.util.KryoNamespace;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.core.CoreService;
+import org.onosproject.mastership.MastershipService;
 import org.onosproject.net.Device;
 import org.onosproject.net.DeviceId;
+import org.onosproject.net.MastershipRole;
 import org.onosproject.net.device.DeviceEvent;
 import org.onosproject.net.device.DeviceListener;
 import org.onosproject.net.device.DeviceService;
@@ -69,10 +74,18 @@
     protected GroupService groupService;
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected CoreService coreService;
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected MastershipService mastershipService;
 
     private DeviceListener deviceListener = new InternalDeviceListener();
     private LinkListener linkListener = new InternalLinkListener();
 
+    protected KryoNamespace.Builder kryo = new KryoNamespace.Builder()
+                        .register(URI.class)
+                        .register(HashSet.class)
+                        .register(DeviceId.class)
+                        .register(NeighborSet.class);
+
     @Activate
     public void activate() {
         appId = coreService.registerApplication("org.onosproject.defaultgrouphandler");
@@ -80,14 +93,23 @@
         deviceService.addListener(deviceListener);
         linkService.addListener(linkListener);
         for (Device device: deviceService.getDevices()) {
-            log.debug("Initiating default group handling for {}", device.id());
-            DefaultGroupHandler dgh = DefaultGroupHandler.createGroupHandler(device.id(),
-                                                              appId,
-                                                              config,
-                                                              linkService,
-                                                              groupService);
-            dgh.createGroups();
-            dghMap.put(device.id(), dgh);
+            if (mastershipService.
+                    getLocalRole(device.id()) == MastershipRole.MASTER) {
+                log.debug("Initiating default group handling for {}", device.id());
+                DefaultGroupHandler dgh = DefaultGroupHandler.createGroupHandler(device.id(),
+                                                                  appId,
+                                                                  config,
+                                                                  linkService,
+                                                                  groupService);
+                dgh.createGroups();
+                dghMap.put(device.id(), dgh);
+            } else {
+                log.debug("Activate: Local role {} "
+                        + "is not MASTER for device {}",
+                          mastershipService.
+                          getLocalRole(device.id()),
+                          device.id());
+            }
         }
         log.info("Activated");
     }
@@ -165,7 +187,15 @@
 
         @Override
         public void event(DeviceEvent event) {
-            switch (event.type()) {
+           if (mastershipService.
+                    getLocalRole(event.subject().id()) != MastershipRole.MASTER) {
+               log.debug("Local role {} is not MASTER for device {}",
+                         mastershipService.
+                         getLocalRole(event.subject().id()),
+                         event.subject().id());
+               return;
+           }
+           switch (event.type()) {
             case DEVICE_ADDED:
                 log.debug("Initiating default group handling for {}", event.subject().id());
                 DefaultGroupHandler dgh = DefaultGroupHandler.createGroupHandler(
@@ -193,6 +223,16 @@
 
         @Override
         public void event(LinkEvent event) {
+            if (mastershipService.
+                    getLocalRole(event.subject().src().deviceId()) !=
+                    MastershipRole.MASTER) {
+                log.debug("InternalLinkListener: Local role {} "
+                        + "is not MASTER for device {}",
+                          mastershipService.
+                          getLocalRole(event.subject().src().deviceId()),
+                          event.subject().src().deviceId());
+                return;
+            }
             switch (event.type()) {
             case LINK_ADDED:
                 if (dghMap.get(event.subject().src().deviceId()) != null) {
diff --git a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultTransitGroupHandler.java b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultTransitGroupHandler.java
index a6129c2..1b5bb50 100644
--- a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultTransitGroupHandler.java
+++ b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultTransitGroupHandler.java
@@ -112,16 +112,23 @@
             tBuilder.setOutput(newNeighborLink.src().port())
                     .setEthDst(deviceConfig.getDeviceMac(
                           newNeighborLink.dst().deviceId()))
-                    .setEthSrc(nodeMacAddr)
-                    .pushMpls()
-                    .setMpls(MplsLabel.mplsLabel(ns.getEdgeLabel()));
+                    .setEthSrc(nodeMacAddr);
+            if (ns.getEdgeLabel() != NeighborSet.NO_EDGE_LABEL) {
+                tBuilder.pushMpls()
+                        .setMpls(MplsLabel.
+                                 mplsLabel(ns.getEdgeLabel()));
+            }
             GroupBucket updatedBucket = DefaultGroupBucket.
                     createSelectGroupBucket(tBuilder.build());
             GroupBuckets updatedBuckets = new GroupBuckets(
                                         Arrays.asList(updatedBucket));
             log.debug("newPortToExistingNeighborAtEdgeRouter: "
                     + "groupService.addBucketsToGroup for neighborset{}", ns);
-            groupService.addBucketsToGroup(deviceId, ns, updatedBuckets, ns, appId);
+            groupService.addBucketsToGroup(deviceId,
+                                           getGroupKey(ns),
+                                           updatedBuckets,
+                                           getGroupKey(ns),
+                                           appId);
         }
     }
 
diff --git a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/GroupBucketIdentifier.java b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/GroupBucketIdentifier.java
index cf0ae5e..3a46ce6 100644
--- a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/GroupBucketIdentifier.java
+++ b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/GroupBucketIdentifier.java
@@ -18,7 +18,6 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import org.onosproject.net.PortNumber;
-import org.onosproject.net.group.GroupKey;
 
 /**
  * Representation of policy group bucket identifier. Not exposed to
@@ -28,7 +27,7 @@
     private int label;
     private BucketOutputType type;
     private PortNumber outPort;
-    private GroupKey outGroup;
+    private PolicyGroupIdentifier outGroup;
 
     protected enum BucketOutputType {
         PORT,
@@ -44,7 +43,7 @@
     }
 
     protected GroupBucketIdentifier(int label,
-                                    GroupKey outGroup) {
+                                    PolicyGroupIdentifier outGroup) {
         this.label = label;
         this.type = BucketOutputType.GROUP;
         this.outPort = null;
@@ -63,7 +62,7 @@
         return this.outPort;
     }
 
-    protected GroupKey outGroup() {
+    protected PolicyGroupIdentifier outGroup() {
         return this.outGroup;
     }
 }
diff --git a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/NeighborSet.java b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/NeighborSet.java
index 497b352..ce739ce 100644
--- a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/NeighborSet.java
+++ b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/NeighborSet.java
@@ -23,7 +23,6 @@
 import java.util.Set;
 
 import org.onosproject.net.DeviceId;
-import org.onosproject.net.group.GroupKey;
 
 /**
  * Representation of a set of neighbor switch dpids along with edge node
@@ -31,9 +30,10 @@
  * ECMP-group that hashes packets to a set of ports connecting to the
  * neighbors in this set.
  */
-public class NeighborSet implements GroupKey {
+public class NeighborSet {
     private final Set<DeviceId> neighbors;
     private final int edgeLabel;
+    public static final int NO_EDGE_LABEL = -1;
 
     /**
      * Constructor with set of neighbors. Edge label is
@@ -43,7 +43,7 @@
      */
     public NeighborSet(Set<DeviceId> neighbors) {
         checkNotNull(neighbors);
-        this.edgeLabel = -1;
+        this.edgeLabel = NO_EDGE_LABEL;
         this.neighbors = new HashSet<DeviceId>();
         this.neighbors.addAll(neighbors);
     }
@@ -65,7 +65,7 @@
      * Default constructor for kryo serialization.
      */
     public NeighborSet() {
-        this.edgeLabel = -1;
+        this.edgeLabel = NO_EDGE_LABEL;
         this.neighbors = new HashSet<DeviceId>();
     }
 
diff --git a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/PolicyGroupHandler.java b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/PolicyGroupHandler.java
index d2b43b3..e0cfe52 100644
--- a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/PolicyGroupHandler.java
+++ b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/PolicyGroupHandler.java
@@ -37,7 +37,6 @@
 import org.onosproject.net.group.GroupBuckets;
 import org.onosproject.net.group.GroupDescription;
 import org.onosproject.net.group.GroupEvent;
-import org.onosproject.net.group.GroupKey;
 import org.onosproject.net.group.GroupService;
 import org.onosproject.net.link.LinkService;
 import org.slf4j.Logger;
@@ -49,18 +48,17 @@
 public class PolicyGroupHandler extends DefaultGroupHandler {
 
     private final Logger log = getLogger(getClass());
-    private HashMap<GroupKey, GroupKey> dependentGroups =
-            new HashMap<GroupKey, GroupKey>();
+    private HashMap<PolicyGroupIdentifier, PolicyGroupIdentifier> dependentGroups =
+            new HashMap<PolicyGroupIdentifier, PolicyGroupIdentifier>();
 
     /**
-     * Creates policy group handler object.
+     * Policy group handler constructor.
      *
      * @param deviceId device identifier
      * @param appId application identifier
      * @param config interface to retrieve the device properties
      * @param linkService link service object
      * @param groupService group service object
-     * @return policy group handler type
      */
     public PolicyGroupHandler(DeviceId deviceId,
                               ApplicationId appId,
@@ -175,9 +173,11 @@
                     tBuilder.setOutput(bucketId.outPort())
                             .setEthDst(deviceConfig.
                                        getDeviceMac(neighbor))
-                            .setEthSrc(nodeMacAddr)
-                            .pushMpls()
+                            .setEthSrc(nodeMacAddr);
+                    if (bucketId.label() != NeighborSet.NO_EDGE_LABEL) {
+                        tBuilder.pushMpls()
                             .setMpls(MplsLabel.mplsLabel(bucketId.label()));
+                    }
                     //TODO: BoS
                     outBuckets.add(DefaultGroupBucket.
                                    createSelectGroupBucket(tBuilder.build()));
@@ -196,8 +196,7 @@
     protected void handleGroupEvent(GroupEvent event) {
         if (event.type() == GroupEvent.Type.GROUP_ADDED) {
             if (dependentGroups.get(event.subject().appCookie()) != null) {
-                PolicyGroupIdentifier dependentGroupKey = (PolicyGroupIdentifier)
-                        dependentGroups.get(event.subject().appCookie());
+                PolicyGroupIdentifier dependentGroupKey = dependentGroups.get(event.subject().appCookie());
                 dependentGroups.remove(event.subject().appCookie());
                 boolean fullyResolved = true;
                 for (GroupBucketIdentifier bucketId:
@@ -217,8 +216,11 @@
                                 dependentGroupKey.bucketIds()) {
                         TrafficTreatment.Builder tBuilder =
                                 DefaultTrafficTreatment.builder();
-                        tBuilder.pushMpls()
-                                .setMpls(MplsLabel.mplsLabel(bucketId.label()));
+                        if (bucketId.label() != NeighborSet.NO_EDGE_LABEL) {
+                            tBuilder.pushMpls()
+                                    .setMpls(MplsLabel.
+                                             mplsLabel(bucketId.label()));
+                        }
                         //TODO: BoS
                         if (bucketId.type() == BucketOutputType.PORT) {
                             DeviceId neighbor = portDeviceMap.
@@ -230,12 +232,14 @@
                         } else {
                             if (groupService.
                                     getGroup(deviceId,
-                                             bucketId.outGroup()) == null) {
+                                             getGroupKey(bucketId.
+                                                       outGroup())) == null) {
                                 throw new IllegalStateException();
                             }
                             GroupId indirectGroupId = groupService.
                                     getGroup(deviceId,
-                                             bucketId.outGroup()).id();
+                                             getGroupKey(bucketId.
+                                                         outGroup())).id();
                             tBuilder.group(indirectGroupId);
                         }
                         outBuckets.add(DefaultGroupBucket.
@@ -251,7 +255,7 @@
         }
     }
 
