Merge branch 'master' of ssh://gerrit.onlab.us:29418/onos-next

Conflicts:
	core/net/src/main/java/org/onlab/onos/cluster/impl/MastershipManager.java
	core/net/src/main/java/org/onlab/onos/net/device/impl/DeviceManager.java
	core/store/hz/cluster/src/main/java/org/onlab/onos/store/cluster/impl/DistributedMastershipStore.java

Change-Id: I6a8b756fc20968e18ea3fd145e155d6282cea945

@@ -28,10 +28,6 @@
             <version>${project.version}</version>
             <version>${project.version}</version>
         </dependency>
         </dependency>
         <dependency>
         <dependency>
-            <groupId>org.livetribe.slp</groupId>
-            <artifactId>livetribe-slp</artifactId>
-        </dependency>
-        <dependency>
             <groupId>org.apache.karaf.shell</groupId>
             <groupId>org.apache.karaf.shell</groupId>
             <artifactId>org.apache.karaf.shell.console</artifactId>
             <artifactId>org.apache.karaf.shell.console</artifactId>
         </dependency>
         </dependency>

@@ -233,7 +233,7 @@ public class IOLoopTestClient {
         }
         }
 
 
         @Override
         @Override
-        protected void connect(SelectionKey key) {
+        protected void connect(SelectionKey key) throws IOException {
             super.connect(key);
             super.connect(key);
             TestMessageStream b = (TestMessageStream) key.attachment();
             TestMessageStream b = (TestMessageStream) key.attachment();
             Worker w = ((CustomIOLoop) b.loop()).worker;
             Worker w = ((CustomIOLoop) b.loop()).worker;

 /**
 /**
  * Sample application for use in various experiments.
  * Sample application for use in various experiments.
  */
  */
-package org.onlab.onos.foo;
\ No newline at end of file
+package org.onlab.onos.foo;

+livetribe.slp.da.expired.services.purge.period=60
+livetribe.slp.sa.client.connect.address=127.0.0.1
+livetribe.slp.sa.client.factory=org.livetribe.slp.sa.StandardServiceAgentClient$Factory
+livetribe.slp.sa.factory=org.livetribe.slp.sa.StandardServiceAgent$Factory
+livetribe.slp.sa.service.renewal.enabled=true
+livetribe.slp.sa.unicast.prefer.tcp=false
+livetribe.slp.tcp.connector.factory=org.livetribe.slp.spi.net.SocketTCPConnector$Factory
+livetribe.slp.tcp.connector.server.factory=org.livetribe.slp.spi.net.SocketTCPConnectorServer$Factory
+livetribe.slp.tcp.message.max.length=4096
+livetribe.slp.tcp.read.timeout=300000
+livetribe.slp.ua.client.factory=org.livetribe.slp.ua.StandardUserAgentClient$Factory
+livetribe.slp.ua.factory=org.livetribe.slp.ua.StandardUserAgent$Factory
+livetribe.slp.ua.unicast.prefer.tcp=false
+livetribe.slp.udp.connector.factory=org.livetribe.slp.spi.net.SocketUDPConnector$Factory
+livetribe.slp.udp.connector.server.factory=org.livetribe.slp.spi.net.SocketUDPConnectorServer$Factory
+net.slp.DAAddresses=
+net.slp.DAAttributes=
+net.slp.DAHeartBeat=10800
+net.slp.MTU=1400
+net.slp.SAAttributes=
+net.slp.broadcastAddress=255.255.255.255
+net.slp.datagramTimeouts=150,250,400
+net.slp.interfaces=0.0.0.0
+net.slp.isBroadcastOnly=false
+net.slp.locale=en
+net.slp.multicastAddress=239.255.255.253
+net.slp.multicastMaximumWait=15000
+net.slp.multicastTTL=255
+net.slp.multicastTimeouts=150,250,400,600,1000
+net.slp.notificationPort=1847
+net.slp.port=427
+net.slp.useScopes=default
+
+org.onlab.cluster.name = TV-ONOS

+package org.onlab.onos.cli;
+
+import org.apache.karaf.shell.commands.Argument;
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cluster.ClusterAdminService;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.packet.IpPrefix;
+
+/**
+ * Adds a new controller cluster node.
+ */
+@Command(scope = "onos", name = "add-node",
+         description = "Adds a new controller cluster node")
+public class NodeAddCommand extends AbstractShellCommand {
+
+    @Argument(index = 0, name = "nodeId", description = "Node ID",
+              required = true, multiValued = false)
+    String nodeId = null;
+
+    @Argument(index = 1, name = "ip", description = "Node IP address",
+              required = true, multiValued = false)
+    String ip = null;
+
+    @Argument(index = 2, name = "tcpPort", description = "Node TCP listen port",
+              required = false, multiValued = false)
+    int tcpPort = 9876;
+
+    @Override
+    protected void execute() {
+        ClusterAdminService service = get(ClusterAdminService.class);
+        service.addNode(new NodeId(nodeId), IpPrefix.valueOf(ip), tcpPort);
+    }
+
+}

+package org.onlab.onos.cli;
+
+import org.apache.karaf.shell.commands.Argument;
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cluster.ClusterAdminService;
+import org.onlab.onos.cluster.NodeId;
+
+/**
+ * Removes a controller cluster node.
+ */
+@Command(scope = "onos", name = "remove-node",
+         description = "Removes a new controller cluster node")
+public class NodeRemoveCommand extends AbstractShellCommand {
+
+    @Argument(index = 0, name = "nodeId", description = "Node ID",
+              required = true, multiValued = false)
+    String nodeId = null;
+
+    @Override
+    protected void execute() {
+        ClusterAdminService service = get(ClusterAdminService.class);
+        service.removeNode(new NodeId(nodeId));
+    }
+
+}

@@ -17,7 +17,7 @@ import static com.google.common.collect.Lists.newArrayList;
 public class NodesListCommand extends AbstractShellCommand {
 public class NodesListCommand extends AbstractShellCommand {
 
 
     private static final String FMT =
     private static final String FMT =
-            "id=%s, ip=%s, state=%s %s";
+            "id=%s, address=%s:%s, state=%s %s";
 
 
     @Override
     @Override
     protected void execute() {
     protected void execute() {
@@ -26,7 +26,7 @@ public class NodesListCommand extends AbstractShellCommand {
         Collections.sort(nodes, Comparators.NODE_COMPARATOR);
         Collections.sort(nodes, Comparators.NODE_COMPARATOR);
         ControllerNode self = service.getLocalNode();
         ControllerNode self = service.getLocalNode();
         for (ControllerNode node : nodes) {
         for (ControllerNode node : nodes) {
-            print(FMT, node.id(), node.ip(),
+            print(FMT, node.id(), node.ip(), node.tcpPort(),
                   service.getState(node.id()),
                   service.getState(node.id()),
                   node.equals(self) ? "*" : "");
                   node.equals(self) ? "*" : "");
         }
         }

@@ -103,4 +103,4 @@ public class FlowsListCommand extends AbstractShellCommand {
 
 
     }
     }
 
 
-}
\ No newline at end of file
+}

@@ -5,6 +5,12 @@
             <action class="org.onlab.onos.cli.NodesListCommand"/>
             <action class="org.onlab.onos.cli.NodesListCommand"/>
         </command>
         </command>
         <command>
         <command>
+            <action class="org.onlab.onos.cli.NodeAddCommand"/>
+        </command>
+        <command>
+            <action class="org.onlab.onos.cli.NodeRemoveCommand"/>
+        </command>
+        <command>
             <action class="org.onlab.onos.cli.MastersListCommand"/>
             <action class="org.onlab.onos.cli.MastersListCommand"/>
             <completers>
             <completers>
                 <ref component-id="clusterIdCompleter"/>
                 <ref component-id="clusterIdCompleter"/>

 package org.onlab.onos.cluster;
 package org.onlab.onos.cluster;
 
 
+import org.onlab.packet.IpPrefix;
+
 /**
 /**
  * Service for administering the cluster node membership.
  * Service for administering the cluster node membership.
  */
  */
 public interface ClusterAdminService {
 public interface ClusterAdminService {
 
 
     /**
     /**
+     * Adds a new controller node to the cluster.
+     *
+     * @param nodeId  controller node identifier
+     * @param ip      node IP listen address
+     * @param tcpPort tcp listen port
+     * @return newly added node
+     */
+    ControllerNode addNode(NodeId nodeId, IpPrefix ip, int tcpPort);
+
+    /**
      * Removes the specified node from the cluster node list.
      * Removes the specified node from the cluster node list.
      *
      *
      * @param nodeId controller node identifier
      * @param nodeId controller node identifier

 package org.onlab.onos.cluster;
 package org.onlab.onos.cluster;
 
 
 import org.onlab.onos.store.Store;
 import org.onlab.onos.store.Store;
+import org.onlab.packet.IpPrefix;
 
 
 import java.util.Set;
 import java.util.Set;
 
 
@@ -40,6 +41,16 @@ public interface ClusterStore extends Store<ClusterEvent, ClusterStoreDelegate>
     ControllerNode.State getState(NodeId nodeId);
     ControllerNode.State getState(NodeId nodeId);
 
 
     /**
     /**
+     * Adds a new controller node to the cluster.
+     *
+     * @param nodeId  controller node identifier
+     * @param ip      node IP listen address
+     * @param tcpPort tcp listen port
+     * @return newly added node
+     */
+    ControllerNode addNode(NodeId nodeId, IpPrefix ip, int tcpPort);
+
+    /**
      * Removes the specified node from the inventory of cluster nodes.
      * Removes the specified node from the inventory of cluster nodes.
      *
      *
      * @param nodeId controller instance identifier
      * @param nodeId controller instance identifier

@@ -35,4 +35,12 @@ public interface ControllerNode {
      */
      */
     IpPrefix ip();
     IpPrefix ip();
 
 
+
+    /**
+     * Returns the TCP port on which the node listens for connections.
+     *
+     * @return TCP port
+     */
+    int tcpPort();
+
 }
 }

@@ -11,13 +11,17 @@ import static com.google.common.base.MoreObjects.toStringHelper;
  */
  */
 public class DefaultControllerNode implements ControllerNode {
 public class DefaultControllerNode implements ControllerNode {
 
 
+    private static final int DEFAULT_PORT = 9876;
+
     private final NodeId id;
     private final NodeId id;
     private final IpPrefix ip;
     private final IpPrefix ip;
+    private final int tcpPort;
 
 
     // For serialization
     // For serialization
     private DefaultControllerNode() {
     private DefaultControllerNode() {
         this.id = null;
         this.id = null;
         this.ip = null;
         this.ip = null;
+        this.tcpPort = 0;
     }
     }
 
 
     /**
     /**
@@ -27,8 +31,19 @@ public class DefaultControllerNode implements ControllerNode {
      * @param ip instance IP address
      * @param ip instance IP address
      */
      */
     public DefaultControllerNode(NodeId id, IpPrefix ip) {
     public DefaultControllerNode(NodeId id, IpPrefix ip) {
+        this(id, ip, DEFAULT_PORT);
+    }
+
+    /**
+     * Creates a new instance with the specified id and IP address and TCP port.
+     *
+     * @param id instance identifier
+     * @param ip instance IP address
+     */
+    public DefaultControllerNode(NodeId id, IpPrefix ip, int tcpPort) {
         this.id = id;
         this.id = id;
         this.ip = ip;
         this.ip = ip;
+        this.tcpPort = tcpPort;
     }
     }
 
 
     @Override
     @Override
@@ -42,6 +57,11 @@ public class DefaultControllerNode implements ControllerNode {
     }
     }
 
 
     @Override
     @Override
+    public int tcpPort() {
+        return tcpPort;
+    }
+
+    @Override
     public int hashCode() {
     public int hashCode() {
         return Objects.hash(id);
         return Objects.hash(id);
     }
     }
@@ -60,7 +80,8 @@ public class DefaultControllerNode implements ControllerNode {
 
 
     @Override
     @Override
     public String toString() {
     public String toString() {
-        return toStringHelper(this).add("id", id).add("ip", ip).toString();
+        return toStringHelper(this).add("id", id)
+                .add("ip", ip).add("tcpPort", tcpPort).toString();
     }
     }
 
 
 }
 }

+package org.onlab.onos.net.proxyarp;
+
+import org.onlab.packet.Ethernet;
+import org.onlab.packet.IpPrefix;
+
+/**
+ * Service for processing arp requests on behalf of applications.
+ */
+public interface ProxyArpService {
+
+    /**
+     * Returns whether this particular ip address is known to the system.
+     *
+     * @param addr
+     *            a ip address
+     * @return true if know, false otherwise
+     */
+    boolean known(IpPrefix addr);
+
+    /**
+     * Sends a reply for a given request. If the host is not known then the arp
+     * will be flooded at all edge ports.
+     *
+     * @param request
+     *            an arp request
+     */
+    void reply(Ethernet request);
+
+}

+/**
+ * Base abstractions related to the proxy arp service.
+ */
+package org.onlab.onos.net.proxyarp;

+package org.onlab.onos.store;
+
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.net.DeviceId;
+
+// TODO: Consider renaming to DeviceClockService?
+/**
+ * Interface for a logical clock service that vends per device timestamps.
+ */
+public interface ClockService {
+
+    /**
+     * Returns a new timestamp for the specified deviceId.
+     * @param deviceId device identifier.
+     * @return timestamp.
+     */
+    public Timestamp getTimestamp(DeviceId deviceId);
+
+    // TODO: Should this be here or separate as Admin service, etc.?
+    /**
+     * Updates the mastership term for the specified deviceId.
+     * @param deviceId device identifier.
+     * @param term mastership term.
+     */
+    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term);
+}

 /**
 /**
  * Abstractions for creating and interacting with distributed stores.
  * Abstractions for creating and interacting with distributed stores.
  */
  */
-package org.onlab.onos.store;
\ No newline at end of file
+package org.onlab.onos.store;

@@ -40,13 +40,14 @@
               Currently required for DistributedDeviceManagerTest. -->
               Currently required for DistributedDeviceManagerTest. -->
         <dependency>
         <dependency>
             <groupId>org.onlab.onos</groupId>
             <groupId>org.onlab.onos</groupId>
-            <artifactId>onos-core-store</artifactId>
+            <artifactId>onos-core-hz-net</artifactId>
             <version>${project.version}</version>
             <version>${project.version}</version>
             <scope>test</scope>
             <scope>test</scope>
         </dependency>
         </dependency>
         <dependency>
         <dependency>
             <groupId>org.onlab.onos</groupId>
             <groupId>org.onlab.onos</groupId>
-            <artifactId>onos-core-store</artifactId>
+            <!-- FIXME: should be somewhere else -->
+            <artifactId>onos-core-hz-common</artifactId>
             <version>${project.version}</version>
             <version>${project.version}</version>
             <classifier>tests</classifier>
             <classifier>tests</classifier>
             <scope>test</scope>
             <scope>test</scope>

@@ -16,10 +16,12 @@ import org.onlab.onos.cluster.ControllerNode;
 import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.event.AbstractListenerRegistry;
 import org.onlab.onos.event.AbstractListenerRegistry;
 import org.onlab.onos.event.EventDeliveryService;
 import org.onlab.onos.event.EventDeliveryService;
+import org.onlab.packet.IpPrefix;
 import org.slf4j.Logger;
 import org.slf4j.Logger;
 
 
 import java.util.Set;
 import java.util.Set;
 
 
+import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static org.slf4j.LoggerFactory.getLogger;
 import static org.slf4j.LoggerFactory.getLogger;
 
 
@@ -81,6 +83,14 @@ public class ClusterManager implements ClusterService, ClusterAdminService {
     }
     }
 
 
     @Override
     @Override
+    public ControllerNode addNode(NodeId nodeId, IpPrefix ip, int tcpPort) {
+        checkNotNull(nodeId, INSTANCE_ID_NULL);
+        checkNotNull(ip, "IP address cannot be null");
+        checkArgument(tcpPort > 5000, "TCP port must be > 5000");
+        return store.addNode(nodeId, ip, tcpPort);
+    }
+
+    @Override
     public void removeNode(NodeId nodeId) {
     public void removeNode(NodeId nodeId) {
         checkNotNull(nodeId, INSTANCE_ID_NULL);
         checkNotNull(nodeId, INSTANCE_ID_NULL);
         store.removeNode(nodeId);
         store.removeNode(nodeId);

 package org.onlab.onos.cluster.impl;
 package org.onlab.onos.cluster.impl;
 
 
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Set;
+
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
 import org.apache.felix.scr.annotations.Deactivate;
@@ -14,6 +19,7 @@ import org.onlab.onos.cluster.MastershipEvent;
 import org.onlab.onos.cluster.MastershipListener;
 import org.onlab.onos.cluster.MastershipListener;
 import org.onlab.onos.cluster.MastershipService;
 import org.onlab.onos.cluster.MastershipService;
 import org.onlab.onos.cluster.MastershipStore;
 import org.onlab.onos.cluster.MastershipStore;
+import org.onlab.onos.cluster.MastershipStoreDelegate;
 import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.cluster.MastershipTermService;
 import org.onlab.onos.cluster.MastershipTermService;
 import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.cluster.NodeId;
@@ -23,15 +29,10 @@ import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.MastershipRole;
 import org.onlab.onos.net.MastershipRole;
 import org.slf4j.Logger;
 import org.slf4j.Logger;
 
 
-import java.util.Set;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-import static org.slf4j.LoggerFactory.getLogger;
-
 @Component(immediate = true)
 @Component(immediate = true)
 @Service
 @Service
 public class MastershipManager
 public class MastershipManager
-        implements MastershipService, MastershipAdminService {
+implements MastershipService, MastershipAdminService {
 
 
     private static final String NODE_ID_NULL = "Node ID cannot be null";
     private static final String NODE_ID_NULL = "Node ID cannot be null";
     private static final String DEVICE_ID_NULL = "Device ID cannot be null";
     private static final String DEVICE_ID_NULL = "Device ID cannot be null";
@@ -40,7 +41,9 @@ public class MastershipManager
     private final Logger log = getLogger(getClass());
     private final Logger log = getLogger(getClass());
 
 
     protected final AbstractListenerRegistry<MastershipEvent, MastershipListener>
     protected final AbstractListenerRegistry<MastershipEvent, MastershipListener>
-            listenerRegistry = new AbstractListenerRegistry<>();
+    listenerRegistry = new AbstractListenerRegistry<>();
+
+    private final MastershipStoreDelegate delegate = new InternalDelegate();
 
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected MastershipStore store;
     protected MastershipStore store;
@@ -57,6 +60,7 @@ public class MastershipManager
     public void activate() {
     public void activate() {
         eventDispatcher.addSink(MastershipEvent.class, listenerRegistry);
         eventDispatcher.addSink(MastershipEvent.class, listenerRegistry);
         clusterService.addListener(clusterListener);
         clusterService.addListener(clusterListener);
+        store.setDelegate(delegate);
         log.info("Started");
         log.info("Started");
     }
     }
 
 
@@ -64,6 +68,7 @@ public class MastershipManager
     public void deactivate() {
     public void deactivate() {
         eventDispatcher.removeSink(MastershipEvent.class);
         eventDispatcher.removeSink(MastershipEvent.class);
         clusterService.removeListener(clusterListener);
         clusterService.removeListener(clusterListener);
+        store.unsetDelegate(delegate);
         log.info("Stopped");
         log.info("Stopped");
     }
     }
 
 
@@ -188,4 +193,15 @@ public class MastershipManager
         }
         }
 
 
     }
     }
+
+    public class InternalDelegate implements MastershipStoreDelegate {
+
+        @Override
+        public void notify(MastershipEvent event) {
+            log.info("dispatching mastership event {}", event);
+            eventDispatcher.post(event);
+        }
+
+    }
+
 }
 }

 /**
 /**
  * Subsystem for tracking controller cluster nodes.
  * Subsystem for tracking controller cluster nodes.
  */
  */
-package org.onlab.onos.cluster.impl;
\ No newline at end of file
+package org.onlab.onos.cluster.impl;

 package org.onlab.onos.net.device.impl;
 package org.onlab.onos.net.device.impl;
 
 
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onlab.onos.net.device.DeviceEvent.Type.DEVICE_MASTERSHIP_CHANGED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.List;
+
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
 import org.apache.felix.scr.annotations.Deactivate;
@@ -11,6 +17,7 @@ import org.onlab.onos.cluster.MastershipEvent;
 import org.onlab.onos.cluster.MastershipListener;
 import org.onlab.onos.cluster.MastershipListener;
 import org.onlab.onos.cluster.MastershipService;
 import org.onlab.onos.cluster.MastershipService;
 import org.onlab.onos.cluster.MastershipTermService;
 import org.onlab.onos.cluster.MastershipTermService;
+import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.event.AbstractListenerRegistry;
 import org.onlab.onos.event.AbstractListenerRegistry;
 import org.onlab.onos.event.EventDeliveryService;
 import org.onlab.onos.event.EventDeliveryService;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.Device;
@@ -31,22 +38,17 @@ import org.onlab.onos.net.device.DeviceStoreDelegate;
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.provider.AbstractProviderRegistry;
 import org.onlab.onos.net.provider.AbstractProviderRegistry;
 import org.onlab.onos.net.provider.AbstractProviderService;
 import org.onlab.onos.net.provider.AbstractProviderService;
+import org.onlab.onos.store.ClockService;
 import org.slf4j.Logger;
 import org.slf4j.Logger;
 
 
-import java.util.List;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-import static org.onlab.onos.net.device.DeviceEvent.Type.DEVICE_MASTERSHIP_CHANGED;
-import static org.slf4j.LoggerFactory.getLogger;
-
 /**
 /**
  * Provides implementation of the device SB & NB APIs.
  * Provides implementation of the device SB & NB APIs.
  */
  */
 @Component(immediate = true)
 @Component(immediate = true)
 @Service
 @Service
 public class DeviceManager
 public class DeviceManager
-        extends AbstractProviderRegistry<DeviceProvider, DeviceProviderService>
-        implements DeviceService, DeviceAdminService, DeviceProviderRegistry {
+    extends AbstractProviderRegistry<DeviceProvider, DeviceProviderService>
+    implements DeviceService, DeviceAdminService, DeviceProviderRegistry {
 
 
     private static final String DEVICE_ID_NULL = "Device ID cannot be null";
     private static final String DEVICE_ID_NULL = "Device ID cannot be null";
     private static final String PORT_NUMBER_NULL = "Port number cannot be null";
     private static final String PORT_NUMBER_NULL = "Port number cannot be null";
@@ -56,10 +58,10 @@ public class DeviceManager
 
 
     private final Logger log = getLogger(getClass());
     private final Logger log = getLogger(getClass());
 
 
-    protected final AbstractListenerRegistry<DeviceEvent, DeviceListener>
-            listenerRegistry = new AbstractListenerRegistry<>();
+    protected final AbstractListenerRegistry<DeviceEvent, DeviceListener> listenerRegistry =
+            new AbstractListenerRegistry<>();
 
 
-    private DeviceStoreDelegate delegate = new InternalStoreDelegate();
+    private final DeviceStoreDelegate delegate = new InternalStoreDelegate();
 
 
     private final MastershipListener mastershipListener = new InternalMastershipListener();
     private final MastershipListener mastershipListener = new InternalMastershipListener();
 
 
@@ -77,6 +79,9 @@ public class DeviceManager
 
 
     protected MastershipTermService termService;
     protected MastershipTermService termService;
 
 
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClockService clockService;
+
     @Activate
     @Activate
     public void activate() {
     public void activate() {
         store.setDelegate(delegate);
         store.setDelegate(delegate);
@@ -168,33 +173,36 @@ public class DeviceManager
     }
     }
 
 
     @Override
     @Override
-    protected DeviceProviderService createProviderService(DeviceProvider provider) {
+    protected DeviceProviderService createProviderService(
+            DeviceProvider provider) {
         return new InternalDeviceProviderService(provider);
         return new InternalDeviceProviderService(provider);
     }
     }
 
 
     // Personalized device provider service issued to the supplied provider.
     // Personalized device provider service issued to the supplied provider.
     private class InternalDeviceProviderService
     private class InternalDeviceProviderService
-            extends AbstractProviderService<DeviceProvider>
-            implements DeviceProviderService {
+    extends AbstractProviderService<DeviceProvider>
+    implements DeviceProviderService {
 
 
         InternalDeviceProviderService(DeviceProvider provider) {
         InternalDeviceProviderService(DeviceProvider provider) {
             super(provider);
             super(provider);
         }
         }
 
 
         @Override
         @Override
-        public void deviceConnected(DeviceId deviceId, DeviceDescription deviceDescription) {
+        public void deviceConnected(DeviceId deviceId,
+                DeviceDescription deviceDescription) {
             checkNotNull(deviceId, DEVICE_ID_NULL);
             checkNotNull(deviceId, DEVICE_ID_NULL);
             checkNotNull(deviceDescription, DEVICE_DESCRIPTION_NULL);
             checkNotNull(deviceDescription, DEVICE_DESCRIPTION_NULL);
             checkValidity();
             checkValidity();
             DeviceEvent event = store.createOrUpdateDevice(provider().id(),
             DeviceEvent event = store.createOrUpdateDevice(provider().id(),
-                                                           deviceId, deviceDescription);
+                    deviceId, deviceDescription);
 
 
-            // If there was a change of any kind, trigger role selection process.
+            // If there was a change of any kind, trigger role selection
+            // process.
             if (event != null) {
             if (event != null) {
                 log.info("Device {} connected", deviceId);
                 log.info("Device {} connected", deviceId);
                 mastershipService.requestRoleFor(deviceId);
                 mastershipService.requestRoleFor(deviceId);
                 provider().roleChanged(event.subject(),
                 provider().roleChanged(event.subject(),
-                                       mastershipService.getLocalRole(deviceId));
+                        mastershipService.getLocalRole(deviceId));
                 post(event);
                 post(event);
             }
             }
         }
         }
@@ -214,25 +222,30 @@ public class DeviceManager
         }
         }
 
 
         @Override
         @Override
-        public void updatePorts(DeviceId deviceId, List<PortDescription> portDescriptions) {
+        public void updatePorts(DeviceId deviceId,
+                List<PortDescription> portDescriptions) {
             checkNotNull(deviceId, DEVICE_ID_NULL);
             checkNotNull(deviceId, DEVICE_ID_NULL);
-            checkNotNull(portDescriptions, "Port descriptions list cannot be null");
+            checkNotNull(portDescriptions,
+                    "Port descriptions list cannot be null");
             checkValidity();
             checkValidity();
-            List<DeviceEvent> events = store.updatePorts(deviceId, portDescriptions);
+            List<DeviceEvent> events = store.updatePorts(deviceId,
+                    portDescriptions);
             for (DeviceEvent event : events) {
             for (DeviceEvent event : events) {
                 post(event);
                 post(event);
             }
             }
         }
         }
 
 
         @Override
         @Override
-        public void portStatusChanged(DeviceId deviceId, PortDescription portDescription) {
+        public void portStatusChanged(DeviceId deviceId,
+                PortDescription portDescription) {
             checkNotNull(deviceId, DEVICE_ID_NULL);
             checkNotNull(deviceId, DEVICE_ID_NULL);
             checkNotNull(portDescription, PORT_DESCRIPTION_NULL);
             checkNotNull(portDescription, PORT_DESCRIPTION_NULL);
             checkValidity();
             checkValidity();
-            DeviceEvent event = store.updatePortStatus(deviceId, portDescription);
+            DeviceEvent event = store.updatePortStatus(deviceId,
+                    portDescription);
             if (event != null) {
             if (event != null) {
-                log.info("Device {} port {} status changed", deviceId,
-                         event.port().number());
+                log.info("Device {} port {} status changed", deviceId, event
+                        .port().number());
                 post(event);
                 post(event);
             }
             }
         }
         }
@@ -240,8 +253,8 @@ public class DeviceManager
         @Override
         @Override
         public void unableToAssertRole(DeviceId deviceId, MastershipRole role) {
         public void unableToAssertRole(DeviceId deviceId, MastershipRole role) {
             // FIXME: implement response to this notification
             // FIXME: implement response to this notification
-            log.warn("Failed to assert role [{}] onto Device {}",
-                    role, deviceId);
+            log.warn("Failed to assert role [{}] onto Device {}", role,
+                    deviceId);
         }
         }
     }
     }
 
 
@@ -253,18 +266,24 @@ public class DeviceManager
     }
     }
 
 
     // Intercepts mastership events
     // Intercepts mastership events
-    private class InternalMastershipListener implements MastershipListener {
+    private class InternalMastershipListener
+    implements MastershipListener {
         @Override
         @Override
         public void event(MastershipEvent event) {
         public void event(MastershipEvent event) {
-            // FIXME: for now we're taking action only on becoming master
             if (event.master().equals(clusterService.getLocalNode().id())) {
             if (event.master().equals(clusterService.getLocalNode().id())) {
+                MastershipTerm term = mastershipService.requestTermService()
+                        .getMastershipTerm(event.subject());
+                clockService.setMastershipTerm(event.subject(), term);
                 applyRole(event.subject(), MastershipRole.MASTER);
                 applyRole(event.subject(), MastershipRole.MASTER);
+            } else {
+                applyRole(event.subject(), MastershipRole.STANDBY);
             }
             }
         }
         }
     }
     }
 
 
     // Store delegate to re-post events emitted from the store.
     // Store delegate to re-post events emitted from the store.
-    private class InternalStoreDelegate implements DeviceStoreDelegate {
+    private class InternalStoreDelegate
+    implements DeviceStoreDelegate {
         @Override
         @Override
         public void notify(DeviceEvent event) {
         public void notify(DeviceEvent event) {
             post(event);
             post(event);

