Merge remote-tracking branch 'origin/master'

Conflicts:
	apps/foo/pom.xml
	apps/foo/src/main/java/org/onlab/onos/ccc/DistributedClusterStore.java
	cli/src/main/java/org/onlab/onos/cli/NodeAddCommand.java
	cli/src/main/resources/OSGI-INF/blueprint/shell-config.xml
	tools/test/bin/onos-config
	utils/nio/src/main/java/org/onlab/nio/IOLoop.java

+<?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-apps</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-app-config</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS simple network configuration reader</description>
+
+    <dependencies>
+      <dependency>
+	<groupId>org.codehaus.jackson</groupId>
+	<artifactId>jackson-core-asl</artifactId>
+      </dependency>
+      <dependency>
+	<groupId>org.codehaus.jackson</groupId>
+	<artifactId>jackson-mapper-asl</artifactId>
+      </dependency>
+      <dependency>
+        <groupId>com.fasterxml.jackson.core</groupId>
+        <artifactId>jackson-annotations</artifactId>
+        <version>2.4.2</version>
+        <scope>provided</scope>
+      </dependency>
+    </dependencies> 
+
+</project>

+package org.onlab.onos.config;
+
+import java.util.Collections;
+import java.util.List;
+
+import org.codehaus.jackson.annotate.JsonProperty;
+
+/**
+ * Object to store address configuration read from a JSON file.
+ */
+public class AddressConfiguration {
+
+    private List<AddressEntry> addresses;
+
+    /**
+     * Gets a list of addresses in the system.
+     *
+     * @return the list of addresses
+     */
+    public List<AddressEntry> getAddresses() {
+        return Collections.unmodifiableList(addresses);
+    }
+
+    /**
+     * Sets a list of addresses in the system.
+     *
+     * @param addresses the list of addresses
+     */
+    @JsonProperty("addresses")
+    public void setAddresses(List<AddressEntry> addresses) {
+        this.addresses = addresses;
+    }
+
+}

+package org.onlab.onos.config;
+
+import java.util.List;
+
+import org.codehaus.jackson.annotate.JsonProperty;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.MacAddress;
+
+/**
+ * Represents a set of addresses bound to a port.
+ */
+public class AddressEntry {
+    private String dpid;
+    private short portNumber;
+    private List<IpPrefix> ipAddresses;
+    private MacAddress macAddress;
+
+    public String getDpid() {
+        return dpid;
+    }
+
+    @JsonProperty("dpid")
+    public void setDpid(String strDpid) {
+        this.dpid = strDpid;
+    }
+
+    public short getPortNumber() {
+        return portNumber;
+    }
+
+    @JsonProperty("port")
+    public void setPortNumber(short portNumber) {
+        this.portNumber = portNumber;
+    }
+
+    public List<IpPrefix> getIpAddresses() {
+        return ipAddresses;
+    }
+
+    @JsonProperty("ips")
+    public void setIpAddresses(List<IpPrefix> ipAddresses) {
+        this.ipAddresses = ipAddresses;
+    }
+
+    public MacAddress getMacAddress() {
+        return macAddress;
+    }
+
+    @JsonProperty("mac")
+    public void setMacAddress(MacAddress macAddress) {
+        this.macAddress = macAddress;
+    }
+}

+package org.onlab.onos.config;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
+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.codehaus.jackson.map.ObjectMapper;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.host.HostAdminService;
+import org.onlab.onos.net.host.PortAddresses;
+import org.slf4j.Logger;
+
+import com.google.common.collect.Sets;
+
+/**
+ * Simple configuration module to read in supplementary network configuration
+ * from a file.
+ */
+@Component(immediate = true)
+public class NetworkConfigReader {
+
+    private final Logger log = getLogger(getClass());
+
+    private static final String DEFAULT_CONFIG_FILE = "config/addresses.json";
+    private String configFileName = DEFAULT_CONFIG_FILE;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected HostAdminService hostAdminService;
+
+    @Activate
+    protected void activate() {
+        log.info("Started network config reader");
+
+        log.info("Config file set to {}", configFileName);
+
+        AddressConfiguration config = readNetworkConfig();
+
+        if (config != null) {
+            for (AddressEntry entry : config.getAddresses()) {
+
+                ConnectPoint cp = new ConnectPoint(
+                        DeviceId.deviceId(dpidToUri(entry.getDpid())),
+                        PortNumber.portNumber(entry.getPortNumber()));
+
+                PortAddresses addresses = new PortAddresses(cp,
+                        Sets.newHashSet(entry.getIpAddresses()),
+                        entry.getMacAddress());
+
+                hostAdminService.bindAddressesToPort(addresses);
+            }
+        }
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        log.info("Stopped");
+    }
+
+    private AddressConfiguration readNetworkConfig() {
+        File configFile = new File(configFileName);
+
+        ObjectMapper mapper = new ObjectMapper();
+
+        try {
+            AddressConfiguration config =
+                    mapper.readValue(configFile, AddressConfiguration.class);
+
+            return config;
+        } catch (FileNotFoundException e) {
+            log.warn("Configuration file not found: {}", configFileName);
+        } catch (IOException e) {
+            log.error("Unable to read config from file:", e);
+        }
+
+        return null;
+    }
+
+    private static String dpidToUri(String dpid) {
+        return "of:" + dpid.replace(":", "");
+    }
+}

+/**
+ * Simple configuration module to read in supplementary network configuration
+ * from a file.
+ */
+package org.onlab.onos.config;

+{
+    "interfaces" : [
+	{
+	    "dpid" : "00:00:00:00:00:00:01",
+	    "port" : "1",
+	    "ips" : ["192.168.10.101/24"],
+	    "mac" : "00:00:00:11:22:33"
+	},
+	{
+	    "dpid" : "00:00:00:00:00:00:02",
+	    "port" : "1",
+	    "ips" : ["192.168.20.101/24", "192.168.30.101/24"]
+	},
+	{
+	    "dpid" : "00:00:00:00:00:00:03",
+	    "port" : "1",
+	    "ips" : ["10.1.0.1/16"],
+	    "mac" : "00:00:00:00:00:01"
+	}
+    ]
+}

@@ -28,20 +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>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.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>

-package org.onlab.onos.ccc;
-
-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.ServerSocketChannel;
-import java.nio.channels.SocketChannel;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-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 final Logger log = LoggerFactory.getLogger(getClass());
-
-    private static final long CONNECTION_CUSTODIAN_DELAY = 100L;
-    private static final long CONNECTION_CUSTODIAN_FREQUENCY = 5000;
-
-    private static final long SELECT_TIMEOUT = 50;
-    private static final int WORKERS = 3;
-    private static final int INITIATORS = 2;
-    private static final int COMM_BUFFER_SIZE = 16 * 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 = 128 * 1024;
-    private static final int SO_RCV_BUFFER_SIZE = 128 * 1024;
-
-    private DefaultControllerNode self;
-    private final Map<NodeId, DefaultControllerNode> nodes = new ConcurrentHashMap<>();
-    private final Map<NodeId, State> states = new ConcurrentHashMap<>();
-    private final Map<NodeId, TLVMessageStream> streams = new ConcurrentHashMap<>();
-    private final Map<SocketChannel, DefaultControllerNode> nodesByChannel = new ConcurrentHashMap<>();
-
-    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 ExecutorService initiatorExecutors =
-            Executors.newFixedThreadPool(INITIATORS, namedThreads("onos-comm-initiator"));
-
-    private final Timer timer = new Timer();
-    private final TimerTask connectionCustodian = new ConnectionCustodian();
-
-    private ListenLoop listenLoop;
-    private List<CommLoop> commLoops = new ArrayList<>(WORKERS);
-
-    @Activate
-    public void activate() {
-        establishIdentity();
-        startCommunications();
-        startListening();
-        startInitiating();
-        log.info("Started");
-    }
-
-    @Deactivate
-    public void deactivate() {
-        listenLoop.shutdown();
-        for (CommLoop loop : commLoops) {
-            loop.shutdown();
-        }
-        log.info("Stopped");
-    }
-
-
-    // Establishes the controller's own identity.
-    private void establishIdentity() {
-        IpPrefix ip = valueOf(System.getProperty("onos.ip", "127.0.1.1"));
-        self = new DefaultControllerNode(new NodeId(ip.toString()), ip);
-        nodes.put(self.id(), self);
-    }
-
-    // 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);
-            }
-        }
-    }
-
-    // Starts listening for connections from peer cluster members.
-    private void startListening() {
-        try {
-            listenLoop = new ListenLoop(self.ip(), self.tcpPort());
-            listenExecutor.execute(listenLoop);
-        } 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);
-        loop.connectStream(ch);
-        ch.connect(sa);
-    }
-
-
-    // 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);
-    }
-
-    // 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);
-            log.info("Connected client");
-        }
-    }
-
-    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) {
-
-        }
-
-        @Override
-        public TLVMessageStream acceptStream(SocketChannel channel) {
-            TLVMessageStream stream = super.acceptStream(channel);
-            try {
-                InetSocketAddress sa = (InetSocketAddress) channel.getRemoteAddress();
-                log.info("Accepted a new connection from {}", IpPrefix.valueOf(sa.getAddress().getAddress()));
-            } 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.info("Opened connection to {}", node.id());
-                streams.put(node.id(), stream);
-            }
-            return stream;
-        }
-    }
-
-
-    // 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.warn("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.ccc;
-
-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 Object data;
-
-    /**
-     * Creates an immutable TLV message.
-     *
-     * @param type   message type
-     * @param length message length
-     * @param data   message data
-     */
-    public TLVMessage(int type, int length, Object data) {
-        this.length = length;
-        this.type = type;
-        this.data = data;
-    }
-
-    /**
-     * Returns the message type indicator.
-     *
-     * @return message type
-     */
-    public int type() {
-        return type;
-    }
-
-    /**
-     * Returns the data object.
-     *
-     * @return message data
-     */
-    public Object 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.ccc;
-
-import org.onlab.nio.IOLoop;
-import org.onlab.nio.MessageStream;
-
-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> {
-
-    private static final long MARKER = 0xfeedcafecafefeedL;
-
-    /**
-     * 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);
-    }
-
-    @Override
-    protected TLVMessage read(ByteBuffer buffer) {
-        long marker = buffer.getLong();
-        checkState(marker == MARKER, "Incorrect message marker");
-
-        int type = buffer.getInt();
-        int length = buffer.getInt();
-
-        // TODO: add deserialization hook here
-
-        return new TLVMessage(type, length, null);
-    }
-
-    @Override
-    protected void write(TLVMessage message, ByteBuffer buffer) {
-        buffer.putLong(MARKER);
-        buffer.putInt(message.type());
-        buffer.putInt(message.length());
-
-        // TODO: add serialization hook here
-    }
-}