-    public GroupKey generatePolicyGroupKey(String id,
+    public PolicyGroupIdentifier generatePolicyGroupKey(String id,
                                    List<PolicyGroupParams> params) {
         List<GroupBucketIdentifier> bucketIds = new ArrayList<GroupBucketIdentifier>();
         for (PolicyGroupParams param: params) {
@@ -320,25 +324,28 @@
         return innermostGroupkey;
     }
 
-    public void removeGroupChain(GroupKey key) {
+    public void removeGroupChain(PolicyGroupIdentifier key) {
         if (!(key instanceof PolicyGroupIdentifier)) {
             throw new IllegalArgumentException();
         }
-        List<GroupKey> groupsToBeDeleted = new ArrayList<GroupKey>();
+        List<PolicyGroupIdentifier> groupsToBeDeleted =
+                new ArrayList<PolicyGroupIdentifier>();
         groupsToBeDeleted.add(key);
 
-        Iterator<GroupKey> it = groupsToBeDeleted.iterator();
+        Iterator<PolicyGroupIdentifier> it =
+                groupsToBeDeleted.iterator();
 
         while (it.hasNext()) {
-            PolicyGroupIdentifier innerMostGroupKey =
-                    (PolicyGroupIdentifier) it.next();
+            PolicyGroupIdentifier innerMostGroupKey = it.next();
             for (GroupBucketIdentifier bucketId:
                         innerMostGroupKey.bucketIds()) {
                 if (bucketId.type() != BucketOutputType.GROUP) {
                     groupsToBeDeleted.add(bucketId.outGroup());
                 }
             }
-            groupService.removeGroup(deviceId, innerMostGroupKey, appId);
+            groupService.removeGroup(deviceId,
+                                     getGroupKey(innerMostGroupKey),
+                                     appId);
             it.remove();
         }
     }
diff --git a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/PolicyGroupIdentifier.java b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/PolicyGroupIdentifier.java
index d213e0c..3c19b29 100644
--- a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/PolicyGroupIdentifier.java
+++ b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/PolicyGroupIdentifier.java
@@ -17,14 +17,12 @@
 
 import java.util.List;
 
-import org.onosproject.net.group.GroupKey;
-
 /**
  * Representation of policy based group identifiers.
  * Opaque to group handler applications and only the outermost
  * policy group identifier in a chain is visible to the applications.
  */
-public class PolicyGroupIdentifier implements GroupKey {
+public class PolicyGroupIdentifier {
     private String id;
     private List<PolicyGroupParams> inputParams;
     private List<GroupBucketIdentifier> bucketIds;
diff --git a/core/api/src/main/java/org/onosproject/net/group/DefaultGroup.java b/core/api/src/main/java/org/onosproject/net/group/DefaultGroup.java
index 9248625..c52f771 100644
--- a/core/api/src/main/java/org/onosproject/net/group/DefaultGroup.java
+++ b/core/api/src/main/java/org/onosproject/net/group/DefaultGroup.java
@@ -16,13 +16,11 @@
 package org.onosproject.net.group;
 
 import static com.google.common.base.MoreObjects.toStringHelper;
-import static org.slf4j.LoggerFactory.getLogger;
 
 import java.util.Objects;
 
 import org.onosproject.core.GroupId;
 import org.onosproject.net.DeviceId;
-import org.slf4j.Logger;
 
 /**
  * ONOS implementation of default group that is stored in the system.
@@ -30,9 +28,8 @@
 public class DefaultGroup extends DefaultGroupDescription
     implements Group, StoredGroupEntry {
 
-    private final Logger log = getLogger(getClass());
-
     private GroupState state;
+    private boolean isGroupStateAddedFirstTime;
     private long life;
     private long packets;
     private long bytes;
@@ -215,4 +212,14 @@
                 .add("state", state)
                 .toString();
     }
+
+    @Override
+    public void setIsGroupStateAddedFirstTime(boolean isGroupStateAddedFirstTime) {
+        this.isGroupStateAddedFirstTime = isGroupStateAddedFirstTime;
+    }
+
+    @Override
+    public boolean isGroupStateAddedFirstTime() {
+        return isGroupStateAddedFirstTime;
+    }
 }
diff --git a/core/api/src/main/java/org/onosproject/net/group/DefaultGroupDescription.java b/core/api/src/main/java/org/onosproject/net/group/DefaultGroupDescription.java
index 385a5d6..3ffb2c2 100644
--- a/core/api/src/main/java/org/onosproject/net/group/DefaultGroupDescription.java
+++ b/core/api/src/main/java/org/onosproject/net/group/DefaultGroupDescription.java
@@ -41,7 +41,8 @@
      * @param deviceId device identifier
      * @param type type of the group
      * @param buckets immutable list of group bucket
-     * @param appCookie immutable application cookie to be associated with the group
+     * @param appCookie immutable application cookie of type DefaultGroupKey
+     * to be associated with the group
      * @param appId application id
      */
     public DefaultGroupDescription(DeviceId deviceId,
diff --git a/core/api/src/main/java/org/onosproject/net/group/DefaultGroupKey.java b/core/api/src/main/java/org/onosproject/net/group/DefaultGroupKey.java
new file mode 100644
index 0000000..7f00ae7
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/group/DefaultGroupKey.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.net.group;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Arrays;
+
+/**
+ * Default implementation of group key interface.
+ */
+public class DefaultGroupKey implements GroupKey {
+
+    private final byte[] key;
+
+    public DefaultGroupKey(byte[] key) {
+        this.key = checkNotNull(key);
+    }
+
+    @Override
+    public byte[] key() {
+        return key;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof DefaultGroupKey)) {
+            return false;
+        }
+        DefaultGroupKey that = (DefaultGroupKey) o;
+        return (Arrays.equals(this.key, that.key));
+    }
+
+    @Override
+    public int hashCode() {
+        return Arrays.hashCode(this.key);
+    }
+
+}
\ No newline at end of file
diff --git a/core/api/src/main/java/org/onosproject/net/group/GroupKey.java b/core/api/src/main/java/org/onosproject/net/group/GroupKey.java
index da8d449..9c87b83 100644
--- a/core/api/src/main/java/org/onosproject/net/group/GroupKey.java
+++ b/core/api/src/main/java/org/onosproject/net/group/GroupKey.java
@@ -17,8 +17,15 @@
 
 /**
  * Representation of generalized Key that would be used to store
- * groups in &lt; Key, Value &gt; store. Implementation of this interface
- * MUST override "equals()" and "hashcode()" methods.
+ * groups in &lt; Key, Value &gt; store. This key uses a generic
+ * byte array so that applications can associate their groups with
+ * any of their data by translating it into a byte array.
  */
 public interface GroupKey  {
+    /**
+     * Returns the byte representation of key.
+     *
+     * @return byte array
+     */
+    public byte[] key();
 }
diff --git a/core/api/src/main/java/org/onosproject/net/group/GroupStore.java b/core/api/src/main/java/org/onosproject/net/group/GroupStore.java
index e7bf4f8..7ccab8a 100644
--- a/core/api/src/main/java/org/onosproject/net/group/GroupStore.java
+++ b/core/api/src/main/java/org/onosproject/net/group/GroupStore.java
@@ -15,6 +15,7 @@
  */
 package org.onosproject.net.group;
 
+import org.onosproject.core.GroupId;
 import org.onosproject.net.DeviceId;
 import org.onosproject.store.Store;
 
@@ -60,6 +61,15 @@
     Group getGroup(DeviceId deviceId, GroupKey appCookie);
 
     /**
+     * Returns the stored group entry for an id.
+     *
+     * @param deviceId the device ID
+     * @param groupId the group identifier
+     * @return a group associated with the key
+     */
+    Group getGroup(DeviceId deviceId, GroupId groupId);
+
+    /**
      * Stores a new group entry using the information from group description.
      *
      * @param groupDesc group description to be used to store group entry
diff --git a/core/api/src/main/java/org/onosproject/net/group/StoredGroupEntry.java b/core/api/src/main/java/org/onosproject/net/group/StoredGroupEntry.java
index 297663f..47d3612 100644
--- a/core/api/src/main/java/org/onosproject/net/group/StoredGroupEntry.java
+++ b/core/api/src/main/java/org/onosproject/net/group/StoredGroupEntry.java
@@ -29,6 +29,23 @@
     void setState(Group.GroupState newState);
 
     /**
+     * Sets if group has transitioned to ADDED state for the first time.
+     * This is to differentiate state transitions "from PENDING_ADD to ADDED"
+     * and "from PENDING_UPDATE to ADDED". For internal use only.
+     *
+     * @param isGroupAddedFirstTime true if group moves to ADDED state
+     * for the first time.
+     */
+    void setIsGroupStateAddedFirstTime(boolean isGroupAddedFirstTime);
+
+    /**
+     * Returns the isGroupStateAddedFirstTime value. For internal use only.
+     *
+     * @return isGroupStateAddedFirstTime value
+     */
+    boolean isGroupStateAddedFirstTime();
+
+    /**
      * Sets how long this entry has been entered in the system.
      *
      * @param life epoch time
diff --git a/core/net/src/main/java/org/onosproject/net/group/impl/GroupManager.java b/core/net/src/main/java/org/onosproject/net/group/impl/GroupManager.java
index 2d8f81c..6601cbf 100644
--- a/core/net/src/main/java/org/onosproject/net/group/impl/GroupManager.java
+++ b/core/net/src/main/java/org/onosproject/net/group/impl/GroupManager.java
@@ -15,7 +15,13 @@
  */
 package org.onosproject.net.group.impl;
 