+package org.onlab.onos.proxyarp.impl;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.nio.ByteBuffer;
+import java.util.Set;
+
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onlab.onos.net.Host;
+import org.onlab.onos.net.flow.DefaultTrafficTreatment;
+import org.onlab.onos.net.flow.TrafficTreatment;
+import org.onlab.onos.net.host.HostService;
+import org.onlab.onos.net.packet.DefaultOutboundPacket;
+import org.onlab.onos.net.packet.PacketService;
+import org.onlab.onos.net.proxyarp.ProxyArpService;
+import org.onlab.onos.net.topology.TopologyService;
+import org.onlab.packet.ARP;
+import org.onlab.packet.Ethernet;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.VlanId;
+
+public class ProxyArpManager implements ProxyArpService {
+
+    private static final String MAC_ADDR_NULL = "Mac address cannot be null.";
+    private static final String REQUEST_NULL = "Arp request cannot be null.";
+    private static final String REQUEST_NOT_ARP = "Ethernet frame does not contain ARP request.";
+    private static final String NOT_ARP_REQUEST = "ARP is not a request.";
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected HostService hostService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected PacketService packetService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected TopologyService topologyService;
+
+    @Override
+    public boolean known(IpPrefix addr) {
+        checkNotNull(MAC_ADDR_NULL, addr);
+        Set<Host> hosts = hostService.getHostsByIp(addr);
+        return !hosts.isEmpty();
+    }
+
+    @Override
+    public void reply(Ethernet request) {
+        checkNotNull(REQUEST_NULL, request);
+        checkArgument(request.getEtherType() == Ethernet.TYPE_ARP,
+                REQUEST_NOT_ARP);
+        ARP arp = (ARP) request.getPayload();
+        checkArgument(arp.getOpCode() == ARP.OP_REQUEST, NOT_ARP_REQUEST);
+
+        VlanId vlan = VlanId.vlanId(request.getVlanID());
+        Set<Host> hosts = hostService.getHostsByIp(IpPrefix.valueOf(arp
+                .getTargetProtocolAddress()));
+
+        Host h = null;
+        for (Host host : hosts) {
+            if (host.vlan().equals(vlan)) {
+                h = host;
+                break;
+            }
+        }
+
+        if (h == null) {
+            flood(request);
+            return;
+        }
+
+        Ethernet arpReply = buildArpReply(h, request);
+        // TODO: check send status with host service.
+        TrafficTreatment.Builder builder = new DefaultTrafficTreatment.Builder();
+        builder.setOutput(h.location().port());
+        packetService.emit(new DefaultOutboundPacket(h.location().deviceId(),
+                builder.build(), ByteBuffer.wrap(arpReply.serialize())));
+    }
+
+    private void flood(Ethernet request) {
+        // TODO: flood on all edge ports.
+    }
+
+    private Ethernet buildArpReply(Host h, Ethernet request) {
+        Ethernet eth = new Ethernet();
+        eth.setDestinationMACAddress(request.getSourceMACAddress());
+        eth.setSourceMACAddress(h.mac().getAddress());
+        eth.setEtherType(Ethernet.TYPE_ARP);
+        ARP arp = new ARP();
+        arp.setOpCode(ARP.OP_REPLY);
+        arp.setSenderHardwareAddress(h.mac().getAddress());
+        arp.setTargetHardwareAddress(request.getSourceMACAddress());
+
+        arp.setTargetProtocolAddress(((ARP) request.getPayload())
+                .getSenderProtocolAddress());
+        arp.setSenderProtocolAddress(h.ipAddresses().iterator().next().toInt());
+        eth.setPayload(arp);
+        return eth;
+    }
+}

+/**
+ * Core subsystem for responding to arp requests.
+ */
+package org.onlab.onos.proxyarp.impl;

@@ -32,9 +32,9 @@ import org.onlab.onos.net.device.DeviceService;
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.provider.AbstractProvider;
 import org.onlab.onos.net.provider.AbstractProvider;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.common.StoreManager;
+import org.onlab.onos.store.common.TestStoreManager;
 import org.onlab.onos.store.device.impl.DistributedDeviceStore;
 import org.onlab.onos.store.device.impl.DistributedDeviceStore;
-import org.onlab.onos.store.impl.StoreManager;
-import org.onlab.onos.store.impl.TestStoreManager;
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.IpPrefix;
 
 
 import java.util.ArrayList;
 import java.util.ArrayList;
@@ -163,7 +163,7 @@ public class DistributedDeviceManagerTest {
     public void deviceDisconnected() {
     public void deviceDisconnected() {
         connectDevice(DID1, SW1);
         connectDevice(DID1, SW1);
         connectDevice(DID2, SW1);
         connectDevice(DID2, SW1);
-        validateEvents(DEVICE_ADDED, DEVICE_ADDED, DEVICE_ADDED, DEVICE_ADDED);
+        validateEvents(DEVICE_ADDED, DEVICE_ADDED);
         assertTrue("device should be available", service.isAvailable(DID1));
         assertTrue("device should be available", service.isAvailable(DID1));
 
 
         // Disconnect
         // Disconnect
@@ -182,10 +182,10 @@ public class DistributedDeviceManagerTest {
     @Test
     @Test
     public void deviceUpdated() {
     public void deviceUpdated() {
         connectDevice(DID1, SW1);
         connectDevice(DID1, SW1);
-        validateEvents(DEVICE_ADDED, DEVICE_ADDED);
+        validateEvents(DEVICE_ADDED);
 
 
         connectDevice(DID1, SW2);
         connectDevice(DID1, SW2);
-        validateEvents(DEVICE_UPDATED, DEVICE_UPDATED);
+        validateEvents(DEVICE_UPDATED);
     }
     }
 
 
     @Test
     @Test
@@ -202,7 +202,7 @@ public class DistributedDeviceManagerTest {
         pds.add(new DefaultPortDescription(P2, true));
         pds.add(new DefaultPortDescription(P2, true));
         pds.add(new DefaultPortDescription(P3, true));
         pds.add(new DefaultPortDescription(P3, true));
         providerService.updatePorts(DID1, pds);
         providerService.updatePorts(DID1, pds);
-        validateEvents(DEVICE_ADDED, DEVICE_ADDED, PORT_ADDED, PORT_ADDED, PORT_ADDED);
+        validateEvents(DEVICE_ADDED, PORT_ADDED, PORT_ADDED, PORT_ADDED);
         pds.clear();
         pds.clear();
 
 
         pds.add(new DefaultPortDescription(P1, false));
         pds.add(new DefaultPortDescription(P1, false));
@@ -218,7 +218,7 @@ public class DistributedDeviceManagerTest {
         pds.add(new DefaultPortDescription(P1, true));
         pds.add(new DefaultPortDescription(P1, true));
         pds.add(new DefaultPortDescription(P2, true));
         pds.add(new DefaultPortDescription(P2, true));
         providerService.updatePorts(DID1, pds);
         providerService.updatePorts(DID1, pds);
-        validateEvents(DEVICE_ADDED, DEVICE_ADDED, PORT_ADDED, PORT_ADDED);
+        validateEvents(DEVICE_ADDED, PORT_ADDED, PORT_ADDED);
 
 
         providerService.portStatusChanged(DID1, new DefaultPortDescription(P1, false));
         providerService.portStatusChanged(DID1, new DefaultPortDescription(P1, false));
         validateEvents(PORT_UPDATED);
         validateEvents(PORT_UPDATED);
@@ -233,7 +233,7 @@ public class DistributedDeviceManagerTest {
         pds.add(new DefaultPortDescription(P1, true));
         pds.add(new DefaultPortDescription(P1, true));
         pds.add(new DefaultPortDescription(P2, true));
         pds.add(new DefaultPortDescription(P2, true));
         providerService.updatePorts(DID1, pds);
         providerService.updatePorts(DID1, pds);
-        validateEvents(DEVICE_ADDED, DEVICE_ADDED, PORT_ADDED, PORT_ADDED);
+        validateEvents(DEVICE_ADDED, PORT_ADDED, PORT_ADDED);
         assertEquals("wrong port count", 2, service.getPorts(DID1).size());
         assertEquals("wrong port count", 2, service.getPorts(DID1).size());
 
 
         Port port = service.getPort(DID1, P1);
         Port port = service.getPort(DID1, P1);
@@ -247,7 +247,7 @@ public class DistributedDeviceManagerTest {
         connectDevice(DID2, SW2);
         connectDevice(DID2, SW2);
         assertEquals("incorrect device count", 2, service.getDeviceCount());
         assertEquals("incorrect device count", 2, service.getDeviceCount());
         admin.removeDevice(DID1);
         admin.removeDevice(DID1);
-        validateEvents(DEVICE_ADDED, DEVICE_ADDED, DEVICE_ADDED, DEVICE_ADDED, DEVICE_REMOVED, DEVICE_REMOVED);
+        validateEvents(DEVICE_ADDED, DEVICE_ADDED, DEVICE_REMOVED);
         assertNull("device should not be found", service.getDevice(DID1));
         assertNull("device should not be found", service.getDevice(DID1));
         assertNotNull("device should be found", service.getDevice(DID2));
         assertNotNull("device should be found", service.getDevice(DID2));
         assertEquals("incorrect device count", 1, service.getDeviceCount());
         assertEquals("incorrect device count", 1, service.getDeviceCount());

@@ -20,7 +20,6 @@
         <module>api</module>
         <module>api</module>
         <module>net</module>
         <module>net</module>
         <module>store</module>
         <module>store</module>
-        <module>trivial</module>
     </modules>
     </modules>
 
 
     <dependencies>
     <dependencies>

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-core-store</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-core-dist</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS Gossip based distributed store subsystems</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-core-serializers</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+
+
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onlab-nio</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-annotations</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.felix</groupId>
+            <artifactId>org.apache.felix.scr.annotations</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>de.javakaffee</groupId>
+          <artifactId>kryo-serializers</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-scr-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

+package org.onlab.onos.store.cluster.impl;
+
+import com.fasterxml.jackson.core.JsonEncoding;
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onlab.onos.cluster.DefaultControllerNode;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.packet.IpPrefix;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Set;
+
+/**
+ * Allows for reading and writing cluster definition as a JSON file.
+ */
+public class ClusterDefinitionStore {
+
+    private final File file;
+
+    /**
+     * Creates a reader/writer of the cluster definition file.
+     *
+     * @param filePath location of the definition file
+     */
+    public ClusterDefinitionStore(String filePath) {
+        file = new File(filePath);
+    }
+
+    /**
+     * Returns set of the controller nodes, including self.
+     *
+     * @return set of controller nodes
+     */
+    public Set<DefaultControllerNode> read() throws IOException {
+        Set<DefaultControllerNode> nodes = new HashSet<>();
+        ObjectMapper mapper = new ObjectMapper();
+        ObjectNode clusterNodeDef = (ObjectNode) mapper.readTree(file);
+        Iterator<JsonNode> it = ((ArrayNode) clusterNodeDef.get("nodes")).elements();
+        while (it.hasNext()) {
+            ObjectNode nodeDef = (ObjectNode) it.next();
+            nodes.add(new DefaultControllerNode(new NodeId(nodeDef.get("id").asText()),
+                                                IpPrefix.valueOf(nodeDef.get("ip").asText()),
+                                                nodeDef.get("tcpPort").asInt(9876)));
+        }
+        return nodes;
+    }
+
+    /**
+     * Writes the given set of the controller nodes.
+     *
+     * @param nodes set of controller nodes
+     */
+    public void write(Set<DefaultControllerNode> nodes) throws IOException {
+        ObjectMapper mapper = new ObjectMapper();
+        ObjectNode clusterNodeDef = mapper.createObjectNode();
+        ArrayNode nodeDefs = mapper.createArrayNode();
+        clusterNodeDef.set("nodes", nodeDefs);
+        for (DefaultControllerNode node : nodes) {
+            ObjectNode nodeDef = mapper.createObjectNode();
+            nodeDef.put("id", node.id().toString())
+                    .put("ip", node.ip().toString())
+                    .put("tcpPort", node.tcpPort());
+            nodeDefs.add(nodeDef);
+        }
+        mapper.writeTree(new JsonFactory().createGenerator(file, JsonEncoding.UTF8),
+                         clusterNodeDef);
+    }
+
+}

+package org.onlab.onos.store.cluster.impl;
+
+import com.google.common.collect.ImmutableSet;
+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.Service;
+import org.onlab.nio.AcceptorLoop;
+import org.onlab.nio.IOLoop;
+import org.onlab.nio.MessageStream;
+import org.onlab.onos.cluster.ClusterEvent;
+import org.onlab.onos.cluster.ClusterStore;
+import org.onlab.onos.cluster.ClusterStoreDelegate;
+import org.onlab.onos.cluster.ControllerNode;
+import org.onlab.onos.cluster.DefaultControllerNode;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.store.AbstractStore;
+import org.onlab.packet.IpPrefix;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.net.SocketAddress;
+import java.nio.channels.ByteChannel;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.ServerSocketChannel;
+import java.nio.channels.SocketChannel;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.Timer;
+import java.util.TimerTask;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static java.net.InetAddress.getByAddress;
+import static org.onlab.onos.cluster.ControllerNode.State;
+import static org.onlab.packet.IpPrefix.valueOf;
+import static org.onlab.util.Tools.namedThreads;
+
+/**
+ * Distributed implementation of the cluster nodes store.
+ */
+@Component(immediate = true)
+@Service
+public class DistributedClusterStore
+        extends AbstractStore<ClusterEvent, ClusterStoreDelegate>
+        implements ClusterStore {
+
+    private static final int HELLO_MSG = 1;
+    private static final int ECHO_MSG = 2;
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private static final long CONNECTION_CUSTODIAN_DELAY = 1000L;
+    private static final long CONNECTION_CUSTODIAN_FREQUENCY = 5000;
+
+    private static final long START_TIMEOUT = 1000;
+    private static final long SELECT_TIMEOUT = 50;
+    private static final int WORKERS = 3;
+    private static final int COMM_BUFFER_SIZE = 32 * 1024;
+    private static final int COMM_IDLE_TIME = 500;
+
+    private static final boolean SO_NO_DELAY = false;
+    private static final int SO_SEND_BUFFER_SIZE = COMM_BUFFER_SIZE;
+    private static final int SO_RCV_BUFFER_SIZE = COMM_BUFFER_SIZE;
+
+    private DefaultControllerNode self;
+    private final Map<NodeId, DefaultControllerNode> nodes = new ConcurrentHashMap<>();
+    private final Map<NodeId, State> states = new ConcurrentHashMap<>();
+
+    // Means to track message streams to other nodes.
+    private final Map<NodeId, TLVMessageStream> streams = new ConcurrentHashMap<>();
+    private final Map<SocketChannel, DefaultControllerNode> nodesByChannel = new ConcurrentHashMap<>();
+
+    // Executor pools for listening and managing connections to other nodes.
+    private final ExecutorService listenExecutor =
+            Executors.newSingleThreadExecutor(namedThreads("onos-comm-listen"));
+    private final ExecutorService commExecutors =
+            Executors.newFixedThreadPool(WORKERS, namedThreads("onos-comm-cluster"));
+    private final ExecutorService heartbeatExecutor =
+            Executors.newSingleThreadExecutor(namedThreads("onos-comm-heartbeat"));
+
+    private final Timer timer = new Timer("onos-comm-initiator");
+    private final TimerTask connectionCustodian = new ConnectionCustodian();
+
+    private ListenLoop listenLoop;
+    private List<CommLoop> commLoops = new ArrayList<>(WORKERS);
+
+    @Activate
+    public void activate() {
+        loadClusterDefinition();
+        startCommunications();
+        startListening();
+        startInitiating();
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        listenLoop.shutdown();
+        for (CommLoop loop : commLoops) {
+            loop.shutdown();
+        }
+        log.info("Stopped");
+    }
+
+    // Loads the cluster definition file
+    private void loadClusterDefinition() {
+//        ClusterDefinitionStore cds = new ClusterDefinitionStore("../config/cluster.json");
+//        try {
+//            Set<DefaultControllerNode> storedNodes = cds.read();
+//            for (DefaultControllerNode node : storedNodes) {
+//                nodes.put(node.id(), node);
+//            }
+//        } catch (IOException e) {
+//            log.error("Unable to read cluster definitions", e);
+//        }
+
+        // Establishes the controller's own identity.
+        IpPrefix ip = valueOf(System.getProperty("onos.ip", "127.0.1.1"));
+        self = nodes.get(new NodeId(ip.toString()));
+
+        // As a fall-back, let's make sure we at least know who we are.
+        if (self == null) {
+            self = new DefaultControllerNode(new NodeId(ip.toString()), ip);
+            nodes.put(self.id(), self);
+            states.put(self.id(), State.ACTIVE);
+        }
+    }
+
+    // Kicks off the IO loops.
+    private void startCommunications() {
+        for (int i = 0; i < WORKERS; i++) {
+            try {
+                CommLoop loop = new CommLoop();
+                commLoops.add(loop);
+                commExecutors.execute(loop);
+            } catch (IOException e) {
+                log.warn("Unable to start comm IO loop", e);
+            }
+        }
+
+        // Wait for the IO loops to start
+        for (CommLoop loop : commLoops) {
+            if (!loop.awaitStart(START_TIMEOUT)) {
+                log.warn("Comm loop did not start on-time; moving on...");
+            }
+        }
+    }
+
+    // Starts listening for connections from peer cluster members.
+    private void startListening() {
+        try {
+            listenLoop = new ListenLoop(self.ip(), self.tcpPort());
+            listenExecutor.execute(listenLoop);
+            if (!listenLoop.awaitStart(START_TIMEOUT)) {
+                log.warn("Listen loop did not start on-time; moving on...");
+            }
+        } catch (IOException e) {
+            log.error("Unable to listen for cluster connections", e);
+        }
+    }
+
+    /**
+     * Initiates open connection request and registers the pending socket
+     * channel with the given IO loop.
+     *
+     * @param loop loop with which the channel should be registered
+     * @throws java.io.IOException if the socket could not be open or connected
+     */
+    private void openConnection(DefaultControllerNode node, CommLoop loop) throws IOException {
+        SocketAddress sa = new InetSocketAddress(getByAddress(node.ip().toOctets()), node.tcpPort());
+        SocketChannel ch = SocketChannel.open();
+        nodesByChannel.put(ch, node);
+        ch.configureBlocking(false);
+        ch.connect(sa);
+        loop.connectStream(ch);
+    }
+
+
+    // Attempts to connect to any nodes that do not have an associated connection.
+    private void startInitiating() {
+        timer.schedule(connectionCustodian, CONNECTION_CUSTODIAN_DELAY, CONNECTION_CUSTODIAN_FREQUENCY);
+    }
+
+    @Override
+    public ControllerNode getLocalNode() {
+        return self;
+    }
+
+    @Override
+    public Set<ControllerNode> getNodes() {
+        ImmutableSet.Builder<ControllerNode> builder = ImmutableSet.builder();
+        return builder.addAll(nodes.values()).build();
+    }
+
+    @Override
+    public ControllerNode getNode(NodeId nodeId) {
+        return nodes.get(nodeId);
+    }
+
+    @Override
+    public State getState(NodeId nodeId) {
+        State state = states.get(nodeId);
+        return state == null ? State.INACTIVE : state;
+    }
+
+    @Override
+    public ControllerNode addNode(NodeId nodeId, IpPrefix ip, int tcpPort) {
+        DefaultControllerNode node = new DefaultControllerNode(nodeId, ip, tcpPort);
+        nodes.put(nodeId, node);
+        return node;
+    }
+
+    @Override
+    public void removeNode(NodeId nodeId) {
+        nodes.remove(nodeId);
+        TLVMessageStream stream = streams.remove(nodeId);
+        if (stream != null) {
+            stream.close();
+        }
+    }
+
+    // Listens and accepts inbound connections from other cluster nodes.
+    private class ListenLoop extends AcceptorLoop {
+        ListenLoop(IpPrefix ip, int tcpPort) throws IOException {
+            super(SELECT_TIMEOUT, new InetSocketAddress(getByAddress(ip.toOctets()), tcpPort));
+        }
+
+        @Override
+        protected void acceptConnection(ServerSocketChannel channel) throws IOException {
+            SocketChannel sc = channel.accept();
+            sc.configureBlocking(false);
+
+            Socket so = sc.socket();
+            so.setTcpNoDelay(SO_NO_DELAY);
+            so.setReceiveBufferSize(SO_RCV_BUFFER_SIZE);
+            so.setSendBufferSize(SO_SEND_BUFFER_SIZE);
+
+            findLeastUtilizedLoop().acceptStream(sc);
+        }
+    }
+
+    private class CommLoop extends IOLoop<TLVMessage, TLVMessageStream> {
+        CommLoop() throws IOException {
+            super(SELECT_TIMEOUT);
+        }
+
+        @Override
+        protected TLVMessageStream createStream(ByteChannel byteChannel) {
+            return new TLVMessageStream(this, byteChannel, COMM_BUFFER_SIZE, COMM_IDLE_TIME);
+        }
+
+        @Override
+        protected void processMessages(List<TLVMessage> messages, MessageStream<TLVMessage> stream) {
+            TLVMessageStream tlvStream = (TLVMessageStream) stream;
+            for (TLVMessage message : messages) {
+                // TODO: add type-based dispatching here... this is just a hack to get going
+                if (message.type() == HELLO_MSG) {
+                    processHello(message, tlvStream);
+                } else if (message.type() == ECHO_MSG) {
+                    processEcho(message, tlvStream);
+                } else {
+                    log.info("Deal with other messages");
+                }
+            }
+        }
+
+        @Override
+        public TLVMessageStream acceptStream(SocketChannel channel) {
+            TLVMessageStream stream = super.acceptStream(channel);
+            try {
+                InetSocketAddress sa = (InetSocketAddress) channel.getRemoteAddress();
+                log.info("Accepted connection from node {}", valueOf(sa.getAddress().getAddress()));
+                stream.write(createHello(self));
+
+            } catch (IOException e) {
+                log.warn("Unable to accept connection from an unknown end-point", e);
+            }
+            return stream;
+        }
+
+        @Override
+        public TLVMessageStream connectStream(SocketChannel channel) {
+            TLVMessageStream stream = super.connectStream(channel);
+            DefaultControllerNode node = nodesByChannel.get(channel);
+            if (node != null) {
+                log.debug("Opened connection to node {}", node.id());
+                nodesByChannel.remove(channel);
+            }
+            return stream;
+        }
+
+        @Override
+        protected void connect(SelectionKey key) throws IOException {
+            try {
+                super.connect(key);
+                TLVMessageStream stream = (TLVMessageStream) key.attachment();
+                send(stream, createHello(self));
+            } catch (IOException e) {
+                if (!Objects.equals(e.getMessage(), "Connection refused")) {
+                    throw e;
+                }
+            }
+        }
+
+        @Override
+        protected void removeStream(MessageStream<TLVMessage> stream) {
+            DefaultControllerNode node = ((TLVMessageStream) stream).node();
+            if (node != null) {
+                log.info("Closed connection to node {}", node.id());
+                states.put(node.id(), State.INACTIVE);
+                streams.remove(node.id());
+            }
+            super.removeStream(stream);
+        }
+    }
+
+    // Processes a HELLO message from a peer controller node.
+    private void processHello(TLVMessage message, TLVMessageStream stream) {
+        // FIXME: pure hack for now
+        String data = new String(message.data());
+        String[] fields = data.split(":");
+        DefaultControllerNode node = new DefaultControllerNode(new NodeId(fields[0]),
+                                                               valueOf(fields[1]),
+                                                               Integer.parseInt(fields[2]));
+        stream.setNode(node);
+        nodes.put(node.id(), node);
+        streams.put(node.id(), stream);
+        states.put(node.id(), State.ACTIVE);
+    }
+
+    // Processes an ECHO message from a peer controller node.
+    private void processEcho(TLVMessage message, TLVMessageStream tlvStream) {
+        // TODO: implement heart-beat refresh
+        log.info("Dealing with echoes...");
+    }
+
+    // Sends message to the specified stream.
+    private void send(TLVMessageStream stream, TLVMessage message) {
+        try {
+            stream.write(message);
+        } catch (IOException e) {
+            log.warn("Unable to send message to {}", stream.node().id());
+        }
+    }
+
+    // Creates a hello message to be sent to a peer controller node.
+    private TLVMessage createHello(DefaultControllerNode self) {
+        return new TLVMessage(HELLO_MSG, (self.id() + ":" + self.ip() + ":" + self.tcpPort()).getBytes());
+    }
+
+    // Sweeps through all controller nodes and attempts to open connection to
+    // those that presently do not have one.
+    private class ConnectionCustodian extends TimerTask {
+        @Override
+        public void run() {
+            for (DefaultControllerNode node : nodes.values()) {
+                if (node != self && !streams.containsKey(node.id())) {
+                    try {
+                        openConnection(node, findLeastUtilizedLoop());
+                    } catch (IOException e) {
+                        log.debug("Unable to connect", e);
+                    }
+                }
+            }
+        }
+    }
+
+    // Finds the least utilities IO loop.
+    private CommLoop findLeastUtilizedLoop() {
+        CommLoop leastUtilized = null;
+        int minCount = Integer.MAX_VALUE;
+        for (CommLoop loop : commLoops) {
+            int count = loop.streamCount();
+            if (count == 0) {
+                return loop;
+            }
+
+            if (count < minCount) {
+                leastUtilized = loop;
+                minCount = count;
+            }
+        }
+        return leastUtilized;
+    }
+}

+package org.onlab.onos.store.cluster.impl;
+
+import org.onlab.nio.AbstractMessage;
+
+import java.util.Objects;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * Base message for cluster-wide communications using TLVs.
+ */
+public class TLVMessage extends AbstractMessage {
+
+    private final int type;
+    private final byte[] data;
+
+    /**
+     * Creates an immutable TLV message.
+     *
+     * @param type   message type
+     * @param data   message data bytes
+     */
+    public TLVMessage(int type, byte[] data) {
+        this.length = data.length + TLVMessageStream.METADATA_LENGTH;
+        this.type = type;
+        this.data = data;
+    }
+
+    /**
+     * Returns the message type indicator.
+     *
+     * @return message type
+     */
+    public int type() {
+        return type;
+    }
+
+    /**
+     * Returns the data bytes.
+     *
+     * @return message data
+     */
+    public byte[] data() {
+        return data;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(type, data);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        final TLVMessage other = (TLVMessage) obj;
+        return Objects.equals(this.type, other.type) &&
+                Objects.equals(this.data, other.data);
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this).add("type", type).add("length", length).toString();
+    }
+
+}

+package org.onlab.onos.store.cluster.impl;
+
+import org.onlab.nio.IOLoop;
+import org.onlab.nio.MessageStream;
+import org.onlab.onos.cluster.DefaultControllerNode;
+
+import java.nio.ByteBuffer;
+import java.nio.channels.ByteChannel;
+
+import static com.google.common.base.Preconditions.checkState;
+
+/**
+ * Stream for transferring TLV messages between cluster members.
+ */
+public class TLVMessageStream extends MessageStream<TLVMessage> {
+
+    public static final int METADATA_LENGTH = 16; // 8 + 4 + 4
+
+    private static final int LENGTH_OFFSET = 12;
+    private static final long MARKER = 0xfeedcafecafefeedL;
+
+    private DefaultControllerNode node;
+
+    /**
+     * Creates a message stream associated with the specified IO loop and
+     * backed by the given byte channel.
+     *
+     * @param loop          IO loop
+     * @param byteChannel   backing byte channel
+     * @param bufferSize    size of the backing byte buffers
+     * @param maxIdleMillis maximum number of millis the stream can be idle
+     */
+    protected TLVMessageStream(IOLoop<TLVMessage, ?> loop, ByteChannel byteChannel,
+                               int bufferSize, int maxIdleMillis) {
+        super(loop, byteChannel, bufferSize, maxIdleMillis);
+    }
+
+    /**
+     * Returns the node with which this stream is associated.
+     *
+     * @return controller node
+     */
+    DefaultControllerNode node() {
+        return node;
+    }
+
+    /**
+     * Sets the node with which this stream is affiliated.
+     *
+     * @param node controller node
+     */
+    void setNode(DefaultControllerNode node) {
+        checkState(this.node == null, "Stream is already bound to a node");
+        this.node = node;
+    }
+
+    @Override
+    protected TLVMessage read(ByteBuffer buffer) {
+        // Do we have enough bytes to read the header? If not, bail.
+        if (buffer.remaining() < METADATA_LENGTH) {
+            return null;
+        }
+
+        // Peek at the length and if we have enough to read the entire message
+        // go ahead, otherwise bail.
+        int length = buffer.getInt(buffer.position() + LENGTH_OFFSET);
+        if (buffer.remaining() < length) {
+            return null;
+        }
+
+        // At this point, we have enough data to read a complete message.
+        long marker = buffer.getLong();
+        checkState(marker == MARKER, "Incorrect message marker");
+
+        int type = buffer.getInt();
+        length = buffer.getInt();
+
+        // TODO: add deserialization hook here
+        byte[] data = new byte[length - METADATA_LENGTH];
+        buffer.get(data);
+
+        return new TLVMessage(type, data);
+    }
+
+    @Override
+    protected void write(TLVMessage message, ByteBuffer buffer) {
+        buffer.putLong(MARKER);
+        buffer.putInt(message.type());
+        buffer.putInt(message.length());
+
+        // TODO: add serialization hook here
+        buffer.put(message.data());
+    }
+
+}

+package org.onlab.onos.store.device.impl;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.atomic.AtomicInteger;
+
+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.Service;
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.store.ClockService;
+import org.onlab.onos.store.Timestamp;
+import org.onlab.onos.store.impl.OnosTimestamp;
+import org.slf4j.Logger;
+
+@Component(immediate = true)
+@Service
+public class OnosClockService implements ClockService {
+
+    private final Logger log = getLogger(getClass());
+
+    // TODO: Implement per device ticker that is reset to 0 at the beginning of a new term.
+    private final AtomicInteger ticker = new AtomicInteger(0);
+    private ConcurrentMap<DeviceId, MastershipTerm> deviceMastershipTerms = new ConcurrentHashMap<>();
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public Timestamp getTimestamp(DeviceId deviceId) {
+        MastershipTerm term = deviceMastershipTerms.get(deviceId);
+        if (term == null) {
+            throw new IllegalStateException("Requesting timestamp for a deviceId without mastership");
+        }
+        return new OnosTimestamp(term.termNumber(), ticker.incrementAndGet());
+    }
+
+    @Override
+    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term) {
+        deviceMastershipTerms.put(deviceId, term);
+    }
+}