@@ -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;

@@ -26,7 +26,9 @@ import org.onlab.onos.net.packet.InboundPacket;
 import org.onlab.onos.net.packet.PacketContext;
 import org.onlab.onos.net.packet.PacketContext;
 import org.onlab.onos.net.packet.PacketProcessor;
 import org.onlab.onos.net.packet.PacketProcessor;
 import org.onlab.onos.net.packet.PacketService;
 import org.onlab.onos.net.packet.PacketService;
+import org.onlab.onos.net.proxyarp.ProxyArpService;
 import org.onlab.onos.net.topology.TopologyService;
 import org.onlab.onos.net.topology.TopologyService;
+import org.onlab.packet.ARP;
 import org.onlab.packet.Ethernet;
 import org.onlab.packet.Ethernet;
 import org.slf4j.Logger;
 import org.slf4j.Logger;
 
 
@@ -50,6 +52,9 @@ public class ReactiveForwarding {
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected FlowRuleService flowRuleService;
     protected FlowRuleService flowRuleService;
 
 
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ProxyArpService proxyArpService;
+
     private ReactivePacketProcessor processor = new ReactivePacketProcessor();
     private ReactivePacketProcessor processor = new ReactivePacketProcessor();
 
 
     private ApplicationId appId;
     private ApplicationId appId;
@@ -85,6 +90,16 @@ public class ReactiveForwarding {
 
 
             InboundPacket pkt = context.inPacket();
             InboundPacket pkt = context.inPacket();
             Ethernet ethPkt = pkt.parsed();
             Ethernet ethPkt = pkt.parsed();
+            if (ethPkt.getEtherType() == Ethernet.TYPE_ARP) {
+                ARP arp = (ARP) ethPkt.getPayload();
+                if (arp.getOpCode() == ARP.OP_REPLY) {
+                    proxyArpService.forward(ethPkt);
+                } else if (arp.getOpCode() == ARP.OP_REQUEST) {
+                    proxyArpService.reply(ethPkt);
+                }
+                context.block();
+                return;
+            }
             HostId id = HostId.hostId(ethPkt.getDestinationMAC());
             HostId id = HostId.hostId(ethPkt.getDestinationMAC());
 
 
             // Do we know who this is for? If not, flood and bail.
             // Do we know who this is for? If not, flood and bail.

@@ -20,6 +20,7 @@
         <module>tvue</module>
         <module>tvue</module>
         <module>fwd</module>
         <module>fwd</module>
         <module>foo</module>
         <module>foo</module>
+	<module>config</module>
     </modules>
     </modules>
 
 
     <properties>
     <properties>

@@ -7,10 +7,10 @@ import org.onlab.onos.cluster.NodeId;
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.IpPrefix;
 
 
 /**
 /**
- * Lists all controller cluster nodes.
+ * Adds a new controller cluster node.
  */
  */
 @Command(scope = "onos", name = "add-node",
 @Command(scope = "onos", name = "add-node",
-         description = "Lists all controller cluster nodes")
+         description = "Adds a new controller cluster node")
 public class NodeAddCommand extends AbstractShellCommand {
 public class NodeAddCommand extends AbstractShellCommand {
 
 
     @Argument(index = 0, name = "nodeId", description = "Node ID",
     @Argument(index = 0, name = "nodeId", description = "Node ID",
@@ -21,7 +21,7 @@ public class NodeAddCommand extends AbstractShellCommand {
               required = true, multiValued = false)
               required = true, multiValued = false)
     String ip = null;
     String ip = null;
 
 
-    @Argument(index = 2, name = "tcpPort", description = "TCP port",
+    @Argument(index = 2, name = "tcpPort", description = "Node TCP listen port",
               required = false, multiValued = false)
               required = false, multiValued = false)
     int tcpPort = 9876;
     int tcpPort = 9876;
 
 

+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));
+    }
+
+}

@@ -8,6 +8,9 @@
             <action class="org.onlab.onos.cli.NodeAddCommand"/>
             <action class="org.onlab.onos.cli.NodeAddCommand"/>
         </command>
         </command>
         <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"/>

@@ -9,6 +9,8 @@ import org.onlab.onos.net.ConnectPoint;
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.MacAddress;
 
 
+import com.google.common.base.MoreObjects;
+
 /**
 /**
  * Represents address information bound to a port.
  * Represents address information bound to a port.
  */
  */
@@ -83,4 +85,13 @@ public class PortAddresses {
     public int hashCode() {
     public int hashCode() {
         return Objects.hash(connectPoint, ipAddresses, macAddress);
         return Objects.hash(connectPoint, ipAddresses, macAddress);
     }
     }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+            .add("connect-point", connectPoint)
+            .add("ip-addresses", ipAddresses)
+            .add("mac-address", macAddress)
+            .toString();
+    }
 }
 }

 package org.onlab.onos.net.link;
 package org.onlab.onos.net.link;
 
 
+import java.util.Set;
+
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.Link;
 
 
-import java.util.Set;
-
 /**
 /**
  * Service for interacting with the inventory of infrastructure links.
  * Service for interacting with the inventory of infrastructure links.
  */
  */

@@ -21,9 +21,16 @@ public interface ProxyArpService {
      * Sends a reply for a given request. If the host is not known then the arp
      * Sends a reply for a given request. If the host is not known then the arp
      * will be flooded at all edge ports.
      * will be flooded at all edge ports.
      *
      *
-     * @param request
+     * @param eth
      *            an arp request
      *            an arp request
      */
      */
-    void reply(Ethernet request);
+    void reply(Ethernet eth);
+
+    /**
+     * Forwards an ARP request to its destination. Floods at the edge the ARP request if the
+     * destination is not known.
+     * @param eth an ethernet frame containing an ARP request.
+     */
+    void forward(Ethernet eth);
 
 
 }
 }

 package org.onlab.onos.net.link;
 package org.onlab.onos.net.link;
 
 
+import java.util.Set;
+
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.Link;
 
 
-import java.util.Set;
-
 /**
 /**
  * Test adapter for link service.
  * Test adapter for link service.
  */
  */
@@ -63,4 +63,5 @@ public class LinkServiceAdapter implements LinkService {
     public void removeListener(LinkListener listener) {
     public void removeListener(LinkListener listener) {
     }
     }
 
 
+
 }
 }

@@ -53,7 +53,7 @@ public class LinkManager
     protected final AbstractListenerRegistry<LinkEvent, LinkListener>
     protected final AbstractListenerRegistry<LinkEvent, LinkListener>
             listenerRegistry = new AbstractListenerRegistry<>();
             listenerRegistry = new AbstractListenerRegistry<>();
 
 
-    private LinkStoreDelegate delegate = new InternalStoreDelegate();
+    private final LinkStoreDelegate delegate = new InternalStoreDelegate();
 
 
     private final DeviceListener deviceListener = new InternalDeviceListener();
     private final DeviceListener deviceListener = new InternalDeviceListener();
 
 