-import com.google.common.collect.Sets;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Set;
+
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
@@ -48,12 +54,7 @@
 import org.onosproject.net.provider.AbstractProviderService;
 import org.slf4j.Logger;
 
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Iterator;
-import java.util.Set;
-
-import static org.slf4j.LoggerFactory.getLogger;
+import com.google.common.collect.Sets;
 
 /**
  * Provides implementation of the group service APIs.
@@ -103,6 +104,7 @@
      */
     @Override
     public void addGroup(GroupDescription groupDesc) {
+        log.trace("In addGroup API");
         store.storeGroupDescription(groupDesc);
     }
 
@@ -121,6 +123,7 @@
      */
     @Override
     public Group getGroup(DeviceId deviceId, GroupKey appCookie) {
+        log.trace("In getGroup API");
         return store.getGroup(deviceId, appCookie);
     }
 
@@ -142,6 +145,7 @@
                            GroupBuckets buckets,
                            GroupKey newCookie,
                            ApplicationId appId) {
+        log.trace("In addBucketsToGroup API");
         store.updateGroupDescription(deviceId,
                                      oldCookie,
                                      UpdateType.ADD,
@@ -167,6 +171,7 @@
                                 GroupBuckets buckets,
                                 GroupKey newCookie,
                                 ApplicationId appId) {
+        log.trace("In removeBucketsFromGroup API");
         store.updateGroupDescription(deviceId,
                                      oldCookie,
                                      UpdateType.REMOVE,
@@ -188,6 +193,7 @@
     public void removeGroup(DeviceId deviceId,
                             GroupKey appCookie,
                             ApplicationId appId) {
+        log.trace("In removeGroup API");
         store.deleteGroupDescription(deviceId, appCookie);
     }
 
@@ -202,11 +208,13 @@
     @Override
     public Iterable<Group> getGroups(DeviceId deviceId,
                                      ApplicationId appId) {
+        log.trace("In getGroups API");
         return store.getGroups(deviceId);
     }
 
     @Override
     public Iterable<Group> getGroups(DeviceId deviceId) {
+        log.trace("In getGroups API");
         return store.getGroups(deviceId);
     }
 
@@ -217,6 +225,7 @@
      */
     @Override
     public void addListener(GroupListener listener) {
+        log.trace("In addListener API");
         listenerRegistry.addListener(listener);
     }
 
@@ -227,6 +236,7 @@
      */
     @Override
     public void removeListener(GroupListener listener) {
+        log.trace("In removeListener API");
         listenerRegistry.removeListener(listener);
     }
 
@@ -364,36 +374,52 @@
             Set<Group> extraneousStoredEntries =
                     Sets.newHashSet(store.getExtraneousGroups(deviceId));
 
-            log.trace("Displaying all southboundGroupEntries for device {}", deviceId);
+            log.trace("Displaying all ({}) southboundGroupEntries for device {}",
+                      southboundGroupEntries.size(),
+                      deviceId);
             for (Iterator<Group> it = southboundGroupEntries.iterator(); it.hasNext();) {
                 Group group = it.next();
                 log.trace("Group {} in device {}", group, deviceId);
             }
 
-            log.trace("Displaying all stored group entries for device {}", deviceId);
-            for (Iterator<Group> it = storedGroupEntries.iterator(); it.hasNext();) {
-                Group group = it.next();
+            log.trace("Displaying all ({}) stored group entries for device {}",
+                      storedGroupEntries.size(),
+                      deviceId);
+            for (Iterator<Group> it1 = storedGroupEntries.iterator(); it1.hasNext();) {
+                Group group = it1.next();
                 log.trace("Stored Group {} for device {}", group, deviceId);
             }
 
-            for (Iterator<Group> it = southboundGroupEntries.iterator(); it.hasNext();) {
-                Group group = it.next();
+            for (Iterator<Group> it2 = southboundGroupEntries.iterator(); it2.hasNext();) {
+                Group group = it2.next();
                 if (storedGroupEntries.remove(group)) {
                     // we both have the group, let's update some info then.
                     log.trace("Group AUDIT: group {} exists "
                             + "in both planes for device {}",
                             group.id(), deviceId);
                     groupAdded(group);
-                    it.remove();
+                    it2.remove();
                 }
             }
             for (Group group : southboundGroupEntries) {
-                // there are groups in the switch that aren't in the store
-                log.trace("Group AUDIT: extraneous group {} exists "
-                        + "in data plane for device {}",
-                        group.id(), deviceId);
-                extraneousStoredEntries.remove(group);
-                extraneousGroup(group);
+                if (store.getGroup(group.deviceId(), group.id()) != null) {
+                    // There is a group existing with the same id
+                    // It is possible that group update is
+                    // in progress while we got a stale info from switch
+                    if (!storedGroupEntries.remove(store.getGroup(
+                                 group.deviceId(), group.id()))) {
+                        log.warn("Group AUDIT: Inconsistent state:"
+                                + "Group exists in ID based table while "
+                                + "not present in key based table");
+                    }
+                } else {
+                    // there are groups in the switch that aren't in the store
+                    log.trace("Group AUDIT: extraneous group {} exists "
+                            + "in data plane for device {}",
+                            group.id(), deviceId);
+                    extraneousStoredEntries.remove(group);
+                    extraneousGroup(group);
+                }
             }
             for (Group group : storedGroupEntries) {
                 // there are groups in the store that aren't in the switch
diff --git a/core/net/src/test/java/org/onosproject/net/group/impl/GroupManagerTest.java b/core/net/src/test/java/org/onosproject/net/group/impl/GroupManagerTest.java
index 2fe5e4b..fa3e987 100644
--- a/core/net/src/test/java/org/onosproject/net/group/impl/GroupManagerTest.java
+++ b/core/net/src/test/java/org/onosproject/net/group/impl/GroupManagerTest.java
@@ -15,6 +15,12 @@
  */
 package org.onosproject.net.group.impl;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -38,6 +44,7 @@
 import org.onosproject.net.group.DefaultGroup;
 import org.onosproject.net.group.DefaultGroupBucket;
 import org.onosproject.net.group.DefaultGroupDescription;
+import org.onosproject.net.group.DefaultGroupKey;
 import org.onosproject.net.group.Group;
 import org.onosproject.net.group.GroupBucket;
 import org.onosproject.net.group.GroupBuckets;
@@ -58,8 +65,6 @@
 
 import com.google.common.collect.Iterables;
 
-import static org.junit.Assert.*;
-
 /**
  * Test codifying the group service & group provider service contracts.
  */
@@ -108,31 +113,6 @@
         mgr.eventDispatcher = null;
     }
 
-    private class TestGroupKey implements GroupKey {
-        private String groupId;
-
-        public TestGroupKey(String id) {
-            this.groupId = id;
-        }
-
-        public String id() {
-            return this.groupId;
-        }
-
-        @Override
-        public int hashCode() {
-            return groupId.hashCode();
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (obj instanceof TestGroupKey) {
-                return this.groupId.equals(((TestGroupKey) obj).id());
-            }
-            return false;
-        }
-    }
-
     /**
      * Tests group service north bound and south bound interfaces.
      * The following operations are tested:
@@ -177,7 +157,7 @@
                                PortNumber.portNumber(32)};
         PortNumber[] ports2 = {PortNumber.portNumber(41),
                                PortNumber.portNumber(42)};
-        TestGroupKey key = new TestGroupKey("group1BeforeAudit");
+        GroupKey key = new DefaultGroupKey("group1BeforeAudit".getBytes());
         List<GroupBucket> buckets = new ArrayList<GroupBucket>();
         List<PortNumber> outPorts = new ArrayList<PortNumber>();
         outPorts.addAll(Arrays.asList(ports1));
@@ -224,7 +204,7 @@
         providerService.pushGroupMetrics(DID, groupEntries);
         // First group metrics would trigger the device audit completion
         // post which all pending group requests are also executed.
-        TestGroupKey key = new TestGroupKey("group1BeforeAudit");
+        GroupKey key = new DefaultGroupKey("group1BeforeAudit".getBytes());
         Group createdGroup = groupService.getGroup(DID, key);
         int createdGroupId = createdGroup.id().id();
         assertNotEquals(gId1.id(), createdGroupId);
@@ -256,7 +236,7 @@
                                             0);
         List<Group> groupEntries = Arrays.asList(group1, group2);
         providerService.pushGroupMetrics(DID, groupEntries);
-        TestGroupKey key = new TestGroupKey("group1BeforeAudit");
+        GroupKey key = new DefaultGroupKey("group1BeforeAudit".getBytes());
         Group createdGroup = groupService.getGroup(DID, key);
         List<GroupOperation> expectedGroupOps = Arrays.asList(
                 GroupOperation.createDeleteGroupOperation(gId1,
@@ -271,7 +251,7 @@
 
     // Test AUDIT with confirmed groups
     private void testAuditWithConfirmedGroups() {
-        TestGroupKey key = new TestGroupKey("group1BeforeAudit");
+        GroupKey key = new DefaultGroupKey("group1BeforeAudit".getBytes());
         Group createdGroup = groupService.getGroup(DID, key);
         createdGroup = new DefaultGroup(createdGroup.id(),
                                         DID,
@@ -284,9 +264,9 @@
 
     // Test group add bucket operations
     private void testAddBuckets() {
-        TestGroupKey addKey = new TestGroupKey("group1AddBuckets");
+        GroupKey addKey = new DefaultGroupKey("group1AddBuckets".getBytes());
 
-        TestGroupKey prevKey = new TestGroupKey("group1BeforeAudit");
+        GroupKey prevKey = new DefaultGroupKey("group1BeforeAudit".getBytes());
         Group createdGroup = groupService.getGroup(DID, prevKey);
         List<GroupBucket> buckets = new ArrayList<GroupBucket>();
         buckets.addAll(createdGroup.buckets().buckets());
@@ -328,9 +308,9 @@
 