+package org.onlab.onos.store.device.impl;
+
+import static com.google.common.base.Predicates.notNull;
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.common.collect.FluentIterable;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSet.Builder;
+
+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.onos.net.DefaultDevice;
+import org.onlab.onos.net.DefaultPort;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.device.DeviceDescription;
+import org.onlab.onos.net.device.DeviceEvent;
+import org.onlab.onos.net.device.DeviceStore;
+import org.onlab.onos.net.device.DeviceStoreDelegate;
+import org.onlab.onos.net.device.PortDescription;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.AbstractStore;
+import org.onlab.onos.store.ClockService;
+import org.onlab.onos.store.Timestamp;
+import org.slf4j.Logger;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static org.onlab.onos.net.device.DeviceEvent.Type.*;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Manages inventory of infrastructure devices using a protocol that takes into consideration
+ * the order in which device events occur.
+ */
+@Component(immediate = true)
+@Service
+public class OnosDistributedDeviceStore
+        extends AbstractStore<DeviceEvent, DeviceStoreDelegate>
+        implements DeviceStore {
+
+    private final Logger log = getLogger(getClass());
+
+    public static final String DEVICE_NOT_FOUND = "Device with ID %s not found";
+
+    private ConcurrentHashMap<DeviceId, VersionedValue<Device>> devices;
+    private ConcurrentHashMap<DeviceId, Map<PortNumber, VersionedValue<Port>>> devicePorts;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClockService clockService;
+
+    @Activate
+    public void activate() {
+
+        devices = new ConcurrentHashMap<>();
+        devicePorts = new ConcurrentHashMap<>();
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public int getDeviceCount() {
+        return devices.size();
+    }
+
+    @Override
+    public Iterable<Device> getDevices() {
+        Builder<Device> builder = ImmutableSet.builder();
+        synchronized (this) {
+            for (VersionedValue<Device> device : devices.values()) {
+                builder.add(device.entity());
+            }
+            return builder.build();
+        }
+    }
+
+    @Override
+    public Device getDevice(DeviceId deviceId) {
+        VersionedValue<Device> device = devices.get(deviceId);
+        checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+        return device.entity();
+    }
+
+    @Override
+    public DeviceEvent createOrUpdateDevice(ProviderId providerId, DeviceId deviceId,
+                                            DeviceDescription deviceDescription) {
+        Timestamp newTimestamp = clockService.getTimestamp(deviceId);
+        VersionedValue<Device> device = devices.get(deviceId);
+
+        if (device == null) {
+            return createDevice(providerId, deviceId, deviceDescription, newTimestamp);
+        }
+
+        checkState(newTimestamp.compareTo(device.timestamp()) > 0,
+                "Existing device has a timestamp in the future!");
+
+        return updateDevice(providerId, device.entity(), deviceDescription, newTimestamp);
+    }
+
+    // Creates the device and returns the appropriate event if necessary.
+    private DeviceEvent createDevice(ProviderId providerId, DeviceId deviceId,
+                                     DeviceDescription desc, Timestamp timestamp) {
+        Device device = new DefaultDevice(providerId, deviceId, desc.type(),
+                                                 desc.manufacturer(),
+                                                 desc.hwVersion(), desc.swVersion(),
+                                                 desc.serialNumber());
+
+        devices.put(deviceId, new VersionedValue<>(device, true, timestamp));
+        // TODO,FIXME: broadcast a message telling peers of a device event.
+        return new DeviceEvent(DEVICE_ADDED, device, null);
+    }
+
+    // Updates the device and returns the appropriate event if necessary.
+    private DeviceEvent updateDevice(ProviderId providerId, Device device,
+                                     DeviceDescription desc, Timestamp timestamp) {
+        // We allow only certain attributes to trigger update
+        if (!Objects.equals(device.hwVersion(), desc.hwVersion()) ||
+                !Objects.equals(device.swVersion(), desc.swVersion())) {
+
+            Device updated = new DefaultDevice(providerId, device.id(),
+                                                      desc.type(),
+                                                      desc.manufacturer(),
+                                                      desc.hwVersion(),
+                                                      desc.swVersion(),
+                                                      desc.serialNumber());
+            devices.put(device.id(), new VersionedValue<Device>(updated, true, timestamp));
+            // FIXME: broadcast a message telling peers of a device event.
+            return new DeviceEvent(DeviceEvent.Type.DEVICE_UPDATED, updated, null);
+        }
+
+        // Otherwise merely attempt to change availability
+        Device updated = new DefaultDevice(providerId, device.id(),
+                desc.type(),
+                desc.manufacturer(),
+                desc.hwVersion(),
+                desc.swVersion(),
+                desc.serialNumber());
+
+        VersionedValue<Device> oldDevice = devices.put(device.id(),
+                new VersionedValue<Device>(updated, true, timestamp));
+        if (!oldDevice.isUp()) {
+            return new DeviceEvent(DEVICE_AVAILABILITY_CHANGED, device, null);
+        } else {
+            return null;
+        }
+    }
+
+    @Override
+    public DeviceEvent markOffline(DeviceId deviceId) {
+        VersionedValue<Device> device = devices.get(deviceId);
+        boolean willRemove = device != null && device.isUp();
+        if (!willRemove) {
+            return null;
+        }
+        Timestamp timestamp = clockService.getTimestamp(deviceId);
+        if (replaceIfLatest(device.entity(), false, timestamp)) {
+            return new DeviceEvent(DEVICE_AVAILABILITY_CHANGED, device.entity(), null);
+        }
+        return null;
+    }
+
+    // Replace existing value if its timestamp is older.
+    private synchronized boolean replaceIfLatest(Device device, boolean isUp, Timestamp timestamp) {
+        VersionedValue<Device> existingValue = devices.get(device.id());
+        if (timestamp.compareTo(existingValue.timestamp()) > 0) {
+            devices.put(device.id(), new VersionedValue<Device>(device, isUp, timestamp));
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public List<DeviceEvent> updatePorts(DeviceId deviceId,
+                                         List<PortDescription> portDescriptions) {
+        List<DeviceEvent> events = new ArrayList<>();
+        synchronized (this) {
+            VersionedValue<Device> device = devices.get(deviceId);
+            checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+            Map<PortNumber, VersionedValue<Port>> ports = getPortMap(deviceId);
+            Timestamp newTimestamp = clockService.getTimestamp(deviceId);
+
+            // Add new ports
+            Set<PortNumber> processed = new HashSet<>();
+            for (PortDescription portDescription : portDescriptions) {
+                VersionedValue<Port> port = ports.get(portDescription.portNumber());
+                if (port == null) {
+                    events.add(createPort(device, portDescription, ports, newTimestamp));
+                }
+                checkState(newTimestamp.compareTo(port.timestamp()) > 0,
+                        "Existing port state has a timestamp in the future!");
+                events.add(updatePort(device.entity(), port.entity(), portDescription, ports, newTimestamp));
+                processed.add(portDescription.portNumber());
+            }
+
+            updatePortMap(deviceId, ports);
+
+            events.addAll(pruneOldPorts(device.entity(), ports, processed));
+        }
+        return FluentIterable.from(events).filter(notNull()).toList();
+    }
+
+    // Creates a new port based on the port description adds it to the map and
+    // Returns corresponding event.
+    //@GuardedBy("this")
+    private DeviceEvent createPort(VersionedValue<Device> device, PortDescription portDescription,
+                                   Map<PortNumber, VersionedValue<Port>> ports, Timestamp timestamp) {
+        Port port = new DefaultPort(device.entity(), portDescription.portNumber(),
+                                           portDescription.isEnabled());
+        ports.put(port.number(), new VersionedValue<Port>(port, true, timestamp));
+        updatePortMap(device.entity().id(), ports);
+        return new DeviceEvent(PORT_ADDED, device.entity(), port);
+    }
+
+    // Checks if the specified port requires update and if so, it replaces the
+    // existing entry in the map and returns corresponding event.
+    //@GuardedBy("this")
+    private DeviceEvent updatePort(Device device, Port port,
+                                   PortDescription portDescription,
+                                   Map<PortNumber, VersionedValue<Port>> ports,
+                                   Timestamp timestamp) {
+        if (port.isEnabled() != portDescription.isEnabled()) {
+            VersionedValue<Port> updatedPort = new VersionedValue<Port>(
+                    new DefaultPort(device, portDescription.portNumber(),
+                                    portDescription.isEnabled()),
+                    portDescription.isEnabled(),
+                    timestamp);
+            ports.put(port.number(), updatedPort);
+            updatePortMap(device.id(), ports);
+            return new DeviceEvent(PORT_UPDATED, device, updatedPort.entity());
+        }
+        return null;
+    }
+
+    // Prunes the specified list of ports based on which ports are in the
+    // processed list and returns list of corresponding events.
+    //@GuardedBy("this")
+    private List<DeviceEvent> pruneOldPorts(Device device,
+                                            Map<PortNumber, VersionedValue<Port>> ports,
+                                            Set<PortNumber> processed) {
+        List<DeviceEvent> events = new ArrayList<>();
+        Iterator<PortNumber> iterator = ports.keySet().iterator();
+        while (iterator.hasNext()) {
+            PortNumber portNumber = iterator.next();
+            if (!processed.contains(portNumber)) {
+                events.add(new DeviceEvent(PORT_REMOVED, device,
+                                           ports.get(portNumber).entity()));
+                iterator.remove();
+            }
+        }
+        if (!events.isEmpty()) {
+            updatePortMap(device.id(), ports);
+        }
+        return events;
+    }
+
+    // Gets the map of ports for the specified device; if one does not already
+    // exist, it creates and registers a new one.
+    // WARN: returned value is a copy, changes made to the Map
+    //       needs to be written back using updatePortMap
+    //@GuardedBy("this")
+    private Map<PortNumber, VersionedValue<Port>> getPortMap(DeviceId deviceId) {
+        Map<PortNumber, VersionedValue<Port>> ports = devicePorts.get(deviceId);
+        if (ports == null) {
+            ports = new HashMap<>();
+            // this probably is waste of time in most cases.
+            updatePortMap(deviceId, ports);
+        }
+        return ports;
+    }
+
+    //@GuardedBy("this")
+    private void updatePortMap(DeviceId deviceId, Map<PortNumber, VersionedValue<Port>> ports) {
+        devicePorts.put(deviceId, ports);
+    }
+
+    @Override
+    public DeviceEvent updatePortStatus(DeviceId deviceId,
+                                        PortDescription portDescription) {
+        VersionedValue<Device> device = devices.get(deviceId);
+        checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+        Map<PortNumber, VersionedValue<Port>> ports = getPortMap(deviceId);
+        VersionedValue<Port> port = ports.get(portDescription.portNumber());
+        Timestamp timestamp = clockService.getTimestamp(deviceId);
+        return updatePort(device.entity(), port.entity(), portDescription, ports, timestamp);
+    }
+
+    @Override
+    public List<Port> getPorts(DeviceId deviceId) {
+        Map<PortNumber, VersionedValue<Port>> versionedPorts = devicePorts.get(deviceId);
+        if (versionedPorts == null) {
+            return Collections.emptyList();
+        }
+        List<Port> ports = new ArrayList<>();
+        for (VersionedValue<Port> port : versionedPorts.values()) {
+            ports.add(port.entity());
+        }
+        return ports;
+    }
+
+    @Override
+    public Port getPort(DeviceId deviceId, PortNumber portNumber) {
+        Map<PortNumber, VersionedValue<Port>> ports = devicePorts.get(deviceId);
+        return ports == null ? null : ports.get(portNumber).entity();
+    }
+
+    @Override
+    public boolean isAvailable(DeviceId deviceId) {
+        return devices.get(deviceId).isUp();
+    }
+
+    @Override
+    public DeviceEvent removeDevice(DeviceId deviceId) {
+        VersionedValue<Device> previousDevice = devices.remove(deviceId);
+        return previousDevice == null ? null :
+            new DeviceEvent(DEVICE_REMOVED, previousDevice.entity(), null);
+    }
+}

+package org.onlab.onos.store.device.impl;
+
+import org.onlab.onos.store.Timestamp;
+
+/**
+ * Wrapper class for a entity that is versioned
+ * and can either be up or down.
+ *
+ * @param <T> type of the value.
+ */
+public class VersionedValue<T> {
+    private final T entity;
+    private final Timestamp timestamp;
+    private final boolean isUp;
+
+    public VersionedValue(T entity, boolean isUp, Timestamp timestamp) {
+        this.entity = entity;
+        this.isUp = isUp;
+        this.timestamp = timestamp;
+    }
+
+    /**
+     * Returns the value.
+     * @return value.
+     */
+    public T entity() {
+        return entity;
+    }
+
+    /**
+     * Tells whether the entity is up or down.
+     * @return true if up, false otherwise.
+     */
+    public boolean isUp() {
+        return isUp;
+    }
+
+    /**
+     * Returns the timestamp (version) associated with this entity.
+     * @return timestamp.
+     */
+    public Timestamp timestamp() {
+        return timestamp;
+    }
+}

+/**
+ * Implementation of device store using distributed structures.
+ */
+package org.onlab.onos.store.device.impl;

+package org.onlab.onos.store.flow.impl;
+
+import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_ADDED;
+import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_REMOVED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Collection;
+import java.util.Collections;
+
+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.Service;
+import org.onlab.onos.ApplicationId;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.flow.DefaultFlowRule;
+import org.onlab.onos.net.flow.FlowRule;
+import org.onlab.onos.net.flow.FlowRule.FlowRuleState;
+import org.onlab.onos.net.flow.FlowRuleEvent;
+import org.onlab.onos.net.flow.FlowRuleEvent.Type;
+import org.onlab.onos.net.flow.FlowRuleStore;
+import org.onlab.onos.net.flow.FlowRuleStoreDelegate;
+import org.onlab.onos.store.AbstractStore;
+import org.slf4j.Logger;
+
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Multimap;
+
+/**
+ * Manages inventory of flow rules using trivial in-memory implementation.
+ */
+//FIXME: I LIE I AM NOT DISTRIBUTED
+@Component(immediate = true)
+@Service
+public class DistributedFlowRuleStore
+extends AbstractStore<FlowRuleEvent, FlowRuleStoreDelegate>
+implements FlowRuleStore {
+
+    private final Logger log = getLogger(getClass());
+
+    // store entries as a pile of rules, no info about device tables
+    private final Multimap<DeviceId, FlowRule> flowEntries =
+            ArrayListMultimap.<DeviceId, FlowRule>create();
+
+    private final Multimap<ApplicationId, FlowRule> flowEntriesById =
+            ArrayListMultimap.<ApplicationId, FlowRule>create();
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+
+    @Override
+    public synchronized FlowRule getFlowRule(FlowRule rule) {
+        for (FlowRule f : flowEntries.get(rule.deviceId())) {
+            if (f.equals(rule)) {
+                return f;
+            }
+        }
+        return null;
+    }
+
+    @Override
+    public synchronized Iterable<FlowRule> getFlowEntries(DeviceId deviceId) {
+        Collection<FlowRule> rules = flowEntries.get(deviceId);
+        if (rules == null) {
+            return Collections.emptyList();
+        }
+        return ImmutableSet.copyOf(rules);
+    }
+
+    @Override
+    public synchronized Iterable<FlowRule> getFlowEntriesByAppId(ApplicationId appId) {
+        Collection<FlowRule> rules = flowEntriesById.get(appId);
+        if (rules == null) {
+            return Collections.emptyList();
+        }
+        return ImmutableSet.copyOf(rules);
+    }
+
+    @Override
+    public synchronized void storeFlowRule(FlowRule rule) {
+        FlowRule f = new DefaultFlowRule(rule, FlowRuleState.PENDING_ADD);
+        DeviceId did = f.deviceId();
+        if (!flowEntries.containsEntry(did, f)) {
+            flowEntries.put(did, f);
+            flowEntriesById.put(rule.appId(), f);
+        }
+    }
+
+    @Override
+    public synchronized void deleteFlowRule(FlowRule rule) {
+        FlowRule f = new DefaultFlowRule(rule, FlowRuleState.PENDING_REMOVE);
+        DeviceId did = f.deviceId();
+
+        /*
+         *  find the rule and mark it for deletion.
+         *  Ultimately a flow removed will come remove it.
+         */
+
+        if (flowEntries.containsEntry(did, f)) {
+            //synchronized (flowEntries) {
+            flowEntries.remove(did, f);
+            flowEntries.put(did, f);
+            flowEntriesById.remove(rule.appId(), rule);
+            //}
+        }
+    }
+
+    @Override
+    public synchronized FlowRuleEvent addOrUpdateFlowRule(FlowRule rule) {
+        DeviceId did = rule.deviceId();
+
+        // check if this new rule is an update to an existing entry
+        if (flowEntries.containsEntry(did, rule)) {
+            //synchronized (flowEntries) {
+            // Multimaps support duplicates so we have to remove our rule
+            // and replace it with the current version.
+            flowEntries.remove(did, rule);
+            flowEntries.put(did, rule);
+            //}
+            return new FlowRuleEvent(Type.RULE_UPDATED, rule);
+        }
+
+        flowEntries.put(did, rule);
+        return new FlowRuleEvent(RULE_ADDED, rule);
+    }
+
+    @Override
+    public synchronized FlowRuleEvent removeFlowRule(FlowRule rule) {
+        //synchronized (this) {
+        if (flowEntries.remove(rule.deviceId(), rule)) {
+            return new FlowRuleEvent(RULE_REMOVED, rule);
+        } else {
+            return null;
+        }
+        //}
+    }
+
+
+
+
+
+
+
+}

+package org.onlab.onos.store.host.impl;
+
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_ADDED;
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_MOVED;
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_REMOVED;
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_UPDATED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+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.Service;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultHost;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Host;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.host.HostDescription;
+import org.onlab.onos.net.host.HostEvent;
+import org.onlab.onos.net.host.HostStore;
+import org.onlab.onos.net.host.HostStoreDelegate;
+import org.onlab.onos.net.host.PortAddresses;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.AbstractStore;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.VlanId;
+import org.slf4j.Logger;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Sets;
+
+/**
+ * Manages inventory of end-station hosts using trivial in-memory
+ * implementation.
+ */
+//FIXME: I LIE I AM NOT DISTRIBUTED
+@Component(immediate = true)
+@Service
+public class DistributedHostStore
+extends AbstractStore<HostEvent, HostStoreDelegate>
+implements HostStore {
+
+    private final Logger log = getLogger(getClass());
+
+    // Host inventory
+    private final Map<HostId, Host> hosts = new ConcurrentHashMap<>();
+
+    // Hosts tracked by their location
+    private final Multimap<ConnectPoint, Host> locations = HashMultimap.create();
+
+    private final Map<ConnectPoint, PortAddresses> portAddresses =
+            new ConcurrentHashMap<>();
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public HostEvent createOrUpdateHost(ProviderId providerId, HostId hostId,
+            HostDescription hostDescription) {
+        Host host = hosts.get(hostId);
+        if (host == null) {
+            return createHost(providerId, hostId, hostDescription);
+        }
+        return updateHost(providerId, host, hostDescription);
+    }
+
+    // creates a new host and sends HOST_ADDED
+    private HostEvent createHost(ProviderId providerId, HostId hostId,
+            HostDescription descr) {
+        DefaultHost newhost = new DefaultHost(providerId, hostId,
+                descr.hwAddress(),
+                descr.vlan(),
+                descr.location(),
+                descr.ipAddresses());
+        synchronized (this) {
+            hosts.put(hostId, newhost);
+            locations.put(descr.location(), newhost);
+        }
+        return new HostEvent(HOST_ADDED, newhost);
+    }
+
+    // checks for type of update to host, sends appropriate event
+    private HostEvent updateHost(ProviderId providerId, Host host,
+            HostDescription descr) {
+        DefaultHost updated;
+        HostEvent event;
+        if (!host.location().equals(descr.location())) {
+            updated = new DefaultHost(providerId, host.id(),
+                    host.mac(),
+                    host.vlan(),
+                    descr.location(),
+                    host.ipAddresses());
+            event = new HostEvent(HOST_MOVED, updated);
+
+        } else if (!(host.ipAddresses().equals(descr.ipAddresses()))) {
+            updated = new DefaultHost(providerId, host.id(),
+                    host.mac(),
+                    host.vlan(),
+                    descr.location(),
+                    descr.ipAddresses());
+            event = new HostEvent(HOST_UPDATED, updated);
+        } else {
+            return null;
+        }
+        synchronized (this) {
+            hosts.put(host.id(), updated);
+            locations.remove(host.location(), host);
+            locations.put(updated.location(), updated);
+        }
+        return event;
+    }
+
+    @Override
+    public HostEvent removeHost(HostId hostId) {
+        synchronized (this) {
+            Host host = hosts.remove(hostId);
+            if (host != null) {
+                locations.remove((host.location()), host);
+                return new HostEvent(HOST_REMOVED, host);
+            }
+            return null;
+        }
+    }
+
+    @Override
+    public int getHostCount() {
+        return hosts.size();
+    }
+
+    @Override
+    public Iterable<Host> getHosts() {
+        return Collections.unmodifiableSet(new HashSet<>(hosts.values()));
+    }
+
+    @Override
+    public Host getHost(HostId hostId) {
+        return hosts.get(hostId);
+    }
+
+    @Override
+    public Set<Host> getHosts(VlanId vlanId) {
+        Set<Host> vlanset = new HashSet<>();
+        for (Host h : hosts.values()) {
+            if (h.vlan().equals(vlanId)) {
+                vlanset.add(h);
+            }
+        }
+        return vlanset;
+    }
+
+    @Override
+    public Set<Host> getHosts(MacAddress mac) {
+        Set<Host> macset = new HashSet<>();
+        for (Host h : hosts.values()) {
+            if (h.mac().equals(mac)) {
+                macset.add(h);
+            }
+        }
+        return macset;
+    }
+
+    @Override
+    public Set<Host> getHosts(IpPrefix ip) {
+        Set<Host> ipset = new HashSet<>();
+        for (Host h : hosts.values()) {
+            if (h.ipAddresses().contains(ip)) {
+                ipset.add(h);
+            }
+        }
+        return ipset;
+    }
+
+    @Override
+    public Set<Host> getConnectedHosts(ConnectPoint connectPoint) {
+        return ImmutableSet.copyOf(locations.get(connectPoint));
+    }
+
+    @Override
+    public Set<Host> getConnectedHosts(DeviceId deviceId) {
+        Set<Host> hostset = new HashSet<>();
+        for (ConnectPoint p : locations.keySet()) {
+            if (p.deviceId().equals(deviceId)) {
+                hostset.addAll(locations.get(p));
+            }
+        }
+        return hostset;
+    }
+
+    @Override
+    public void updateAddressBindings(PortAddresses addresses) {
+        synchronized (portAddresses) {
+            PortAddresses existing = portAddresses.get(addresses.connectPoint());
+            if (existing == null) {
+                portAddresses.put(addresses.connectPoint(), addresses);
+            } else {
+                Set<IpPrefix> union = Sets.union(existing.ips(), addresses.ips())
+                        .immutableCopy();
+
+                MacAddress newMac = (addresses.mac() == null) ? existing.mac()
+                        : addresses.mac();
+
+                PortAddresses newAddresses =
+                        new PortAddresses(addresses.connectPoint(), union, newMac);
+
+                portAddresses.put(newAddresses.connectPoint(), newAddresses);
+            }
+        }
+    }
+
+    @Override
+    public void removeAddressBindings(PortAddresses addresses) {
+        synchronized (portAddresses) {
+            PortAddresses existing = portAddresses.get(addresses.connectPoint());
+            if (existing != null) {
+                Set<IpPrefix> difference =
+                        Sets.difference(existing.ips(), addresses.ips()).immutableCopy();
+
+                // If they removed the existing mac, set the new mac to null.
+                // Otherwise, keep the existing mac.
+                MacAddress newMac = existing.mac();
+                if (addresses.mac() != null && addresses.mac().equals(existing.mac())) {
+                    newMac = null;
+                }
+
+                PortAddresses newAddresses =
+                        new PortAddresses(addresses.connectPoint(), difference, newMac);
+
+                portAddresses.put(newAddresses.connectPoint(), newAddresses);
+            }
+        }
+    }
+
+    @Override
+    public void clearAddressBindings(ConnectPoint connectPoint) {
+        synchronized (portAddresses) {
+            portAddresses.remove(connectPoint);
+        }
+    }
+
+    @Override
+    public Set<PortAddresses> getAddressBindings() {
+        synchronized (portAddresses) {
+            return new HashSet<>(portAddresses.values());
+        }
+    }
+
+    @Override
+    public PortAddresses getAddressBindingsForPort(ConnectPoint connectPoint) {
+        PortAddresses addresses;
+
+        synchronized (portAddresses) {
+            addresses = portAddresses.get(connectPoint);
+        }
+
+        if (addresses == null) {
+            addresses = new PortAddresses(connectPoint, null, null);
+        }
+
+        return addresses;
+    }
+
+}

 package org.onlab.onos.store.impl;
 package org.onlab.onos.store.impl;
 
 
-import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkArgument;
 
 
 import java.util.Objects;
 import java.util.Objects;
 
 
-import org.onlab.onos.net.ElementId;
 import org.onlab.onos.store.Timestamp;
 import org.onlab.onos.store.Timestamp;
 
 
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects;
@@ -14,22 +12,20 @@ import com.google.common.collect.ComparisonChain;
 // If it is store specific, implement serializable interfaces?
 // If it is store specific, implement serializable interfaces?
 /**
 /**
  * Default implementation of Timestamp.
  * Default implementation of Timestamp.
+ * TODO: Better documentation.
  */
  */
 public final class OnosTimestamp implements Timestamp {
 public final class OnosTimestamp implements Timestamp {
 
 
-    private final ElementId id;
     private final int termNumber;
     private final int termNumber;
     private final int sequenceNumber;
     private final int sequenceNumber;
 
 
     /**
     /**
      * Default version tuple.
      * Default version tuple.
      *
      *
-     * @param id identifier of the element
      * @param termNumber the mastership termNumber
      * @param termNumber the mastership termNumber
      * @param sequenceNumber  the sequenceNumber number within the termNumber
      * @param sequenceNumber  the sequenceNumber number within the termNumber
      */
      */
-    public OnosTimestamp(ElementId id, int termNumber, int sequenceNumber) {
-        this.id = checkNotNull(id);
+    public OnosTimestamp(int termNumber, int sequenceNumber) {
         this.termNumber = termNumber;
         this.termNumber = termNumber;
         this.sequenceNumber = sequenceNumber;
         this.sequenceNumber = sequenceNumber;
     }
     }
@@ -38,9 +34,6 @@ public final class OnosTimestamp implements Timestamp {
     public int compareTo(Timestamp o) {
     public int compareTo(Timestamp o) {
         checkArgument(o instanceof OnosTimestamp, "Must be OnosTimestamp", o);
         checkArgument(o instanceof OnosTimestamp, "Must be OnosTimestamp", o);
         OnosTimestamp that = (OnosTimestamp) o;
         OnosTimestamp that = (OnosTimestamp) o;
-        checkArgument(this.id.equals(that.id),
-                "Cannot compare version for different element this:%s, that:%s",
-                    this, that);
 
 
         return ComparisonChain.start()
         return ComparisonChain.start()
                 .compare(this.termNumber, that.termNumber)
                 .compare(this.termNumber, that.termNumber)
@@ -50,7 +43,7 @@ public final class OnosTimestamp implements Timestamp {
 
 
     @Override
     @Override
     public int hashCode() {
     public int hashCode() {
-        return Objects.hash(id, termNumber, sequenceNumber);
+        return Objects.hash(termNumber, sequenceNumber);
     }
     }
 
 
     @Override
     @Override
@@ -62,30 +55,19 @@ public final class OnosTimestamp implements Timestamp {
             return false;
             return false;
         }
         }
         OnosTimestamp that = (OnosTimestamp) obj;
         OnosTimestamp that = (OnosTimestamp) obj;
-        return Objects.equals(this.id, that.id) &&
-                Objects.equals(this.termNumber, that.termNumber) &&
+        return Objects.equals(this.termNumber, that.termNumber) &&
                 Objects.equals(this.sequenceNumber, that.sequenceNumber);
                 Objects.equals(this.sequenceNumber, that.sequenceNumber);
     }
     }
 
 
     @Override
     @Override
     public String toString() {
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
         return MoreObjects.toStringHelper(getClass())
-                    .add("id", id)
                     .add("termNumber", termNumber)
                     .add("termNumber", termNumber)
                     .add("sequenceNumber", sequenceNumber)
                     .add("sequenceNumber", sequenceNumber)
                     .toString();
                     .toString();
     }
     }
 
 
     /**
     /**
-     * Returns the element.
-     *
-     * @return element identifier
-     */
-    public ElementId id() {
-        return id;
-    }
-
-    /**
      * Returns the termNumber.
      * Returns the termNumber.
      *
      *
      * @return termNumber
      * @return termNumber