+package org.onlab.onos.net.proxyarp.impl;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.nio.ByteBuffer;
+import java.util.List;
+import java.util.Map.Entry;
+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.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.Host;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.device.DeviceEvent;
+import org.onlab.onos.net.device.DeviceListener;
+import org.onlab.onos.net.device.DeviceService;
+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.link.LinkEvent;
+import org.onlab.onos.net.link.LinkListener;
+import org.onlab.onos.net.link.LinkService;
+import org.onlab.onos.net.packet.DefaultOutboundPacket;
+import org.onlab.onos.net.packet.PacketService;
+import org.onlab.onos.net.proxyarp.ProxyArpService;
+import org.onlab.packet.ARP;
+import org.onlab.packet.Ethernet;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.VlanId;
+import org.slf4j.Logger;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Multimap;
+
+
+@Component(immediate = true)
+@Service
+public class ProxyArpManager implements ProxyArpService {
+
+    private final Logger log = getLogger(getClass());
+
+    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 LinkService linkService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected DeviceService deviceService;
+
+    private final Multimap<Device, PortNumber> internalPorts =
+            HashMultimap.<Device, PortNumber>create();
+
+    private final Multimap<Device, PortNumber> externalPorts =
+            HashMultimap.<Device, PortNumber>create();
+
+    /**
+     * Listens to both device service and link service to determine
+     * whether a port is internal or external.
+     */
+    @Activate
+    public void activate() {
+        deviceService.addListener(new InternalDeviceListener());
+        linkService.addListener(new InternalLinkListener());
+        determinePortLocations();
+        log.info("Started");
+    }
+
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @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 eth) {
+        checkNotNull(REQUEST_NULL, eth);
+        checkArgument(eth.getEtherType() == Ethernet.TYPE_ARP,
+                REQUEST_NOT_ARP);
+        ARP arp = (ARP) eth.getPayload();
+        checkArgument(arp.getOpCode() == ARP.OP_REQUEST, NOT_ARP_REQUEST);
+
+        VlanId vlan = VlanId.vlanId(eth.getVlanID());
+        Set<Host> hosts = hostService.getHostsByIp(IpPrefix.valueOf(arp
+                .getTargetProtocolAddress()));
+
+        Host dst = null;
+        Host src = hostService.getHost(HostId.hostId(eth.getSourceMAC(),
+                VlanId.vlanId(eth.getVlanID())));
+
+        for (Host host : hosts) {
+            if (host.vlan().equals(vlan)) {
+                dst = host;
+                break;
+            }
+        }
+
+        if (src == null || dst == null) {
+            flood(eth);
+            return;
+        }
+
+        Ethernet arpReply = buildArpReply(dst, eth);
+        // TODO: check send status with host service.
+        TrafficTreatment.Builder builder = new DefaultTrafficTreatment.Builder();
+        builder.setOutput(src.location().port());
+        packetService.emit(new DefaultOutboundPacket(src.location().deviceId(),
+                builder.build(), ByteBuffer.wrap(arpReply.serialize())));
+    }
+
+    @Override
+    public void forward(Ethernet eth) {
+        checkNotNull(REQUEST_NULL, eth);
+        checkArgument(eth.getEtherType() == Ethernet.TYPE_ARP,
+                REQUEST_NOT_ARP);
+        ARP arp = (ARP) eth.getPayload();
+        checkArgument(arp.getOpCode() == ARP.OP_REPLY, NOT_ARP_REQUEST);
+
+        Host h = hostService.getHost(HostId.hostId(eth.getDestinationMAC(),
+                VlanId.vlanId(eth.getVlanID())));
+
+        if (h == null) {
+            flood(eth);
+        } else {
+            TrafficTreatment.Builder builder = new DefaultTrafficTreatment.Builder();
+            builder.setOutput(h.location().port());
+            packetService.emit(new DefaultOutboundPacket(h.location().deviceId(),
+                    builder.build(), ByteBuffer.wrap(eth.serialize())));
+        }
+
+    }
+
+    /**
+     * Flood the arp request at all edges in the network.
+     * @param request the arp request.
+     */
+    private void flood(Ethernet request) {
+        TrafficTreatment.Builder builder = null;
+        ByteBuffer buf = ByteBuffer.wrap(request.serialize());
+
+        synchronized (externalPorts) {
+            for (Entry<Device, PortNumber> entry : externalPorts.entries()) {
+                builder = new DefaultTrafficTreatment.Builder();
+                builder.setOutput(entry.getValue());
+                packetService.emit(new DefaultOutboundPacket(entry.getKey().id(),
+                        builder.build(), buf));
+            }
+
+        }
+    }
+
+    /**
+     * Determines the location of all known ports in the system.
+     */
+    private void determinePortLocations() {
+        Iterable<Device> devices = deviceService.getDevices();
+        Iterable<Link> links = null;
+        List<PortNumber> ports = null;
+        for (Device d : devices) {
+            ports = buildPortNumberList(deviceService.getPorts(d.id()));
+            links = linkService.getLinks();
+            for (Link l : links) {
+                // for each link, mark the concerned ports as internal
+                // and the remaining ports are therefore external.
+                if (l.src().deviceId().equals(d)
+                        && ports.contains(l.src().port())) {
+                    ports.remove(l.src().port());
+                    internalPorts.put(d, l.src().port());
+                }
+                if (l.dst().deviceId().equals(d)
+                        && ports.contains(l.dst().port())) {
+                    ports.remove(l.dst().port());
+                    internalPorts.put(d, l.dst().port());
+                }
+            }
+            synchronized (externalPorts) {
+                externalPorts.putAll(d, ports);
+            }
+        }
+
+    }
+
+    private List<PortNumber> buildPortNumberList(List<Port> ports) {
+        List<PortNumber> portNumbers = Lists.newLinkedList();
+        for (Port p : ports) {
+            portNumbers.add(p.number());
+        }
+        return portNumbers;
+    }
+
+    /**
+     * Builds an arp reply based on a request.
+     * @param h the host we want to send to
+     * @param request the arp request we got
+     * @return an ethernet frame containing the arp reply
+     */
+    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);
+        eth.setVlanID(request.getVlanID());
+
+        ARP arp = new ARP();
+        arp.setOpCode(ARP.OP_REPLY);
+        arp.setProtocolType(ARP.PROTO_TYPE_IP);
+        arp.setHardwareType(ARP.HW_TYPE_ETHERNET);
+        arp.setProtocolAddressLength((byte) IpPrefix.INET_LEN);
+        arp.setHardwareAddressLength((byte) Ethernet.DATALAYER_ADDRESS_LENGTH);
+        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;
+    }
+
+    public class InternalLinkListener implements LinkListener {
+
+        @Override
+        public void event(LinkEvent event) {
+            Link link = event.subject();
+            Device src = deviceService.getDevice(link.src().deviceId());
+            Device dst = deviceService.getDevice(link.dst().deviceId());
+            switch (event.type()) {
+                case LINK_ADDED:
+                    synchronized (externalPorts) {
+                        externalPorts.remove(src, link.src().port());
+                        externalPorts.remove(dst, link.dst().port());
+                        internalPorts.put(src, link.src().port());
+                        internalPorts.put(dst, link.dst().port());
+                    }
+
+                    break;
+                case LINK_REMOVED:
+                    synchronized (externalPorts) {
+                        externalPorts.put(src, link.src().port());
+                        externalPorts.put(dst, link.dst().port());
+                        internalPorts.remove(src, link.src().port());
+                        internalPorts.remove(dst, link.dst().port());
+                    }
+
+                    break;
+                case LINK_UPDATED:
+                    // don't care about links being updated.
+                    break;
+                default:
+                    break;
+            }
+
+        }
+
+    }
+
+    public class InternalDeviceListener implements DeviceListener {
+
+        @Override
+        public void event(DeviceEvent event) {
+            Device device = event.subject();
+            switch (event.type()) {
+                case DEVICE_ADDED:
+                case DEVICE_AVAILABILITY_CHANGED:
+                case DEVICE_MASTERSHIP_CHANGED:
+                case DEVICE_SUSPENDED:
+                case DEVICE_UPDATED:
+                case PORT_UPDATED:
+                 // nothing to do in these cases; handled when links get reported
+                    break;
+                case DEVICE_REMOVED:
+                    synchronized (externalPorts) {
+                        externalPorts.removeAll(device);
+                        internalPorts.removeAll(device);
+                    }
+                    break;
+                case PORT_ADDED:
+                    synchronized (externalPorts) {
+                        externalPorts.put(device, event.port().number());
+                        internalPorts.remove(device, event.port().number());
+                    }
+                    break;
+                case PORT_REMOVED:
+                    synchronized (externalPorts) {
+                        externalPorts.remove(device, event.port().number());
+                        internalPorts.remove(device, event.port().number());
+                    }
+                    break;
+                default:
+                    break;
+
+            }
+
+        }
+
+}
+
+
+}

 /**
 /**
  * Core subsystem for responding to arp requests.
  * Core subsystem for responding to arp requests.
  */
  */
-package org.onlab.onos.proxyarp.impl;
\ No newline at end of file
+package org.onlab.onos.net.proxyarp.impl;

-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;
-    }
-}

@@ -33,8 +33,11 @@ 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.StoreManager;
+import org.onlab.onos.store.common.StoreService;
 import org.onlab.onos.store.common.TestStoreManager;
 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.serializers.KryoSerializationManager;
+import org.onlab.onos.store.serializers.KryoSerializationService;
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.IpPrefix;
 
 
 import java.util.ArrayList;
 import java.util.ArrayList;
@@ -92,6 +95,7 @@ public class DistributedDeviceManagerTest {
     private DistributedDeviceStore dstore;
     private DistributedDeviceStore dstore;
     private TestMastershipManager masterManager;
     private TestMastershipManager masterManager;
     private EventDeliveryService eventService;
     private EventDeliveryService eventService;
+    private KryoSerializationManager serializationMgr;
 
 
     @Before
     @Before
     public void setUp() {
     public void setUp() {
@@ -107,7 +111,10 @@ public class DistributedDeviceManagerTest {
         storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
         storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
         storeManager.activate();
         storeManager.activate();
 
 
-        dstore = new TestDistributedDeviceStore();
+        serializationMgr = new KryoSerializationManager();
+        serializationMgr.activate();
+
+        dstore = new TestDistributedDeviceStore(storeManager, serializationMgr);
         dstore.activate();
         dstore.activate();
 
 
         mgr.store = dstore;
         mgr.store = dstore;
@@ -133,6 +140,7 @@ public class DistributedDeviceManagerTest {
         mgr.deactivate();
         mgr.deactivate();
 
 
         dstore.deactivate();
         dstore.deactivate();
+        serializationMgr.deactivate();
         storeManager.deactivate();
         storeManager.deactivate();
     }
     }
 