     // Test group remove bucket operations
     private void testRemoveBuckets() {
-        TestGroupKey removeKey = new TestGroupKey("group1RemoveBuckets");
+        GroupKey removeKey = new DefaultGroupKey("group1RemoveBuckets".getBytes());
 
-        TestGroupKey prevKey = new TestGroupKey("group1AddBuckets");
+        GroupKey prevKey = new DefaultGroupKey("group1AddBuckets".getBytes());
         Group createdGroup = groupService.getGroup(DID, prevKey);
         List<GroupBucket> buckets = new ArrayList<GroupBucket>();
         buckets.addAll(createdGroup.buckets().buckets());
@@ -372,7 +352,7 @@
 
     // Test group remove operations
     private void testRemoveGroup() {
-        TestGroupKey currKey = new TestGroupKey("group1RemoveBuckets");
+        GroupKey currKey = new DefaultGroupKey("group1RemoveBuckets".getBytes());
         Group existingGroup = groupService.getGroup(DID, currKey);
         groupService.removeGroup(DID, currKey, appId);
         List<GroupOperation> expectedGroupOps = Arrays.asList(
@@ -397,7 +377,7 @@
         PortNumber[] ports2 = {PortNumber.portNumber(41),
                 PortNumber.portNumber(42)};
         // Test Group creation before AUDIT process
-        TestGroupKey key = new TestGroupKey("group1BeforeAudit");
+        GroupKey key = new DefaultGroupKey("group1BeforeAudit".getBytes());
         List<GroupBucket> buckets = new ArrayList<GroupBucket>();
         List<PortNumber> outPorts = new ArrayList<PortNumber>();
         outPorts.addAll(Arrays.asList(ports1));
diff --git a/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java b/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java
index c914784..a571b4e 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/group/impl/DistributedGroupStore.java
@@ -16,25 +16,48 @@
 package org.onosproject.store.group.impl;
 
 import static org.apache.commons.lang3.concurrent.ConcurrentUtils.createIfAbsentUnchecked;
+import static org.onlab.util.Tools.groupedThreads;
 import static org.slf4j.LoggerFactory.getLogger;
 
+import java.net.URI;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Objects;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.stream.Collectors;
 
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.apache.felix.scr.annotations.Service;
+import org.onlab.util.KryoNamespace;
 import org.onlab.util.NewConcurrentHashMap;
+import org.onosproject.cluster.ClusterService;
+import org.onosproject.core.DefaultApplicationId;
 import org.onosproject.core.DefaultGroupId;
 import org.onosproject.core.GroupId;
+import org.onosproject.mastership.MastershipService;
 import org.onosproject.net.DeviceId;
+import org.onosproject.net.MastershipRole;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.FlowRule;
+import org.onosproject.net.flow.instructions.Instructions;
+import org.onosproject.net.flow.instructions.L0ModificationInstruction;
+import org.onosproject.net.flow.instructions.L2ModificationInstruction;
+import org.onosproject.net.flow.instructions.L3ModificationInstruction;
 import org.onosproject.net.group.DefaultGroup;
+import org.onosproject.net.group.DefaultGroupBucket;
 import org.onosproject.net.group.DefaultGroupDescription;
+import org.onosproject.net.group.DefaultGroupKey;
 import org.onosproject.net.group.Group;
 import org.onosproject.net.group.Group.GroupState;
 import org.onosproject.net.group.GroupBucket;
@@ -48,10 +71,21 @@
 import org.onosproject.net.group.GroupStoreDelegate;
 import org.onosproject.net.group.StoredGroupEntry;
 import org.onosproject.store.AbstractStore;
+import org.onosproject.store.Timestamp;
+import org.onosproject.store.cluster.messaging.ClusterCommunicationService;
+import org.onosproject.store.cluster.messaging.ClusterMessage;
+import org.onosproject.store.cluster.messaging.ClusterMessageHandler;
+import org.onosproject.store.ecmap.EventuallyConsistentMap;
+import org.onosproject.store.ecmap.EventuallyConsistentMapEvent;
+import org.onosproject.store.ecmap.EventuallyConsistentMapImpl;
+import org.onosproject.store.ecmap.EventuallyConsistentMapListener;
+import org.onosproject.store.impl.ClockService;
+import org.onosproject.store.impl.MultiValuedTimestamp;
+import org.onosproject.store.serializers.KryoNamespaces;
 import org.slf4j.Logger;
 
-import com.google.common.base.Function;
 import com.google.common.collect.FluentIterable;
+import com.google.common.collect.Iterables;
 
 /**
  * Manages inventory of group entries using trivial in-memory implementation.
@@ -67,85 +101,165 @@
     private final int dummyId = 0xffffffff;
     private final GroupId dummyGroupId = new DefaultGroupId(dummyId);
 
-    // inner Map is per device group table
-    private final ConcurrentMap<DeviceId, ConcurrentMap<GroupKey, StoredGroupEntry>>
-            groupEntriesByKey = new ConcurrentHashMap<>();
-    private final ConcurrentMap<DeviceId, ConcurrentMap<GroupId, StoredGroupEntry>>
-            groupEntriesById = new ConcurrentHashMap<>();
-    private final ConcurrentMap<DeviceId, ConcurrentMap<GroupKey, StoredGroupEntry>>
-            pendingGroupEntriesByKey = new ConcurrentHashMap<>();
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClusterCommunicationService clusterCommunicator;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClusterService clusterService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected MastershipService mastershipService;
+
+    // Per device group table with (device id + app cookie) as key
+    private EventuallyConsistentMap<GroupStoreKeyMapKey,
+        StoredGroupEntry> groupStoreEntriesByKey = null;
+    // Per device group table with (device id + group id) as key
+    private EventuallyConsistentMap<GroupStoreIdMapKey,
+        StoredGroupEntry> groupStoreEntriesById = null;
+    private EventuallyConsistentMap<GroupStoreKeyMapKey,
+        StoredGroupEntry> auditPendingReqQueue = null;
     private final ConcurrentMap<DeviceId, ConcurrentMap<GroupId, Group>>
             extraneousGroupEntriesById = new ConcurrentHashMap<>();
+    private ExecutorService messageHandlingExecutor;
+    private static final int MESSAGE_HANDLER_THREAD_POOL_SIZE = 1;
 
     private final HashMap<DeviceId, Boolean> deviceAuditStatus =
             new HashMap<DeviceId, Boolean>();
 
     private final AtomicInteger groupIdGen = new AtomicInteger();
 
+    private KryoNamespace.Builder kryoBuilder = null;
+
     @Activate
     public void activate() {
+        kryoBuilder = new KryoNamespace.Builder()
+            .register(DefaultGroup.class,
+                      DefaultGroupBucket.class,
+                      DefaultGroupDescription.class,
+                      DefaultGroupKey.class,
+                      GroupDescription.Type.class,
+                      Group.GroupState.class,
+                      GroupBuckets.class,
+                      DefaultGroupId.class,
+                      GroupStoreMessage.class,
+                      GroupStoreMessage.Type.class,
+                      UpdateType.class,
+                      GroupStoreMessageSubjects.class,
+                      MultiValuedTimestamp.class,
+                      GroupStoreKeyMapKey.class,
+                      GroupStoreIdMapKey.class,
+                      GroupStoreMapKey.class
+                    )
+            .register(URI.class)
+            .register(DeviceId.class)
+            .register(PortNumber.class)
+            .register(DefaultApplicationId.class)
+            .register(DefaultTrafficTreatment.class,
+                      Instructions.DropInstruction.class,
+                      Instructions.OutputInstruction.class,
+                      Instructions.GroupInstruction.class,
+                      Instructions.TableTypeTransition.class,
+                      FlowRule.Type.class,
+                      L0ModificationInstruction.class,
+                      L0ModificationInstruction.L0SubType.class,
+                      L0ModificationInstruction.ModLambdaInstruction.class,
+                      L2ModificationInstruction.class,
+                      L2ModificationInstruction.L2SubType.class,
+                      L2ModificationInstruction.ModEtherInstruction.class,
+                      L2ModificationInstruction.PushHeaderInstructions.class,
+                      L2ModificationInstruction.ModVlanIdInstruction.class,
+                      L2ModificationInstruction.ModVlanPcpInstruction.class,
+                      L2ModificationInstruction.ModMplsLabelInstruction.class,
+                      L2ModificationInstruction.ModMplsTtlInstruction.class,
+                      L3ModificationInstruction.class,
+                      L3ModificationInstruction.L3SubType.class,
+                      L3ModificationInstruction.ModIPInstruction.class,
+                      L3ModificationInstruction.ModIPv6FlowLabelInstruction.class,
+                      L3ModificationInstruction.ModTtlInstruction.class,
+                      org.onlab.packet.MplsLabel.class
+                    )
+            .register(org.onosproject.cluster.NodeId.class)
+            .register(KryoNamespaces.BASIC)
+            .register(KryoNamespaces.MISC);
+
+        messageHandlingExecutor = Executors.
+                newFixedThreadPool(MESSAGE_HANDLER_THREAD_POOL_SIZE,
+                                   groupedThreads("onos/store/group",
+                                                  "message-handlers"));
+        clusterCommunicator.
+            addSubscriber(GroupStoreMessageSubjects.REMOTE_GROUP_OP_REQUEST,
+                          new ClusterGroupMsgHandler(),
+                          messageHandlingExecutor);
+
+        log.debug("Creating EC map groupstorekeymap");
+        groupStoreEntriesByKey =
+                new EventuallyConsistentMapImpl<>("groupstorekeymap",
+                        clusterService,
+                        clusterCommunicator,
+                        kryoBuilder,
+                        new GroupStoreLogicalClockManager<>());
+        log.trace("Current size {}", groupStoreEntriesByKey.size());
+
+        log.debug("Creating EC map groupstoreidmap");
+        groupStoreEntriesById =
+                new EventuallyConsistentMapImpl<>("groupstoreidmap",
+                        clusterService,
+                        clusterCommunicator,
+                        kryoBuilder,
+                        new GroupStoreLogicalClockManager<>());
+        groupStoreEntriesById.addListener(new GroupStoreIdMapListener());
+        log.trace("Current size {}", groupStoreEntriesById.size());
+
+        log.debug("Creating EC map pendinggroupkeymap");
+        auditPendingReqQueue =
+                new EventuallyConsistentMapImpl<>("pendinggroupkeymap",
+                clusterService,
+                clusterCommunicator,
+                kryoBuilder,
+                new GroupStoreLogicalClockManager<>());
+        log.trace("Current size {}", auditPendingReqQueue.size());
+
         log.info("Started");
     }
 