+package org.onlab.onos.store.link.impl;
+
+import static org.onlab.onos.net.Link.Type.DIRECT;
+import static org.onlab.onos.net.Link.Type.INDIRECT;
+import static org.onlab.onos.net.link.LinkEvent.Type.LINK_ADDED;
+import static org.onlab.onos.net.link.LinkEvent.Type.LINK_REMOVED;
+import static org.onlab.onos.net.link.LinkEvent.Type.LINK_UPDATED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+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.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultLink;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.LinkKey;
+import org.onlab.onos.net.link.LinkDescription;
+import org.onlab.onos.net.link.LinkEvent;
+import org.onlab.onos.net.link.LinkStore;
+import org.onlab.onos.net.link.LinkStoreDelegate;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.AbstractStore;
+import org.onlab.onos.store.ClockService;
+import org.onlab.onos.store.Timestamp;
+import org.onlab.onos.store.device.impl.VersionedValue;
+import org.slf4j.Logger;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.ImmutableSet.Builder;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkState;
+
+/**
+ * Manages inventory of infrastructure links using a protocol that takes into consideration
+ * the order in which events occur.
+ */
+// FIXME: This does not yet implement the full protocol.
+// The full protocol requires the sender of LLDP message to include the
+// version information of src device/port and the receiver to
+// take that into account when figuring out if a more recent src
+// device/port down event renders the link discovery obsolete.
+@Component(immediate = true)
+@Service
+public class OnosDistributedLinkStore
+    extends AbstractStore<LinkEvent, LinkStoreDelegate>
+    implements LinkStore {
+
+    private final Logger log = getLogger(getClass());
+
+    // Link inventory
+    private ConcurrentMap<LinkKey, VersionedValue<Link>> links;
+
+    public static final String LINK_NOT_FOUND = "Link between %s and %s not found";
+
+    // TODO synchronize?
+    // Egress and ingress link sets
+    private final Multimap<DeviceId, VersionedValue<Link>> srcLinks = HashMultimap.create();
+    private final Multimap<DeviceId, VersionedValue<Link>> dstLinks = HashMultimap.create();
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClockService clockService;
+
+    @Activate
+    public void activate() {
+
+        links = new ConcurrentHashMap<>();
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public int getLinkCount() {
+        return links.size();
+    }
+
+    @Override
+    public Iterable<Link> getLinks() {
+        Builder<Link> builder = ImmutableSet.builder();
+        synchronized (this) {
+            for (VersionedValue<Link> link : links.values()) {
+                builder.add(link.entity());
+            }
+            return builder.build();
+        }
+    }
+
+    @Override
+    public Set<Link> getDeviceEgressLinks(DeviceId deviceId) {
+        Set<VersionedValue<Link>> egressLinks = ImmutableSet.copyOf(srcLinks.get(deviceId));
+        Set<Link> rawEgressLinks = new HashSet<>();
+        for (VersionedValue<Link> link : egressLinks) {
+            rawEgressLinks.add(link.entity());
+        }
+        return rawEgressLinks;
+    }
+
+    @Override
+    public Set<Link> getDeviceIngressLinks(DeviceId deviceId) {
+        Set<VersionedValue<Link>> ingressLinks = ImmutableSet.copyOf(dstLinks.get(deviceId));
+        Set<Link> rawIngressLinks = new HashSet<>();
+        for (VersionedValue<Link> link : ingressLinks) {
+            rawIngressLinks.add(link.entity());
+        }
+        return rawIngressLinks;
+    }
+
+    @Override
+    public Link getLink(ConnectPoint src, ConnectPoint dst) {
+        VersionedValue<Link> link = links.get(new LinkKey(src, dst));
+        checkArgument(link != null, "LINK_NOT_FOUND", src, dst);
+        return link.entity();
+    }
+
+    @Override
+    public Set<Link> getEgressLinks(ConnectPoint src) {
+        Set<Link> egressLinks = new HashSet<>();
+        for (VersionedValue<Link> link : srcLinks.get(src.deviceId())) {
+            if (link.entity().src().equals(src)) {
+                egressLinks.add(link.entity());
+            }
+        }
+        return egressLinks;
+    }
+
+    @Override
+    public Set<Link> getIngressLinks(ConnectPoint dst) {
+        Set<Link> ingressLinks = new HashSet<>();
+        for (VersionedValue<Link> link : dstLinks.get(dst.deviceId())) {
+            if (link.entity().dst().equals(dst)) {
+                ingressLinks.add(link.entity());
+            }
+        }
+        return ingressLinks;
+    }
+
+    @Override
+    public LinkEvent createOrUpdateLink(ProviderId providerId,
+                                        LinkDescription linkDescription) {
+
+        final DeviceId destinationDeviceId = linkDescription.dst().deviceId();
+        final Timestamp newTimestamp = clockService.getTimestamp(destinationDeviceId);
+
+        LinkKey key = new LinkKey(linkDescription.src(), linkDescription.dst());
+        VersionedValue<Link> link = links.get(key);
+        if (link == null) {
+            return createLink(providerId, key, linkDescription, newTimestamp);
+        }
+
+        checkState(newTimestamp.compareTo(link.timestamp()) > 0,
+                "Existing Link has a timestamp in the future!");
+
+        return updateLink(providerId, link, key, linkDescription, newTimestamp);
+    }
+
+    // Creates and stores the link and returns the appropriate event.
+    private LinkEvent createLink(ProviderId providerId, LinkKey key,
+            LinkDescription linkDescription, Timestamp timestamp) {
+        VersionedValue<Link> link = new VersionedValue<Link>(new DefaultLink(providerId, key.src(), key.dst(),
+                linkDescription.type()), true, timestamp);
+        synchronized (this) {
+            links.put(key, link);
+            addNewLink(link, timestamp);
+        }
+        // FIXME: notify peers.
+        return new LinkEvent(LINK_ADDED, link.entity());
+    }
+
+    // update Egress and ingress link sets
+    private void addNewLink(VersionedValue<Link> link, Timestamp timestamp) {
+        Link rawLink = link.entity();
+        synchronized (this) {
+            srcLinks.put(rawLink.src().deviceId(), link);
+            dstLinks.put(rawLink.dst().deviceId(), link);
+        }
+    }
+
+    // Updates, if necessary the specified link and returns the appropriate event.
+    private LinkEvent updateLink(ProviderId providerId, VersionedValue<Link> existingLink,
+                                 LinkKey key, LinkDescription linkDescription, Timestamp timestamp) {
+        // FIXME confirm Link update condition is OK
+        if (existingLink.entity().type() == INDIRECT && linkDescription.type() == DIRECT) {
+            synchronized (this) {
+
+                VersionedValue<Link> updatedLink = new VersionedValue<Link>(
+                        new DefaultLink(providerId, existingLink.entity().src(), existingLink.entity().dst(),
+                                        linkDescription.type()), true, timestamp);
+                links.replace(key, existingLink, updatedLink);
+
+                replaceLink(existingLink, updatedLink);
+                // FIXME: notify peers.
+                return new LinkEvent(LINK_UPDATED, updatedLink.entity());
+            }
+        }
+        return null;
+    }
+
+    // update Egress and ingress link sets
+    private void replaceLink(VersionedValue<Link> current, VersionedValue<Link> updated) {
+        synchronized (this) {
+            srcLinks.remove(current.entity().src().deviceId(), current);
+            dstLinks.remove(current.entity().dst().deviceId(), current);
+
+            srcLinks.put(current.entity().src().deviceId(), updated);
+            dstLinks.put(current.entity().dst().deviceId(), updated);
+        }
+    }
+
+    @Override
+    public LinkEvent removeLink(ConnectPoint src, ConnectPoint dst) {
+        synchronized (this) {
+            LinkKey key = new LinkKey(src, dst);
+            VersionedValue<Link> link = links.remove(key);
+            if (link != null) {
+                removeLink(link);
+                // notify peers
+                return new LinkEvent(LINK_REMOVED, link.entity());
+            }
+            return null;
+        }
+    }
+
+    // update Egress and ingress link sets
+    private void removeLink(VersionedValue<Link> link) {
+        synchronized (this) {
+            srcLinks.remove(link.entity().src().deviceId(), link);
+            dstLinks.remove(link.entity().dst().deviceId(), link);
+        }
+    }
+}

 package org.onlab.onos.store.serializers;
 package org.onlab.onos.store.serializers;
 
 
-import org.onlab.onos.net.ElementId;
 import org.onlab.onos.store.impl.OnosTimestamp;
 import org.onlab.onos.store.impl.OnosTimestamp;
 
 
 import com.esotericsoftware.kryo.Kryo;
 import com.esotericsoftware.kryo.Kryo;
@@ -20,18 +19,17 @@ public class OnosTimestampSerializer extends Serializer<OnosTimestamp> {
         // non-null, immutable
         // non-null, immutable
         super(false, true);
         super(false, true);
     }
     }
+
     @Override
     @Override
     public void write(Kryo kryo, Output output, OnosTimestamp object) {
     public void write(Kryo kryo, Output output, OnosTimestamp object) {
-        kryo.writeClassAndObject(output, object.id());
         output.writeInt(object.termNumber());
         output.writeInt(object.termNumber());
         output.writeInt(object.sequenceNumber());
         output.writeInt(object.sequenceNumber());
     }
     }
 
 
     @Override
     @Override
     public OnosTimestamp read(Kryo kryo, Input input, Class<OnosTimestamp> type) {
     public OnosTimestamp read(Kryo kryo, Input input, Class<OnosTimestamp> type) {
-        ElementId id = (ElementId) kryo.readClassAndObject(input);
         final int term = input.readInt();
         final int term = input.readInt();
         final int sequence = input.readInt();
         final int sequence = input.readInt();
-        return new OnosTimestamp(id, term, sequence);
+        return new OnosTimestamp(term, sequence);
     }
     }
 }
 }

+package org.onlab.onos.store.topology.impl;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSetMultimap;
+import org.onlab.graph.DijkstraGraphSearch;
+import org.onlab.graph.GraphPathSearch;
+import org.onlab.graph.TarjanGraphSearch;
+import org.onlab.onos.net.AbstractModel;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultPath;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.net.topology.ClusterId;
+import org.onlab.onos.net.topology.DefaultTopologyCluster;
+import org.onlab.onos.net.topology.DefaultTopologyVertex;
+import org.onlab.onos.net.topology.GraphDescription;
+import org.onlab.onos.net.topology.LinkWeight;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyCluster;
+import org.onlab.onos.net.topology.TopologyEdge;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyVertex;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.collect.ImmutableSetMultimap.Builder;
+import static org.onlab.graph.GraphPathSearch.Result;
+import static org.onlab.graph.TarjanGraphSearch.SCCResult;
+import static org.onlab.onos.net.Link.Type.INDIRECT;
+
+/**
+ * Default implementation of the topology descriptor. This carries the
+ * backing topology data.
+ */
+public class DefaultTopology extends AbstractModel implements Topology {
+
+    private static final DijkstraGraphSearch<TopologyVertex, TopologyEdge> DIJKSTRA =
+            new DijkstraGraphSearch<>();
+    private static final TarjanGraphSearch<TopologyVertex, TopologyEdge> TARJAN =
+            new TarjanGraphSearch<>();
+
+    private static final ProviderId PID = new ProviderId("core", "org.onlab.onos.net");
+
+    private final long time;
+    private final TopologyGraph graph;
+
+    private final SCCResult<TopologyVertex, TopologyEdge> clusterResults;
+    private final ImmutableMap<DeviceId, Result<TopologyVertex, TopologyEdge>> results;
+    private final ImmutableSetMultimap<PathKey, Path> paths;
+
+    private final ImmutableMap<ClusterId, TopologyCluster> clusters;
+    private final ImmutableSet<ConnectPoint> infrastructurePoints;
+    private final ImmutableSetMultimap<ClusterId, ConnectPoint> broadcastSets;
+
+    private ImmutableMap<DeviceId, TopologyCluster> clustersByDevice;
+    private ImmutableSetMultimap<TopologyCluster, DeviceId> devicesByCluster;
+    private ImmutableSetMultimap<TopologyCluster, Link> linksByCluster;
+
+
+    /**
+     * Creates a topology descriptor attributed to the specified provider.
+     *
+     * @param providerId  identity of the provider
+     * @param description data describing the new topology
+     */
+    DefaultTopology(ProviderId providerId, GraphDescription description) {
+        super(providerId);
+        this.time = description.timestamp();
+
+        // Build the graph
+        this.graph = new DefaultTopologyGraph(description.vertexes(),
+                                              description.edges());
+
+        this.results = searchForShortestPaths();
+        this.paths = buildPaths();
+
+        this.clusterResults = searchForClusters();
+        this.clusters = buildTopologyClusters();
+
+        buildIndexes();
+
+        this.broadcastSets = buildBroadcastSets();
+        this.infrastructurePoints = findInfrastructurePoints();
+    }
+
+    @Override
+    public long time() {
+        return time;
+    }
+
+    @Override
+    public int clusterCount() {
+        return clusters.size();
+    }
+
+    @Override
+    public int deviceCount() {
+        return graph.getVertexes().size();
+    }
+
+    @Override
+    public int linkCount() {
+        return graph.getEdges().size();
+    }
+
+    @Override
+    public int pathCount() {
+        return paths.size();
+    }
+
+    /**
+     * Returns the backing topology graph.
+     *
+     * @return topology graph
+     */
+    TopologyGraph getGraph() {
+        return graph;
+    }
+
+    /**
+     * Returns the set of topology clusters.
+     *
+     * @return set of clusters
+     */
+    Set<TopologyCluster> getClusters() {
+        return ImmutableSet.copyOf(clusters.values());
+    }
+
+    /**
+     * Returns the specified topology cluster.
+     *
+     * @param clusterId cluster identifier
+     * @return topology cluster
+     */
+    TopologyCluster getCluster(ClusterId clusterId) {
+        return clusters.get(clusterId);
+    }
+
+    /**
+     * Returns the topology cluster that contains the given device.
+     *
+     * @param deviceId device identifier
+     * @return topology cluster
+     */
+    TopologyCluster getCluster(DeviceId deviceId) {
+        return clustersByDevice.get(deviceId);
+    }
+
+    /**
+     * Returns the set of cluster devices.
+     *
+     * @param cluster topology cluster
+     * @return cluster devices
+     */
+    Set<DeviceId> getClusterDevices(TopologyCluster cluster) {
+        return devicesByCluster.get(cluster);
+    }
+
+    /**
+     * Returns the set of cluster links.
+     *
+     * @param cluster topology cluster
+     * @return cluster links
+     */
+    Set<Link> getClusterLinks(TopologyCluster cluster) {
+        return linksByCluster.get(cluster);
+    }
+
+    /**
+     * Indicates whether the given point is an infrastructure link end-point.
+     *
+     * @param connectPoint connection point
+     * @return true if infrastructure
+     */
+    boolean isInfrastructure(ConnectPoint connectPoint) {
+        return infrastructurePoints.contains(connectPoint);
+    }
+
+    /**
+     * Indicates whether the given point is part of a broadcast set.
+     *
+     * @param connectPoint connection point
+     * @return true if in broadcast set
+     */
+    boolean isBroadcastPoint(ConnectPoint connectPoint) {
+        // Any non-infrastructure, i.e. edge points are assumed to be OK.
+        if (!isInfrastructure(connectPoint)) {
+            return true;
+        }
+
+        // Find the cluster to which the device belongs.
+        TopologyCluster cluster = clustersByDevice.get(connectPoint.deviceId());
+        if (cluster == null) {
+            throw new IllegalArgumentException("No cluster found for device " + connectPoint.deviceId());
+        }
+
+        // If the broadcast set is null or empty, or if the point explicitly
+        // belongs to it, return true;
+        Set<ConnectPoint> points = broadcastSets.get(cluster.id());
+        return points == null || points.isEmpty() || points.contains(connectPoint);
+    }
+
+    /**
+     * Returns the size of the cluster broadcast set.
+     *
+     * @param clusterId cluster identifier
+     * @return size of the cluster broadcast set
+     */
+    int broadcastSetSize(ClusterId clusterId) {
+        return broadcastSets.get(clusterId).size();
+    }
+
+    /**
+     * Returns the set of pre-computed shortest paths between source and
+     * destination devices.
+     *
+     * @param src source device
+     * @param dst destination device
+     * @return set of shortest paths
+     */
+    Set<Path> getPaths(DeviceId src, DeviceId dst) {
+        return paths.get(new PathKey(src, dst));
+    }
+
+    /**
+     * Computes on-demand the set of shortest paths between source and
+     * destination devices.
+     *
+     * @param src source device
+     * @param dst destination device
+     * @return set of shortest paths
+     */
+    Set<Path> getPaths(DeviceId src, DeviceId dst, LinkWeight weight) {
+        GraphPathSearch.Result<TopologyVertex, TopologyEdge> result =
+                DIJKSTRA.search(graph, new DefaultTopologyVertex(src),
+                                new DefaultTopologyVertex(dst), weight);
+        ImmutableSet.Builder<Path> builder = ImmutableSet.builder();
+        for (org.onlab.graph.Path<TopologyVertex, TopologyEdge> path : result.paths()) {
+            builder.add(networkPath(path));
+        }
+        return builder.build();
+    }
+
+
+    // Searches the graph for all shortest paths and returns the search results.
+    private ImmutableMap<DeviceId, Result<TopologyVertex, TopologyEdge>> searchForShortestPaths() {
+        ImmutableMap.Builder<DeviceId, Result<TopologyVertex, TopologyEdge>> builder = ImmutableMap.builder();
+
+        // Search graph paths for each source to all destinations.
+        LinkWeight weight = new HopCountLinkWeight(graph.getVertexes().size());
+        for (TopologyVertex src : graph.getVertexes()) {
+            builder.put(src.deviceId(), DIJKSTRA.search(graph, src, null, weight));
+        }
+        return builder.build();
+    }
+
+    // Builds network paths from the graph path search results
+    private ImmutableSetMultimap<PathKey, Path> buildPaths() {
+        Builder<PathKey, Path> builder = ImmutableSetMultimap.builder();
+        for (DeviceId deviceId : results.keySet()) {
+            Result<TopologyVertex, TopologyEdge> result = results.get(deviceId);
+            for (org.onlab.graph.Path<TopologyVertex, TopologyEdge> path : result.paths()) {
+                builder.put(new PathKey(path.src().deviceId(), path.dst().deviceId()),
+                            networkPath(path));
+            }
+        }
+        return builder.build();
+    }
+
+    // Converts graph path to a network path with the same cost.
+    private Path networkPath(org.onlab.graph.Path<TopologyVertex, TopologyEdge> path) {
+        List<Link> links = new ArrayList<>();
+        for (TopologyEdge edge : path.edges()) {
+            links.add(edge.link());
+        }
+        return new DefaultPath(PID, links, path.cost());
+    }
+
+
+    // Searches for SCC clusters in the network topology graph using Tarjan
+    // algorithm.
+    private SCCResult<TopologyVertex, TopologyEdge> searchForClusters() {
+        return TARJAN.search(graph, new NoIndirectLinksWeight());
+    }
+
+    // Builds the topology clusters and returns the id-cluster bindings.
+    private ImmutableMap<ClusterId, TopologyCluster> buildTopologyClusters() {
+        ImmutableMap.Builder<ClusterId, TopologyCluster> clusterBuilder = ImmutableMap.builder();
+        SCCResult<TopologyVertex, TopologyEdge> result =
+                TARJAN.search(graph, new NoIndirectLinksWeight());
+
+        // Extract both vertexes and edges from the results; the lists form
+        // pairs along the same index.
+        List<Set<TopologyVertex>> clusterVertexes = result.clusterVertexes();
+        List<Set<TopologyEdge>> clusterEdges = result.clusterEdges();
+
+        // Scan over the lists and create a cluster from the results.
+        for (int i = 0, n = result.clusterCount(); i < n; i++) {
+            Set<TopologyVertex> vertexSet = clusterVertexes.get(i);
+            Set<TopologyEdge> edgeSet = clusterEdges.get(i);
+
+            ClusterId cid = ClusterId.clusterId(i);
+            DefaultTopologyCluster cluster =
+                    new DefaultTopologyCluster(cid, vertexSet.size(), edgeSet.size(),
+                                               findRoot(vertexSet).deviceId());
+            clusterBuilder.put(cid, cluster);
+        }
+        return clusterBuilder.build();
+    }
+
+    // Finds the vertex whose device id is the lexicographical minimum in the
+    // specified set.
+    private TopologyVertex findRoot(Set<TopologyVertex> vertexSet) {
+        TopologyVertex minVertex = null;
+        for (TopologyVertex vertex : vertexSet) {
+            if (minVertex == null ||
+                    minVertex.deviceId().toString()
+                            .compareTo(minVertex.deviceId().toString()) < 0) {
+                minVertex = vertex;
+            }
+        }
+        return minVertex;
+    }
+
+    // Processes a map of broadcast sets for each cluster.
+    private ImmutableSetMultimap<ClusterId, ConnectPoint> buildBroadcastSets() {
+        Builder<ClusterId, ConnectPoint> builder = ImmutableSetMultimap.builder();
+        for (TopologyCluster cluster : clusters.values()) {
+            addClusterBroadcastSet(cluster, builder);
+        }
+        return builder.build();
+    }
+
+    // Finds all broadcast points for the cluster. These are those connection
+    // points which lie along the shortest paths between the cluster root and
+    // all other devices within the cluster.
+    private void addClusterBroadcastSet(TopologyCluster cluster,
+                                        Builder<ClusterId, ConnectPoint> builder) {
+        // Use the graph root search results to build the broadcast set.
+        Result<TopologyVertex, TopologyEdge> result = results.get(cluster.root());
+        for (Map.Entry<TopologyVertex, Set<TopologyEdge>> entry : result.parents().entrySet()) {
+            TopologyVertex vertex = entry.getKey();
+
+            // Ignore any parents that lead outside the cluster.
+            if (clustersByDevice.get(vertex.deviceId()) != cluster) {
+                continue;
+            }
+
+            // Ignore any back-link sets that are empty.
+            Set<TopologyEdge> parents = entry.getValue();
+            if (parents.isEmpty()) {
+                continue;
+            }
+
+            // Use the first back-link source and destinations to add to the
+            // broadcast set.
+            Link link = parents.iterator().next().link();
+            builder.put(cluster.id(), link.src());
+            builder.put(cluster.id(), link.dst());
+        }
+    }
+
+    // Collects and returns an set of all infrastructure link end-points.
+    private ImmutableSet<ConnectPoint> findInfrastructurePoints() {
+        ImmutableSet.Builder<ConnectPoint> builder = ImmutableSet.builder();
+        for (TopologyEdge edge : graph.getEdges()) {
+            builder.add(edge.link().src());
+            builder.add(edge.link().dst());
+        }
+        return builder.build();
+    }
+
+    // Builds cluster-devices, cluster-links and device-cluster indexes.
+    private void buildIndexes() {
+        // Prepare the index builders
+        ImmutableMap.Builder<DeviceId, TopologyCluster> clusterBuilder = ImmutableMap.builder();
+        ImmutableSetMultimap.Builder<TopologyCluster, DeviceId> devicesBuilder = ImmutableSetMultimap.builder();
+        ImmutableSetMultimap.Builder<TopologyCluster, Link> linksBuilder = ImmutableSetMultimap.builder();
+
+        // Now scan through all the clusters
+        for (TopologyCluster cluster : clusters.values()) {
+            int i = cluster.id().index();
+
+            // Scan through all the cluster vertexes.
+            for (TopologyVertex vertex : clusterResults.clusterVertexes().get(i)) {
+                devicesBuilder.put(cluster, vertex.deviceId());
+                clusterBuilder.put(vertex.deviceId(), cluster);
+            }
+
+            // Scan through all the cluster edges.
+            for (TopologyEdge edge : clusterResults.clusterEdges().get(i)) {
+                linksBuilder.put(cluster, edge.link());
+            }
+        }
+
+        // Finalize all indexes.
+        clustersByDevice = clusterBuilder.build();
+        devicesByCluster = devicesBuilder.build();
+        linksByCluster = linksBuilder.build();
+    }
+
+    // Link weight for measuring link cost as hop count with indirect links
+    // being as expensive as traversing the entire graph to assume the worst.
+    private static class HopCountLinkWeight implements LinkWeight {
+        private final int indirectLinkCost;
+
+        HopCountLinkWeight(int indirectLinkCost) {
+            this.indirectLinkCost = indirectLinkCost;
+        }
+
+        @Override
+        public double weight(TopologyEdge edge) {
+            // To force preference to use direct paths first, make indirect
+            // links as expensive as the linear vertex traversal.
+            return edge.link().type() == INDIRECT ? indirectLinkCost : 1;
+        }
+    }
+
+    // Link weight for preventing traversal over indirect links.
+    private static class NoIndirectLinksWeight implements LinkWeight {
+        @Override
+        public double weight(TopologyEdge edge) {
+            return edge.link().type() == INDIRECT ? -1 : 1;
+        }
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("time", time)
+                .add("clusters", clusterCount())
+                .add("devices", deviceCount())
+                .add("links", linkCount())
+                .add("pathCount", pathCount())
+                .toString();
+    }
+}

+package org.onlab.onos.store.topology.impl;
+
+import org.onlab.graph.AdjacencyListsGraph;
+import org.onlab.onos.net.topology.TopologyEdge;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyVertex;
+
+import java.util.Set;
+
+/**
+ * Default implementation of an immutable topology graph based on a generic
+ * implementation of adjacency lists graph.
+ */
+public class DefaultTopologyGraph
+        extends AdjacencyListsGraph<TopologyVertex, TopologyEdge>
+        implements TopologyGraph {
+
+    /**
+     * Creates a topology graph comprising of the specified vertexes and edges.
+     *
+     * @param vertexes set of graph vertexes
+     * @param edges    set of graph edges
+     */
+    public DefaultTopologyGraph(Set<TopologyVertex> vertexes, Set<TopologyEdge> edges) {
+        super(vertexes, edges);
+    }
+
+}

+package org.onlab.onos.store.topology.impl;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.List;
+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;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.event.Event;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.net.topology.ClusterId;
+import org.onlab.onos.net.topology.GraphDescription;
+import org.onlab.onos.net.topology.LinkWeight;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyCluster;
+import org.onlab.onos.net.topology.TopologyEvent;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyStore;
+import org.onlab.onos.net.topology.TopologyStoreDelegate;
+import org.onlab.onos.store.AbstractStore;
+import org.slf4j.Logger;
+
+/**
+ * Manages inventory of topology snapshots using trivial in-memory
+ * structures implementation.
+ */
+//FIXME: I LIE I AM NOT DISTRIBUTED
+@Component(immediate = true)
+@Service
+public class DistributedTopologyStore
+extends AbstractStore<TopologyEvent, TopologyStoreDelegate>
+implements TopologyStore {
+
+    private final Logger log = getLogger(getClass());
+
+    private volatile DefaultTopology current;
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+    @Override
+    public Topology currentTopology() {
+        return current;
+    }
+
+    @Override
+    public boolean isLatest(Topology topology) {
+        // Topology is current only if it is the same as our current topology
+        return topology == current;
+    }
+
+    @Override
+    public TopologyGraph getGraph(Topology topology) {
+        return defaultTopology(topology).getGraph();
+    }
+
+    @Override
+    public Set<TopologyCluster> getClusters(Topology topology) {
+        return defaultTopology(topology).getClusters();
+    }
+
+    @Override
+    public TopologyCluster getCluster(Topology topology, ClusterId clusterId) {
+        return defaultTopology(topology).getCluster(clusterId);
+    }
+
+    @Override
+    public Set<DeviceId> getClusterDevices(Topology topology, TopologyCluster cluster) {
+        return defaultTopology(topology).getClusterDevices(cluster);
+    }
+
+    @Override
+    public Set<Link> getClusterLinks(Topology topology, TopologyCluster cluster) {
+        return defaultTopology(topology).getClusterLinks(cluster);
+    }
+
+    @Override
+    public Set<Path> getPaths(Topology topology, DeviceId src, DeviceId dst) {
+        return defaultTopology(topology).getPaths(src, dst);
+    }
+
+    @Override
+    public Set<Path> getPaths(Topology topology, DeviceId src, DeviceId dst,
+            LinkWeight weight) {
+        return defaultTopology(topology).getPaths(src, dst, weight);
+    }
+
+    @Override
+    public boolean isInfrastructure(Topology topology, ConnectPoint connectPoint) {
+        return defaultTopology(topology).isInfrastructure(connectPoint);
+    }
+
+    @Override
+    public boolean isBroadcastPoint(Topology topology, ConnectPoint connectPoint) {
+        return defaultTopology(topology).isBroadcastPoint(connectPoint);
+    }
+
+    @Override
+    public TopologyEvent updateTopology(ProviderId providerId,
+            GraphDescription graphDescription,
+            List<Event> reasons) {
+        // First off, make sure that what we're given is indeed newer than
+        // what we already have.
+        if (current != null && graphDescription.timestamp() < current.time()) {
+            return null;
+        }
+
+        // Have the default topology construct self from the description data.
+        DefaultTopology newTopology =
+                new DefaultTopology(providerId, graphDescription);
+
+        // Promote the new topology to current and return a ready-to-send event.
+        synchronized (this) {
+            current = newTopology;
+            return new TopologyEvent(TopologyEvent.Type.TOPOLOGY_CHANGED, current);
+        }
+    }
+
+    // Validates the specified topology and returns it as a default
+    private DefaultTopology defaultTopology(Topology topology) {
+        if (topology instanceof DefaultTopology) {
+            return (DefaultTopology) topology;
+        }
+        throw new IllegalArgumentException("Topology class " + topology.getClass() +
+                " not supported");
+    }
+
+}

+package org.onlab.onos.store.topology.impl;
+
+import org.onlab.onos.net.DeviceId;
+
+import java.util.Objects;
+
+/**
+ * Key for filing pre-computed paths between source and destination devices.
+ */
+class PathKey {
+    private final DeviceId src;
+    private final DeviceId dst;
+
+    /**
+     * Creates a path key from the given source/dest pair.
+     * @param src source device
+     * @param dst destination device
+     */
+    PathKey(DeviceId src, DeviceId dst) {
+        this.src = src;
+        this.dst = dst;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(src, dst);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof PathKey) {
+            final PathKey other = (PathKey) obj;
+            return Objects.equals(this.src, other.src) && Objects.equals(this.dst, other.dst);
+        }
+        return false;
+    }
+}

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-core-hz</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-core-hz-cluster</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS Hazelcast based distributed store subsystems</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-core-serializers</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-core-hz-common</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-core-hz-common</artifactId>
+            <classifier>tests</classifier>
+            <scope>test</scope>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.felix</groupId>
+            <artifactId>org.apache.felix.scr.annotations</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>com.hazelcast</groupId>
+          <artifactId>hazelcast</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>de.javakaffee</groupId>
+          <artifactId>kryo-serializers</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-scr-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

@@ -8,6 +8,7 @@ import com.hazelcast.core.Member;
 import com.hazelcast.core.MemberAttributeEvent;
 import com.hazelcast.core.MemberAttributeEvent;
 import com.hazelcast.core.MembershipEvent;
 import com.hazelcast.core.MembershipEvent;
 import com.hazelcast.core.MembershipListener;
 import com.hazelcast.core.MembershipListener;
+
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
 import org.apache.felix.scr.annotations.Deactivate;
@@ -18,9 +19,9 @@ import org.onlab.onos.cluster.ClusterStoreDelegate;
 import org.onlab.onos.cluster.ControllerNode;
 import org.onlab.onos.cluster.ControllerNode;
 import org.onlab.onos.cluster.DefaultControllerNode;
 import org.onlab.onos.cluster.DefaultControllerNode;
 import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.cluster.NodeId;
-import org.onlab.onos.store.impl.AbsentInvalidatingLoadingCache;
-import org.onlab.onos.store.impl.AbstractDistributedStore;
-import org.onlab.onos.store.impl.OptionalCacheLoader;
+import org.onlab.onos.store.common.AbsentInvalidatingLoadingCache;
+import org.onlab.onos.store.common.AbstractHazelcastStore;
+import org.onlab.onos.store.common.OptionalCacheLoader;
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.IpPrefix;
 
 
 import java.util.Map;
 import java.util.Map;
@@ -38,7 +39,7 @@ import static org.onlab.onos.cluster.ControllerNode.State;
 @Component(immediate = true)
 @Component(immediate = true)
 @Service
 @Service
 public class DistributedClusterStore
 public class DistributedClusterStore
-        extends AbstractDistributedStore<ClusterEvent, ClusterStoreDelegate>
+        extends AbstractHazelcastStore<ClusterEvent, ClusterStoreDelegate>
         implements ClusterStore {
         implements ClusterStore {
 
 
     private IMap<byte[], byte[]> rawNodes;
     private IMap<byte[], byte[]> rawNodes;
@@ -57,7 +58,7 @@ public class DistributedClusterStore
         OptionalCacheLoader<NodeId, DefaultControllerNode> nodeLoader
         OptionalCacheLoader<NodeId, DefaultControllerNode> nodeLoader
                 = new OptionalCacheLoader<>(storeService, rawNodes);
                 = new OptionalCacheLoader<>(storeService, rawNodes);
         nodes = new AbsentInvalidatingLoadingCache<>(newBuilder().build(nodeLoader));
         nodes = new AbsentInvalidatingLoadingCache<>(newBuilder().build(nodeLoader));
-        rawNodes.addEntryListener(new RemoteEventHandler<>(nodes), true);
+        rawNodes.addEntryListener(new RemoteCacheEventHandler<>(nodes), true);
 
 
         loadClusterNodes();
         loadClusterNodes();
 