 
@@ -163,7 +171,7 @@ 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 +190,10 @@ 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 +210,7 @@ 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 +226,7 @@ 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 +241,7 @@ 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 +255,7 @@ 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());
@@ -298,8 +306,10 @@ public class DistributedDeviceManagerTest {
 
 
     private class TestDistributedDeviceStore extends DistributedDeviceStore {
     private class TestDistributedDeviceStore extends DistributedDeviceStore {
 
 
-        public TestDistributedDeviceStore() {
-            this.storeService = storeManager;
+        public TestDistributedDeviceStore(StoreService storeService,
+                                    KryoSerializationService kryoSerializationService) {
+            this.storeService = storeService;
+            this.kryoSerializationService = kryoSerializationService;
         }
         }
     }
     }
 
 

@@ -26,6 +26,23 @@
             <artifactId>onos-core-serializers</artifactId>
             <artifactId>onos-core-serializers</artifactId>
             <version>${project.version}</version>
             <version>${project.version}</version>
         </dependency>
         </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>
         <dependency>
             <groupId>org.apache.felix</groupId>
             <groupId>org.apache.felix</groupId>
             <artifactId>org.apache.felix.scr.annotations</artifactId>
             <artifactId>org.apache.felix.scr.annotations</artifactId>

+package org.onlab.onos.store.cluster.impl;
+
+import org.onlab.nio.AcceptorLoop;
+import org.onlab.packet.IpPrefix;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.nio.channels.ServerSocketChannel;
+import java.nio.channels.SocketChannel;
+
+import static java.net.InetAddress.getByAddress;
+
+/**
+ * Listens to inbound connection requests and accepts them.
+ */
+public class ClusterConnectionListener extends AcceptorLoop {
+
+    private static final long SELECT_TIMEOUT = 50;
+    private static final int COMM_BUFFER_SIZE = 32 * 1024;
+
+    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 final WorkerFinder workerFinder;
+
+    ClusterConnectionListener(IpPrefix ip, int tcpPort,
+                              WorkerFinder workerFinder) throws IOException {
+        super(SELECT_TIMEOUT, new InetSocketAddress(getByAddress(ip.toOctets()), tcpPort));
+        this.workerFinder = workerFinder;
+    }
+
+    @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);
+
+        workerFinder.findWorker().acceptStream(sc);
+    }
+
+}

+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 org.onlab.nio.IOLoop;
+import org.onlab.nio.MessageStream;
+import org.onlab.onos.cluster.DefaultControllerNode;
+import org.onlab.onos.store.cluster.messaging.ClusterMessage;
+import org.onlab.onos.store.cluster.messaging.ClusterMessageStream;
+import org.onlab.onos.store.cluster.messaging.SerializationService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.nio.channels.ByteChannel;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.SocketChannel;
+import java.util.List;
+import java.util.Objects;
+
+import static org.onlab.packet.IpPrefix.valueOf;
+
+/**
+ * Performs the IO operations related to a cluster-wide communications.
+ */
+public class ClusterIOWorker extends
+        IOLoop<ClusterMessage, ClusterMessageStream> {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private static final long SELECT_TIMEOUT = 50;
+
+    private final ConnectionManager connectionManager;
+    private final CommunicationsDelegate commsDelegate;
+    private final SerializationService serializationService;
+    private final ClusterMessage helloMessage;
+
+    /**
+     * Creates a new cluster IO worker.
+     *
+     * @param connectionManager    parent connection manager
+     * @param commsDelegate        communications delegate for dispatching
+     * @param serializationService serialization service for encode/decode
+     * @param helloMessage         hello message for greeting peers
+     * @throws IOException if errors occur during IO loop ignition
+     */
+    ClusterIOWorker(ConnectionManager connectionManager,
+                    CommunicationsDelegate commsDelegate,
+                    SerializationService serializationService,
+                    ClusterMessage helloMessage) throws IOException {
+        super(SELECT_TIMEOUT);
+        this.connectionManager = connectionManager;
+        this.commsDelegate = commsDelegate;
+        this.serializationService = serializationService;
+        this.helloMessage = helloMessage;
+    }
+
+    @Override
+    protected ClusterMessageStream createStream(ByteChannel byteChannel) {
+        return new ClusterMessageStream(serializationService, this, byteChannel);
+    }
+
+    @Override
+    protected void processMessages(List<ClusterMessage> messages, MessageStream<ClusterMessage> stream) {
+        for (ClusterMessage message : messages) {
+            commsDelegate.dispatch(message);
+        }
+    }
+
+    @Override
+    public ClusterMessageStream acceptStream(SocketChannel channel) {
+        ClusterMessageStream stream = super.acceptStream(channel);
+        try {
+            InetSocketAddress sa = (InetSocketAddress) channel.getRemoteAddress();
+            log.info("Accepted connection from node {}", valueOf(sa.getAddress().getAddress()));
+            stream.write(helloMessage);
+
+        } catch (IOException e) {
+            log.warn("Unable to accept connection from an unknown end-point", e);
+        }
+        return stream;
+    }
+
+    @Override
+    protected void connect(SelectionKey key) throws IOException {
+        try {
+            super.connect(key);
+            ClusterMessageStream stream = (ClusterMessageStream) key.attachment();
+            stream.write(helloMessage);
+
+        } catch (IOException e) {
+            if (!Objects.equals(e.getMessage(), "Connection refused")) {
+                throw e;
+            }
+        }
+    }
+
+    @Override
+    protected void removeStream(MessageStream<ClusterMessage> stream) {
+        DefaultControllerNode node = ((ClusterMessageStream) stream).node();
+        if (node != null) {
+            log.info("Closed connection to node {}", node.id());
+            connectionManager.removeNodeStream(node);
+        }
+        super.removeStream(stream);
+    }
+
+}

+package org.onlab.onos.store.cluster.impl;
+
+import org.onlab.onos.cluster.DefaultControllerNode;
+
+/**
+ * Simple back interface through which connection manager can interact with
+ * the cluster store.
+ */
+public interface ClusterNodesDelegate {
+
+    /**
+     * Notifies about a new cluster node being detected.
+     *
+     * @param node newly detected cluster node
+     */
+    void nodeDetected(DefaultControllerNode node);
+
+    /**
+     * Notifies about cluster node going offline.
+     *
+     * @param node cluster node that vanished
+     */
+    void nodeVanished(DefaultControllerNode node);
+
+}

+package org.onlab.onos.store.cluster.impl;
+
+import org.onlab.onos.store.cluster.messaging.ClusterMessage;
+
+/**
+ * Simple back interface for interacting with the communications service.
+ */
+public interface CommunicationsDelegate {
+
+    /**
+     * Dispatches the specified message to all registered subscribers.
+     *
+     * @param message message to be dispatched
+     */
+    void dispatch(ClusterMessage message);
+
+    /**
+     * Sets the sender.
+     *
+     * @param messageSender message sender
+     */
+    void setSender(MessageSender messageSender);
+
+}