     @Deactivate
     public void deactivate() {
-        groupEntriesByKey.clear();
-        groupEntriesById.clear();
         log.info("Stopped");
     }
 
-    private static NewConcurrentHashMap<GroupKey, StoredGroupEntry>
-    lazyEmptyGroupKeyTable() {
-        return NewConcurrentHashMap.<GroupKey, StoredGroupEntry>ifNeeded();
-    }
-
-    private static NewConcurrentHashMap<GroupId, StoredGroupEntry>
-    lazyEmptyGroupIdTable() {
-        return NewConcurrentHashMap.<GroupId, StoredGroupEntry>ifNeeded();
-    }
-
-    private static NewConcurrentHashMap<GroupKey, StoredGroupEntry>
-    lazyEmptyPendingGroupKeyTable() {
-        return NewConcurrentHashMap.<GroupKey, StoredGroupEntry>ifNeeded();
-    }
-
     private static NewConcurrentHashMap<GroupId, Group>
-    lazyEmptyExtraneousGroupIdTable() {
+        lazyEmptyExtraneousGroupIdTable() {
         return NewConcurrentHashMap.<GroupId, Group>ifNeeded();
     }
 
     /**
-     * Returns the group key table for specified device.
+     * Returns the group store eventual consistent key map.
      *
-     * @param deviceId identifier of the device
-     * @return Map representing group key table of given device.
+     * @return Map representing group key table.
      */
-    private ConcurrentMap<GroupKey, StoredGroupEntry> getGroupKeyTable(DeviceId deviceId) {
-        return createIfAbsentUnchecked(groupEntriesByKey,
-                                       deviceId, lazyEmptyGroupKeyTable());
+    private EventuallyConsistentMap<GroupStoreKeyMapKey, StoredGroupEntry>
+        getGroupStoreKeyMap() {
+        return groupStoreEntriesByKey;
     }
 
     /**
-     * Returns the group id table for specified device.
+     * Returns the group store eventual consistent id map.
      *
-     * @param deviceId identifier of the device
-     * @return Map representing group key table of given device.
+     * @return Map representing group id table.
      */
-    private ConcurrentMap<GroupId, StoredGroupEntry> getGroupIdTable(DeviceId deviceId) {
-        return createIfAbsentUnchecked(groupEntriesById,
-                                       deviceId, lazyEmptyGroupIdTable());
+    private EventuallyConsistentMap<GroupStoreIdMapKey, StoredGroupEntry>
+        getGroupStoreIdMap() {
+        return groupStoreEntriesById;
     }
 
     /**
-     * Returns the pending group key table for specified device.
+     * Returns the pending group request table.
      *
-     * @param deviceId identifier of the device
-     * @return Map representing group key table of given device.
+     * @return Map representing group key table.
      */
-    private ConcurrentMap<GroupKey, StoredGroupEntry>
-    getPendingGroupKeyTable(DeviceId deviceId) {
-        return createIfAbsentUnchecked(pendingGroupEntriesByKey,
-                                       deviceId, lazyEmptyPendingGroupKeyTable());
+    private EventuallyConsistentMap<GroupStoreKeyMapKey, StoredGroupEntry>
+        getPendingGroupKeyTable() {
+        return auditPendingReqQueue;
     }
 
     /**
@@ -168,8 +282,8 @@
      */
     @Override
     public int getGroupCount(DeviceId deviceId) {
-        return (groupEntriesByKey.get(deviceId) != null) ?
-                groupEntriesByKey.get(deviceId).size() : 0;
+        return (getGroups(deviceId) != null) ?
+                         Iterables.size(getGroups(deviceId)) : 0;
     }
 
     /**
@@ -182,16 +296,11 @@
     @Override
     public Iterable<Group> getGroups(DeviceId deviceId) {
         // flatten and make iterator unmodifiable
-        return FluentIterable.from(getGroupKeyTable(deviceId).values())
-                .transform(
-                        new Function<StoredGroupEntry, Group>() {
-
-                            @Override
-                            public Group apply(
-                                    StoredGroupEntry input) {
-                                return input;
-                            }
-                        });
+        log.trace("getGroups: for device {} total number of groups {}",
+                  deviceId, getGroupStoreKeyMap().values().size());
+        return FluentIterable.from(getGroupStoreKeyMap().values())
+                .filter(input -> input.deviceId().equals(deviceId))
+                .transform(input -> input);
     }
 
     /**
@@ -204,19 +313,31 @@
      */
     @Override
     public Group getGroup(DeviceId deviceId, GroupKey appCookie) {
-        return (groupEntriesByKey.get(deviceId) != null) ?
-                groupEntriesByKey.get(deviceId).get(appCookie) :
-                null;
+        return getStoredGroupEntry(deviceId, appCookie);
+    }
+
+    private StoredGroupEntry getStoredGroupEntry(DeviceId deviceId,
+                                                 GroupKey appCookie) {
+        return getGroupStoreKeyMap().get(new GroupStoreKeyMapKey(deviceId,
+                                                                 appCookie));
+    }
+
+    @Override
+    public Group getGroup(DeviceId deviceId, GroupId groupId) {
+        return getStoredGroupEntry(deviceId, groupId);
+    }
+
+    private StoredGroupEntry getStoredGroupEntry(DeviceId deviceId,
+                                                 GroupId groupId) {
+        return getGroupStoreIdMap().get(new GroupStoreIdMapKey(deviceId,
+                                                               groupId));
     }
 
     private int getFreeGroupIdValue(DeviceId deviceId) {
         int freeId = groupIdGen.incrementAndGet();
 
         while (true) {
-            Group existing = (
-                    groupEntriesById.get(deviceId) != null) ?
-                    groupEntriesById.get(deviceId).get(new DefaultGroupId(freeId)) :
-                    null;
+            Group existing = getGroup(deviceId, new DefaultGroupId(freeId));
             if (existing == null) {
                 existing = (
                         extraneousGroupEntriesById.get(deviceId) != null) ?
@@ -240,23 +361,45 @@
      */
     @Override
     public void storeGroupDescription(GroupDescription groupDesc) {
+        log.trace("In storeGroupDescription");
         // Check if a group is existing with the same key
         if (getGroup(groupDesc.deviceId(), groupDesc.appCookie()) != null) {
+            log.warn("Group already exists with the same key {}",
+                     groupDesc.appCookie());
             return;
         }
 
-        if (deviceAuditStatus.get(groupDesc.deviceId()) == null) {
-            // Device group audit has not completed yet
-            // Add this group description to pending group key table
-            // Create a group entry object with Dummy Group ID
-            StoredGroupEntry group = new DefaultGroup(dummyGroupId, groupDesc);
-            group.setState(GroupState.WAITING_AUDIT_COMPLETE);
-            ConcurrentMap<GroupKey, StoredGroupEntry> pendingKeyTable =
-                    getPendingGroupKeyTable(groupDesc.deviceId());
-            pendingKeyTable.put(groupDesc.appCookie(), group);
+        // Check if group to be created by a remote instance
+        if (mastershipService.getLocalRole(
+                     groupDesc.deviceId()) != MastershipRole.MASTER) {
+            log.debug("Device {} local role is not MASTER",
+                      groupDesc.deviceId());
+            GroupStoreMessage groupOp = GroupStoreMessage.
+                    createGroupAddRequestMsg(groupDesc.deviceId(),
+                                             groupDesc);
+            ClusterMessage message = new ClusterMessage(
+                                    clusterService.getLocalNode().id(),
+                                    GroupStoreMessageSubjects.
+                                    REMOTE_GROUP_OP_REQUEST,
+                                    kryoBuilder.build().serialize(groupOp));
+            if (!clusterCommunicator.unicast(message,
+                                             mastershipService.
+                                             getMasterFor(
+                                                groupDesc.deviceId()))) {
+                log.warn("Failed to send request to master: {} to {}",
+                         message,
+                         mastershipService.getMasterFor(groupDesc.deviceId()));
+                //TODO: Send Group operation failure event
+            }
+            log.debug("Sent Group operation request for device {} "
+                    + "to remote MASTER {}",
+                      groupDesc.deviceId(),
+                      mastershipService.getMasterFor(groupDesc.deviceId()));
             return;
         }
 
+        log.debug("Store group for device {} is getting handled locally",
+                  groupDesc.deviceId());
         storeGroupDescriptionInternal(groupDesc);
     }
 