 
@@ -67,7 +68,7 @@ public class DistributedClusterStore
     // Loads the initial set of cluster nodes
     // Loads the initial set of cluster nodes
     private void loadClusterNodes() {
     private void loadClusterNodes() {
         for (Member member : theInstance.getCluster().getMembers()) {
         for (Member member : theInstance.getCluster().getMembers()) {
-            addMember(member);
+            addNode(node(member));
         }
         }
     }
     }
 
 
@@ -103,6 +104,11 @@ public class DistributedClusterStore
     }
     }
 
 
     @Override
     @Override
+    public ControllerNode addNode(NodeId nodeId, IpPrefix ip, int tcpPort) {
+        return addNode(new DefaultControllerNode(nodeId, ip, tcpPort));
+    }
+
+    @Override
     public void removeNode(NodeId nodeId) {
     public void removeNode(NodeId nodeId) {
         synchronized (this) {
         synchronized (this) {
             rawNodes.remove(serialize(nodeId));
             rawNodes.remove(serialize(nodeId));
@@ -111,8 +117,7 @@ public class DistributedClusterStore
     }
     }
 
 
     // Adds a new node based on the specified member
     // Adds a new node based on the specified member
-    private synchronized ControllerNode addMember(Member member) {
-        DefaultControllerNode node = node(member);
+    private synchronized ControllerNode addNode(DefaultControllerNode node) {
         rawNodes.put(serialize(node.id()), serialize(node));
         rawNodes.put(serialize(node.id()), serialize(node));
         nodes.put(node.id(), Optional.of(node));
         nodes.put(node.id(), Optional.of(node));
         states.put(node.id(), State.ACTIVE);
         states.put(node.id(), State.ACTIVE);
@@ -135,7 +140,7 @@ public class DistributedClusterStore
         @Override
         @Override
         public void memberAdded(MembershipEvent membershipEvent) {
         public void memberAdded(MembershipEvent membershipEvent) {
             log.info("Member {} added", membershipEvent.getMember());
             log.info("Member {} added", membershipEvent.getMember());
-            ControllerNode node = addMember(membershipEvent.getMember());
+            ControllerNode node = addNode(node(membershipEvent.getMember()));
             notifyDelegate(new ClusterEvent(INSTANCE_ACTIVATED, node));
             notifyDelegate(new ClusterEvent(INSTANCE_ACTIVATED, node));
         }
         }
 
 

 package org.onlab.onos.store.cluster.impl;
 package org.onlab.onos.store.cluster.impl;
 
 
-import com.google.common.base.Optional;
-import com.google.common.cache.LoadingCache;
-import com.google.common.collect.ImmutableSet;
-import com.hazelcast.core.IMap;
+import static com.google.common.cache.CacheBuilder.newBuilder;
+import static org.onlab.onos.cluster.MastershipEvent.Type.MASTER_CHANGED;
+
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
 
 
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Component;
@@ -19,15 +21,14 @@ import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.MastershipRole;
 import org.onlab.onos.net.MastershipRole;
-import org.onlab.onos.store.impl.AbsentInvalidatingLoadingCache;
-import org.onlab.onos.store.impl.AbstractDistributedStore;
-import org.onlab.onos.store.impl.OptionalCacheLoader;
+import org.onlab.onos.store.common.AbsentInvalidatingLoadingCache;
+import org.onlab.onos.store.common.AbstractHazelcastStore;
+import org.onlab.onos.store.common.OptionalCacheLoader;
 
 
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
-
-import static com.google.common.cache.CacheBuilder.newBuilder;
+import com.google.common.base.Optional;
+import com.google.common.cache.LoadingCache;
+import com.google.common.collect.ImmutableSet;
+import com.hazelcast.core.IMap;
 
 
 /**
 /**
  * Distributed implementation of the cluster nodes store.
  * Distributed implementation of the cluster nodes store.
@@ -35,8 +36,8 @@ import static com.google.common.cache.CacheBuilder.newBuilder;
 @Component(immediate = true)
 @Component(immediate = true)
 @Service
 @Service
 public class DistributedMastershipStore
 public class DistributedMastershipStore
-        extends AbstractDistributedStore<MastershipEvent, MastershipStoreDelegate>
-        implements MastershipStore {
+extends AbstractHazelcastStore<MastershipEvent, MastershipStoreDelegate>
+implements MastershipStore {
 
 
     private IMap<byte[], byte[]> rawMasters;
     private IMap<byte[], byte[]> rawMasters;
     private LoadingCache<DeviceId, Optional<NodeId>> masters;
     private LoadingCache<DeviceId, Optional<NodeId>> masters;
@@ -51,9 +52,9 @@ public class DistributedMastershipStore
 
 
         rawMasters = theInstance.getMap("masters");
         rawMasters = theInstance.getMap("masters");
         OptionalCacheLoader<DeviceId, NodeId> nodeLoader
         OptionalCacheLoader<DeviceId, NodeId> nodeLoader
-                = new OptionalCacheLoader<>(storeService, rawMasters);
+        = new OptionalCacheLoader<>(storeService, rawMasters);
         masters = new AbsentInvalidatingLoadingCache<>(newBuilder().build(nodeLoader));
         masters = new AbsentInvalidatingLoadingCache<>(newBuilder().build(nodeLoader));
-        rawMasters.addEntryListener(new RemoteEventHandler<>(masters), true);
+        rawMasters.addEntryListener(new RemoteMasterShipEventHandler(masters), true);
 
 
         loadMasters();
         loadMasters();
 
 
@@ -128,4 +129,25 @@ public class DistributedMastershipStore
         return null;
         return null;
     }
     }
 
 
+    private class RemoteMasterShipEventHandler extends RemoteCacheEventHandler<DeviceId, NodeId> {
+        public RemoteMasterShipEventHandler(LoadingCache<DeviceId, Optional<NodeId>> cache) {
+            super(cache);
+        }
+
+        @Override
+        protected void onAdd(DeviceId deviceId, NodeId nodeId) {
+            notifyDelegate(new MastershipEvent(MASTER_CHANGED, deviceId, nodeId));
+        }
+
+        @Override
+        protected void onRemove(DeviceId deviceId, NodeId nodeId) {
+            notifyDelegate(new MastershipEvent(MASTER_CHANGED, deviceId, nodeId));
+        }
+
+        @Override
+        protected void onUpdate(DeviceId deviceId, NodeId oldNodeId, NodeId nodeId) {
+            notifyDelegate(new MastershipEvent(MASTER_CHANGED, deviceId, nodeId));
+        }
+    }
+
 }
 }

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-core-hz</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-core-hz-common</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS Hazelcast based distributed store subsystems</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-core-serializers</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.felix</groupId>
+            <artifactId>org.apache.felix.scr.annotations</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>com.hazelcast</groupId>
+          <artifactId>hazelcast</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>de.javakaffee</groupId>
+          <artifactId>kryo-serializers</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-scr-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

-package org.onlab.onos.store.impl;
+package org.onlab.onos.store.common;
 
 
 import java.util.concurrent.Callable;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutionException;

-package org.onlab.onos.store.impl;
+package org.onlab.onos.store.common;
 
 
 import com.google.common.base.Optional;
 import com.google.common.base.Optional;
 import com.google.common.cache.LoadingCache;
 import com.google.common.cache.LoadingCache;
@@ -6,6 +6,8 @@ import com.hazelcast.core.EntryAdapter;
 import com.hazelcast.core.EntryEvent;
 import com.hazelcast.core.EntryEvent;
 import com.hazelcast.core.HazelcastInstance;
 import com.hazelcast.core.HazelcastInstance;
 import com.hazelcast.core.MapEvent;
 import com.hazelcast.core.MapEvent;
+import com.hazelcast.core.Member;
+
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Reference;
 import org.apache.felix.scr.annotations.Reference;
@@ -13,7 +15,6 @@ import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.onlab.onos.event.Event;
 import org.onlab.onos.event.Event;
 import org.onlab.onos.store.AbstractStore;
 import org.onlab.onos.store.AbstractStore;
 import org.onlab.onos.store.StoreDelegate;
 import org.onlab.onos.store.StoreDelegate;
-import org.onlab.onos.store.common.StoreService;
 import org.slf4j.Logger;
 import org.slf4j.Logger;
 
 
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -23,7 +24,7 @@ import static org.slf4j.LoggerFactory.getLogger;
  * Abstraction of a distributed store based on Hazelcast.
  * Abstraction of a distributed store based on Hazelcast.
  */
  */
 @Component(componentAbstract = true)
 @Component(componentAbstract = true)
-public abstract class AbstractDistributedStore<E extends Event, D extends StoreDelegate<E>>
+public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDelegate<E>>
         extends AbstractStore<E, D> {
         extends AbstractStore<E, D> {
 
 
     protected final Logger log = getLogger(getClass());
     protected final Logger log = getLogger(getClass());
@@ -66,8 +67,9 @@ public abstract class AbstractDistributedStore<E extends Event, D extends StoreD
      * @param <K> IMap key type after deserialization
      * @param <K> IMap key type after deserialization
      * @param <V> IMap value type after deserialization
      * @param <V> IMap value type after deserialization
      */
      */
-    public class RemoteEventHandler<K, V> extends EntryAdapter<byte[], byte[]> {
+    public class RemoteCacheEventHandler<K, V> extends EntryAdapter<byte[], byte[]> {
 
 
+        private final Member localMember;
         private LoadingCache<K, Optional<V>> cache;
         private LoadingCache<K, Optional<V>> cache;
 
 
         /**
         /**
@@ -75,17 +77,26 @@ public abstract class AbstractDistributedStore<E extends Event, D extends StoreD
          *
          *
          * @param cache cache to update
          * @param cache cache to update
          */
          */
-        public RemoteEventHandler(LoadingCache<K, Optional<V>> cache) {
+        public RemoteCacheEventHandler(LoadingCache<K, Optional<V>> cache) {
+            this.localMember = theInstance.getCluster().getLocalMember();
             this.cache = checkNotNull(cache);
             this.cache = checkNotNull(cache);
         }
         }
 
 
         @Override
         @Override
         public void mapCleared(MapEvent event) {
         public void mapCleared(MapEvent event) {
+            if (localMember.equals(event.getMember())) {
+                // ignore locally triggered event
+                return;
+            }
             cache.invalidateAll();
             cache.invalidateAll();
         }
         }
 
 
         @Override
         @Override
         public void entryAdded(EntryEvent<byte[], byte[]> event) {
         public void entryAdded(EntryEvent<byte[], byte[]> event) {
+            if (localMember.equals(event.getMember())) {
+                // ignore locally triggered event
+                return;
+            }
             K key = deserialize(event.getKey());
             K key = deserialize(event.getKey());
             V newVal = deserialize(event.getValue());
             V newVal = deserialize(event.getValue());
             Optional<V> newValue = Optional.of(newVal);
             Optional<V> newValue = Optional.of(newVal);
@@ -95,6 +106,10 @@ public abstract class AbstractDistributedStore<E extends Event, D extends StoreD
 
 
         @Override
         @Override
         public void entryUpdated(EntryEvent<byte[], byte[]> event) {
         public void entryUpdated(EntryEvent<byte[], byte[]> event) {
+            if (localMember.equals(event.getMember())) {
+                // ignore locally triggered event
+                return;
+            }
             K key = deserialize(event.getKey());
             K key = deserialize(event.getKey());
             V oldVal = deserialize(event.getOldValue());
             V oldVal = deserialize(event.getOldValue());
             Optional<V> oldValue = Optional.fromNullable(oldVal);
             Optional<V> oldValue = Optional.fromNullable(oldVal);
@@ -106,6 +121,10 @@ public abstract class AbstractDistributedStore<E extends Event, D extends StoreD
 
 
         @Override
         @Override
         public void entryRemoved(EntryEvent<byte[], byte[]> event) {
         public void entryRemoved(EntryEvent<byte[], byte[]> event) {
+            if (localMember.equals(event.getMember())) {
+                // ignore locally triggered event
+                return;
+            }
             K key = deserialize(event.getKey());
             K key = deserialize(event.getKey());
             V val = deserialize(event.getOldValue());
             V val = deserialize(event.getOldValue());
             cache.invalidate(key);
             cache.invalidate(key);
@@ -141,4 +160,80 @@ public abstract class AbstractDistributedStore<E extends Event, D extends StoreD
         }
         }
     }
     }
 
 
+    /**
+     * Distributed object remote event entry listener.
+     *
+     * @param <K> Entry key type after deserialization
+     * @param <V> Entry value type after deserialization
+     */
+    public class RemoteEventHandler<K, V> extends EntryAdapter<byte[], byte[]> {
+
+        private final Member localMember;
+
+        public RemoteEventHandler() {
+            this.localMember = theInstance.getCluster().getLocalMember();
+        }
+        @Override
+        public void entryAdded(EntryEvent<byte[], byte[]> event) {
+            if (localMember.equals(event.getMember())) {
+                // ignore locally triggered event
+                return;
+            }
+            K key = deserialize(event.getKey());
+            V newVal = deserialize(event.getValue());
+            onAdd(key, newVal);
+        }
+
+        @Override
+        public void entryRemoved(EntryEvent<byte[], byte[]> event) {
+            if (localMember.equals(event.getMember())) {
+                // ignore locally triggered event
+                return;
+            }
+            K key = deserialize(event.getKey());
+            V val = deserialize(event.getValue());
+            onRemove(key, val);
+        }
+
+        @Override
+        public void entryUpdated(EntryEvent<byte[], byte[]> event) {
+            if (localMember.equals(event.getMember())) {
+                // ignore locally triggered event
+                return;
+            }
+            K key = deserialize(event.getKey());
+            V oldVal = deserialize(event.getOldValue());
+            V newVal = deserialize(event.getValue());
+            onUpdate(key, oldVal, newVal);
+        }
+
+        /**
+         * Remote entry addition hook.
+         *
+         * @param key    new key
+         * @param newVal new value
+         */
+        protected void onAdd(K key, V newVal) {
+        }
+
+        /**
+         * Remote entry update hook.
+         *
+         * @param key    new key
+         * @param oldValue old value
+         * @param newVal new value
+         */
+        protected void onUpdate(K key, V oldValue, V newVal) {
+        }
+
+        /**
+         * Remote entry remove hook.
+         *
+         * @param key new key
+         * @param val old value
+         */
+        protected void onRemove(K key, V val) {
+        }
+    }
+
 }
 }

-package org.onlab.onos.store.impl;
+package org.onlab.onos.store.common;
 
 
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkNotNull;
 
 
-import org.onlab.onos.store.common.StoreService;
-
 import com.google.common.base.Optional;
 import com.google.common.base.Optional;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.CacheLoader;
 import com.hazelcast.core.IMap;
 import com.hazelcast.core.IMap;

-package org.onlab.onos.store.impl;
+package org.onlab.onos.store.common;
 
 
 import com.hazelcast.config.Config;
 import com.hazelcast.config.Config;
 import com.hazelcast.config.FileSystemXmlConfig;
 import com.hazelcast.config.FileSystemXmlConfig;
@@ -27,7 +27,6 @@ import org.onlab.onos.net.MastershipRole;
 import org.onlab.onos.net.Port;
 import org.onlab.onos.net.Port;
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.net.provider.ProviderId;
-import org.onlab.onos.store.common.StoreService;
 import org.onlab.onos.store.serializers.ConnectPointSerializer;
 import org.onlab.onos.store.serializers.ConnectPointSerializer;
 import org.onlab.onos.store.serializers.DefaultLinkSerializer;
 import org.onlab.onos.store.serializers.DefaultLinkSerializer;
 import org.onlab.onos.store.serializers.DefaultPortSerializer;
 import org.onlab.onos.store.serializers.DefaultPortSerializer;
@@ -35,7 +34,6 @@ import org.onlab.onos.store.serializers.DeviceIdSerializer;
 import org.onlab.onos.store.serializers.IpPrefixSerializer;
 import org.onlab.onos.store.serializers.IpPrefixSerializer;
 import org.onlab.onos.store.serializers.LinkKeySerializer;
 import org.onlab.onos.store.serializers.LinkKeySerializer;
 import org.onlab.onos.store.serializers.NodeIdSerializer;
 import org.onlab.onos.store.serializers.NodeIdSerializer;
-import org.onlab.onos.store.serializers.OnosTimestampSerializer;
 import org.onlab.onos.store.serializers.PortNumberSerializer;
 import org.onlab.onos.store.serializers.PortNumberSerializer;
 import org.onlab.onos.store.serializers.ProviderIdSerializer;
 import org.onlab.onos.store.serializers.ProviderIdSerializer;
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.IpPrefix;
@@ -102,7 +100,6 @@ public class StoreManager implements StoreService {
                 .register(DeviceId.class, new DeviceIdSerializer())
                 .register(DeviceId.class, new DeviceIdSerializer())
                 .register(PortNumber.class, new PortNumberSerializer())
                 .register(PortNumber.class, new PortNumberSerializer())
                 .register(DefaultPort.class, new DefaultPortSerializer())
                 .register(DefaultPort.class, new DefaultPortSerializer())
-                .register(OnosTimestamp.class, new OnosTimestampSerializer())
                 .register(LinkKey.class, new LinkKeySerializer())
                 .register(LinkKey.class, new LinkKeySerializer())
                 .register(ConnectPoint.class, new ConnectPointSerializer())
                 .register(ConnectPoint.class, new ConnectPointSerializer())
                 .register(DefaultLink.class, new DefaultLinkSerializer())
                 .register(DefaultLink.class, new DefaultLinkSerializer())

-package org.onlab.onos.store.impl;
+package org.onlab.onos.store.common;
 
 
 import java.io.FileNotFoundException;
 import java.io.FileNotFoundException;
 import java.util.UUID;
 import java.util.UUID;

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-core-hz</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-core-hz-net</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS Hazelcast based distributed store subsystems</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-core-serializers</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-core-hz-common</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-core-hz-common</artifactId>
+            <classifier>tests</classifier>
+            <scope>test</scope>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.felix</groupId>
+            <artifactId>org.apache.felix.scr.annotations</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>com.hazelcast</groupId>
+          <artifactId>hazelcast</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>de.javakaffee</groupId>
+          <artifactId>kryo-serializers</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-scr-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

 package org.onlab.onos.store.device.impl;
 package org.onlab.onos.store.device.impl;
 
 
 import static com.google.common.base.Predicates.notNull;
 import static com.google.common.base.Predicates.notNull;
+
 import com.google.common.base.Optional;
 import com.google.common.base.Optional;
 import com.google.common.cache.LoadingCache;
 import com.google.common.cache.LoadingCache;
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.FluentIterable;
@@ -26,9 +27,9 @@ import org.onlab.onos.net.device.DeviceStore;
 import org.onlab.onos.net.device.DeviceStoreDelegate;
 import org.onlab.onos.net.device.DeviceStoreDelegate;
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.net.provider.ProviderId;
-import org.onlab.onos.store.impl.AbsentInvalidatingLoadingCache;
-import org.onlab.onos.store.impl.AbstractDistributedStore;
-import org.onlab.onos.store.impl.OptionalCacheLoader;
+import org.onlab.onos.store.common.AbsentInvalidatingLoadingCache;
+import org.onlab.onos.store.common.AbstractHazelcastStore;
+import org.onlab.onos.store.common.OptionalCacheLoader;
 import org.slf4j.Logger;
 import org.slf4j.Logger;
 
 
 import java.util.ArrayList;
 import java.util.ArrayList;
@@ -52,7 +53,7 @@ import static org.slf4j.LoggerFactory.getLogger;
 @Component(immediate = true)
 @Component(immediate = true)
 @Service
 @Service
 public class DistributedDeviceStore
 public class DistributedDeviceStore
-        extends AbstractDistributedStore<DeviceEvent, DeviceStoreDelegate>
+        extends AbstractHazelcastStore<DeviceEvent, DeviceStoreDelegate>
         implements DeviceStore {
         implements DeviceStore {
 
 
     private final Logger log = getLogger(getClass());
     private final Logger log = getLogger(getClass());
@@ -71,6 +72,10 @@ public class DistributedDeviceStore
     private IMap<byte[], byte[]> rawDevicePorts;
     private IMap<byte[], byte[]> rawDevicePorts;
     private LoadingCache<DeviceId, Optional<Map<PortNumber, Port>>> devicePorts;
     private LoadingCache<DeviceId, Optional<Map<PortNumber, Port>>> devicePorts;
 
 
+    private String devicesListener;
+
+    private String portsListener;
+
     @Override
     @Override
     @Activate
     @Activate
     public void activate() {
     public void activate() {
@@ -85,7 +90,7 @@ public class DistributedDeviceStore
                 = new OptionalCacheLoader<>(storeService, rawDevices);
                 = new OptionalCacheLoader<>(storeService, rawDevices);
         devices = new AbsentInvalidatingLoadingCache<>(newBuilder().build(deviceLoader));
         devices = new AbsentInvalidatingLoadingCache<>(newBuilder().build(deviceLoader));
         // refresh/populate cache based on notification from other instance
         // refresh/populate cache based on notification from other instance
-        rawDevices.addEntryListener(new RemoteDeviceEventHandler(devices), includeValue);
+        devicesListener = rawDevices.addEntryListener(new RemoteDeviceEventHandler(devices), includeValue);
 
 
         // TODO cache availableDevices
         // TODO cache availableDevices
         availableDevices = theInstance.getSet("availableDevices");
         availableDevices = theInstance.getSet("availableDevices");
@@ -95,7 +100,7 @@ public class DistributedDeviceStore
                 = new OptionalCacheLoader<>(storeService, rawDevicePorts);
                 = new OptionalCacheLoader<>(storeService, rawDevicePorts);
         devicePorts = new AbsentInvalidatingLoadingCache<>(newBuilder().build(devicePortLoader));
         devicePorts = new AbsentInvalidatingLoadingCache<>(newBuilder().build(devicePortLoader));
         // refresh/populate cache based on notification from other instance
         // refresh/populate cache based on notification from other instance
-        rawDevicePorts.addEntryListener(new RemotePortEventHandler(devicePorts), includeValue);
+        portsListener = rawDevicePorts.addEntryListener(new RemotePortEventHandler(devicePorts), includeValue);
 
 
         loadDeviceCache();
         loadDeviceCache();
         loadDevicePortsCache();
         loadDevicePortsCache();
@@ -105,6 +110,8 @@ public class DistributedDeviceStore
 
 
     @Deactivate
     @Deactivate
     public void deactivate() {
     public void deactivate() {
+        rawDevicePorts.removeEntryListener(portsListener);
+        rawDevices.removeEntryListener(devicesListener);
         log.info("Stopped");
         log.info("Stopped");
     }
     }
 
 
@@ -353,7 +360,7 @@ public class DistributedDeviceStore
         }
         }
     }
     }
 
 
-    private class RemoteDeviceEventHandler extends RemoteEventHandler<DeviceId, DefaultDevice> {
+    private class RemoteDeviceEventHandler extends RemoteCacheEventHandler<DeviceId, DefaultDevice> {
         public RemoteDeviceEventHandler(LoadingCache<DeviceId, Optional<DefaultDevice>> cache) {
         public RemoteDeviceEventHandler(LoadingCache<DeviceId, Optional<DefaultDevice>> cache) {
             super(cache);
             super(cache);
         }
         }
@@ -374,7 +381,7 @@ public class DistributedDeviceStore
         }
         }
     }
     }
 
 
-    private class RemotePortEventHandler extends RemoteEventHandler<DeviceId, Map<PortNumber, Port>> {
+    private class RemotePortEventHandler extends RemoteCacheEventHandler<DeviceId, Map<PortNumber, Port>> {
         public RemotePortEventHandler(LoadingCache<DeviceId, Optional<Map<PortNumber, Port>>> cache) {
         public RemotePortEventHandler(LoadingCache<DeviceId, Optional<Map<PortNumber, Port>>> cache) {
             super(cache);
             super(cache);
         }
         }

+package org.onlab.onos.store.device.impl;
+
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.store.ClockService;
+import org.onlab.onos.store.Timestamp;
+
+// FIXME: Code clone in onos-core-trivial, onos-core-hz-net
+/**
+ * Dummy implementation of {@link ClockService}.
+ */
+@Component(immediate = true)
+@Service
+public class NoOpClockService implements ClockService {
+
+    @Override
+    public Timestamp getTimestamp(DeviceId deviceId) {
+        return new Timestamp() {
+
+            @Override
+            public int compareTo(Timestamp o) {
+                throw new IllegalStateException("Never expected to be used.");
+            }
+        };
+    }
+
+    @Override
+    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term) {
+    }
+}

+package org.onlab.onos.store.flow.impl;
+
+import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_ADDED;
+import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_REMOVED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Collection;
+import java.util.Collections;
+
+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.Service;
+import org.onlab.onos.ApplicationId;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.flow.DefaultFlowRule;
+import org.onlab.onos.net.flow.FlowRule;
+import org.onlab.onos.net.flow.FlowRule.FlowRuleState;
+import org.onlab.onos.net.flow.FlowRuleEvent;
+import org.onlab.onos.net.flow.FlowRuleEvent.Type;
+import org.onlab.onos.net.flow.FlowRuleStore;
+import org.onlab.onos.net.flow.FlowRuleStoreDelegate;
+import org.onlab.onos.store.AbstractStore;
+import org.slf4j.Logger;
+
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Multimap;
+
+/**
+ * Manages inventory of flow rules using trivial in-memory implementation.
+ */
+//FIXME: I LIE I AM NOT DISTRIBUTED
+@Component(immediate = true)
+@Service
+public class DistributedFlowRuleStore
+extends AbstractStore<FlowRuleEvent, FlowRuleStoreDelegate>
+implements FlowRuleStore {
+
+    private final Logger log = getLogger(getClass());
+
+    // store entries as a pile of rules, no info about device tables
+    private final Multimap<DeviceId, FlowRule> flowEntries =
+            ArrayListMultimap.<DeviceId, FlowRule>create();
+
+    private final Multimap<ApplicationId, FlowRule> flowEntriesById =
+            ArrayListMultimap.<ApplicationId, FlowRule>create();
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+
+    @Override
+    public synchronized FlowRule getFlowRule(FlowRule rule) {
+        for (FlowRule f : flowEntries.get(rule.deviceId())) {
+            if (f.equals(rule)) {
+                return f;
+            }
+        }
+        return null;
+    }
+
+    @Override
+    public synchronized Iterable<FlowRule> getFlowEntries(DeviceId deviceId) {
+        Collection<FlowRule> rules = flowEntries.get(deviceId);
+        if (rules == null) {
+            return Collections.emptyList();
+        }
+        return ImmutableSet.copyOf(rules);
+    }
+
+    @Override
+    public synchronized Iterable<FlowRule> getFlowEntriesByAppId(ApplicationId appId) {
+        Collection<FlowRule> rules = flowEntriesById.get(appId);
+        if (rules == null) {
+            return Collections.emptyList();
+        }
+        return ImmutableSet.copyOf(rules);
+    }
+
+    @Override
+    public synchronized void storeFlowRule(FlowRule rule) {
+        FlowRule f = new DefaultFlowRule(rule, FlowRuleState.PENDING_ADD);
+        DeviceId did = f.deviceId();
+        if (!flowEntries.containsEntry(did, f)) {
+            flowEntries.put(did, f);
+            flowEntriesById.put(rule.appId(), f);
+        }
+    }
+
+    @Override
+    public synchronized void deleteFlowRule(FlowRule rule) {
+        FlowRule f = new DefaultFlowRule(rule, FlowRuleState.PENDING_REMOVE);
+        DeviceId did = f.deviceId();
+
+        /*
+         *  find the rule and mark it for deletion.
+         *  Ultimately a flow removed will come remove it.
+         */
+
+        if (flowEntries.containsEntry(did, f)) {
+            //synchronized (flowEntries) {
+            flowEntries.remove(did, f);
+            flowEntries.put(did, f);
+            flowEntriesById.remove(rule.appId(), rule);
+            //}
+        }
+    }
+
+    @Override
+    public synchronized FlowRuleEvent addOrUpdateFlowRule(FlowRule rule) {
+        DeviceId did = rule.deviceId();
+
+        // check if this new rule is an update to an existing entry
+        if (flowEntries.containsEntry(did, rule)) {
+            //synchronized (flowEntries) {
+            // Multimaps support duplicates so we have to remove our rule
+            // and replace it with the current version.
+            flowEntries.remove(did, rule);
+            flowEntries.put(did, rule);
+            //}
+            return new FlowRuleEvent(Type.RULE_UPDATED, rule);
+        }
+
+        flowEntries.put(did, rule);
+        return new FlowRuleEvent(RULE_ADDED, rule);
+    }
+
+    @Override
+    public synchronized FlowRuleEvent removeFlowRule(FlowRule rule) {
+        //synchronized (this) {
+        if (flowEntries.remove(rule.deviceId(), rule)) {
+            return new FlowRuleEvent(RULE_REMOVED, rule);
+        } else {
+            return null;
+        }
+        //}
+    }
+
+
+
+
+
+
+
+}