+package org.onlab.onos.store.cluster.impl;
+
+import org.onlab.onos.cluster.DefaultControllerNode;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.store.cluster.messaging.ClusterMessage;
+import org.onlab.onos.store.cluster.messaging.ClusterMessageStream;
+import org.onlab.onos.store.cluster.messaging.HelloMessage;
+import org.onlab.onos.store.cluster.messaging.SerializationService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.SocketAddress;
+import java.nio.channels.SocketChannel;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+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.util.Tools.namedThreads;
+
+/**
+ * Manages connections to other controller cluster nodes.
+ */
+public class ConnectionManager implements MessageSender {
+
+    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 int WORKERS = 3;
+
+    private ClusterConnectionListener connectionListener;
+    private List<ClusterIOWorker> workers = new ArrayList<>(WORKERS);
+
+    private final DefaultControllerNode localNode;
+    private final ClusterNodesDelegate nodesDelegate;
+    private final CommunicationsDelegate commsDelegate;
+    private final SerializationService serializationService;
+
+    // Nodes to be monitored to make sure they have a connection.
+    private final Set<DefaultControllerNode> nodes = new HashSet<>();
+
+    // Means to track message streams to other nodes.
+    private final Map<NodeId, ClusterMessageStream> streams = 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 final WorkerFinder workerFinder = new LeastUtilitiedWorkerFinder();
+
+
+    /**
+     * Creates a new connection manager.
+     */
+    ConnectionManager(DefaultControllerNode localNode,
+                      ClusterNodesDelegate nodesDelegate,
+                      CommunicationsDelegate commsDelegate,
+                      SerializationService serializationService) {
+        this.localNode = localNode;
+        this.nodesDelegate = nodesDelegate;
+        this.commsDelegate = commsDelegate;
+        this.serializationService = serializationService;
+
+        commsDelegate.setSender(this);
+        startCommunications();
+        startListening();
+        startInitiating();
+        log.info("Started");
+    }
+
+    /**
+     * Shuts down the connection manager.
+     */
+    void shutdown() {
+        connectionListener.shutdown();
+        for (ClusterIOWorker worker : workers) {
+            worker.shutdown();
+        }
+        log.info("Stopped");
+    }
+
+    /**
+     * Adds the node to the list of monitored nodes.
+     *
+     * @param node node to be added
+     */
+    void addNode(DefaultControllerNode node) {
+        nodes.add(node);
+    }
+
+    /**
+     * Removes the node from the list of monitored nodes.
+     *
+     * @param node node to be removed
+     */
+    void removeNode(DefaultControllerNode node) {
+        nodes.remove(node);
+        ClusterMessageStream stream = streams.remove(node.id());
+        if (stream != null) {
+            stream.close();
+        }
+    }
+
+    /**
+     * Removes the stream associated with the specified node.
+     *
+     * @param node node whose stream to remove
+     */
+    void removeNodeStream(DefaultControllerNode node) {
+        nodesDelegate.nodeVanished(node);
+        streams.remove(node.id());
+    }
+
+    @Override
+    public boolean send(NodeId nodeId, ClusterMessage message) {
+        ClusterMessageStream stream = streams.get(nodeId);
+        if (stream != null) {
+            try {
+                stream.write(message);
+                return true;
+            } catch (IOException e) {
+                log.warn("Unable to send a message about {} to node {}",
+                         message.subject(), nodeId);
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Kicks off the IO loops and waits for them to startup.
+     */
+    private void startCommunications() {
+        HelloMessage hello = new HelloMessage(localNode.id(), localNode.ip(),
+                                              localNode.tcpPort());
+        for (int i = 0; i < WORKERS; i++) {
+            try {
+                ClusterIOWorker worker =
+                        new ClusterIOWorker(this, commsDelegate,
+                                            serializationService, hello);
+                workers.add(worker);
+                commExecutors.execute(worker);
+            } catch (IOException e) {
+                log.warn("Unable to start communication worker", e);
+            }
+        }
+
+        // Wait for the IO loops to start
+        for (ClusterIOWorker loop : workers) {
+            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 {
+            connectionListener =
+                    new ClusterConnectionListener(localNode.ip(), localNode.tcpPort(),
+                                                  workerFinder);
+            listenExecutor.execute(connectionListener);
+            if (!connectionListener.awaitStart(START_TIMEOUT)) {
+                log.warn("Listener 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 initiateConnection(DefaultControllerNode node,
+                                    ClusterIOWorker loop) throws IOException {
+        SocketAddress sa = new InetSocketAddress(getByAddress(node.ip().toOctets()), node.tcpPort());
+        SocketChannel ch = SocketChannel.open();
+        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);
+    }
+
+    // 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) {
+                if (node != localNode && !streams.containsKey(node.id())) {
+                    try {
+                        initiateConnection(node, workerFinder.findWorker());
+                    } catch (IOException e) {
+                        log.debug("Unable to connect", e);
+                    }
+                }
+            }
+        }
+    }
+
+    // Finds the least utilitied IO loop.
+    private class LeastUtilitiedWorkerFinder implements WorkerFinder {
+
+        @Override
+        public ClusterIOWorker findWorker() {
+            ClusterIOWorker leastUtilized = null;
+            int minCount = Integer.MAX_VALUE;
+            for (ClusterIOWorker worker : workers) {
+                int count = worker.streamCount();
+                if (count == 0) {
+                    return worker;
+                }
+
+                if (count < minCount) {
+                    leastUtilized = worker;
+                    minCount = count;
+                }
+            }
+            return leastUtilized;
+        }
+    }
+
+}

+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.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+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.onos.store.cluster.messaging.SerializationService;
+import org.onlab.packet.IpPrefix;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static org.onlab.onos.cluster.ControllerNode.State;
+import static org.onlab.packet.IpPrefix.valueOf;
+
+/**
+ * Distributed implementation of the cluster nodes store.
+ */
+@Component(immediate = true)
+@Service
+public class DistributedClusterStore
+        extends AbstractStore<ClusterEvent, ClusterStoreDelegate>
+        implements ClusterStore {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private DefaultControllerNode localNode;
+    private final Map<NodeId, DefaultControllerNode> nodes = new ConcurrentHashMap<>();
+    private final Map<NodeId, State> states = new ConcurrentHashMap<>();
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    private CommunicationsDelegate commsDelegate;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    private SerializationService serializationService;
+
+    private final ClusterNodesDelegate nodesDelegate = new InnerNodesDelegate();
+    private ConnectionManager connectionManager;
+
+    @Activate
+    public void activate() {
+        loadClusterDefinition();
+        establishSelfIdentity();
+        connectionManager = new ConnectionManager(localNode, nodesDelegate,
+                                                  commsDelegate, serializationService);
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        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);
+        }
+    }
+
+    /**
+     * Determines who the local controller node is.
+     */
+    private void establishSelfIdentity() {
+        // Establishes the controller's own identity.
+        IpPrefix ip = valueOf(System.getProperty("onos.ip", "127.0.1.1"));
+        localNode = nodes.get(new NodeId(ip.toString()));
+
+        // As a fall-back, let's make sure we at least know who we are.
+        if (localNode == null) {
+            localNode = new DefaultControllerNode(new NodeId(ip.toString()), ip);
+            nodes.put(localNode.id(), localNode);
+            states.put(localNode.id(), State.ACTIVE);
+        }
+    }
+
+    @Override
+    public ControllerNode getLocalNode() {
+        return localNode;
+    }
+
+    @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);
+        connectionManager.addNode(node);
+        return node;
+    }
+
+    @Override
+    public void removeNode(NodeId nodeId) {
+        DefaultControllerNode node = nodes.remove(nodeId);
+        if (node != null) {
+            connectionManager.removeNode(node);
+        }
+    }
+
+    // Entity to handle back calls from the connection manager.
+    private class InnerNodesDelegate implements ClusterNodesDelegate {
+        @Override
+        public void nodeDetected(DefaultControllerNode node) {
+            nodes.put(node.id(), node);
+            states.put(node.id(), State.ACTIVE);
+        }
+
+        @Override
+        public void nodeVanished(DefaultControllerNode node) {
+            states.put(node.id(), State.INACTIVE);
+        }
+    }
+}

+package org.onlab.onos.store.cluster.impl;
+
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.store.cluster.messaging.ClusterMessage;
+
+/**
+ * Created by tom on 9/29/14.
+ */
+public interface MessageSender {
+
+    /**
+     * Sends the specified message to the given cluster node.
+     *
+     * @param nodeId  node identifier
+     * @param message mesage to send
+     * @return true if the message was sent sucessfully; false if there is
+     * no stream or if there was an error
+     */
+    boolean send(NodeId nodeId, ClusterMessage message);
+
+}

+package org.onlab.onos.store.cluster.impl;
+
+/**
+ * Provides means to find a worker IO loop.
+ */
+public interface WorkerFinder {
+
+    /**
+     * Finds a suitable worker.
+     *
+     * @return available worker
+     */
+    ClusterIOWorker findWorker();
+}

+package org.onlab.onos.store.cluster.messaging;
+
+import org.onlab.onos.cluster.NodeId;
+
+import java.util.Set;
+
+/**
+ * Service for assisting communications between controller cluster nodes.
+ */
+public interface ClusterCommunicationService {
+
+    /**
+     * Sends a message to the specified controller node.
+     *
+     * @param message  message to send
+     * @param toNodeId node identifier
+     * @return true if the message was sent sucessfully; false if there is
+     * no stream or if there was an error
+     */
+    boolean send(ClusterMessage message, NodeId toNodeId);
+
+    /**
+     * Adds a new subscriber for the specified message subject.
+     *
+     * @param subject    message subject
+     * @param subscriber message subscriber
+     */
+    void addSubscriber(MessageSubject subject, MessageSubscriber subscriber);
+
+    /**
+     * Removes the specified subscriber from the given message subject.
+     *
+     * @param subject    message subject
+     * @param subscriber message subscriber
+     */
+    void removeSubscriber(MessageSubject subject, MessageSubscriber subscriber);
+
+    /**
+     * Returns the set of subscribers for the specified message subject.
+     *
+     * @param subject message subject
+     * @return set of message subscribers
+     */
+    Set<MessageSubscriber> getSubscribers(MessageSubject subject);
+
+}

+package org.onlab.onos.store.cluster.messaging;
+
+import org.onlab.nio.AbstractMessage;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * Base message for cluster-wide communications.
+ */
+public abstract class ClusterMessage extends AbstractMessage {
+
+    private final MessageSubject subject;
+
+    /**
+     * Creates a cluster message.
+     *
+     * @param subject message subject
+     */
+    protected ClusterMessage(MessageSubject subject) {
+        this.subject = subject;
+    }
+
+    /**
+     * Returns the message subject indicator.
+     *
+     * @return message subject
+     */
+    public MessageSubject subject() {
+        return subject;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this).add("subject", subject).add("length", length).toString();
+    }
+
+}

+package org.onlab.onos.store.cluster.messaging;
+
+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 messages between two cluster members.
+ */
+public class ClusterMessageStream extends MessageStream<ClusterMessage> {
+
+    private static final int COMM_BUFFER_SIZE = 32 * 1024;
+    private static final int COMM_IDLE_TIME = 500;
+
+    private DefaultControllerNode node;
+    private SerializationService serializationService;
+
+    /**
+     * Creates a message stream associated with the specified IO loop and
+     * backed by the given byte channel.
+     *
+     * @param serializationService service for encoding/decoding messages
+     * @param loop                 IO loop
+     * @param byteChannel          backing byte channel
+     */
+    public ClusterMessageStream(SerializationService serializationService,
+                                IOLoop<ClusterMessage, ?> loop,
+                                ByteChannel byteChannel) {
+        super(loop, byteChannel, COMM_BUFFER_SIZE, COMM_IDLE_TIME);
+        this.serializationService = serializationService;
+    }
+
+    /**
+     * Returns the node with which this stream is associated.
+     *
+     * @return controller node
+     */
+    public DefaultControllerNode node() {
+        return node;
+    }
+
+    /**
+     * Sets the node with which this stream is affiliated.
+     *
+     * @param node controller node
+     */
+    public void setNode(DefaultControllerNode node) {
+        checkState(this.node == null, "Stream is already bound to a node");
+        this.node = node;
+    }
+
+    @Override
+    protected ClusterMessage read(ByteBuffer buffer) {
+        return serializationService.decode(buffer);
+    }
+
+    @Override
+    protected void write(ClusterMessage message, ByteBuffer buffer) {
+        serializationService.encode(message, buffer);
+    }
+
+}