@@ -266,17 +409,34 @@
             return;
         }
 
+        if (deviceAuditStatus.get(groupDesc.deviceId()) == null) {
+            // Device group audit has not completed yet
+            // Add this group description to pending group key table
+            // Create a group entry object with Dummy Group ID
+            log.debug("storeGroupDescriptionInternal: Device {} AUDIT "
+                    + "pending...Queuing Group ADD request",
+                    groupDesc.deviceId());
+            StoredGroupEntry group = new DefaultGroup(dummyGroupId, groupDesc);
+            group.setState(GroupState.WAITING_AUDIT_COMPLETE);
+            EventuallyConsistentMap<GroupStoreKeyMapKey, StoredGroupEntry> pendingKeyTable =
+                    getPendingGroupKeyTable();
+            pendingKeyTable.put(new GroupStoreKeyMapKey(groupDesc.deviceId(),
+                                                        groupDesc.appCookie()),
+                                group);
+            return;
+        }
+
         // Get a new group identifier
         GroupId id = new DefaultGroupId(getFreeGroupIdValue(groupDesc.deviceId()));
         // Create a group entry object
         StoredGroupEntry group = new DefaultGroup(id, groupDesc);
-        // Insert the newly created group entry into concurrent key and id maps
-        ConcurrentMap<GroupKey, StoredGroupEntry> keyTable =
-                getGroupKeyTable(groupDesc.deviceId());
-        keyTable.put(groupDesc.appCookie(), group);
-        ConcurrentMap<GroupId, StoredGroupEntry> idTable =
-                getGroupIdTable(groupDesc.deviceId());
-        idTable.put(id, group);
+        // Insert the newly created group entry into key and id maps
+        getGroupStoreKeyMap().
+            put(new GroupStoreKeyMapKey(groupDesc.deviceId(),
+                                        groupDesc.appCookie()), group);
+        getGroupStoreIdMap().
+            put(new GroupStoreIdMapKey(groupDesc.deviceId(),
+                                    id), group);
         notifyDelegate(new GroupEvent(GroupEvent.Type.GROUP_ADD_REQUESTED,
                                       group));
     }
@@ -297,6 +457,42 @@
                                        UpdateType type,
                                        GroupBuckets newBuckets,
                                        GroupKey newAppCookie) {
+        // Check if group update to be done by a remote instance
+        if (mastershipService.
+                getLocalRole(deviceId) != MastershipRole.MASTER) {
+            GroupStoreMessage groupOp = GroupStoreMessage.
+                    createGroupUpdateRequestMsg(deviceId,
+                                                oldAppCookie,
+                                                type,
+                                                newBuckets,
+                                                newAppCookie);
+            ClusterMessage message =
+                    new ClusterMessage(clusterService.getLocalNode().id(),
+                                       GroupStoreMessageSubjects.
+                                              REMOTE_GROUP_OP_REQUEST,
+                                       kryoBuilder.build().serialize(groupOp));
+            if (!clusterCommunicator.unicast(message,
+                                             mastershipService.
+                                             getMasterFor(deviceId))) {
+                log.warn("Failed to send request to master: {} to {}",
+                         message,
+                         mastershipService.getMasterFor(deviceId));
+                //TODO: Send Group operation failure event
+            }
+            return;
+        }
+        updateGroupDescriptionInternal(deviceId,
+                                       oldAppCookie,
+                                       type,
+                                       newBuckets,
+                                       newAppCookie);
+    }
+
+    private void updateGroupDescriptionInternal(DeviceId deviceId,
+                                       GroupKey oldAppCookie,
+                                       UpdateType type,
+                                       GroupBuckets newBuckets,
+                                       GroupKey newAppCookie) {
         // Check if a group is existing with the provided key
         Group oldGroup = getGroup(deviceId, oldAppCookie);
         if (oldGroup == null) {
@@ -323,14 +519,17 @@
             newGroup.setPackets(oldGroup.packets());
             newGroup.setBytes(oldGroup.bytes());
             // Remove the old entry from maps and add new entry using new key
-            ConcurrentMap<GroupKey, StoredGroupEntry> keyTable =
-                    getGroupKeyTable(oldGroup.deviceId());
-            ConcurrentMap<GroupId, StoredGroupEntry> idTable =
-                    getGroupIdTable(oldGroup.deviceId());
-            keyTable.remove(oldGroup.appCookie());
-            idTable.remove(oldGroup.id());
-            keyTable.put(newGroup.appCookie(), newGroup);
-            idTable.put(newGroup.id(), newGroup);
+            getGroupStoreKeyMap().remove(new GroupStoreKeyMapKey(oldGroup.deviceId(),
+                                        oldGroup.appCookie()));
+            getGroupStoreIdMap().remove(new GroupStoreIdMapKey(oldGroup.deviceId(),
+                                                                 oldGroup.id()));
+            getGroupStoreKeyMap().
+                put(new GroupStoreKeyMapKey(newGroup.deviceId(),
+                                            newGroup.appCookie()), newGroup);
+            getGroupStoreIdMap().
+            put(new GroupStoreIdMapKey(newGroup.deviceId(),
+                                       newGroup.id()), newGroup);
+
             notifyDelegate(new GroupEvent(Type.GROUP_UPDATE_REQUESTED, newGroup));
         }
     }
@@ -379,10 +578,34 @@
     @Override
     public void deleteGroupDescription(DeviceId deviceId,
                                        GroupKey appCookie) {
+        // Check if group to be deleted by a remote instance
+        if (mastershipService.
+                getLocalRole(deviceId) != MastershipRole.MASTER) {
+            GroupStoreMessage groupOp = GroupStoreMessage.
+                    createGroupDeleteRequestMsg(deviceId,
+                                                appCookie);
+            ClusterMessage message =
+                    new ClusterMessage(clusterService.getLocalNode().id(),
+                                       GroupStoreMessageSubjects.
+                                              REMOTE_GROUP_OP_REQUEST,
+                                       kryoBuilder.build().serialize(groupOp));
+            if (!clusterCommunicator.unicast(message,
+                                             mastershipService.
+                                             getMasterFor(deviceId))) {
+                log.warn("Failed to send request to master: {} to {}",
+                         message,
+                         mastershipService.getMasterFor(deviceId));
+                //TODO: Send Group operation failure event
+            }
+            return;
+        }
+        deleteGroupDescriptionInternal(deviceId, appCookie);
+    }
+
+    private void deleteGroupDescriptionInternal(DeviceId deviceId,
+                                                GroupKey appCookie) {
         // Check if a group is existing with the provided key
-        StoredGroupEntry existing = (groupEntriesByKey.get(deviceId) != null) ?
-                groupEntriesByKey.get(deviceId).get(appCookie) :
-                null;
+        StoredGroupEntry existing = getStoredGroupEntry(deviceId, appCookie);
         if (existing == null) {
             return;
         }
@@ -401,26 +624,35 @@
     @Override
     public void addOrUpdateGroupEntry(Group group) {
         // check if this new entry is an update to an existing entry
-        StoredGroupEntry existing = (groupEntriesById.get(
-                group.deviceId()) != null) ?
-                groupEntriesById.get(group.deviceId()).get(group.id()) :
-                null;
+        StoredGroupEntry existing = getStoredGroupEntry(group.deviceId(),
+                                                        group.id());
         GroupEvent event = null;
 
         if (existing != null) {
+            log.trace("addOrUpdateGroupEntry: updating group "
+                    + "entry {} in device {}",
+                    group.id(),
+                    group.deviceId());
             synchronized (existing) {
                 existing.setLife(group.life());
                 existing.setPackets(group.packets());
                 existing.setBytes(group.bytes());
                 if (existing.state() == GroupState.PENDING_ADD) {
                     existing.setState(GroupState.ADDED);
+                    existing.setIsGroupStateAddedFirstTime(true);
                     event = new GroupEvent(Type.GROUP_ADDED, existing);
                 } else {
-                    if (existing.state() == GroupState.PENDING_UPDATE) {
-                        existing.setState(GroupState.PENDING_UPDATE);
-                    }
+                    existing.setState(GroupState.ADDED);
+                    existing.setIsGroupStateAddedFirstTime(false);
                     event = new GroupEvent(Type.GROUP_UPDATED, existing);
                 }
+                //Re-PUT map entries to trigger map update events
+                getGroupStoreKeyMap().
+                    put(new GroupStoreKeyMapKey(existing.deviceId(),
+                                                existing.appCookie()), existing);
+                getGroupStoreIdMap().
+                    put(new GroupStoreIdMapKey(existing.deviceId(),
+                                               existing.id()), existing);
             }
         }
 
@@ -436,18 +668,18 @@
      */
     @Override
     public void removeGroupEntry(Group group) {
-        StoredGroupEntry existing = (groupEntriesById.get(
-                group.deviceId()) != null) ?
-                groupEntriesById.get(group.deviceId()).get(group.id()) :
-                null;
+        StoredGroupEntry existing = getStoredGroupEntry(group.deviceId(),
+                                                        group.id());
 
         if (existing != null) {
-            ConcurrentMap<GroupKey, StoredGroupEntry> keyTable =
-                    getGroupKeyTable(existing.deviceId());
-            ConcurrentMap<GroupId, StoredGroupEntry> idTable =
-                    getGroupIdTable(existing.deviceId());
-            idTable.remove(existing.id());
-            keyTable.remove(existing.appCookie());
+            log.trace("removeGroupEntry: removing group "
+                    + "entry {} in device {}",
+                    group.id(),
+                    group.deviceId());
+            getGroupStoreKeyMap().remove(new GroupStoreKeyMapKey(existing.deviceId(),
+                                                                 existing.appCookie()));
+            getGroupStoreIdMap().remove(new GroupStoreIdMapKey(existing.deviceId(),
+                                                               existing.id()));
             notifyDelegate(new GroupEvent(Type.GROUP_REMOVED, existing));
         }
     }
@@ -461,9 +693,17 @@
                                   + "completed for device {}", deviceId);
                 deviceAuditStatus.put(deviceId, true);
                 // Execute all pending group requests
-                ConcurrentMap<GroupKey, StoredGroupEntry> pendingGroupRequests =
-                        getPendingGroupKeyTable(deviceId);
-                for (Group group:pendingGroupRequests.values()) {
+                List<StoredGroupEntry> pendingGroupRequests =
+                        getPendingGroupKeyTable().values()
+                        .stream()
+                        .filter(g-> g.deviceId().equals(deviceId))
+                        .collect(Collectors.toList());
+                log.trace("deviceInitialAuditCompleted: processing "
+                        + "pending group add requests for device {} and "
+                        + "number of pending requests {}",
+                        deviceId,
+                        pendingGroupRequests.size());
+                for (Group group:pendingGroupRequests) {
                     GroupDescription tmp = new DefaultGroupDescription(
                             group.deviceId(),
                             group.type(),
@@ -471,8 +711,9 @@
                             group.appCookie(),
                             group.appId());
                     storeGroupDescriptionInternal(tmp);
+                    getPendingGroupKeyTable().
+                        remove(new GroupStoreKeyMapKey(deviceId, group.appCookie()));
                 }
-                getPendingGroupKeyTable(deviceId).clear();
             } else {
                 if (deviceAuditStatus.get(deviceId)) {
                     log.debug("deviceInitialAuditCompleted: Clearing AUDIT "
@@ -494,10 +735,8 @@
     @Override
     public void groupOperationFailed(DeviceId deviceId, GroupOperation operation) {
 
-        StoredGroupEntry existing = (groupEntriesById.get(
-                deviceId) != null) ?
-                groupEntriesById.get(deviceId).get(operation.groupId()) :
-                null;
+        StoredGroupEntry existing = getStoredGroupEntry(deviceId,
+                                                        operation.groupId());
 
         if (existing == null) {
             log.warn("No group entry with ID {} found ", operation.groupId());
@@ -518,27 +757,37 @@
                 log.warn("Unknown group operation type {}", operation.opType());
         }
 