+package org.onlab.onos.store.host.impl;
+
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_ADDED;
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_MOVED;
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_REMOVED;
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_UPDATED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+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.Service;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultHost;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Host;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.host.HostDescription;
+import org.onlab.onos.net.host.HostEvent;
+import org.onlab.onos.net.host.HostStore;
+import org.onlab.onos.net.host.HostStoreDelegate;
+import org.onlab.onos.net.host.PortAddresses;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.AbstractStore;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.VlanId;
+import org.slf4j.Logger;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Sets;
+
+/**
+ * Manages inventory of end-station hosts using trivial in-memory
+ * implementation.
+ */
+//FIXME: I LIE I AM NOT DISTRIBUTED
+@Component(immediate = true)
+@Service
+public class DistributedHostStore
+extends AbstractStore<HostEvent, HostStoreDelegate>
+implements HostStore {
+
+    private final Logger log = getLogger(getClass());
+
+    // Host inventory
+    private final Map<HostId, Host> hosts = new ConcurrentHashMap<>();
+
+    // Hosts tracked by their location
+    private final Multimap<ConnectPoint, Host> locations = HashMultimap.create();
+
+    private final Map<ConnectPoint, PortAddresses> portAddresses =
+            new ConcurrentHashMap<>();
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public HostEvent createOrUpdateHost(ProviderId providerId, HostId hostId,
+            HostDescription hostDescription) {
+        Host host = hosts.get(hostId);
+        if (host == null) {
+            return createHost(providerId, hostId, hostDescription);
+        }
+        return updateHost(providerId, host, hostDescription);
+    }
+
+    // creates a new host and sends HOST_ADDED
+    private HostEvent createHost(ProviderId providerId, HostId hostId,
+            HostDescription descr) {
+        DefaultHost newhost = new DefaultHost(providerId, hostId,
+                descr.hwAddress(),
+                descr.vlan(),
+                descr.location(),
+                descr.ipAddresses());
+        synchronized (this) {
+            hosts.put(hostId, newhost);
+            locations.put(descr.location(), newhost);
+        }
+        return new HostEvent(HOST_ADDED, newhost);
+    }
+
+    // checks for type of update to host, sends appropriate event
+    private HostEvent updateHost(ProviderId providerId, Host host,
+            HostDescription descr) {
+        DefaultHost updated;
+        HostEvent event;
+        if (!host.location().equals(descr.location())) {
+            updated = new DefaultHost(providerId, host.id(),
+                    host.mac(),
+                    host.vlan(),
+                    descr.location(),
+                    host.ipAddresses());
+            event = new HostEvent(HOST_MOVED, updated);
+
+        } else if (!(host.ipAddresses().equals(descr.ipAddresses()))) {
+            updated = new DefaultHost(providerId, host.id(),
+                    host.mac(),
+                    host.vlan(),
+                    descr.location(),
+                    descr.ipAddresses());
+            event = new HostEvent(HOST_UPDATED, updated);
+        } else {
+            return null;
+        }
+        synchronized (this) {
+            hosts.put(host.id(), updated);
+            locations.remove(host.location(), host);
+            locations.put(updated.location(), updated);
+        }
+        return event;
+    }
+
+    @Override
+    public HostEvent removeHost(HostId hostId) {
+        synchronized (this) {
+            Host host = hosts.remove(hostId);
+            if (host != null) {
+                locations.remove((host.location()), host);
+                return new HostEvent(HOST_REMOVED, host);
+            }
+            return null;
+        }
+    }
+
+    @Override
+    public int getHostCount() {
+        return hosts.size();
+    }
+
+    @Override
+    public Iterable<Host> getHosts() {
+        return Collections.unmodifiableSet(new HashSet<>(hosts.values()));
+    }
+
+    @Override
+    public Host getHost(HostId hostId) {
+        return hosts.get(hostId);
+    }
+
+    @Override
+    public Set<Host> getHosts(VlanId vlanId) {
+        Set<Host> vlanset = new HashSet<>();
+        for (Host h : hosts.values()) {
+            if (h.vlan().equals(vlanId)) {
+                vlanset.add(h);
+            }
+        }
+        return vlanset;
+    }
+
+    @Override
+    public Set<Host> getHosts(MacAddress mac) {
+        Set<Host> macset = new HashSet<>();
+        for (Host h : hosts.values()) {
+            if (h.mac().equals(mac)) {
+                macset.add(h);
+            }
+        }
+        return macset;
+    }
+
+    @Override
+    public Set<Host> getHosts(IpPrefix ip) {
+        Set<Host> ipset = new HashSet<>();
+        for (Host h : hosts.values()) {
+            if (h.ipAddresses().contains(ip)) {
+                ipset.add(h);
+            }
+        }
+        return ipset;
+    }
+
+    @Override
+    public Set<Host> getConnectedHosts(ConnectPoint connectPoint) {
+        return ImmutableSet.copyOf(locations.get(connectPoint));
+    }
+
+    @Override
+    public Set<Host> getConnectedHosts(DeviceId deviceId) {
+        Set<Host> hostset = new HashSet<>();
+        for (ConnectPoint p : locations.keySet()) {
+            if (p.deviceId().equals(deviceId)) {
+                hostset.addAll(locations.get(p));
+            }
+        }
+        return hostset;
+    }
+
+    @Override
+    public void updateAddressBindings(PortAddresses addresses) {
+        synchronized (portAddresses) {
+            PortAddresses existing = portAddresses.get(addresses.connectPoint());
+            if (existing == null) {
+                portAddresses.put(addresses.connectPoint(), addresses);
+            } else {
+                Set<IpPrefix> union = Sets.union(existing.ips(), addresses.ips())
+                        .immutableCopy();
+
+                MacAddress newMac = (addresses.mac() == null) ? existing.mac()
+                        : addresses.mac();
+
+                PortAddresses newAddresses =
+                        new PortAddresses(addresses.connectPoint(), union, newMac);
+
+                portAddresses.put(newAddresses.connectPoint(), newAddresses);
+            }
+        }
+    }
+
+    @Override
+    public void removeAddressBindings(PortAddresses addresses) {
+        synchronized (portAddresses) {
+            PortAddresses existing = portAddresses.get(addresses.connectPoint());
+            if (existing != null) {
+                Set<IpPrefix> difference =
+                        Sets.difference(existing.ips(), addresses.ips()).immutableCopy();
+
+                // If they removed the existing mac, set the new mac to null.
+                // Otherwise, keep the existing mac.
+                MacAddress newMac = existing.mac();
+                if (addresses.mac() != null && addresses.mac().equals(existing.mac())) {
+                    newMac = null;
+                }
+
+                PortAddresses newAddresses =
+                        new PortAddresses(addresses.connectPoint(), difference, newMac);
+
+                portAddresses.put(newAddresses.connectPoint(), newAddresses);
+            }
+        }
+    }
+
+    @Override
+    public void clearAddressBindings(ConnectPoint connectPoint) {
+        synchronized (portAddresses) {
+            portAddresses.remove(connectPoint);
+        }
+    }
+
+    @Override
+    public Set<PortAddresses> getAddressBindings() {
+        synchronized (portAddresses) {
+            return new HashSet<>(portAddresses.values());
+        }
+    }
+
+    @Override
+    public PortAddresses getAddressBindingsForPort(ConnectPoint connectPoint) {
+        PortAddresses addresses;
+
+        synchronized (portAddresses) {
+            addresses = portAddresses.get(connectPoint);
+        }
+
+        if (addresses == null) {
+            addresses = new PortAddresses(connectPoint, null, null);
+        }
+
+        return addresses;
+    }
+
+}

@@ -10,6 +10,7 @@ import static org.slf4j.LoggerFactory.getLogger;
 
 
 import java.util.HashSet;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.Set;
+
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
 import org.apache.felix.scr.annotations.Deactivate;
@@ -24,9 +25,9 @@ import org.onlab.onos.net.link.LinkEvent;
 import org.onlab.onos.net.link.LinkStore;
 import org.onlab.onos.net.link.LinkStore;
 import org.onlab.onos.net.link.LinkStoreDelegate;
 import org.onlab.onos.net.link.LinkStoreDelegate;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.net.provider.ProviderId;
-import org.onlab.onos.store.impl.AbsentInvalidatingLoadingCache;
-import org.onlab.onos.store.impl.AbstractDistributedStore;
-import org.onlab.onos.store.impl.OptionalCacheLoader;
+import org.onlab.onos.store.common.AbsentInvalidatingLoadingCache;
+import org.onlab.onos.store.common.AbstractHazelcastStore;
+import org.onlab.onos.store.common.OptionalCacheLoader;
 import org.slf4j.Logger;
 import org.slf4j.Logger;
 
 
 import com.google.common.base.Optional;
 import com.google.common.base.Optional;
@@ -43,7 +44,7 @@ import com.hazelcast.core.IMap;
 @Component(immediate = true)
 @Component(immediate = true)
 @Service
 @Service
 public class DistributedLinkStore
 public class DistributedLinkStore
-    extends AbstractDistributedStore<LinkEvent, LinkStoreDelegate>
+    extends AbstractHazelcastStore<LinkEvent, LinkStoreDelegate>
     implements LinkStore {
     implements LinkStore {
 
 
     private final Logger log = getLogger(getClass());
     private final Logger log = getLogger(getClass());
@@ -57,6 +58,8 @@ public class DistributedLinkStore
     private final Multimap<DeviceId, Link> srcLinks = HashMultimap.create();
     private final Multimap<DeviceId, Link> srcLinks = HashMultimap.create();
     private final Multimap<DeviceId, Link> dstLinks = HashMultimap.create();
     private final Multimap<DeviceId, Link> dstLinks = HashMultimap.create();
 
 
+    private String linksListener;
+
     @Override
     @Override
     @Activate
     @Activate
     public void activate() {
     public void activate() {
@@ -70,7 +73,7 @@ public class DistributedLinkStore
                 = new OptionalCacheLoader<>(storeService, rawLinks);
                 = new OptionalCacheLoader<>(storeService, rawLinks);
         links = new AbsentInvalidatingLoadingCache<>(newBuilder().build(linkLoader));
         links = new AbsentInvalidatingLoadingCache<>(newBuilder().build(linkLoader));
         // refresh/populate cache based on notification from other instance
         // refresh/populate cache based on notification from other instance
-        rawLinks.addEntryListener(new RemoteLinkEventHandler(links), includeValue);
+        linksListener = rawLinks.addEntryListener(new RemoteLinkEventHandler(links), includeValue);
 
 
         loadLinkCache();
         loadLinkCache();
 
 
@@ -79,7 +82,7 @@ public class DistributedLinkStore
 
 
     @Deactivate
     @Deactivate
     public void deactivate() {
     public void deactivate() {
-        super.activate();
+        rawLinks.removeEntryListener(linksListener);
         log.info("Stopped");
         log.info("Stopped");
     }
     }
 
 
@@ -232,7 +235,7 @@ public class DistributedLinkStore
         }
         }
     }
     }
 
 
-    private class RemoteLinkEventHandler extends RemoteEventHandler<LinkKey, DefaultLink> {
+    private class RemoteLinkEventHandler extends RemoteCacheEventHandler<LinkKey, DefaultLink> {
         public RemoteLinkEventHandler(LoadingCache<LinkKey, Optional<DefaultLink>> cache) {
         public RemoteLinkEventHandler(LoadingCache<LinkKey, Optional<DefaultLink>> cache) {
             super(cache);
             super(cache);
         }
         }

+package org.onlab.onos.store.topology.impl;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSetMultimap;
+import org.onlab.graph.DijkstraGraphSearch;
+import org.onlab.graph.GraphPathSearch;
+import org.onlab.graph.TarjanGraphSearch;
+import org.onlab.onos.net.AbstractModel;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultPath;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.net.topology.ClusterId;
+import org.onlab.onos.net.topology.DefaultTopologyCluster;
+import org.onlab.onos.net.topology.DefaultTopologyVertex;
+import org.onlab.onos.net.topology.GraphDescription;
+import org.onlab.onos.net.topology.LinkWeight;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyCluster;
+import org.onlab.onos.net.topology.TopologyEdge;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyVertex;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.collect.ImmutableSetMultimap.Builder;
+import static org.onlab.graph.GraphPathSearch.Result;
+import static org.onlab.graph.TarjanGraphSearch.SCCResult;
+import static org.onlab.onos.net.Link.Type.INDIRECT;
+
+/**
+ * Default implementation of the topology descriptor. This carries the
+ * backing topology data.
+ */
+public class DefaultTopology extends AbstractModel implements Topology {
+
+    private static final DijkstraGraphSearch<TopologyVertex, TopologyEdge> DIJKSTRA =
+            new DijkstraGraphSearch<>();
+    private static final TarjanGraphSearch<TopologyVertex, TopologyEdge> TARJAN =
+            new TarjanGraphSearch<>();
+
+    private static final ProviderId PID = new ProviderId("core", "org.onlab.onos.net");
+
+    private final long time;
+    private final TopologyGraph graph;
+
+    private final SCCResult<TopologyVertex, TopologyEdge> clusterResults;
+    private final ImmutableMap<DeviceId, Result<TopologyVertex, TopologyEdge>> results;
+    private final ImmutableSetMultimap<PathKey, Path> paths;
+
+    private final ImmutableMap<ClusterId, TopologyCluster> clusters;
+    private final ImmutableSet<ConnectPoint> infrastructurePoints;
+    private final ImmutableSetMultimap<ClusterId, ConnectPoint> broadcastSets;
+
+    private ImmutableMap<DeviceId, TopologyCluster> clustersByDevice;
+    private ImmutableSetMultimap<TopologyCluster, DeviceId> devicesByCluster;
+    private ImmutableSetMultimap<TopologyCluster, Link> linksByCluster;
+
+
+    /**
+     * Creates a topology descriptor attributed to the specified provider.
+     *
+     * @param providerId  identity of the provider
+     * @param description data describing the new topology
+     */
+    DefaultTopology(ProviderId providerId, GraphDescription description) {
+        super(providerId);
+        this.time = description.timestamp();
+
+        // Build the graph
+        this.graph = new DefaultTopologyGraph(description.vertexes(),
+                                              description.edges());
+
+        this.results = searchForShortestPaths();
+        this.paths = buildPaths();
+
+        this.clusterResults = searchForClusters();
+        this.clusters = buildTopologyClusters();
+
+        buildIndexes();
+
+        this.broadcastSets = buildBroadcastSets();
+        this.infrastructurePoints = findInfrastructurePoints();
+    }
+
+    @Override
+    public long time() {
+        return time;
+    }
+
+    @Override
+    public int clusterCount() {
+        return clusters.size();
+    }
+
+    @Override
+    public int deviceCount() {
+        return graph.getVertexes().size();
+    }
+
+    @Override
+    public int linkCount() {
+        return graph.getEdges().size();
+    }
+
+    @Override
+    public int pathCount() {
+        return paths.size();
+    }
+
+    /**
+     * Returns the backing topology graph.
+     *
+     * @return topology graph
+     */
+    TopologyGraph getGraph() {
+        return graph;
+    }
+
+    /**
+     * Returns the set of topology clusters.
+     *
+     * @return set of clusters
+     */
+    Set<TopologyCluster> getClusters() {
+        return ImmutableSet.copyOf(clusters.values());
+    }
+
+    /**
+     * Returns the specified topology cluster.
+     *
+     * @param clusterId cluster identifier
+     * @return topology cluster
+     */
+    TopologyCluster getCluster(ClusterId clusterId) {
+        return clusters.get(clusterId);
+    }
+
+    /**
+     * Returns the topology cluster that contains the given device.
+     *
+     * @param deviceId device identifier
+     * @return topology cluster
+     */
+    TopologyCluster getCluster(DeviceId deviceId) {
+        return clustersByDevice.get(deviceId);
+    }
+
+    /**
+     * Returns the set of cluster devices.
+     *
+     * @param cluster topology cluster
+     * @return cluster devices
+     */
+    Set<DeviceId> getClusterDevices(TopologyCluster cluster) {
+        return devicesByCluster.get(cluster);
+    }
+
+    /**
+     * Returns the set of cluster links.
+     *
+     * @param cluster topology cluster
+     * @return cluster links
+     */
+    Set<Link> getClusterLinks(TopologyCluster cluster) {
+        return linksByCluster.get(cluster);
+    }
+
+    /**
+     * Indicates whether the given point is an infrastructure link end-point.
+     *
+     * @param connectPoint connection point
+     * @return true if infrastructure
+     */
+    boolean isInfrastructure(ConnectPoint connectPoint) {
+        return infrastructurePoints.contains(connectPoint);
+    }
+
+    /**
+     * Indicates whether the given point is part of a broadcast set.
+     *
+     * @param connectPoint connection point
+     * @return true if in broadcast set
+     */
+    boolean isBroadcastPoint(ConnectPoint connectPoint) {
+        // Any non-infrastructure, i.e. edge points are assumed to be OK.
+        if (!isInfrastructure(connectPoint)) {
+            return true;
+        }
+
+        // Find the cluster to which the device belongs.
+        TopologyCluster cluster = clustersByDevice.get(connectPoint.deviceId());
+        if (cluster == null) {
+            throw new IllegalArgumentException("No cluster found for device " + connectPoint.deviceId());
+        }
+
+        // If the broadcast set is null or empty, or if the point explicitly
+        // belongs to it, return true;
+        Set<ConnectPoint> points = broadcastSets.get(cluster.id());
+        return points == null || points.isEmpty() || points.contains(connectPoint);
+    }
+
+    /**
+     * Returns the size of the cluster broadcast set.
+     *
+     * @param clusterId cluster identifier
+     * @return size of the cluster broadcast set
+     */
+    int broadcastSetSize(ClusterId clusterId) {
+        return broadcastSets.get(clusterId).size();
+    }
+
+    /**
+     * Returns the set of pre-computed shortest paths between source and
+     * destination devices.
+     *
+     * @param src source device
+     * @param dst destination device
+     * @return set of shortest paths
+     */
+    Set<Path> getPaths(DeviceId src, DeviceId dst) {
+        return paths.get(new PathKey(src, dst));
+    }
+
+    /**
+     * Computes on-demand the set of shortest paths between source and
+     * destination devices.
+     *
+     * @param src source device
+     * @param dst destination device
+     * @return set of shortest paths
+     */
+    Set<Path> getPaths(DeviceId src, DeviceId dst, LinkWeight weight) {
+        GraphPathSearch.Result<TopologyVertex, TopologyEdge> result =
+                DIJKSTRA.search(graph, new DefaultTopologyVertex(src),
+                                new DefaultTopologyVertex(dst), weight);
+        ImmutableSet.Builder<Path> builder = ImmutableSet.builder();
+        for (org.onlab.graph.Path<TopologyVertex, TopologyEdge> path : result.paths()) {
+            builder.add(networkPath(path));
+        }
+        return builder.build();
+    }
+
+
+    // Searches the graph for all shortest paths and returns the search results.
+    private ImmutableMap<DeviceId, Result<TopologyVertex, TopologyEdge>> searchForShortestPaths() {
+        ImmutableMap.Builder<DeviceId, Result<TopologyVertex, TopologyEdge>> builder = ImmutableMap.builder();
+
+        // Search graph paths for each source to all destinations.
+        LinkWeight weight = new HopCountLinkWeight(graph.getVertexes().size());
+        for (TopologyVertex src : graph.getVertexes()) {
+            builder.put(src.deviceId(), DIJKSTRA.search(graph, src, null, weight));
+        }
+        return builder.build();
+    }
+
+    // Builds network paths from the graph path search results
+    private ImmutableSetMultimap<PathKey, Path> buildPaths() {
+        Builder<PathKey, Path> builder = ImmutableSetMultimap.builder();
+        for (DeviceId deviceId : results.keySet()) {
+            Result<TopologyVertex, TopologyEdge> result = results.get(deviceId);
+            for (org.onlab.graph.Path<TopologyVertex, TopologyEdge> path : result.paths()) {
+                builder.put(new PathKey(path.src().deviceId(), path.dst().deviceId()),
+                            networkPath(path));
+            }
+        }
+        return builder.build();
+    }
+
+    // Converts graph path to a network path with the same cost.
+    private Path networkPath(org.onlab.graph.Path<TopologyVertex, TopologyEdge> path) {
+        List<Link> links = new ArrayList<>();
+        for (TopologyEdge edge : path.edges()) {
+            links.add(edge.link());
+        }
+        return new DefaultPath(PID, links, path.cost());
+    }
+
+
+    // Searches for SCC clusters in the network topology graph using Tarjan
+    // algorithm.
+    private SCCResult<TopologyVertex, TopologyEdge> searchForClusters() {
+        return TARJAN.search(graph, new NoIndirectLinksWeight());
+    }
+
+    // Builds the topology clusters and returns the id-cluster bindings.
+    private ImmutableMap<ClusterId, TopologyCluster> buildTopologyClusters() {
+        ImmutableMap.Builder<ClusterId, TopologyCluster> clusterBuilder = ImmutableMap.builder();
+        SCCResult<TopologyVertex, TopologyEdge> result =
+                TARJAN.search(graph, new NoIndirectLinksWeight());
+
+        // Extract both vertexes and edges from the results; the lists form
+        // pairs along the same index.
+        List<Set<TopologyVertex>> clusterVertexes = result.clusterVertexes();
+        List<Set<TopologyEdge>> clusterEdges = result.clusterEdges();
+
+        // Scan over the lists and create a cluster from the results.
+        for (int i = 0, n = result.clusterCount(); i < n; i++) {
+            Set<TopologyVertex> vertexSet = clusterVertexes.get(i);
+            Set<TopologyEdge> edgeSet = clusterEdges.get(i);
+
+            ClusterId cid = ClusterId.clusterId(i);
+            DefaultTopologyCluster cluster =
+                    new DefaultTopologyCluster(cid, vertexSet.size(), edgeSet.size(),
+                                               findRoot(vertexSet).deviceId());
+            clusterBuilder.put(cid, cluster);
+        }
+        return clusterBuilder.build();
+    }
+
+    // Finds the vertex whose device id is the lexicographical minimum in the
+    // specified set.
+    private TopologyVertex findRoot(Set<TopologyVertex> vertexSet) {
+        TopologyVertex minVertex = null;
+        for (TopologyVertex vertex : vertexSet) {
+            if (minVertex == null ||
+                    minVertex.deviceId().toString()
+                            .compareTo(minVertex.deviceId().toString()) < 0) {
+                minVertex = vertex;
+            }
+        }
+        return minVertex;
+    }
+
+    // Processes a map of broadcast sets for each cluster.
+    private ImmutableSetMultimap<ClusterId, ConnectPoint> buildBroadcastSets() {
+        Builder<ClusterId, ConnectPoint> builder = ImmutableSetMultimap.builder();
+        for (TopologyCluster cluster : clusters.values()) {
+            addClusterBroadcastSet(cluster, builder);
+        }
+        return builder.build();
+    }
+
+    // Finds all broadcast points for the cluster. These are those connection
+    // points which lie along the shortest paths between the cluster root and
+    // all other devices within the cluster.
+    private void addClusterBroadcastSet(TopologyCluster cluster,
+                                        Builder<ClusterId, ConnectPoint> builder) {
+        // Use the graph root search results to build the broadcast set.
+        Result<TopologyVertex, TopologyEdge> result = results.get(cluster.root());
+        for (Map.Entry<TopologyVertex, Set<TopologyEdge>> entry : result.parents().entrySet()) {
+            TopologyVertex vertex = entry.getKey();
+
+            // Ignore any parents that lead outside the cluster.
+            if (clustersByDevice.get(vertex.deviceId()) != cluster) {
+                continue;
+            }
+
+            // Ignore any back-link sets that are empty.
+            Set<TopologyEdge> parents = entry.getValue();
+            if (parents.isEmpty()) {
+                continue;
+            }
+
+            // Use the first back-link source and destinations to add to the
+            // broadcast set.
+            Link link = parents.iterator().next().link();
+            builder.put(cluster.id(), link.src());
+            builder.put(cluster.id(), link.dst());
+        }
+    }
+
+    // Collects and returns an set of all infrastructure link end-points.
+    private ImmutableSet<ConnectPoint> findInfrastructurePoints() {
+        ImmutableSet.Builder<ConnectPoint> builder = ImmutableSet.builder();
+        for (TopologyEdge edge : graph.getEdges()) {
+            builder.add(edge.link().src());
+            builder.add(edge.link().dst());
+        }
+        return builder.build();
+    }
+
+    // Builds cluster-devices, cluster-links and device-cluster indexes.
+    private void buildIndexes() {
+        // Prepare the index builders
+        ImmutableMap.Builder<DeviceId, TopologyCluster> clusterBuilder = ImmutableMap.builder();
+        ImmutableSetMultimap.Builder<TopologyCluster, DeviceId> devicesBuilder = ImmutableSetMultimap.builder();
+        ImmutableSetMultimap.Builder<TopologyCluster, Link> linksBuilder = ImmutableSetMultimap.builder();
+
+        // Now scan through all the clusters
+        for (TopologyCluster cluster : clusters.values()) {
+            int i = cluster.id().index();
+
+            // Scan through all the cluster vertexes.
+            for (TopologyVertex vertex : clusterResults.clusterVertexes().get(i)) {
+                devicesBuilder.put(cluster, vertex.deviceId());
+                clusterBuilder.put(vertex.deviceId(), cluster);
+            }
+
+            // Scan through all the cluster edges.
+            for (TopologyEdge edge : clusterResults.clusterEdges().get(i)) {
+                linksBuilder.put(cluster, edge.link());
+            }
+        }
+
+        // Finalize all indexes.
+        clustersByDevice = clusterBuilder.build();
+        devicesByCluster = devicesBuilder.build();
+        linksByCluster = linksBuilder.build();
+    }
+
+    // Link weight for measuring link cost as hop count with indirect links
+    // being as expensive as traversing the entire graph to assume the worst.
+    private static class HopCountLinkWeight implements LinkWeight {
+        private final int indirectLinkCost;
+
+        HopCountLinkWeight(int indirectLinkCost) {
+            this.indirectLinkCost = indirectLinkCost;
+        }
+
+        @Override
+        public double weight(TopologyEdge edge) {
+            // To force preference to use direct paths first, make indirect
+            // links as expensive as the linear vertex traversal.
+            return edge.link().type() == INDIRECT ? indirectLinkCost : 1;
+        }
+    }
+
+    // Link weight for preventing traversal over indirect links.
+    private static class NoIndirectLinksWeight implements LinkWeight {
+        @Override
+        public double weight(TopologyEdge edge) {
+            return edge.link().type() == INDIRECT ? -1 : 1;
+        }
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("time", time)
+                .add("clusters", clusterCount())
+                .add("devices", deviceCount())
+                .add("links", linkCount())
+                .add("pathCount", pathCount())
+                .toString();
+    }
+}

+package org.onlab.onos.store.topology.impl;
+
+import org.onlab.graph.AdjacencyListsGraph;
+import org.onlab.onos.net.topology.TopologyEdge;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyVertex;
+
+import java.util.Set;
+
+/**
+ * Default implementation of an immutable topology graph based on a generic
+ * implementation of adjacency lists graph.
+ */
+public class DefaultTopologyGraph
+        extends AdjacencyListsGraph<TopologyVertex, TopologyEdge>
+        implements TopologyGraph {
+
+    /**
+     * Creates a topology graph comprising of the specified vertexes and edges.
+     *
+     * @param vertexes set of graph vertexes
+     * @param edges    set of graph edges
+     */
+    public DefaultTopologyGraph(Set<TopologyVertex> vertexes, Set<TopologyEdge> edges) {
+        super(vertexes, edges);
+    }
+
+}

+package org.onlab.onos.store.topology.impl;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.List;
+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;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.event.Event;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.net.topology.ClusterId;
+import org.onlab.onos.net.topology.GraphDescription;
+import org.onlab.onos.net.topology.LinkWeight;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyCluster;
+import org.onlab.onos.net.topology.TopologyEvent;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyStore;
+import org.onlab.onos.net.topology.TopologyStoreDelegate;
+import org.onlab.onos.store.AbstractStore;
+import org.slf4j.Logger;
+
+/**
+ * Manages inventory of topology snapshots using trivial in-memory
+ * structures implementation.
+ */
+//FIXME: I LIE I AM NOT DISTRIBUTED
+@Component(immediate = true)
+@Service
+public class DistributedTopologyStore
+extends AbstractStore<TopologyEvent, TopologyStoreDelegate>
+implements TopologyStore {
+
+    private final Logger log = getLogger(getClass());
+
+    private volatile DefaultTopology current;
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+    @Override
+    public Topology currentTopology() {
+        return current;
+    }
+
+    @Override
+    public boolean isLatest(Topology topology) {
+        // Topology is current only if it is the same as our current topology
+        return topology == current;
+    }
+
+    @Override
+    public TopologyGraph getGraph(Topology topology) {
+        return defaultTopology(topology).getGraph();
+    }
+
+    @Override
+    public Set<TopologyCluster> getClusters(Topology topology) {
+        return defaultTopology(topology).getClusters();
+    }
+
+    @Override
+    public TopologyCluster getCluster(Topology topology, ClusterId clusterId) {
+        return defaultTopology(topology).getCluster(clusterId);
+    }
+
+    @Override
+    public Set<DeviceId> getClusterDevices(Topology topology, TopologyCluster cluster) {
+        return defaultTopology(topology).getClusterDevices(cluster);
+    }
+
+    @Override
+    public Set<Link> getClusterLinks(Topology topology, TopologyCluster cluster) {
+        return defaultTopology(topology).getClusterLinks(cluster);
+    }
+
+    @Override
+    public Set<Path> getPaths(Topology topology, DeviceId src, DeviceId dst) {
+        return defaultTopology(topology).getPaths(src, dst);
+    }
+
+    @Override
+    public Set<Path> getPaths(Topology topology, DeviceId src, DeviceId dst,
+            LinkWeight weight) {
+        return defaultTopology(topology).getPaths(src, dst, weight);
+    }
+
+    @Override
+    public boolean isInfrastructure(Topology topology, ConnectPoint connectPoint) {
+        return defaultTopology(topology).isInfrastructure(connectPoint);
+    }
+
+    @Override
+    public boolean isBroadcastPoint(Topology topology, ConnectPoint connectPoint) {
+        return defaultTopology(topology).isBroadcastPoint(connectPoint);
+    }
+
+    @Override
+    public TopologyEvent updateTopology(ProviderId providerId,
+            GraphDescription graphDescription,
+            List<Event> reasons) {
+        // First off, make sure that what we're given is indeed newer than
+        // what we already have.
+        if (current != null && graphDescription.timestamp() < current.time()) {
+            return null;
+        }
+
+        // Have the default topology construct self from the description data.
+        DefaultTopology newTopology =
+                new DefaultTopology(providerId, graphDescription);
+
+        // Promote the new topology to current and return a ready-to-send event.
+        synchronized (this) {
+            current = newTopology;
+            return new TopologyEvent(TopologyEvent.Type.TOPOLOGY_CHANGED, current);
+        }
+    }
+
+    // Validates the specified topology and returns it as a default
+    private DefaultTopology defaultTopology(Topology topology) {
+        if (topology instanceof DefaultTopology) {
+            return (DefaultTopology) topology;
+        }
+        throw new IllegalArgumentException("Topology class " + topology.getClass() +
+                " not supported");
+    }
+
+}