+package org.onlab.onos.store.cluster.messaging;
+
+import org.onlab.onos.cluster.NodeId;
+
+/**l
+ * Echo heart-beat message that nodes send to each other.
+ */
+public class EchoMessage extends ClusterMessage {
+
+    private NodeId nodeId;
+
+    // For serialization
+    private EchoMessage() {
+        super(MessageSubject.HELLO);
+        nodeId = null;
+    }
+
+    /**
+     * Creates a new heart-beat echo message.
+     *
+     * @param nodeId    sending node identification
+     */
+    public EchoMessage(NodeId nodeId) {
+        super(MessageSubject.HELLO);
+        nodeId = nodeId;
+    }
+
+    /**
+     * Returns the sending node identifer.
+     *
+     * @return node identifier
+     */
+    public NodeId nodeId() {
+        return nodeId;
+    }
+
+}

+package org.onlab.onos.store.cluster.messaging;
+
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.packet.IpPrefix;
+
+/**
+ * Hello message that nodes use to greet each other.
+ */
+public class HelloMessage extends ClusterMessage {
+
+    private NodeId nodeId;
+    private IpPrefix ipAddress;
+    private int tcpPort;
+
+    // For serialization
+    private HelloMessage() {
+        super(MessageSubject.HELLO);
+        nodeId = null;
+        ipAddress = null;
+        tcpPort = 0;
+    }
+
+    /**
+     * Creates a new hello message for the specified end-point data.
+     *
+     * @param nodeId    sending node identification
+     * @param ipAddress sending node IP address
+     * @param tcpPort   sending node TCP port
+     */
+    public HelloMessage(NodeId nodeId, IpPrefix ipAddress, int tcpPort) {
+        super(MessageSubject.HELLO);
+        nodeId = nodeId;
+        ipAddress = ipAddress;
+        tcpPort = tcpPort;
+    }
+
+    /**
+     * Returns the sending node identifer.
+     *
+     * @return node identifier
+     */
+    public NodeId nodeId() {
+        return nodeId;
+    }
+
+    /**
+     * Returns the sending node IP address.
+     *
+     * @return node IP address
+     */
+    public IpPrefix ipAddress() {
+        return ipAddress;
+    }
+
+    /**
+     * Returns the sending node TCP listen port.
+     *
+     * @return TCP listen port
+     */
+    public int tcpPort() {
+        return tcpPort;
+    }
+}

+package org.onlab.onos.store.cluster.messaging;
+
+/**
+ * Representation of a message subject.
+ */
+public enum MessageSubject {
+
+    /** Represents a first greeting message. */
+    HELLO,
+
+    /** Signifies a heart-beat message. */
+    ECHO
+
+}

+package org.onlab.onos.store.cluster.messaging;
+
+/**
+ * Represents a message consumer.
+ */
+public interface MessageSubscriber {
+
+    /**
+     * Receives the specified cluster message.
+     *
+     * @param message message to be received
+     */
+    void receive(ClusterMessage message);
+
+}

+package org.onlab.onos.store.cluster.messaging;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Service for serializing/deserializing intra-cluster messages.
+ */
+public interface SerializationService {
+
+    /**
+     * Decodes the specified byte buffer to obtain a message within.
+     *
+     * @param buffer byte buffer with message(s)
+     * @return parsed message
+     */
+    ClusterMessage decode(ByteBuffer buffer);
+
+    /**
+     * Encodes the specified message into the given byte buffer.
+     *
+     * @param message message to be encoded
+     * @param buffer byte buffer to receive the message data
+     */
+    void encode(ClusterMessage message, ByteBuffer buffer);
+
+}

+package org.onlab.onos.store.cluster.messaging.impl;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Multimap;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.store.cluster.impl.CommunicationsDelegate;
+import org.onlab.onos.store.cluster.impl.MessageSender;
+import org.onlab.onos.store.cluster.messaging.ClusterCommunicationService;
+import org.onlab.onos.store.cluster.messaging.ClusterMessage;
+import org.onlab.onos.store.cluster.messaging.MessageSubject;
+import org.onlab.onos.store.cluster.messaging.MessageSubscriber;
+
+import java.util.Set;
+
+/**
+ * Implements the cluster communication services to use by other stores.
+ */
+@Component(immediate = true)
+@Service
+public class ClusterCommunicationManager
+        implements ClusterCommunicationService, CommunicationsDelegate {
+
+    // TODO: use something different that won't require synchronization
+    private Multimap<MessageSubject, MessageSubscriber> subscribers = HashMultimap.create();
+    private MessageSender messageSender;
+
+    @Override
+    public boolean send(ClusterMessage message, NodeId toNodeId) {
+        return messageSender.send(toNodeId, message);
+    }
+
+    @Override
+    public synchronized void addSubscriber(MessageSubject subject, MessageSubscriber subscriber) {
+        subscribers.put(subject, subscriber);
+    }
+
+    @Override
+    public synchronized void removeSubscriber(MessageSubject subject, MessageSubscriber subscriber) {
+        subscribers.remove(subject, subscriber);
+    }
+
+    @Override
+    public Set<MessageSubscriber> getSubscribers(MessageSubject subject) {
+        return ImmutableSet.copyOf(subscribers.get(subject));
+    }
+
+    @Override
+    public void dispatch(ClusterMessage message) {
+        Set<MessageSubscriber> set = getSubscribers(message.subject());
+        if (set != null) {
+            for (MessageSubscriber subscriber : set) {
+                subscriber.receive(message);
+            }
+        }
+    }
+
+    @Override
+    public void setSender(MessageSender messageSender) {
+        this.messageSender = messageSender;
+    }
+}

+package org.onlab.onos.store.cluster.messaging.impl;
+
+import org.onlab.onos.store.cluster.messaging.ClusterMessage;
+import org.onlab.onos.store.cluster.messaging.MessageSubject;
+import org.onlab.onos.store.cluster.messaging.SerializationService;
+
+import java.nio.ByteBuffer;
+
+import static com.google.common.base.Preconditions.checkState;
+
+/**
+ * Factory for parsing messages sent between cluster members.
+ */
+public class MessageSerializer implements SerializationService {
+
+    private static final int METADATA_LENGTH = 16; // 8 + 4 + 4
+    private static final int LENGTH_OFFSET = 12;
+
+    private static final long MARKER = 0xfeedcafebeaddeadL;
+
+    @Override
+    public ClusterMessage decode(ByteBuffer buffer) {
+        try {
+            // 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 subjectOrdinal = buffer.getInt();
+            MessageSubject subject = MessageSubject.values()[subjectOrdinal];
+            length = buffer.getInt();
+
+            // TODO: sanity checking for length
+            byte[] data = new byte[length - METADATA_LENGTH];
+            buffer.get(data);
+
+            // TODO: add deserialization hook here; for now this hack
+            return null; // actually deserialize
+
+        } catch (Exception e) {
+            // TODO: recover from exceptions by forwarding stream to next marker
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    @Override
+    public void encode(ClusterMessage message, ByteBuffer buffer) {
+        try {
+            int i = 0;
+            // Type based lookup for proper encoder
+        } catch (Exception e) {
+            // TODO: recover from exceptions by forwarding stream to next marker
+            e.printStackTrace();
+        }
+    }
+
+}

@@ -86,46 +86,48 @@ public class OnosDistributedDeviceStore
 
 
     @Override
     @Override
     public Iterable<Device> getDevices() {
     public Iterable<Device> getDevices() {
-        // TODO builder v.s. copyOf. Guava semms to be using copyOf?
-        // FIXME: synchronize.
         Builder<Device> builder = ImmutableSet.builder();
         Builder<Device> builder = ImmutableSet.builder();
-        for (VersionedValue<? extends Device> device : devices.values()) {
+        synchronized (this) {
+            for (VersionedValue<Device> device : devices.values()) {
                 builder.add(device.entity());
                 builder.add(device.entity());
             }
             }
             return builder.build();
             return builder.build();
         }
         }
+    }
 
 
     @Override
     @Override
     public Device getDevice(DeviceId deviceId) {
     public Device getDevice(DeviceId deviceId) {
-        return devices.get(deviceId).entity();
+        VersionedValue<Device> device = devices.get(deviceId);
+        checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+        return device.entity();
     }
     }
 
 
     @Override
     @Override
     public DeviceEvent createOrUpdateDevice(ProviderId providerId, DeviceId deviceId,
     public DeviceEvent createOrUpdateDevice(ProviderId providerId, DeviceId deviceId,
                                             DeviceDescription deviceDescription) {
                                             DeviceDescription deviceDescription) {
-        Timestamp now = clockService.getTimestamp(deviceId);
+        Timestamp newTimestamp = clockService.getTimestamp(deviceId);
         VersionedValue<Device> device = devices.get(deviceId);
         VersionedValue<Device> device = devices.get(deviceId);
 
 
         if (device == null) {
         if (device == null) {
-            return createDevice(providerId, deviceId, deviceDescription, now);
+            return createDevice(providerId, deviceId, deviceDescription, newTimestamp);
         }
         }
 