-        ConcurrentMap<GroupKey, StoredGroupEntry> keyTable =
-                getGroupKeyTable(existing.deviceId());
-        ConcurrentMap<GroupId, StoredGroupEntry> idTable =
-                getGroupIdTable(existing.deviceId());
-        idTable.remove(existing.id());
-        keyTable.remove(existing.appCookie());
+        getGroupStoreKeyMap().remove(new GroupStoreKeyMapKey(existing.deviceId(),
+                                                             existing.appCookie()));
+        getGroupStoreIdMap().remove(new GroupStoreIdMapKey(existing.deviceId(),
+                                                           existing.id()));
     }
 
     @Override
     public void addOrUpdateExtraneousGroupEntry(Group group) {
+        log.trace("addOrUpdateExtraneousGroupEntry: add/update extraneous "
+                + "group entry {} in device {}",
+                group.id(),
+                group.deviceId());
         ConcurrentMap<GroupId, Group> extraneousIdTable =
                 getExtraneousGroupIdTable(group.deviceId());
         extraneousIdTable.put(group.id(), group);
         // Check the reference counter
         if (group.referenceCount() == 0) {
+            log.trace("addOrUpdateExtraneousGroupEntry: Flow reference "
+                    + "counter is zero and triggering remove",
+                    group.id(),
+                    group.deviceId());
             notifyDelegate(new GroupEvent(Type.GROUP_REMOVE_REQUESTED, group));
         }
     }
 
     @Override
     public void removeExtraneousGroupEntry(Group group) {
+        log.trace("removeExtraneousGroupEntry: remove extraneous "
+                + "group entry {} of device {} from store",
+                group.id(),
+                group.deviceId());
         ConcurrentMap<GroupId, Group> extraneousIdTable =
                 getExtraneousGroupIdTable(group.deviceId());
         extraneousIdTable.remove(group.id());
@@ -551,5 +800,192 @@
                 getExtraneousGroupIdTable(deviceId).values());
     }
 
+    /**
+     * ClockService that generates wallclock based timestamps.
+     */
+    private class GroupStoreLogicalClockManager<T, U>
+        implements ClockService<T, U> {
 
+        private final AtomicLong sequenceNumber = new AtomicLong(0);
+
+        @Override
+        public Timestamp getTimestamp(T t1, U u1) {
+            return new MultiValuedTimestamp<>(System.currentTimeMillis(),
+                    sequenceNumber.getAndIncrement());
+        }
+    }
+
+    /**
+     * Map handler to receive any events when the group map is updated.
+     */
+    private class GroupStoreIdMapListener implements
+        EventuallyConsistentMapListener<GroupStoreIdMapKey, StoredGroupEntry> {
+
+        @Override
+        public void event(EventuallyConsistentMapEvent<GroupStoreIdMapKey,
+                          StoredGroupEntry> mapEvent) {
+            GroupEvent groupEvent = null;
+            log.trace("GroupStoreIdMapListener: received groupid map event {}",
+                      mapEvent.type());
+            if (mapEvent.type() == EventuallyConsistentMapEvent.Type.PUT) {
+                log.trace("GroupIdMapListener: Received PUT event");
+                if (mapEvent.value().state() == Group.GroupState.ADDED) {
+                    if (mapEvent.value().isGroupStateAddedFirstTime()) {
+                        groupEvent = new GroupEvent(Type.GROUP_ADDED,
+                                                    mapEvent.value());
+                        log.trace("GroupIdMapListener: Received first time "
+                                + "GROUP_ADDED state update");
+                    } else {
+                        groupEvent = new GroupEvent(Type.GROUP_UPDATED,
+                                                    mapEvent.value());
+                        log.trace("GroupIdMapListener: Received following "
+                                + "GROUP_ADDED state update");
+                    }
+                }
+            } else if (mapEvent.type() == EventuallyConsistentMapEvent.Type.REMOVE) {
+                log.trace("GroupIdMapListener: Received REMOVE event");
+                groupEvent = new GroupEvent(Type.GROUP_REMOVED, mapEvent.value());
+            }
+
+            if (groupEvent != null) {
+                notifyDelegate(groupEvent);
+            }
+        }
+    }
+    /**
+     * Message handler to receive messages from group subsystems of
+     * other cluster members.
+     */
+    private final class ClusterGroupMsgHandler
+                    implements ClusterMessageHandler {
+        @Override
+        public void handle(ClusterMessage message) {
+            log.trace("ClusterGroupMsgHandler: received remote group message");
+            if (message.subject() ==
+                    GroupStoreMessageSubjects.REMOTE_GROUP_OP_REQUEST) {
+                GroupStoreMessage groupOp = kryoBuilder.
+                        build().deserialize(message.payload());
+                log.trace("received remote group operation request");
+                if (!(mastershipService.
+                        getLocalRole(groupOp.deviceId()) !=
+                        MastershipRole.MASTER)) {
+                    log.warn("ClusterGroupMsgHandler: This node is not "
+                            + "MASTER for device {}", groupOp.deviceId());
+                    return;
+                }
+                if (groupOp.type() == GroupStoreMessage.Type.ADD) {
+                    log.trace("processing remote group "
+                            + "add operation request");
+                    storeGroupDescriptionInternal(groupOp.groupDesc());
+                } else if (groupOp.type() == GroupStoreMessage.Type.UPDATE) {
+                    log.trace("processing remote group "
+                            + "update operation request");
+                    updateGroupDescriptionInternal(groupOp.deviceId(),
+                                                   groupOp.appCookie(),
+                                                   groupOp.updateType(),
+                                                   groupOp.updateBuckets(),
+                                                   groupOp.newAppCookie());
+                } else if (groupOp.type() == GroupStoreMessage.Type.DELETE) {
+                    log.trace("processing remote group "
+                            + "delete operation request");
+                    deleteGroupDescriptionInternal(groupOp.deviceId(),
+                                                   groupOp.appCookie());
+                }
+            }
+        }
+    }
+
+    /**
+     * Flattened map key to be used to store group entries.
+     */
+    private class GroupStoreMapKey {
+        private final DeviceId deviceId;
+
+        public GroupStoreMapKey(DeviceId deviceId) {
+            this.deviceId = deviceId;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) {
+                return true;
+            }
+            if (!(o instanceof GroupStoreMapKey)) {
+                return false;
+            }
+            GroupStoreMapKey that = (GroupStoreMapKey) o;
+            return this.deviceId.equals(that.deviceId);
+        }
+
+        @Override
+        public int hashCode() {
+            int result = 17;
+
+            result = 31 * result + Objects.hash(this.deviceId);
+
+            return result;
+        }
+    }
+
+    private class GroupStoreKeyMapKey extends GroupStoreMapKey {
+        private final GroupKey appCookie;
+        public GroupStoreKeyMapKey(DeviceId deviceId,
+                                   GroupKey appCookie) {
+            super(deviceId);
+            this.appCookie = appCookie;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) {
+                return true;
+            }
+            if (!(o instanceof GroupStoreKeyMapKey)) {
+                return false;
+            }
+            GroupStoreKeyMapKey that = (GroupStoreKeyMapKey) o;
+            return (super.equals(that) &&
+                    this.appCookie.equals(that.appCookie));
+        }
+
+        @Override
+        public int hashCode() {
+            int result = 17;
+
+            result = 31 * result + super.hashCode() + Objects.hash(this.appCookie);
+
+            return result;
+        }
+    }
+
+    private class GroupStoreIdMapKey extends GroupStoreMapKey {
+        private final GroupId groupId;
+        public GroupStoreIdMapKey(DeviceId deviceId,
+                                  GroupId groupId) {
+            super(deviceId);
+            this.groupId = groupId;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) {
+                return true;
+            }
+            if (!(o instanceof GroupStoreIdMapKey)) {
+                return false;
+            }
+            GroupStoreIdMapKey that = (GroupStoreIdMapKey) o;
+            return (super.equals(that) &&
+                    this.groupId.equals(that.groupId));
+        }
+
+        @Override
+        public int hashCode() {
+            int result = 17;
+
+            result = 31 * result + super.hashCode() + Objects.hash(this.groupId);
+
+            return result;
+        }
+    }
 }
diff --git a/core/store/dist/src/main/java/org/onosproject/store/group/impl/GroupStoreMessage.java b/core/store/dist/src/main/java/org/onosproject/store/group/impl/GroupStoreMessage.java
new file mode 100644
index 0000000..b82754b
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onosproject/store/group/impl/GroupStoreMessage.java
@@ -0,0 +1,184 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.store.group.impl;
+
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.group.GroupBuckets;
+import org.onosproject.net.group.GroupDescription;
+import org.onosproject.net.group.GroupKey;
+import org.onosproject.net.group.GroupStore.UpdateType;
+
+/**
+ * Format of the Group store message that is used to
+ * communicate with the peer nodes in the cluster.
+ */
+public final class GroupStoreMessage {
+    private final DeviceId deviceId;
+    private final GroupKey appCookie;
+    private final GroupDescription groupDesc;
+    private final UpdateType updateType;
+    private final GroupBuckets updateBuckets;
+    private final GroupKey newAppCookie;
+    private final Type type;
+
+    /**
+     * Type of group store request.
+     */
+    public enum Type {
+        ADD,
+        UPDATE,
+        DELETE
+    }
+
+    private GroupStoreMessage(Type type,
+                             DeviceId deviceId,
+                             GroupKey appCookie,
+                             GroupDescription groupDesc,
+                             UpdateType updateType,
+                             GroupBuckets updateBuckets,
+                             GroupKey newAppCookie) {
+        this.type = type;
+        this.deviceId = deviceId;
+        this.appCookie = appCookie;
+        this.groupDesc = groupDesc;
+        this.updateType = updateType;
+        this.updateBuckets = updateBuckets;
+        this.newAppCookie = newAppCookie;
+    }
+
+    /**
+     * Creates a group store message for group ADD request.
+     *
+     * @param deviceId device identifier in which group to be added
+     * @param desc group creation parameters
+     * @return constructed group store message
+     */
+    public static GroupStoreMessage createGroupAddRequestMsg(DeviceId deviceId,
+                                                             GroupDescription desc) {
+        return new GroupStoreMessage(Type.ADD,
+                              deviceId,
+                              null,
+                              desc,
+                              null,
+                              null,
+                              null);
+    }
+
+    /**
+     * Creates a group store message for group UPDATE request.
+     *
+     * @param deviceId the device ID
+     * @param appCookie the current group key
+     * @param updateType update (add or delete) type
+     * @param updateBuckets group buckets for updates
+     * @param newAppCookie optional new group key
+     * @return constructed group store message
+     */
+    public static GroupStoreMessage createGroupUpdateRequestMsg(DeviceId deviceId,
+                                                        GroupKey appCookie,
+                                                        UpdateType updateType,
+                                                        GroupBuckets updateBuckets,
+                                                        GroupKey newAppCookie) {
+        return new GroupStoreMessage(Type.UPDATE,
+                              deviceId,
+                              appCookie,
+                              null,
+                              updateType,
+                              updateBuckets,
+                              newAppCookie);
+    }
+
+    /**
+     * Creates a group store message for group DELETE request.
+     *
+     * @param deviceId the device ID
+     * @param appCookie the group key
+     * @return constructed group store message
+     */
+    public static GroupStoreMessage createGroupDeleteRequestMsg(DeviceId deviceId,
+                                                                GroupKey appCookie) {
+        return new GroupStoreMessage(Type.DELETE,
+                                     deviceId,
+                                     appCookie,
+                                     null,
+                                     null,
+                                     null,
+                                     null);
+    }
+
+    /**
+     * Returns the device identifier of this group request.
+     *
+     * @return device identifier
+     */
+    public DeviceId deviceId() {
+        return deviceId;
+    }
+
+    /**
+     * Returns the application cookie associated with this group request.
+     *
+     * @return application cookie
+     */
+    public GroupKey appCookie() {
+        return appCookie;
+    }
+
+    /**
+     * Returns the group create parameters associated with this group request.
+     *
+     * @return group create parameters
+     */
+    public GroupDescription groupDesc() {
+        return groupDesc;
+    }
+
+    /**
+     * Returns the group buckets to be updated as part of this group request.
+     *
+     * @return group buckets to be updated
+     */
+    public GroupBuckets updateBuckets() {
+        return updateBuckets;
+    }
+
+    /**
+     * Returns the update group operation type.
+     *
+     * @return update operation type
+     */
+    public UpdateType updateType() {
+        return updateType;
+    }
+
+    /**
+     * Returns the new application cookie associated with this group operation.
+     *
+     * @return new application cookie
+     */
+    public GroupKey newAppCookie() {
+        return newAppCookie;
+    }
+
+    /**
+     * Returns the type of this group operation.
+     *
+     * @return group message type
+     */
+    public Type type() {
+        return type;
+    }
+}
diff --git a/core/store/dist/src/main/java/org/onosproject/store/group/impl/GroupStoreMessageSubjects.java b/core/store/dist/src/main/java/org/onosproject/store/group/impl/GroupStoreMessageSubjects.java
new file mode 100644
index 0000000..dbee22c
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onosproject/store/group/impl/GroupStoreMessageSubjects.java
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.store.group.impl;
+
+import org.onosproject.store.cluster.messaging.MessageSubject;
+
+/**
+ * MessageSubjects used by DistributedGroupRuleStore peer-peer communication.
+ */
+public final class GroupStoreMessageSubjects {
+    private GroupStoreMessageSubjects() {}
+
+    public static final  MessageSubject REMOTE_GROUP_OP_REQUEST
+        = new MessageSubject("peer-forward-group-op-req");
+}
diff --git a/core/store/trivial/src/main/java/org/onosproject/store/trivial/impl/SimpleGroupStore.java b/core/store/trivial/src/main/java/org/onosproject/store/trivial/impl/SimpleGroupStore.java
index e2adf8c..d35a5c0 100644
--- a/core/store/trivial/src/main/java/org/onosproject/store/trivial/impl/SimpleGroupStore.java
+++ b/core/store/trivial/src/main/java/org/onosproject/store/trivial/impl/SimpleGroupStore.java
@@ -209,6 +209,13 @@
                       null;
     }
 