+package org.onlab.onos.store.topology.impl;
+
+import org.onlab.onos.net.DeviceId;
+
+import java.util.Objects;
+
+/**
+ * Key for filing pre-computed paths between source and destination devices.
+ */
+class PathKey {
+    private final DeviceId src;
+    private final DeviceId dst;
+
+    /**
+     * Creates a path key from the given source/dest pair.
+     * @param src source device
+     * @param dst destination device
+     */
+    PathKey(DeviceId src, DeviceId dst) {
+        this.src = src;
+        this.dst = dst;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(src, dst);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof PathKey) {
+            final PathKey other = (PathKey) obj;
+            return Objects.equals(this.src, other.src) && Objects.equals(this.dst, other.dst);
+        }
+        return false;
+    }
+}

@@ -20,6 +20,7 @@ import org.junit.After;
 import org.junit.AfterClass;
 import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.BeforeClass;
+import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.Test;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.DeviceId;
@@ -32,15 +33,18 @@ import org.onlab.onos.net.device.DeviceEvent;
 import org.onlab.onos.net.device.DeviceStoreDelegate;
 import org.onlab.onos.net.device.DeviceStoreDelegate;
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.common.StoreManager;
 import org.onlab.onos.store.common.StoreService;
 import org.onlab.onos.store.common.StoreService;
-import org.onlab.onos.store.impl.StoreManager;
-import org.onlab.onos.store.impl.TestStoreManager;
+import org.onlab.onos.store.common.TestStoreManager;
 
 
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Sets;
 import com.google.common.collect.Sets;
 import com.hazelcast.config.Config;
 import com.hazelcast.config.Config;
 import com.hazelcast.core.Hazelcast;
 import com.hazelcast.core.Hazelcast;
 
 
+/**
+ * Test of the Hazelcast based distributed DeviceStore implementation.
+ */
 public class DistributedDeviceStoreTest {
 public class DistributedDeviceStoreTest {
 
 
     private static final ProviderId PID = new ProviderId("of", "foo");
     private static final ProviderId PID = new ProviderId("of", "foo");
@@ -326,6 +330,7 @@ public class DistributedDeviceStoreTest {
     }
     }
 
 
     // TODO add test for Port events when we have them
     // TODO add test for Port events when we have them
+    @Ignore("Ignore until Delegate spec. is clear.")
     @Test
     @Test
     public final void testEvents() throws InterruptedException {
     public final void testEvents() throws InterruptedException {
         final CountDownLatch addLatch = new CountDownLatch(1);
         final CountDownLatch addLatch = new CountDownLatch(1);

@@ -15,6 +15,7 @@ import org.junit.After;
 import org.junit.AfterClass;
 import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.BeforeClass;
+import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.Test;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.DeviceId;
@@ -26,24 +27,22 @@ import org.onlab.onos.net.link.DefaultLinkDescription;
 import org.onlab.onos.net.link.LinkEvent;
 import org.onlab.onos.net.link.LinkEvent;
 import org.onlab.onos.net.link.LinkStoreDelegate;
 import org.onlab.onos.net.link.LinkStoreDelegate;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.common.StoreManager;
 import org.onlab.onos.store.common.StoreService;
 import org.onlab.onos.store.common.StoreService;
-import org.onlab.onos.store.impl.StoreManager;
-import org.onlab.onos.store.impl.TestStoreManager;
+import org.onlab.onos.store.common.TestStoreManager;
 
 
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Iterables;
 import com.hazelcast.config.Config;
 import com.hazelcast.config.Config;
 import com.hazelcast.core.Hazelcast;
 import com.hazelcast.core.Hazelcast;
 
 
+/**
+ * Test of the Hazelcast based distributed LinkStore implementation.
+ */
 public class DistributedLinkStoreTest {
 public class DistributedLinkStoreTest {
 
 
     private static final ProviderId PID = new ProviderId("of", "foo");
     private static final ProviderId PID = new ProviderId("of", "foo");
     private static final DeviceId DID1 = deviceId("of:foo");
     private static final DeviceId DID1 = deviceId("of:foo");
     private static final DeviceId DID2 = deviceId("of:bar");
     private static final DeviceId DID2 = deviceId("of:bar");
-//    private static final String MFR = "whitebox";
-//    private static final String HW = "1.1.x";
-//    private static final String SW1 = "3.8.1";
-//    private static final String SW2 = "3.9.5";
-//    private static final String SN = "43311-12345";
 
 
     private static final PortNumber P1 = PortNumber.portNumber(1);
     private static final PortNumber P1 = PortNumber.portNumber(1);
     private static final PortNumber P2 = PortNumber.portNumber(2);
     private static final PortNumber P2 = PortNumber.portNumber(2);
@@ -302,6 +301,7 @@ public class DistributedLinkStoreTest {
         assertLink(linkId2, DIRECT, linkStore.getLink(d2P2, d1P1));
         assertLink(linkId2, DIRECT, linkStore.getLink(d2P2, d1P1));
     }
     }
 
 
+    @Ignore("Ignore until Delegate spec. is clear.")
     @Test
     @Test
     public final void testEvents() throws InterruptedException {
     public final void testEvents() throws InterruptedException {
 
 

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-core-store</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-core-hz</artifactId>
+    <packaging>pom</packaging>
+
+    <description>ONOS Core Hazelcast Store subsystem</description>
+
+    <modules>
+        <module>common</module>
+        <module>cluster</module>
+        <module>net</module>
+    </modules>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onlab-misc</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onlab-junit</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>com.hazelcast</groupId>
+          <artifactId>hazelcast</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-bundle-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

 <?xml version="1.0" encoding="UTF-8"?>
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <modelVersion>4.0.0</modelVersion>
 
 
     <parent>
     <parent>
@@ -12,34 +10,41 @@
     </parent>
     </parent>
 
 
     <artifactId>onos-core-store</artifactId>
     <artifactId>onos-core-store</artifactId>
-    <packaging>bundle</packaging>
+    <packaging>pom</packaging>
 
 
-    <description>ONOS distributed store subsystems</description>
+    <description>ONOS Core Store subsystem</description>
+
+    <modules>
+        <module>trivial</module>
+        <module>dist</module>
+        <module>hz</module>
+        <module>serializers</module>
+  </modules>
 
 
     <dependencies>
     <dependencies>
         <dependency>
         <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+        </dependency>
+        <dependency>
             <groupId>org.onlab.onos</groupId>
             <groupId>org.onlab.onos</groupId>
-            <artifactId>onos-api</artifactId>
+            <artifactId>onlab-misc</artifactId>
         </dependency>
         </dependency>
         <dependency>
         <dependency>
-            <groupId>org.apache.felix</groupId>
-            <artifactId>org.apache.felix.scr.annotations</artifactId>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onlab-junit</artifactId>
         </dependency>
         </dependency>
         <dependency>
         <dependency>
           <groupId>com.hazelcast</groupId>
           <groupId>com.hazelcast</groupId>
           <artifactId>hazelcast</artifactId>
           <artifactId>hazelcast</artifactId>
         </dependency>
         </dependency>
-        <dependency>
-          <groupId>de.javakaffee</groupId>
-          <artifactId>kryo-serializers</artifactId>
-        </dependency>
     </dependencies>
     </dependencies>
 
 
     <build>
     <build>
         <plugins>
         <plugins>
             <plugin>
             <plugin>
                 <groupId>org.apache.felix</groupId>
                 <groupId>org.apache.felix</groupId>
-                <artifactId>maven-scr-plugin</artifactId>
+                <artifactId>maven-bundle-plugin</artifactId>
             </plugin>
             </plugin>
         </plugins>
         </plugins>
     </build>
     </build>

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-core-store</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-core-serializers</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>Serializers for ONOS classes</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.felix</groupId>
+            <artifactId>org.apache.felix.scr.annotations</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>de.javakaffee</groupId>
+          <artifactId>kryo-serializers</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-scr-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

@@ -6,7 +6,7 @@
 
 
     <parent>
     <parent>
         <groupId>org.onlab.onos</groupId>
         <groupId>org.onlab.onos</groupId>
-        <artifactId>onos-core</artifactId>
+        <artifactId>onos-core-store</artifactId>
         <version>1.0.0-SNAPSHOT</version>
         <version>1.0.0-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
         <relativePath>../pom.xml</relativePath>
     </parent>
     </parent>

+package org.onlab.onos.net.trivial.impl;
+
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.store.ClockService;
+import org.onlab.onos.store.Timestamp;
+
+//FIXME: Code clone in onos-core-trivial, onos-core-hz-net
+/**
+ * Dummy implementation of {@link ClockService}.
+ */
+@Component(immediate = true)
+@Service
+public class NoOpClockService implements ClockService {
+
+    @Override
+    public Timestamp getTimestamp(DeviceId deviceId) {
+        return new Timestamp() {
+
+            @Override
+            public int compareTo(Timestamp o) {
+                throw new IllegalStateException("Never expected to be used.");
+            }
+        };
+    }
+
+    @Override
+    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term) {
+    }
+}

@@ -20,7 +20,7 @@ import java.util.Set;
 import static org.slf4j.LoggerFactory.getLogger;
 import static org.slf4j.LoggerFactory.getLogger;
 
 
 /**
 /**
- * Manages inventory of infrastructure DEVICES using trivial in-memory
+ * Manages inventory of infrastructure devices using trivial in-memory
  * structures implementation.
  * structures implementation.
  */
  */
 @Component(immediate = true)
 @Component(immediate = true)
@@ -68,6 +68,11 @@ public class SimpleClusterStore
     }
     }
 
 
     @Override
     @Override
+    public ControllerNode addNode(NodeId nodeId, IpPrefix ip, int tcpPort) {
+        return null;
+    }
+
+    @Override
     public void removeNode(NodeId nodeId) {
     public void removeNode(NodeId nodeId) {
     }
     }
 
 

@@ -101,9 +101,6 @@ public class SimpleDeviceStore
         synchronized (this) {
         synchronized (this) {
             devices.put(deviceId, device);
             devices.put(deviceId, device);
             availableDevices.add(deviceId);
             availableDevices.add(deviceId);
-
-            // For now claim the device as a master automatically.
-            // roles.put(deviceId, MastershipRole.MASTER);
         }
         }
         return new DeviceEvent(DeviceEvent.Type.DEVICE_ADDED, device, null);
         return new DeviceEvent(DeviceEvent.Type.DEVICE_ADDED, device, null);
     }
     }
@@ -189,7 +186,7 @@ public class SimpleDeviceStore
                     new DefaultPort(device, portDescription.portNumber(),
                     new DefaultPort(device, portDescription.portNumber(),
                                     portDescription.isEnabled());
                                     portDescription.isEnabled());
             ports.put(port.number(), updatedPort);
             ports.put(port.number(), updatedPort);
-            return new DeviceEvent(PORT_UPDATED, device, port);
+            return new DeviceEvent(PORT_UPDATED, device, updatedPort);
         }
         }
         return null;
         return null;
     }
     }

@@ -51,8 +51,6 @@ public class SimpleLinkStore
     private final Multimap<DeviceId, Link> srcLinks = HashMultimap.create();
     private final Multimap<DeviceId, Link> srcLinks = HashMultimap.create();
     private final Multimap<DeviceId, Link> dstLinks = HashMultimap.create();
     private final Multimap<DeviceId, Link> dstLinks = HashMultimap.create();
 
 
-    private static final Set<Link> EMPTY = ImmutableSet.of();
-
     @Activate
     @Activate
     public void activate() {
     public void activate() {
         log.info("Started");
         log.info("Started");

+/**
+ *
+ */
+package org.onlab.onos.net.trivial.impl;
+
+import static org.junit.Assert.*;
+import static org.onlab.onos.net.Device.Type.SWITCH;
+import static org.onlab.onos.net.DeviceId.deviceId;
+import static org.onlab.onos.net.device.DeviceEvent.Type.*;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.device.DefaultDeviceDescription;
+import org.onlab.onos.net.device.DefaultPortDescription;
+import org.onlab.onos.net.device.DeviceDescription;
+import org.onlab.onos.net.device.DeviceEvent;
+import org.onlab.onos.net.device.DeviceStore;
+import org.onlab.onos.net.device.DeviceStoreDelegate;
+import org.onlab.onos.net.device.PortDescription;
+import org.onlab.onos.net.provider.ProviderId;
+
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Sets;
+
+/**
+ * Test of the simple DeviceStore implementation.
+ */
+public class SimpleDeviceStoreTest {
+
+    private static final ProviderId PID = new ProviderId("of", "foo");
+    private static final DeviceId DID1 = deviceId("of:foo");
+    private static final DeviceId DID2 = deviceId("of:bar");
+    private static final String MFR = "whitebox";
+    private static final String HW = "1.1.x";
+    private static final String SW1 = "3.8.1";
+    private static final String SW2 = "3.9.5";
+    private static final String SN = "43311-12345";
+
+    private static final PortNumber P1 = PortNumber.portNumber(1);
+    private static final PortNumber P2 = PortNumber.portNumber(2);
+    private static final PortNumber P3 = PortNumber.portNumber(3);
+
+    private SimpleDeviceStore simpleDeviceStore;
+    private DeviceStore deviceStore;
+
+
+
+    @BeforeClass
+    public static void setUpBeforeClass() throws Exception {
+    }
+
+    @AfterClass
+    public static void tearDownAfterClass() throws Exception {
+    }
+
+
+    @Before
+    public void setUp() throws Exception {
+        simpleDeviceStore = new SimpleDeviceStore();
+        simpleDeviceStore.activate();
+        deviceStore = simpleDeviceStore;
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        simpleDeviceStore.deactivate();
+    }
+
+    private void putDevice(DeviceId deviceId, String swVersion) {
+        DeviceDescription description =
+                new DefaultDeviceDescription(deviceId.uri(), SWITCH, MFR,
+                        HW, swVersion, SN);
+        deviceStore.createOrUpdateDevice(PID, deviceId, description);
+    }
+
+    private static void assertDevice(DeviceId id, String swVersion, Device device) {
+        assertNotNull(device);
+        assertEquals(id, device.id());
+        assertEquals(MFR, device.manufacturer());
+        assertEquals(HW, device.hwVersion());
+        assertEquals(swVersion, device.swVersion());
+        assertEquals(SN, device.serialNumber());
+    }
+
+    @Test
+    public final void testGetDeviceCount() {
+        assertEquals("initialy empty", 0, deviceStore.getDeviceCount());
+
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW2);
+        putDevice(DID1, SW1);
+
+        assertEquals("expect 2 uniq devices", 2, deviceStore.getDeviceCount());
+    }
+
+    @Test
+    public final void testGetDevices() {
+        assertEquals("initialy empty", 0, Iterables.size(deviceStore.getDevices()));
+
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW2);
+        putDevice(DID1, SW1);
+
+        assertEquals("expect 2 uniq devices",
+                2, Iterables.size(deviceStore.getDevices()));
+
+        Map<DeviceId, Device> devices = new HashMap<>();
+        for (Device device : deviceStore.getDevices()) {
+            devices.put(device.id(), device);
+        }
+
+        assertDevice(DID1, SW1, devices.get(DID1));
+        assertDevice(DID2, SW2, devices.get(DID2));
+
+        // add case for new node?
+    }
+
+    @Test
+    public final void testGetDevice() {
+
+        putDevice(DID1, SW1);
+
+        assertDevice(DID1, SW1, deviceStore.getDevice(DID1));
+        assertNull("DID2 shouldn't be there", deviceStore.getDevice(DID2));
+    }
+
+    @Test
+    public final void testCreateOrUpdateDevice() {
+        DeviceDescription description =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW1, SN);
+        DeviceEvent event = deviceStore.createOrUpdateDevice(PID, DID1, description);
+        assertEquals(DEVICE_ADDED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+
+        DeviceDescription description2 =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW2, SN);
+        DeviceEvent event2 = deviceStore.createOrUpdateDevice(PID, DID1, description2);
+        assertEquals(DEVICE_UPDATED, event2.type());
+        assertDevice(DID1, SW2, event2.subject());
+
+        assertNull("No change expected", deviceStore.createOrUpdateDevice(PID, DID1, description2));
+    }
+
+    @Test
+    public final void testMarkOffline() {
+
+        putDevice(DID1, SW1);
+        assertTrue(deviceStore.isAvailable(DID1));
+
+        DeviceEvent event = deviceStore.markOffline(DID1);
+        assertEquals(DEVICE_AVAILABILITY_CHANGED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+        assertFalse(deviceStore.isAvailable(DID1));
+
+        DeviceEvent event2 = deviceStore.markOffline(DID1);
+        assertNull("No change, no event", event2);
+}
+
+    @Test
+    public final void testUpdatePorts() {
+        putDevice(DID1, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true),
+                new DefaultPortDescription(P2, true)
+                );
+
+        List<DeviceEvent> events = deviceStore.updatePorts(DID1, pds);
+
+        Set<PortNumber> expectedPorts = Sets.newHashSet(P1, P2);
+        for (DeviceEvent event : events) {
+            assertEquals(PORT_ADDED, event.type());
+            assertDevice(DID1, SW1, event.subject());
+            assertTrue("PortNumber is one of expected",
+                    expectedPorts.remove(event.port().number()));
+            assertTrue("Port is enabled", event.port().isEnabled());
+        }
+        assertTrue("Event for all expectedport appeared", expectedPorts.isEmpty());
+
+
+        List<PortDescription> pds2 = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, false),
+                new DefaultPortDescription(P2, true),
+                new DefaultPortDescription(P3, true)
+                );
+
+        events = deviceStore.updatePorts(DID1, pds2);
+        assertFalse("event should be triggered", events.isEmpty());
+        for (DeviceEvent event : events) {
+            PortNumber num = event.port().number();
+            if (P1.equals(num)) {
+                assertEquals(PORT_UPDATED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                assertFalse("Port is disabled", event.port().isEnabled());
+            } else if (P2.equals(num)) {
+                fail("P2 event not expected.");
+            } else if (P3.equals(num)) {
+                assertEquals(PORT_ADDED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                assertTrue("Port is enabled", event.port().isEnabled());
+            } else {
+                fail("Unknown port number encountered: " + num);
+            }
+        }
+
+        List<PortDescription> pds3 = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, false),
+                new DefaultPortDescription(P2, true)
+                );
+        events = deviceStore.updatePorts(DID1, pds3);
+        assertFalse("event should be triggered", events.isEmpty());
+        for (DeviceEvent event : events) {
+            PortNumber num = event.port().number();
+            if (P1.equals(num)) {
+                fail("P1 event not expected.");
+            } else if (P2.equals(num)) {
+                fail("P2 event not expected.");
+            } else if (P3.equals(num)) {
+                assertEquals(PORT_REMOVED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                assertTrue("Port was enabled", event.port().isEnabled());
+            } else {
+                fail("Unknown port number encountered: " + num);
+            }
+        }
+
+    }
+
+    @Test
+    public final void testUpdatePortStatus() {
+        putDevice(DID1, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true)
+                );
+        deviceStore.updatePorts(DID1, pds);
+
+        DeviceEvent event = deviceStore.updatePortStatus(DID1,
+                new DefaultPortDescription(P1, false));
+        assertEquals(PORT_UPDATED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+        assertEquals(P1, event.port().number());
+        assertFalse("Port is disabled", event.port().isEnabled());
+    }
+
+    @Test
+    public final void testGetPorts() {
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true),
+                new DefaultPortDescription(P2, true)
+                );
+        deviceStore.updatePorts(DID1, pds);
+
+        Set<PortNumber> expectedPorts = Sets.newHashSet(P1, P2);
+        List<Port> ports = deviceStore.getPorts(DID1);
+        for (Port port : ports) {
+            assertTrue("Port is enabled", port.isEnabled());
+            assertTrue("PortNumber is one of expected",
+                    expectedPorts.remove(port.number()));
+        }
+        assertTrue("Event for all expectedport appeared", expectedPorts.isEmpty());
+
+
+        assertTrue("DID2 has no ports", deviceStore.getPorts(DID2).isEmpty());
+    }
+
+    @Test
+    public final void testGetPort() {
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true),
+                new DefaultPortDescription(P2, false)
+                );
+        deviceStore.updatePorts(DID1, pds);
+
+        Port port1 = deviceStore.getPort(DID1, P1);
+        assertEquals(P1, port1.number());
+        assertTrue("Port is enabled", port1.isEnabled());
+
+        Port port2 = deviceStore.getPort(DID1, P2);
+        assertEquals(P2, port2.number());
+        assertFalse("Port is disabled", port2.isEnabled());
+
+        Port port3 = deviceStore.getPort(DID1, P3);
+        assertNull("P3 not expected", port3);
+    }
+
+    @Test
+    public final void testRemoveDevice() {
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW1);
+
+        assertEquals(2, deviceStore.getDeviceCount());
+
+        DeviceEvent event = deviceStore.removeDevice(DID1);
+        assertEquals(DEVICE_REMOVED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+
+        assertEquals(1, deviceStore.getDeviceCount());
+    }
+
+    // If Delegates should be called only on remote events,
+    // then Simple* should never call them, thus not test required.
+    // TODO add test for Port events when we have them
+    @Ignore("Ignore until Delegate spec. is clear.")
+    @Test
+    public final void testEvents() throws InterruptedException {
+        final CountDownLatch addLatch = new CountDownLatch(1);
+        DeviceStoreDelegate checkAdd = new DeviceStoreDelegate() {
+            @Override
+            public void notify(DeviceEvent event) {
+                assertEquals(DEVICE_ADDED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                addLatch.countDown();
+            }
+        };
+        final CountDownLatch updateLatch = new CountDownLatch(1);
+        DeviceStoreDelegate checkUpdate = new DeviceStoreDelegate() {
+            @Override
+            public void notify(DeviceEvent event) {
+                assertEquals(DEVICE_UPDATED, event.type());
+                assertDevice(DID1, SW2, event.subject());
+                updateLatch.countDown();
+            }
+        };
+        final CountDownLatch removeLatch = new CountDownLatch(1);
+        DeviceStoreDelegate checkRemove = new DeviceStoreDelegate() {
+            @Override
+            public void notify(DeviceEvent event) {
+                assertEquals(DEVICE_REMOVED, event.type());
+                assertDevice(DID1, SW2, event.subject());
+                removeLatch.countDown();
+            }
+        };
+
+        DeviceDescription description =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW1, SN);
+        deviceStore.setDelegate(checkAdd);
+        deviceStore.createOrUpdateDevice(PID, DID1, description);
+        assertTrue("Add event fired", addLatch.await(1, TimeUnit.SECONDS));
+
+
+        DeviceDescription description2 =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW2, SN);
+        deviceStore.unsetDelegate(checkAdd);
+        deviceStore.setDelegate(checkUpdate);
+        deviceStore.createOrUpdateDevice(PID, DID1, description2);
+        assertTrue("Update event fired", updateLatch.await(1, TimeUnit.SECONDS));
+
+        deviceStore.unsetDelegate(checkUpdate);
+        deviceStore.setDelegate(checkRemove);
+        deviceStore.removeDevice(DID1);
+        assertTrue("Remove event fired", removeLatch.await(1, TimeUnit.SECONDS));
+    }
+}

+package org.onlab.onos.net.trivial.impl;
+
+import static org.junit.Assert.*;
+import static org.onlab.onos.net.DeviceId.deviceId;
+import static org.onlab.onos.net.Link.Type.*;
+import static org.onlab.onos.net.link.LinkEvent.Type.*;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.LinkKey;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.Link.Type;
+import org.onlab.onos.net.link.DefaultLinkDescription;
+import org.onlab.onos.net.link.LinkEvent;
+import org.onlab.onos.net.link.LinkStore;
+import org.onlab.onos.net.link.LinkStoreDelegate;
+import org.onlab.onos.net.provider.ProviderId;
+
+import com.google.common.collect.Iterables;
+
+/**
+ * Test of the simple LinkStore implementation.
+ */
+public class SimpleLinkStoreTest {
+
+    private static final ProviderId PID = new ProviderId("of", "foo");
+    private static final DeviceId DID1 = deviceId("of:foo");
+    private static final DeviceId DID2 = deviceId("of:bar");
+
+    private static final PortNumber P1 = PortNumber.portNumber(1);
+    private static final PortNumber P2 = PortNumber.portNumber(2);
+    private static final PortNumber P3 = PortNumber.portNumber(3);
+
+
+    private SimpleLinkStore simpleLinkStore;
+    private LinkStore linkStore;
+
+    @BeforeClass
+    public static void setUpBeforeClass() throws Exception {
+    }
+
+    @AfterClass
+    public static void tearDownAfterClass() throws Exception {
+    }
+
+    @Before
+    public void setUp() throws Exception {
+        simpleLinkStore = new SimpleLinkStore();
+        simpleLinkStore.activate();
+        linkStore = simpleLinkStore;
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        simpleLinkStore.deactivate();
+    }
+
+    private void putLink(DeviceId srcId, PortNumber srcNum,
+                         DeviceId dstId, PortNumber dstNum, Type type) {
+        ConnectPoint src = new ConnectPoint(srcId, srcNum);
+        ConnectPoint dst = new ConnectPoint(dstId, dstNum);
+        linkStore.createOrUpdateLink(PID, new DefaultLinkDescription(src, dst, type));
+    }
+
+    private void putLink(LinkKey key, Type type) {
+        putLink(key.src().deviceId(), key.src().port(),
+                key.dst().deviceId(), key.dst().port(),
+                type);
+    }
+
+    private static void assertLink(DeviceId srcId, PortNumber srcNum,
+                            DeviceId dstId, PortNumber dstNum, Type type,
+                            Link link) {
+        assertEquals(srcId, link.src().deviceId());
+        assertEquals(srcNum, link.src().port());
+        assertEquals(dstId, link.dst().deviceId());
+        assertEquals(dstNum, link.dst().port());
+        assertEquals(type, link.type());
+    }
+
+    private static void assertLink(LinkKey key, Type type, Link link) {
+        assertLink(key.src().deviceId(), key.src().port(),
+                   key.dst().deviceId(), key.dst().port(),
+                   type, link);
+    }
+
+    @Test
+    public final void testGetLinkCount() {
+        assertEquals("initialy empty", 0, linkStore.getLinkCount());
+
+        putLink(DID1, P1, DID2, P2, DIRECT);
+        putLink(DID2, P2, DID1, P1, DIRECT);
+        putLink(DID1, P1, DID2, P2, DIRECT);
+
+        assertEquals("expecting 2 unique link", 2, linkStore.getLinkCount());
+    }
+
+    @Test
+    public final void testGetLinks() {
+        assertEquals("initialy empty", 0,
+                Iterables.size(linkStore.getLinks()));
+
+        LinkKey linkId1 = new LinkKey(new ConnectPoint(DID1, P1), new ConnectPoint(DID2, P2));
+        LinkKey linkId2 = new LinkKey(new ConnectPoint(DID2, P2), new ConnectPoint(DID1, P1));
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+        putLink(linkId1, DIRECT);
+
+        assertEquals("expecting 2 unique link", 2,
+                Iterables.size(linkStore.getLinks()));
+
+        Map<LinkKey, Link> links = new HashMap<>();
+        for (Link link : linkStore.getLinks()) {
+            links.put(new LinkKey(link.src(), link.dst()), link);
+        }
+
+        assertLink(linkId1, DIRECT, links.get(linkId1));
+        assertLink(linkId2, DIRECT, links.get(linkId2));
+    }
+
+    @Test
+    public final void testGetDeviceEgressLinks() {
+        LinkKey linkId1 = new LinkKey(new ConnectPoint(DID1, P1), new ConnectPoint(DID2, P2));
+        LinkKey linkId2 = new LinkKey(new ConnectPoint(DID2, P2), new ConnectPoint(DID1, P1));
+        LinkKey linkId3 = new LinkKey(new ConnectPoint(DID1, P2), new ConnectPoint(DID2, P3));
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+        putLink(linkId3, DIRECT);
+
+        // DID1,P1 => DID2,P2
+        // DID2,P2 => DID1,P1
+        // DID1,P2 => DID2,P3
+
+        Set<Link> links1 = linkStore.getDeviceEgressLinks(DID1);
+        assertEquals(2, links1.size());
+        // check
+
+        Set<Link> links2 = linkStore.getDeviceEgressLinks(DID2);
+        assertEquals(1, links2.size());
+        assertLink(linkId2, DIRECT, links2.iterator().next());
+    }
+
+    @Test
+    public final void testGetDeviceIngressLinks() {
+        LinkKey linkId1 = new LinkKey(new ConnectPoint(DID1, P1), new ConnectPoint(DID2, P2));
+        LinkKey linkId2 = new LinkKey(new ConnectPoint(DID2, P2), new ConnectPoint(DID1, P1));
+        LinkKey linkId3 = new LinkKey(new ConnectPoint(DID1, P2), new ConnectPoint(DID2, P3));
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+        putLink(linkId3, DIRECT);
+
+        // DID1,P1 => DID2,P2
+        // DID2,P2 => DID1,P1
+        // DID1,P2 => DID2,P3
+
+        Set<Link> links1 = linkStore.getDeviceIngressLinks(DID2);
+        assertEquals(2, links1.size());
+        // check
+
+        Set<Link> links2 = linkStore.getDeviceIngressLinks(DID1);
+        assertEquals(1, links2.size());
+        assertLink(linkId2, DIRECT, links2.iterator().next());
+    }
+
+    @Test
+    public final void testGetLink() {
+        ConnectPoint src = new ConnectPoint(DID1, P1);
+        ConnectPoint dst = new ConnectPoint(DID2, P2);
+        LinkKey linkId1 = new LinkKey(src, dst);
+
+        putLink(linkId1, DIRECT);
+
+        Link link = linkStore.getLink(src, dst);
+        assertLink(linkId1, DIRECT, link);
+
+        assertNull("There shouldn't be reverese link",
+                linkStore.getLink(dst, src));
+    }
+
+    @Test
+    public final void testGetEgressLinks() {
+        final ConnectPoint d1P1 = new ConnectPoint(DID1, P1);
+        final ConnectPoint d2P2 = new ConnectPoint(DID2, P2);
+        LinkKey linkId1 = new LinkKey(d1P1, d2P2);
+        LinkKey linkId2 = new LinkKey(d2P2, d1P1);
+        LinkKey linkId3 = new LinkKey(new ConnectPoint(DID1, P2), new ConnectPoint(DID2, P3));
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+        putLink(linkId3, DIRECT);
+
+        // DID1,P1 => DID2,P2
+        // DID2,P2 => DID1,P1
+        // DID1,P2 => DID2,P3
+
+        Set<Link> links1 = linkStore.getEgressLinks(d1P1);
+        assertEquals(1, links1.size());
+        assertLink(linkId1, DIRECT, links1.iterator().next());
+
+        Set<Link> links2 = linkStore.getEgressLinks(d2P2);
+        assertEquals(1, links2.size());
+        assertLink(linkId2, DIRECT, links2.iterator().next());
+    }
+
+    @Test
+    public final void testGetIngressLinks() {
+        final ConnectPoint d1P1 = new ConnectPoint(DID1, P1);
+        final ConnectPoint d2P2 = new ConnectPoint(DID2, P2);
+        LinkKey linkId1 = new LinkKey(d1P1, d2P2);
+        LinkKey linkId2 = new LinkKey(d2P2, d1P1);
+        LinkKey linkId3 = new LinkKey(new ConnectPoint(DID1, P2), new ConnectPoint(DID2, P3));
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+        putLink(linkId3, DIRECT);
+
+        // DID1,P1 => DID2,P2
+        // DID2,P2 => DID1,P1
+        // DID1,P2 => DID2,P3
+
+        Set<Link> links1 = linkStore.getIngressLinks(d2P2);
+        assertEquals(1, links1.size());
+        assertLink(linkId1, DIRECT, links1.iterator().next());
+
+        Set<Link> links2 = linkStore.getIngressLinks(d1P1);
+        assertEquals(1, links2.size());
+        assertLink(linkId2, DIRECT, links2.iterator().next());
+    }
+
+    @Test
+    public final void testCreateOrUpdateLink() {
+        ConnectPoint src = new ConnectPoint(DID1, P1);
+        ConnectPoint dst = new ConnectPoint(DID2, P2);
+
+        // add link
+        LinkEvent event = linkStore.createOrUpdateLink(PID,
+                    new DefaultLinkDescription(src, dst, INDIRECT));
+
+        assertLink(DID1, P1, DID2, P2, INDIRECT, event.subject());
+        assertEquals(LINK_ADDED, event.type());
+
+        // update link type
+        LinkEvent event2 = linkStore.createOrUpdateLink(PID,
+                new DefaultLinkDescription(src, dst, DIRECT));
+
+        assertLink(DID1, P1, DID2, P2, DIRECT, event2.subject());
+        assertEquals(LINK_UPDATED, event2.type());
+
+        // no change
+        LinkEvent event3 = linkStore.createOrUpdateLink(PID,
+                new DefaultLinkDescription(src, dst, DIRECT));
+
+        assertNull("No change event expected", event3);
+    }
+
+    @Test
+    public final void testRemoveLink() {
+        final ConnectPoint d1P1 = new ConnectPoint(DID1, P1);
+        final ConnectPoint d2P2 = new ConnectPoint(DID2, P2);
+        LinkKey linkId1 = new LinkKey(d1P1, d2P2);
+        LinkKey linkId2 = new LinkKey(d2P2, d1P1);
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+
+        // DID1,P1 => DID2,P2
+        // DID2,P2 => DID1,P1
+        // DID1,P2 => DID2,P3
+
+        LinkEvent event = linkStore.removeLink(d1P1, d2P2);
+        assertEquals(LINK_REMOVED, event.type());
+        LinkEvent event2 = linkStore.removeLink(d1P1, d2P2);
+        assertNull(event2);
+
+        assertLink(linkId2, DIRECT, linkStore.getLink(d2P2, d1P1));
+    }
+
+    // If Delegates should be called only on remote events,
+    // then Simple* should never call them, thus not test required.
+    @Ignore("Ignore until Delegate spec. is clear.")
+    @Test
+    public final void testEvents() throws InterruptedException {
+
+        final ConnectPoint d1P1 = new ConnectPoint(DID1, P1);
+        final ConnectPoint d2P2 = new ConnectPoint(DID2, P2);
+        final LinkKey linkId1 = new LinkKey(d1P1, d2P2);
+
+        final CountDownLatch addLatch = new CountDownLatch(1);
+        LinkStoreDelegate checkAdd = new LinkStoreDelegate() {
+            @Override
+            public void notify(LinkEvent event) {
+                assertEquals(LINK_ADDED, event.type());
+                assertLink(linkId1, INDIRECT, event.subject());
+                addLatch.countDown();
+            }
+        };
+        final CountDownLatch updateLatch = new CountDownLatch(1);
+        LinkStoreDelegate checkUpdate = new LinkStoreDelegate() {
+            @Override
+            public void notify(LinkEvent event) {
+                assertEquals(LINK_UPDATED, event.type());
+                assertLink(linkId1, DIRECT, event.subject());
+                updateLatch.countDown();
+            }
+        };
+        final CountDownLatch removeLatch = new CountDownLatch(1);
+        LinkStoreDelegate checkRemove = new LinkStoreDelegate() {
+            @Override
+            public void notify(LinkEvent event) {
+                assertEquals(LINK_REMOVED, event.type());
+                assertLink(linkId1, DIRECT, event.subject());
+                removeLatch.countDown();
+            }
+        };
+
+        linkStore.setDelegate(checkAdd);
+        putLink(linkId1, INDIRECT);
+        assertTrue("Add event fired", addLatch.await(1, TimeUnit.SECONDS));
+
+        linkStore.unsetDelegate(checkAdd);
+        linkStore.setDelegate(checkUpdate);
+        putLink(linkId1, DIRECT);
+        assertTrue("Update event fired", updateLatch.await(1, TimeUnit.SECONDS));
+
+        linkStore.unsetDelegate(checkUpdate);
+        linkStore.setDelegate(checkRemove);
+        linkStore.removeLink(d1P1, d2P2);
+        assertTrue("Remove event fired", removeLatch.await(1, TimeUnit.SECONDS));
+    }
+}

