diff --git a/core/store/hz/cluster/src/main/java/org/onlab/onos/store/mastership/impl/DistributedMastershipStore.java b/core/store/hz/cluster/src/main/java/org/onlab/onos/store/mastership/impl/DistributedMastershipStore.java
index bc32375..d0eae2d 100644
--- a/core/store/hz/cluster/src/main/java/org/onlab/onos/store/mastership/impl/DistributedMastershipStore.java
+++ b/core/store/hz/cluster/src/main/java/org/onlab/onos/store/mastership/impl/DistributedMastershipStore.java
@@ -24,11 +24,12 @@
 import org.onlab.onos.net.MastershipRole;
 import org.onlab.onos.store.common.AbstractHazelcastStore;
 import org.onlab.onos.store.common.SMap;
+import org.onlab.onos.store.serializers.KryoPoolUtil;
 import org.onlab.onos.store.serializers.KryoSerializer;
+import org.onlab.util.KryoPool;
 
 import com.google.common.collect.ImmutableSet;
-import com.hazelcast.core.IMap;
-import com.hazelcast.core.MultiMap;
+import com.hazelcast.core.IAtomicLong;
 
 import static org.onlab.onos.net.MastershipRole.*;
 
@@ -49,6 +50,9 @@
     protected SMap<DeviceId, RoleValue> roleMap;
     //devices to terms
     protected SMap<DeviceId, Integer> terms;
+    //last-known cluster size, used for tie-breaking when partitioning occurs
+    protected IAtomicLong clusterSize;
+
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected ClusterService clusterService;
@@ -59,8 +63,21 @@
     public void activate() {
         super.activate();
 
-        roleMap = new SMap(theInstance.getMap("nodeRoles"), new KryoSerializer());
-        terms = new SMap(theInstance.getMap("terms"), new KryoSerializer());
+        this.serializer = new KryoSerializer() {
+            @Override
+            protected void setupKryoPool() {
+                serializerPool = KryoPool.newBuilder()
+                        .register(KryoPoolUtil.API)
+
+                        .register(RoleValue.class, new RoleValueSerializer())
+                        .build()
+                        .populate(1);
+            }
+        };
+
+        roleMap = new SMap(theInstance.getMap("nodeRoles"), this.serializer);
+        terms = new SMap(theInstance.getMap("terms"), this.serializer);
+        clusterSize = theInstance.getAtomicLong("clustersize");
        // roleMap.addEntryListener(new RemoteMasterShipEventHandler(), true);
 
         log.info("Started");
@@ -103,6 +120,7 @@
                 case MASTER:
                     //reinforce mastership
                     rv.reassign(nodeId, STANDBY, NONE);
+                    roleMap.put(deviceId, rv);
                     return null;
                 case STANDBY:
                     NodeId current = rv.get(MASTER);
@@ -115,11 +133,13 @@
                         rv.add(MASTER, nodeId);
                     }
                     rv.reassign(nodeId, STANDBY, NONE);
+                    roleMap.put(deviceId, rv);
                     updateTerm(deviceId);
                     return new MastershipEvent(MASTER_CHANGED, deviceId, nodeId);
                 case NONE:
                     rv.add(MASTER, nodeId);
                     rv.reassign(nodeId, STANDBY, NONE);
+                    roleMap.put(deviceId, rv);
                     updateTerm(deviceId);
                     return new MastershipEvent(MASTER_CHANGED, deviceId, nodeId);
                 default:
@@ -133,7 +153,7 @@
 
     @Override
     public NodeId getMaster(DeviceId deviceId) {
-        return getMaster(deviceId);
+        return getNode(MASTER, deviceId);
     }
 
 
@@ -181,15 +201,18 @@
             switch (role) {
                 case MASTER:
                     rv.reassign(local, STANDBY, NONE);
+                    roleMap.put(deviceId, rv);
                     break;
                 case STANDBY:
                     rv.reassign(local, NONE, STANDBY);
+                    roleMap.put(deviceId, rv);
                     terms.putIfAbsent(deviceId, INIT);
                     break;
                 case NONE:
                     //claim mastership
                     rv.add(MASTER, local);
                     rv.reassign(local, STANDBY, NONE);
+                    roleMap.put(deviceId, rv);
                     updateTerm(deviceId);
                     role = MastershipRole.MASTER;
                     break;
@@ -221,12 +244,13 @@
             MastershipRole role = getRole(nodeId, deviceId);
             switch (role) {
                 case MASTER:
-                    event = reelect(nodeId, deviceId);
+                    event = reelect(nodeId, deviceId, rv);
                     //fall through to reinforce role
                 case STANDBY:
                     //fall through to reinforce role
                 case NONE:
                     rv.reassign(nodeId, NONE, STANDBY);
+                    roleMap.put(deviceId, rv);
                     break;
                 default:
                     log.warn("unknown Mastership Role {}", role);
@@ -247,12 +271,13 @@
             MastershipRole role = getRole(nodeId, deviceId);
             switch (role) {
                 case MASTER:
-                    event = reelect(nodeId, deviceId);
+                    event = reelect(nodeId, deviceId, rv);
                     //fall through to reinforce relinquishment
                 case STANDBY:
                     //fall through to reinforce relinquishment
                 case NONE:
                     rv.reassign(nodeId, STANDBY, NONE);
+                    roleMap.put(deviceId, rv);
                     break;
                 default:
                 log.warn("unknown Mastership Role {}", role);
@@ -264,8 +289,7 @@
     }
 
     //helper to fetch a new master candidate for a given device.
-    private MastershipEvent reelect(NodeId current, DeviceId deviceId) {
-        RoleValue rv = roleMap.get(deviceId);
+    private MastershipEvent reelect(NodeId current, DeviceId deviceId, RoleValue rv) {
 
         //if this is an queue it'd be neater.
         NodeId backup = null;
@@ -278,10 +302,12 @@
 
         if (backup == null) {
             rv.remove(MASTER, current);
+            roleMap.put(deviceId, rv);
             return null;
         } else {
             rv.replace(current, backup, MASTER);
             rv.reassign(backup, STANDBY, NONE);
+            roleMap.put(deviceId, rv);
             Integer term = terms.get(deviceId);
             terms.put(deviceId, ++term);
             return new MastershipEvent(