+    @Override
+    public Group getGroup(DeviceId deviceId, GroupId groupId) {
+        return (groupEntriesById.get(deviceId) != null) ?
+                      groupEntriesById.get(deviceId).get(groupId) :
+                      null;
+    }
+
     private int getFreeGroupIdValue(DeviceId deviceId) {
         int freeId = groupIdGen.incrementAndGet();
 
@@ -551,5 +558,4 @@
                   getExtraneousGroupIdTable(deviceId).values());
     }
 
-
 }
diff --git a/core/store/trivial/src/test/java/org/onosproject/store/trivial/impl/SimpleGroupStoreTest.java b/core/store/trivial/src/test/java/org/onosproject/store/trivial/impl/SimpleGroupStoreTest.java
index 712adcb..92ae5d7 100644
--- a/core/store/trivial/src/test/java/org/onosproject/store/trivial/impl/SimpleGroupStoreTest.java
+++ b/core/store/trivial/src/test/java/org/onosproject/store/trivial/impl/SimpleGroupStoreTest.java
@@ -36,6 +36,7 @@
 import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.group.DefaultGroupBucket;
 import org.onosproject.net.group.DefaultGroupDescription;
+import org.onosproject.net.group.DefaultGroupKey;
 import org.onosproject.net.group.Group;
 import org.onosproject.net.group.GroupBucket;
 import org.onosproject.net.group.GroupBuckets;
@@ -70,31 +71,6 @@
         simpleGroupStore.deactivate();
     }
 
-    public class TestGroupKey implements GroupKey {
-        private String groupId;
-
-        public TestGroupKey(String id) {
-            this.groupId = id;
-        }
-
-        public String id() {
-            return this.groupId;
-        }
-
-        @Override
-        public int hashCode() {
-            return groupId.hashCode();
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (obj instanceof TestGroupKey) {
-                return this.groupId.equals(((TestGroupKey) obj).id());
-            }
-            return false;
-        }
-    }
-
     private class InternalGroupStoreDelegate
                 implements GroupStoreDelegate {
         private GroupId createdGroupId = null;
@@ -173,20 +149,20 @@
         simpleGroupStore.deviceInitialAuditCompleted(D1, true);
 
         // Testing storeGroup operation
-        TestGroupKey newKey = new TestGroupKey("group1");
+        GroupKey newKey = new DefaultGroupKey("group1".getBytes());
         testStoreAndGetGroup(newKey);
 
         // Testing addOrUpdateGroupEntry operation from southbound
-        TestGroupKey currKey = newKey;
+        GroupKey currKey = newKey;
         testAddGroupEntryFromSB(currKey);
 
         // Testing updateGroupDescription for ADD operation from northbound
-        newKey = new TestGroupKey("group1AddBuckets");
+        newKey = new DefaultGroupKey("group1AddBuckets".getBytes());
         testAddBuckets(currKey, newKey);
 
         // Testing updateGroupDescription for REMOVE operation from northbound
         currKey = newKey;
-        newKey = new TestGroupKey("group1RemoveBuckets");
+        newKey = new DefaultGroupKey("group1RemoveBuckets".getBytes());
         testRemoveBuckets(currKey, newKey);
 
         // Testing addOrUpdateGroupEntry operation from southbound
@@ -201,7 +177,7 @@
     }
 
     // Testing storeGroup operation
-    private void testStoreAndGetGroup(TestGroupKey key) {
+    private void testStoreAndGetGroup(GroupKey key) {
         PortNumber[] ports = {PortNumber.portNumber(31),
                               PortNumber.portNumber(32)};
         List<PortNumber> outPorts = new ArrayList<PortNumber>();
@@ -252,7 +228,7 @@
     }
 
     // Testing addOrUpdateGroupEntry operation from southbound
-    private void testAddGroupEntryFromSB(TestGroupKey currKey) {
+    private void testAddGroupEntryFromSB(GroupKey currKey) {
         Group existingGroup = simpleGroupStore.getGroup(D1, currKey);
 
         InternalGroupStoreDelegate addGroupEntryDelegate =
@@ -265,7 +241,7 @@
     }
 
     // Testing addOrUpdateGroupEntry operation from southbound
-    private void testUpdateGroupEntryFromSB(TestGroupKey currKey) {
+    private void testUpdateGroupEntryFromSB(GroupKey currKey) {
         Group existingGroup = simpleGroupStore.getGroup(D1, currKey);
 
         InternalGroupStoreDelegate updateGroupEntryDelegate =
@@ -278,7 +254,7 @@
     }
 
     // Testing updateGroupDescription for ADD operation from northbound
-    private void testAddBuckets(TestGroupKey currKey, TestGroupKey addKey) {
+    private void testAddBuckets(GroupKey currKey, GroupKey addKey) {
         Group existingGroup = simpleGroupStore.getGroup(D1, currKey);
         List<GroupBucket> buckets = new ArrayList<GroupBucket>();
         buckets.addAll(existingGroup.buckets().buckets());
@@ -316,7 +292,7 @@
     }
 
     // Testing updateGroupDescription for REMOVE operation from northbound
-    private void testRemoveBuckets(TestGroupKey currKey, TestGroupKey removeKey) {
+    private void testRemoveBuckets(GroupKey currKey, GroupKey removeKey) {
         Group existingGroup = simpleGroupStore.getGroup(D1, currKey);
         List<GroupBucket> buckets = new ArrayList<GroupBucket>();
         buckets.addAll(existingGroup.buckets().buckets());
@@ -343,7 +319,7 @@
     }
 
     // Testing deleteGroupDescription operation from northbound
-    private void testDeleteGroup(TestGroupKey currKey) {
+    private void testDeleteGroup(GroupKey currKey) {
         Group existingGroup = simpleGroupStore.getGroup(D1, currKey);
         InternalGroupStoreDelegate deleteGroupDescDelegate =
                 new InternalGroupStoreDelegate(currKey,
@@ -355,7 +331,7 @@
     }
 
     // Testing removeGroupEntry operation from southbound
-    private void testRemoveGroupFromSB(TestGroupKey currKey) {
+    private void testRemoveGroupFromSB(GroupKey currKey) {
         Group existingGroup = simpleGroupStore.getGroup(D1, currKey);
         InternalGroupStoreDelegate removeGroupEntryDelegate =
                 new InternalGroupStoreDelegate(currKey,
@@ -380,7 +356,7 @@
 
         ApplicationId appId =
                 new DefaultApplicationId(2, "org.groupstore.test");
-        TestGroupKey key = new TestGroupKey("group1");
+        GroupKey key = new DefaultGroupKey("group1".getBytes());
         PortNumber[] ports = {PortNumber.portNumber(31),
                 PortNumber.portNumber(32)};
         List<PortNumber> outPorts = new ArrayList<PortNumber>();