 
-        checkState(now.compareTo(device.timestamp()) > 0,
+        checkState(newTimestamp.compareTo(device.timestamp()) > 0,
                 "Existing device has a timestamp in the future!");
                 "Existing device has a timestamp in the future!");
 
 
-        return updateDevice(providerId, device.entity(), deviceDescription, now);
+        return updateDevice(providerId, device.entity(), deviceDescription, newTimestamp);
     }
     }
 
 
     // Creates the device and returns the appropriate event if necessary.
     // Creates the device and returns the appropriate event if necessary.
     private DeviceEvent createDevice(ProviderId providerId, DeviceId deviceId,
     private DeviceEvent createDevice(ProviderId providerId, DeviceId deviceId,
                                      DeviceDescription desc, Timestamp timestamp) {
                                      DeviceDescription desc, Timestamp timestamp) {
-        DefaultDevice device = new DefaultDevice(providerId, deviceId, desc.type(),
+        Device device = new DefaultDevice(providerId, deviceId, desc.type(),
                                                  desc.manufacturer(),
                                                  desc.manufacturer(),
                                                  desc.hwVersion(), desc.swVersion(),
                                                  desc.hwVersion(), desc.swVersion(),
                                                  desc.serialNumber());
                                                  desc.serialNumber());
 
 
-        devices.put(deviceId, new VersionedValue<Device>(device, true, timestamp));
-        // FIXME: broadcast a message telling peers of a device event.
+        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);
         return new DeviceEvent(DEVICE_ADDED, device, null);
     }
     }
 
 
@@ -148,7 +150,7 @@ public class OnosDistributedDeviceStore
         }
         }
 
 
         // Otherwise merely attempt to change availability
         // Otherwise merely attempt to change availability
-        DefaultDevice updated = new DefaultDevice(providerId, device.id(),
+        Device updated = new DefaultDevice(providerId, device.id(),
                 desc.type(),
                 desc.type(),
                 desc.manufacturer(),
                 desc.manufacturer(),
                 desc.hwVersion(),
                 desc.hwVersion(),
@@ -196,18 +198,18 @@ public class OnosDistributedDeviceStore
             VersionedValue<Device> device = devices.get(deviceId);
             VersionedValue<Device> device = devices.get(deviceId);
             checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
             checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
             Map<PortNumber, VersionedValue<Port>> ports = getPortMap(deviceId);
             Map<PortNumber, VersionedValue<Port>> ports = getPortMap(deviceId);
-            Timestamp timestamp = clockService.getTimestamp(deviceId);
+            Timestamp newTimestamp = clockService.getTimestamp(deviceId);
 
 
             // Add new ports
             // Add new ports
             Set<PortNumber> processed = new HashSet<>();
             Set<PortNumber> processed = new HashSet<>();
             for (PortDescription portDescription : portDescriptions) {
             for (PortDescription portDescription : portDescriptions) {
                 VersionedValue<Port> port = ports.get(portDescription.portNumber());
                 VersionedValue<Port> port = ports.get(portDescription.portNumber());
                 if (port == null) {
                 if (port == null) {
-                    events.add(createPort(device, portDescription, ports, timestamp));
+                    events.add(createPort(device, portDescription, ports, newTimestamp));
                 }
                 }
-                checkState(timestamp.compareTo(port.timestamp()) > 0,
+                checkState(newTimestamp.compareTo(port.timestamp()) > 0,
                         "Existing port state has a timestamp in the future!");
                         "Existing port state has a timestamp in the future!");
-                events.add(updatePort(device, port, portDescription, ports, timestamp));
+                events.add(updatePort(device.entity(), port.entity(), portDescription, ports, newTimestamp));
                 processed.add(portDescription.portNumber());
                 processed.add(portDescription.portNumber());
             }
             }
 
 
@@ -233,19 +235,19 @@ public class OnosDistributedDeviceStore
     // Checks if the specified port requires update and if so, it replaces the
     // Checks if the specified port requires update and if so, it replaces the
     // existing entry in the map and returns corresponding event.
     // existing entry in the map and returns corresponding event.
     //@GuardedBy("this")
     //@GuardedBy("this")
-    private DeviceEvent updatePort(VersionedValue<Device> device, VersionedValue<Port> port,
+    private DeviceEvent updatePort(Device device, Port port,
                                    PortDescription portDescription,
                                    PortDescription portDescription,
                                    Map<PortNumber, VersionedValue<Port>> ports,
                                    Map<PortNumber, VersionedValue<Port>> ports,
                                    Timestamp timestamp) {
                                    Timestamp timestamp) {
-        if (port.entity().isEnabled() != portDescription.isEnabled()) {
+        if (port.isEnabled() != portDescription.isEnabled()) {
             VersionedValue<Port> updatedPort = new VersionedValue<Port>(
             VersionedValue<Port> updatedPort = new VersionedValue<Port>(
-                    new DefaultPort(device.entity(), portDescription.portNumber(),
+                    new DefaultPort(device, portDescription.portNumber(),
                                     portDescription.isEnabled()),
                                     portDescription.isEnabled()),
                     portDescription.isEnabled(),
                     portDescription.isEnabled(),
                     timestamp);
                     timestamp);
-            ports.put(port.entity().number(), updatedPort);
-            updatePortMap(device.entity().id(), ports);
-            return new DeviceEvent(PORT_UPDATED, device.entity(), updatedPort.entity());
+            ports.put(port.number(), updatedPort);
+            updatePortMap(device.id(), ports);
+            return new DeviceEvent(PORT_UPDATED, device, updatedPort.entity());
         }
         }
         return null;
         return null;
     }
     }
@@ -300,7 +302,7 @@ public class OnosDistributedDeviceStore
         Map<PortNumber, VersionedValue<Port>> ports = getPortMap(deviceId);
         Map<PortNumber, VersionedValue<Port>> ports = getPortMap(deviceId);
         VersionedValue<Port> port = ports.get(portDescription.portNumber());
         VersionedValue<Port> port = ports.get(portDescription.portNumber());
         Timestamp timestamp = clockService.getTimestamp(deviceId);
         Timestamp timestamp = clockService.getTimestamp(deviceId);
-        return updatePort(device, port, portDescription, ports, timestamp);
+        return updatePort(device.entity(), port.entity(), portDescription, ports, timestamp);
     }
     }
 
 
     @Override
     @Override

+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);
+        }
+    }
+}

@@ -49,6 +49,7 @@ public class DistributedClusterStore
     private final MembershipListener listener = new InternalMembershipListener();
     private final MembershipListener listener = new InternalMembershipListener();
     private final Map<NodeId, State> states = new ConcurrentHashMap<>();
     private final Map<NodeId, State> states = new ConcurrentHashMap<>();
 
 
+    @Override
     @Activate
     @Activate
     public void activate() {
     public void activate() {
         super.activate();
         super.activate();
@@ -56,9 +57,9 @@ public class DistributedClusterStore
 
 
         rawNodes = theInstance.getMap("nodes");
         rawNodes = theInstance.getMap("nodes");
         OptionalCacheLoader<NodeId, DefaultControllerNode> nodeLoader
         OptionalCacheLoader<NodeId, DefaultControllerNode> nodeLoader
-                = new OptionalCacheLoader<>(storeService, rawNodes);
+                = new OptionalCacheLoader<>(kryoSerializationService, 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();
 
 

@@ -52,7 +52,7 @@ implements MastershipStore {
 
 
         rawMasters = theInstance.getMap("masters");
         rawMasters = theInstance.getMap("masters");
         OptionalCacheLoader<DeviceId, NodeId> nodeLoader
         OptionalCacheLoader<DeviceId, NodeId> nodeLoader
-        = new OptionalCacheLoader<>(storeService, rawMasters);
+        = new OptionalCacheLoader<>(kryoSerializationService, rawMasters);
         masters = new AbsentInvalidatingLoadingCache<>(newBuilder().build(nodeLoader));
         masters = new AbsentInvalidatingLoadingCache<>(newBuilder().build(nodeLoader));
         rawMasters.addEntryListener(new RemoteMasterShipEventHandler(masters), true);
         rawMasters.addEntryListener(new RemoteMasterShipEventHandler(masters), true);
 
 
@@ -123,7 +123,7 @@ implements MastershipStore {
         return null;
         return null;
     }
     }
 
 
-    private class RemoteMasterShipEventHandler extends RemoteEventHandler<DeviceId, NodeId> {
+    private class RemoteMasterShipEventHandler extends RemoteCacheEventHandler<DeviceId, NodeId> {
         public RemoteMasterShipEventHandler(LoadingCache<DeviceId, Optional<NodeId>> cache) {
         public RemoteMasterShipEventHandler(LoadingCache<DeviceId, Optional<NodeId>> cache) {
             super(cache);
             super(cache);
         }
         }

@@ -6,6 +6,7 @@ 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;
@@ -14,6 +15,7 @@ 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.serializers.KryoSerializationService;
 import org.slf4j.Logger;
 import org.slf4j.Logger;
 
 
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -31,6 +33,9 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected StoreService storeService;
     protected StoreService storeService;
 