@@ -48,7 +48,17 @@
              description="ONOS core components">
              description="ONOS core components">
         <feature>onos-api</feature>
         <feature>onos-api</feature>
         <bundle>mvn:org.onlab.onos/onos-core-net/1.0.0-SNAPSHOT</bundle>
         <bundle>mvn:org.onlab.onos/onos-core-net/1.0.0-SNAPSHOT</bundle>
-        <bundle>mvn:org.onlab.onos/onos-core-store/1.0.0-SNAPSHOT</bundle>
+        <bundle>mvn:org.onlab.onos/onos-core-dist/1.0.0-SNAPSHOT</bundle>
+    </feature>
+
+    <feature name="onos-core-hazelcast" version="1.0.0"
+             description="ONOS core components built on hazelcast">
+        <feature>onos-api</feature>
+        <bundle>mvn:org.onlab.onos/onos-core-net/1.0.0-SNAPSHOT</bundle>
+        <bundle>mvn:org.onlab.onos/onos-core-hz-common/1.0.0-SNAPSHOT</bundle>
+        <bundle>mvn:org.onlab.onos/onos-core-serializers/1.0.0-SNAPSHOT</bundle>
+        <bundle>mvn:org.onlab.onos/onos-core-hz-cluster/1.0.0-SNAPSHOT</bundle>
+        <bundle>mvn:org.onlab.onos/onos-core-hz-net/1.0.0-SNAPSHOT</bundle>
     </feature>
     </feature>
 
 
     <feature name="onos-core-trivial" version="1.0.0"
     <feature name="onos-core-trivial" version="1.0.0"

@@ -93,12 +93,16 @@ public abstract class AbstractOpenFlowSwitch implements OpenFlowSwitchDriver {
 
 
     @Override
     @Override
     public final void sendMsg(OFMessage m) {
     public final void sendMsg(OFMessage m) {
-        this.write(m);
+        if (role == RoleState.MASTER) {
+            this.write(m);
+        }
     }
     }
 
 
     @Override
     @Override
     public final void sendMsg(List<OFMessage> msgs) {
     public final void sendMsg(List<OFMessage> msgs) {
-        this.write(msgs);
+        if (role == RoleState.MASTER) {
+            this.write(msgs);
+        }
     }
     }
 
 
     @Override
     @Override
@@ -164,7 +168,9 @@ public abstract class AbstractOpenFlowSwitch implements OpenFlowSwitchDriver {
      */
      */
     @Override
     @Override
     public final void handleMessage(OFMessage m) {
     public final void handleMessage(OFMessage m) {
-        this.agent.processMessage(dpid, m);
+        if (this.role == RoleState.MASTER) {
+            this.agent.processMessage(dpid, m);
+        }
     }
     }
 
 
     @Override
     @Override
@@ -226,19 +232,34 @@ public abstract class AbstractOpenFlowSwitch implements OpenFlowSwitchDriver {
     @Override
     @Override
     public abstract void processDriverHandshakeMessage(OFMessage m);
     public abstract void processDriverHandshakeMessage(OFMessage m);
 
 
+
+    // Role Handling
+
     @Override
     @Override
     public void setRole(RoleState role) {
     public void setRole(RoleState role) {
         try {
         try {
-            log.info("Sending role {} to switch {}", role, getStringId());
             if (this.roleMan.sendRoleRequest(role, RoleRecvStatus.MATCHED_SET_ROLE)) {
             if (this.roleMan.sendRoleRequest(role, RoleRecvStatus.MATCHED_SET_ROLE)) {
-                this.role = role;
+                log.info("Sending role {} to switch {}", role, getStringId());
+                if (role == RoleState.SLAVE || role == RoleState.EQUAL) {
+                    this.role = role;
+                }
             }
             }
         } catch (IOException e) {
         } catch (IOException e) {
             log.error("Unable to write to switch {}.", this.dpid);
             log.error("Unable to write to switch {}.", this.dpid);
         }
         }
     }
     }
 
 
-    // Role Handling
+    @Override
+    public void reassertRole() {
+        if (this.getRole() == RoleState.MASTER) {
+            log.warn("Received permission error from switch {} while " +
+                    "being master. Reasserting master role.",
+                    this.getStringId());
+            this.setRole(RoleState.MASTER);
+        }
+    }
+
+
 
 
     @Override
     @Override
     public void handleRole(OFMessage m) throws SwitchStateException {
     public void handleRole(OFMessage m) throws SwitchStateException {
@@ -246,11 +267,15 @@ public abstract class AbstractOpenFlowSwitch implements OpenFlowSwitchDriver {
         RoleRecvStatus rrs = roleMan.deliverRoleReply(rri);
         RoleRecvStatus rrs = roleMan.deliverRoleReply(rri);
         if (rrs == RoleRecvStatus.MATCHED_SET_ROLE) {
         if (rrs == RoleRecvStatus.MATCHED_SET_ROLE) {
             if (rri.getRole() == RoleState.MASTER) {
             if (rri.getRole() == RoleState.MASTER) {
+                this.role = rri.getRole();
                 this.transitionToMasterSwitch();
                 this.transitionToMasterSwitch();
             } else if (rri.getRole() == RoleState.EQUAL ||
             } else if (rri.getRole() == RoleState.EQUAL ||
-                    rri.getRole() == RoleState.MASTER) {
+                    rri.getRole() == RoleState.SLAVE) {
                 this.transitionToEqualSwitch();
                 this.transitionToEqualSwitch();
             }
             }
+        }  else {
+            return;
+            //TODO: tell people that we failed.
         }
         }
     }
     }
 
 
@@ -267,11 +292,15 @@ public abstract class AbstractOpenFlowSwitch implements OpenFlowSwitchDriver {
                 new RoleReplyInfo(r, null, m.getXid()));
                 new RoleReplyInfo(r, null, m.getXid()));
         if (rrs == RoleRecvStatus.MATCHED_SET_ROLE) {
         if (rrs == RoleRecvStatus.MATCHED_SET_ROLE) {
             if (r == RoleState.MASTER) {
             if (r == RoleState.MASTER) {
+                this.role = r;
                 this.transitionToMasterSwitch();
                 this.transitionToMasterSwitch();
             } else if (r == RoleState.EQUAL ||
             } else if (r == RoleState.EQUAL ||
                     r == RoleState.SLAVE) {
                     r == RoleState.SLAVE) {
                 this.transitionToEqualSwitch();
                 this.transitionToEqualSwitch();
             }
             }
+        } else {
+            return;
+            //TODO: tell people that we failed.
         }
         }
     }
     }
 
 
@@ -285,12 +314,7 @@ public abstract class AbstractOpenFlowSwitch implements OpenFlowSwitchDriver {
         return true;
         return true;
     }
     }
 
 
-    @Override
-    public void reassertRole() {
-        if (this.getRole() == RoleState.MASTER) {
-            this.setRole(RoleState.MASTER);
-        }
-    }
+
 
 
     @Override
     @Override
     public final void setAgent(OpenFlowAgent ag) {
     public final void setAgent(OpenFlowAgent ag) {

@@ -521,9 +521,7 @@ class OFChannelHandler extends IdleStateAwareChannelHandler {
                     // if two controllers are master (even if its only for
                     // if two controllers are master (even if its only for
                     // a brief period). We might need to see if these errors
                     // a brief period). We might need to see if these errors
                     // persist before we reassert
                     // persist before we reassert
-                    log.warn("Received permission error from switch {} while" +
-                            "being master. Reasserting master role.",
-                            h.getSwitchInfoString());
+
                     h.sw.reassertRole();
                     h.sw.reassertRole();
                 } else if (m.getErrType() == OFErrorType.FLOW_MOD_FAILED &&
                 } else if (m.getErrType() == OFErrorType.FLOW_MOD_FAILED &&
                         ((OFFlowModFailedErrorMsg) m).getCode() ==
                         ((OFFlowModFailedErrorMsg) m).getCode() ==

@@ -142,9 +142,9 @@ class RoleManager implements RoleHandler {
             }
             }
             // OF1.0 switch with support for NX_ROLE_REQUEST vendor extn.
             // OF1.0 switch with support for NX_ROLE_REQUEST vendor extn.
             // make Role.EQUAL become Role.SLAVE
             // make Role.EQUAL become Role.SLAVE
+            pendingRole = role;
             role = (role == RoleState.EQUAL) ? RoleState.SLAVE : role;
             role = (role == RoleState.EQUAL) ? RoleState.SLAVE : role;
             pendingXid = sendNxRoleRequest(role);
             pendingXid = sendNxRoleRequest(role);
-            pendingRole = role;
             requestPending = true;
             requestPending = true;
         } else {
         } else {
             // OF1.3 switch, use OFPT_ROLE_REQUEST message
             // OF1.3 switch, use OFPT_ROLE_REQUEST message

-<project>
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4_0_0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <modelVersion>4.0.0</modelVersion>
   <groupId>org.onlab.tools</groupId>
   <groupId>org.onlab.tools</groupId>
   <artifactId>onos-build-conf</artifactId>
   <artifactId>onos-build-conf</artifactId>

@@ -15,7 +15,7 @@ env JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64
 
 
 pre-stop script
 pre-stop script
     /opt/onos/bin/onos halt 2>/opt/onos/var/stderr.log
     /opt/onos/bin/onos halt 2>/opt/onos/var/stderr.log
-    sleep 3
+    sleep 2
 end script
 end script
 
 
 script
 script

@@ -8,7 +8,21 @@
 
 
 remote=$ONOS_USER@${1:-$OCI}
 remote=$ONOS_USER@${1:-$OCI}
 
 
+# Generate a cluster.json from the ON* environment variables
+CDEF_FILE=/tmp/cluster.json
+echo "{ \"nodes\":[" > $CDEF_FILE
+for node in $(env | sort | egrep "OC[2-9]+" | cut -d= -f2); do
+    echo "  { \"id\": \"$node\", \"ip\": \"$node\", \"tcpPort\": 9876 }," >> $CDEF_FILE
+done
+echo "  { \"id\": \"$OC1\", \"ip\": \"$OC1\", \"tcpPort\": 9876 }" >> $CDEF_FILE
+echo "]}" >> $CDEF_FILE
+
 ssh $remote "
 ssh $remote "
     sudo perl -pi.bak -e \"s/            <interface>.*</            <interface>${ONOS_NIC:-192.168.56.*}</g\" \
     sudo perl -pi.bak -e \"s/            <interface>.*</            <interface>${ONOS_NIC:-192.168.56.*}</g\" \
         $ONOS_INSTALL_DIR/$KARAF_DIST/etc/hazelcast.xml
         $ONOS_INSTALL_DIR/$KARAF_DIST/etc/hazelcast.xml
-"
\ No newline at end of file
+
+    echo \"onos.ip = \$(ifconfig | grep $ONOS_NIC | cut -d: -f2 | cut -d\\  -f1)\" \
+        >> $ONOS_INSTALL_DIR/$KARAF_DIST/etc/system.properties
+"
+
+scp -q $CDEF_FILE $remote:$ONOS_INSTALL_DIR/config/
\ No newline at end of file

@@ -24,6 +24,7 @@ ssh $remote "
     # Make a link to the log file directory and make a home for auxiliaries
     # Make a link to the log file directory and make a home for auxiliaries
     ln -s $ONOS_INSTALL_DIR/$KARAF_DIST/data/log /opt/onos/log
     ln -s $ONOS_INSTALL_DIR/$KARAF_DIST/data/log /opt/onos/log
     mkdir $ONOS_INSTALL_DIR/var
     mkdir $ONOS_INSTALL_DIR/var
+    mkdir $ONOS_INSTALL_DIR/config
 
 
     # Install the upstart configuration file and setup options for debugging
     # Install the upstart configuration file and setup options for debugging
     sudo cp $ONOS_INSTALL_DIR/debian/onos.conf /etc/init/onos.conf
     sudo cp $ONOS_INSTALL_DIR/debian/onos.conf /etc/init/onos.conf

+#!/bin/bash
+#-------------------------------------------------------------------------------
+# Verifies connectivity to each node in ONOS cell.
+#-------------------------------------------------------------------------------
+
+[ ! -d "$ONOS_ROOT" ] && echo "ONOS_ROOT is not defined" >&2 && exit 1
+. $ONOS_ROOT/tools/build/envDefaults
+
+SSHCMD="ssh -o PasswordAuthentication=no"
+SCPCMD="scp -q -o PasswordAuthentication=no"
+
+echo "Copying topology files to mininet vm."
+$SSHCMD -n $ONOS_USER@$OCN mkdir -p topos
+$SCPCMD $ONOS_ROOT/tools/test/topos/* $ONOS_USER@$OCN:topos/
+
+echo "Starting Network."
+$SSHCMD -t $ONOS_USER@$OCN sudo python topos/sol.py $(env | sort | egrep "OC[0-9]+" | cut -d= -f2) 

 # Default virtual box ONOS instances 1,2 & ONOS mininet box
 # Default virtual box ONOS instances 1,2 & ONOS mininet box
 . $ONOS_ROOT/tools/test/cells/.reset
 . $ONOS_ROOT/tools/test/cells/.reset
 
 
+export ONOS_NIC=192.168.56.*
+
 export OC1="192.168.56.101"
 export OC1="192.168.56.101"
 export OC2="192.168.56.102"
 export OC2="192.168.56.102"
 
 

 #!/usr/bin/python
 #!/usr/bin/python
 import sys, solar
 import sys, solar
-topo = solar.Solar(cip=sys.argv[1])
+topo = solar.Solar(cips=sys.argv[1:])
 topo.run()
 topo.run()

@@ -17,22 +17,22 @@ class CustomCLI(CLI):
 class Solar(object):
 class Solar(object):
     """ Create a tiered topology from semi-scratch in Mininet """
     """ Create a tiered topology from semi-scratch in Mininet """
 
 
-    def __init__(self, cname='onos', cip='192.168.56.1', islands=3, edges=2, hosts=2,
-                 proto=None):
+    def __init__(self, cname='onos', cips=['192.168.56.1'], islands=3, edges=2, hosts=2):
         """Create tower topology for mininet"""
         """Create tower topology for mininet"""
 
 
         # We are creating the controller with local-loopback on purpose to avoid
         # We are creating the controller with local-loopback on purpose to avoid
         # having the switches connect immediately. Instead, we'll set controller
         # having the switches connect immediately. Instead, we'll set controller
         # explicitly for each switch after configuring it as we want.
         # explicitly for each switch after configuring it as we want.
-        self.flare = RemoteController(cname, cip, 6633)
-        self.net = Mininet(controller=self.flare, switch = OVSKernelSwitch,
+        self.ctrls = [ RemoteController(cname, cip, 6633) for cip in cips ]
+        self.net = Mininet(controller=RemoteController, switch = OVSKernelSwitch,
                            build=False)
                            build=False)
 
 
-        self.cip = cip
+        self.cips = cips
         self.spines = []
         self.spines = []
         self.leaves = []
         self.leaves = []
         self.hosts = []
         self.hosts = []
-        self.proto = proto
+        for ctrl in self.ctrls:
+            self.net.addController(ctrl)
 
 
         # Create the two core switches and links between them
         # Create the two core switches and links between them
         c1 = self.net.addSwitch('c1',dpid='1111000000000000')
         c1 = self.net.addSwitch('c1',dpid='1111000000000000')
@@ -83,29 +83,11 @@ class Solar(object):
 
 
     def run(self):
     def run(self):
         """ Runs the created network topology and launches mininet cli"""
         """ Runs the created network topology and launches mininet cli"""
-        self.run_silent()
+        self.net.build()
+        self.net.start()
         CustomCLI(self.net)
         CustomCLI(self.net)
         self.net.stop()
         self.net.stop()
 
 
-    def run_silent(self):
-        """ Runs silently - for unit testing """
-        self.net.build()
-
-        # Start the switches, configure them with desired protocols and only
-        # then set the controller
-        for sw in self.spines:
-            sw.start([self.flare])
-            if self.proto:
-                sw.cmd('ovs-vsctl set bridge %(sw)s protocols=%(proto)s' % \
-                           { 'sw': sw.name, 'proto': self.proto})
-            sw.cmdPrint('ovs-vsctl set-controller %(sw)s tcp:%(ctl)s:6633' % \
-                            {'sw': sw.name, 'ctl': self.cip})
-
-        for sw in self.leaves:
-            sw.start([self.flare])
-            sw.cmdPrint('ovs-vsctl set-controller %(sw)s tcp:%(ctl)s:6633' % \
-                            {'sw': sw.name, 'ctl': self.cip})
-
     def pingAll(self):
     def pingAll(self):
         """ PingAll to create flows - for unit testing """
         """ PingAll to create flows - for unit testing """
         self.net.pingAll()
         self.net.pingAll()

 package org.onlab.util;
 package org.onlab.util;
 
 
+import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.List;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.ConcurrentLinkedQueue;
@@ -8,6 +9,8 @@ import org.apache.commons.lang3.tuple.Pair;
 
 
 import com.esotericsoftware.kryo.Kryo;
 import com.esotericsoftware.kryo.Kryo;
 import com.esotericsoftware.kryo.Serializer;
 import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.io.ByteBufferInput;
+import com.esotericsoftware.kryo.io.ByteBufferOutput;
 import com.esotericsoftware.kryo.io.Input;
 import com.esotericsoftware.kryo.io.Input;
 import com.esotericsoftware.kryo.io.Output;
 import com.esotericsoftware.kryo.io.Output;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableList;
@@ -174,6 +177,22 @@ public final class KryoPool {
     }
     }
 
 
     /**
     /**
+     * Serializes given object to byte buffer using Kryo instance in pool.
+     *
+     * @param obj Object to serialize
+     * @param buffer to write to
+     */
+    public void serialize(final Object obj, final ByteBuffer buffer) {
+        ByteBufferOutput out = new ByteBufferOutput(buffer);
+        Kryo kryo = getKryo();
+        try {
+            kryo.writeClassAndObject(out, obj);
+        } finally {
+            putKryo(kryo);
+        }
+    }
+
+    /**
      * Deserializes given byte array to Object using Kryo instance in pool.
      * Deserializes given byte array to Object using Kryo instance in pool.
      *
      *
      * @param bytes serialized bytes
      * @param bytes serialized bytes
@@ -192,6 +211,24 @@ public final class KryoPool {
         }
         }
     }
     }
 
 
+    /**
+     * Deserializes given byte buffer to Object using Kryo instance in pool.
+     *
+     * @param buffer input with serialized bytes
+     * @param <T> deserialized Object type
+     * @return deserialized Object
+     */
+    public <T> T deserialize(final ByteBuffer buffer) {
+        ByteBufferInput in = new ByteBufferInput(buffer);
+        Kryo kryo = getKryo();
+        try {
+            @SuppressWarnings("unchecked")
+            T obj = (T) kryo.readClassAndObject(in);
+            return obj;
+        } finally {
+            putKryo(kryo);
+        }
+    }
 
 
     /**
     /**
      * Creates a Kryo instance with {@link #registeredTypes} pre-registered.
      * Creates a Kryo instance with {@link #registeredTypes} pre-registered.

@@ -54,6 +54,15 @@ public abstract class IOLoop<M extends Message, S extends MessageStream<M>>
     }
     }
 
 
     /**
     /**
+     * Returns the number of message stream in custody of the loop.
+     *
+     * @return number of message streams
+     */
+    public int streamCount() {
+        return streams.size();
+    }
+
+    /**
      * Creates a new message stream backed by the specified socket channel.
      * Creates a new message stream backed by the specified socket channel.
      *
      *
      * @param byteChannel backing byte channel
      * @param byteChannel backing byte channel
@@ -84,14 +93,9 @@ public abstract class IOLoop<M extends Message, S extends MessageStream<M>>
      *
      *
      * @param key selection key holding the pending connect operation.
      * @param key selection key holding the pending connect operation.
      */
      */
-    protected void connect(SelectionKey key) {
-        try {
-            SocketChannel ch = (SocketChannel) key.channel();
-            ch.finishConnect();
-        } catch (IOException | IllegalStateException e) {
-            log.warn("Unable to complete connection", e);
-        }
-
+    protected void connect(SelectionKey key) throws IOException {
+        SocketChannel ch = (SocketChannel) key.channel();
+        ch.finishConnect();
         if (key.isValid()) {
         if (key.isValid()) {
             key.interestOps(SelectionKey.OP_READ);
             key.interestOps(SelectionKey.OP_READ);
         }
         }
@@ -115,7 +119,11 @@ public abstract class IOLoop<M extends Message, S extends MessageStream<M>>
 
 
             // If there is a pending connect operation, complete it.
             // If there is a pending connect operation, complete it.
             if (key.isConnectable()) {
             if (key.isConnectable()) {
-                connect(key);
+                try {
+                    connect(key);
+                } catch (IOException | IllegalStateException e) {
+                    log.warn("Unable to complete connection", e);
+                }
             }
             }
 
 
             // If there is a read operation, slurp as much data as possible.
             // If there is a read operation, slurp as much data as possible.
@@ -182,9 +190,10 @@ public abstract class IOLoop<M extends Message, S extends MessageStream<M>>
      * with a pending accept operation.
      * with a pending accept operation.
      *
      *
      * @param channel backing socket channel
      * @param channel backing socket channel
+     * @return newly accepted message stream
      */
      */
-    public void acceptStream(SocketChannel channel) {
-        createAndAdmit(channel, SelectionKey.OP_READ);
+    public S acceptStream(SocketChannel channel) {
+        return createAndAdmit(channel, SelectionKey.OP_READ);
     }
     }
 
 
 
 
@@ -193,9 +202,10 @@ public abstract class IOLoop<M extends Message, S extends MessageStream<M>>
      * with a pending connect operation.
      * with a pending connect operation.
      *
      *
      * @param channel backing socket channel
      * @param channel backing socket channel
+     * @return newly connected message stream
      */
      */
-    public void connectStream(SocketChannel channel) {
-        createAndAdmit(channel, SelectionKey.OP_CONNECT);
+    public S connectStream(SocketChannel channel) {
+        return createAndAdmit(channel, SelectionKey.OP_CONNECT);
     }
     }
 
 
     /**
     /**
@@ -205,12 +215,14 @@ public abstract class IOLoop<M extends Message, S extends MessageStream<M>>
      * @param channel socket channel
      * @param channel socket channel
      * @param op      pending operations mask to be applied to the selection
      * @param op      pending operations mask to be applied to the selection
      *                key as a set of initial interestedOps
      *                key as a set of initial interestedOps
+     * @return newly created message stream
      */
      */
-    private synchronized void createAndAdmit(SocketChannel channel, int op) {
+    private synchronized S createAndAdmit(SocketChannel channel, int op) {
         S stream = createStream(channel);
         S stream = createStream(channel);
         streams.add(stream);
         streams.add(stream);
         newStreamRequests.add(new NewStreamRequest(stream, channel, op));
         newStreamRequests.add(new NewStreamRequest(stream, channel, op));
         selector.wakeup();
         selector.wakeup();
+        return stream;
     }
     }
 
 
     /**
     /**

@@ -10,6 +10,7 @@ import java.nio.channels.ByteChannel;
 import java.nio.channels.SelectionKey;
 import java.nio.channels.SelectionKey;
 import java.util.ArrayList;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.List;
+import java.util.Objects;
 
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -170,7 +171,7 @@ public abstract class MessageStream<M extends Message> {
     }
     }
 
 
     /**
     /**
-     * Reads, withouth blocking, a list of messages from the stream.
+     * Reads, without blocking, a list of messages from the stream.
      * The list will be empty if there were not messages pending.
      * The list will be empty if there were not messages pending.
      *
      *
      * @return list of messages or null if backing channel has been closed
      * @return list of messages or null if backing channel has been closed
@@ -262,7 +263,7 @@ public abstract class MessageStream<M extends Message> {
                 try {
                 try {
                     channel.write(outbound);
                     channel.write(outbound);
                 } catch (IOException e) {
                 } catch (IOException e) {
-                    if (!closed && !e.getMessage().equals("Broken pipe")) {
+                    if (!closed && !Objects.equals(e.getMessage(), "Broken pipe")) {
                         log.warn("Unable to write data", e);
                         log.warn("Unable to write data", e);
                         ioError = e;
                         ioError = e;
                     }
                     }

@@ -2,4 +2,4 @@
  * Mechanism to transfer messages over network using IO loop and
  * Mechanism to transfer messages over network using IO loop and
  * message stream, backed by NIO byte buffers.
  * message stream, backed by NIO byte buffers.
  */
  */
-package org.onlab.nio;
\ No newline at end of file
+package org.onlab.nio;

@@ -230,7 +230,7 @@ public class IOLoopTestClient {
         }
         }
 
 
         @Override
         @Override
-        protected void connect(SelectionKey key) {
+        protected void connect(SelectionKey key) throws IOException {
             super.connect(key);
             super.connect(key);
             TestMessageStream b = (TestMessageStream) key.attachment();
             TestMessageStream b = (TestMessageStream) key.attachment();
             Worker w = ((CustomIOLoop) b.loop()).worker;
             Worker w = ((CustomIOLoop) b.loop()).worker;