 
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected KryoSerializationService kryoSerializationService;
+
     protected HazelcastInstance theInstance;
     protected HazelcastInstance theInstance;
 
 
     @Activate
     @Activate
@@ -45,7 +50,7 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
      * @return serialized object
      * @return serialized object
      */
      */
     protected byte[] serialize(Object obj) {
     protected byte[] serialize(Object obj) {
-        return storeService.serialize(obj);
+        return kryoSerializationService.serialize(obj);
     }
     }
 
 
     /**
     /**
@@ -56,7 +61,7 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
      * @return deserialized object
      * @return deserialized object
      */
      */
     protected <T> T deserialize(byte[] bytes) {
     protected <T> T deserialize(byte[] bytes) {
-        return storeService.deserialize(bytes);
+        return kryoSerializationService.deserialize(bytes);
     }
     }
 
 
 
 
@@ -66,8 +71,9 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
      * @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 +81,26 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
          *
          *
          * @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 +110,10 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
 
 
         @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 +125,10 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
 
 
         @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 +164,80 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
         }
         }
     }
     }
 
 
+    /**
+     * 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) {
+        }
+    }
+
 }
 }

@@ -2,6 +2,8 @@ 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.serializers.KryoSerializationService;
+
 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;
@@ -16,28 +18,28 @@ import com.hazelcast.core.IMap;
 public final class OptionalCacheLoader<K, V> extends
 public final class OptionalCacheLoader<K, V> extends
         CacheLoader<K, Optional<V>> {
         CacheLoader<K, Optional<V>> {
 
 
-    private final StoreService storeService;
+    private final KryoSerializationService kryoSerializationService;
     private IMap<byte[], byte[]> rawMap;
     private IMap<byte[], byte[]> rawMap;
 
 
     /**
     /**
      * Constructor.
      * Constructor.
      *
      *
-     * @param storeService to use for serialization
+     * @param kryoSerializationService to use for serialization
      * @param rawMap underlying IMap
      * @param rawMap underlying IMap
      */
      */
-    public OptionalCacheLoader(StoreService storeService, IMap<byte[], byte[]> rawMap) {
-        this.storeService = checkNotNull(storeService);
+    public OptionalCacheLoader(KryoSerializationService kryoSerializationService, IMap<byte[], byte[]> rawMap) {
+        this.kryoSerializationService = checkNotNull(kryoSerializationService);
         this.rawMap = checkNotNull(rawMap);
         this.rawMap = checkNotNull(rawMap);
     }
     }
 
 
     @Override
     @Override
     public Optional<V> load(K key) throws Exception {
     public Optional<V> load(K key) throws Exception {
-        byte[] keyBytes = storeService.serialize(key);
+        byte[] keyBytes = kryoSerializationService.serialize(key);
         byte[] valBytes = rawMap.get(keyBytes);
         byte[] valBytes = rawMap.get(keyBytes);
         if (valBytes == null) {
         if (valBytes == null) {
             return Optional.absent();
             return Optional.absent();
         }
         }
-        V dev = storeService.deserialize(valBytes);
+        V dev = kryoSerializationService.deserialize(valBytes);
         return Optional.of(dev);
         return Optional.of(dev);
     }
     }
 }
 }

@@ -5,46 +5,14 @@ import com.hazelcast.config.FileSystemXmlConfig;
 import com.hazelcast.core.Hazelcast;
 import com.hazelcast.core.Hazelcast;
 import com.hazelcast.core.HazelcastInstance;
 import com.hazelcast.core.HazelcastInstance;
 
 
-import de.javakaffee.kryoserializers.URISerializer;
-
 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;
 import org.apache.felix.scr.annotations.Service;
 import org.apache.felix.scr.annotations.Service;
-import org.onlab.onos.cluster.ControllerNode;
-import org.onlab.onos.cluster.DefaultControllerNode;
-import org.onlab.onos.cluster.NodeId;
-import org.onlab.onos.net.ConnectPoint;
-import org.onlab.onos.net.DefaultDevice;
-import org.onlab.onos.net.DefaultLink;
-import org.onlab.onos.net.DefaultPort;
-import org.onlab.onos.net.Device;
-import org.onlab.onos.net.DeviceId;
-import org.onlab.onos.net.Element;
-import org.onlab.onos.net.Link;
-import org.onlab.onos.net.LinkKey;
-import org.onlab.onos.net.MastershipRole;
-import org.onlab.onos.net.Port;
-import org.onlab.onos.net.PortNumber;
-import org.onlab.onos.net.provider.ProviderId;
-import org.onlab.onos.store.serializers.ConnectPointSerializer;
-import org.onlab.onos.store.serializers.DefaultLinkSerializer;
-import org.onlab.onos.store.serializers.DefaultPortSerializer;
-import org.onlab.onos.store.serializers.DeviceIdSerializer;
-import org.onlab.onos.store.serializers.IpPrefixSerializer;
-import org.onlab.onos.store.serializers.LinkKeySerializer;
-import org.onlab.onos.store.serializers.NodeIdSerializer;
-import org.onlab.onos.store.serializers.PortNumberSerializer;
-import org.onlab.onos.store.serializers.ProviderIdSerializer;
-import org.onlab.packet.IpPrefix;
-import org.onlab.util.KryoPool;
 import org.slf4j.Logger;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.slf4j.LoggerFactory;
 
 
 import java.io.FileNotFoundException;
 import java.io.FileNotFoundException;
-import java.net.URI;
-import java.util.ArrayList;
-import java.util.HashMap;
 
 
 /**
 /**
  * Auxiliary bootstrap of distributed store.
  * Auxiliary bootstrap of distributed store.
@@ -58,55 +26,18 @@ public class StoreManager implements StoreService {
     private final Logger log = LoggerFactory.getLogger(getClass());
     private final Logger log = LoggerFactory.getLogger(getClass());
 
 
     protected HazelcastInstance instance;
     protected HazelcastInstance instance;
-    private KryoPool serializerPool;
-
 
 
     @Activate
     @Activate
     public void activate() {
     public void activate() {
         try {
         try {
             Config config = new FileSystemXmlConfig(HAZELCAST_XML_FILE);
             Config config = new FileSystemXmlConfig(HAZELCAST_XML_FILE);
             instance = Hazelcast.newHazelcastInstance(config);
             instance = Hazelcast.newHazelcastInstance(config);
-            setupKryoPool();
             log.info("Started");
             log.info("Started");
         } catch (FileNotFoundException e) {
         } catch (FileNotFoundException e) {
             log.error("Unable to configure Hazelcast", e);
             log.error("Unable to configure Hazelcast", e);
         }
         }
     }
     }
 
 
-    /**
-     * Sets up the common serialzers pool.
-     */
-    protected void setupKryoPool() {
-        // FIXME Slice out types used in common to separate pool/namespace.
-        serializerPool = KryoPool.newBuilder()
-                .register(ArrayList.class,
-                          HashMap.class,
-
-                          ControllerNode.State.class,
-                          Device.Type.class,
-
-                          DefaultControllerNode.class,
-                          DefaultDevice.class,
-                          MastershipRole.class,
-                          Port.class,
-                          Element.class,
-
-                          Link.Type.class
-                )
-                .register(IpPrefix.class, new IpPrefixSerializer())
-                .register(URI.class, new URISerializer())
-                .register(NodeId.class, new NodeIdSerializer())
-                .register(ProviderId.class, new ProviderIdSerializer())
-                .register(DeviceId.class, new DeviceIdSerializer())
-                .register(PortNumber.class, new PortNumberSerializer())
-                .register(DefaultPort.class, new DefaultPortSerializer())
-                .register(LinkKey.class, new LinkKeySerializer())
-                .register(ConnectPoint.class, new ConnectPointSerializer())
-                .register(DefaultLink.class, new DefaultLinkSerializer())
-                .build()
-                .populate(10);
-    }
-
     @Deactivate
     @Deactivate
     public void deactivate() {
     public void deactivate() {
         instance.shutdown();
         instance.shutdown();
@@ -118,18 +49,4 @@ public class StoreManager implements StoreService {
         return instance;
         return instance;
     }
     }
 
 
-
-    @Override
-    public byte[] serialize(final Object obj) {
-        return serializerPool.serialize(obj);
-    }
-
-    @Override
-    public <T> T deserialize(final byte[] bytes) {
-        if (bytes == null) {
-            return null;
-        }
-        return serializerPool.deserialize(bytes);
-    }
-
 }
 }

@@ -15,22 +15,4 @@ public interface StoreService {
      */
      */
     HazelcastInstance getHazelcastInstance();
     HazelcastInstance getHazelcastInstance();
 
 
-    /**
-     * Serializes the specified object into bytes using one of the
-     * pre-registered serializers.
-     *
-     * @param obj object to be serialized
-     * @return serialized bytes
-     */
-    public byte[] serialize(final Object obj);
-
-    /**
-     * Deserializes the specified bytes into an object using one of the
-     * pre-registered serializers.
-     *
-     * @param bytes bytes to be deserialized
-     * @return deserialized object
-     */
-    public <T> T deserialize(final byte[] bytes);
-
 }
 }

@@ -46,9 +46,8 @@ public class TestStoreManager extends StoreManager {
         this.instance = instance;
         this.instance = instance;
     }
     }
 
 
-    // Hazelcast setup removed from original code.
     @Override
     @Override
     public void activate() {
     public void activate() {
-        setupKryoPool();
+        // Hazelcast setup removed from original code.
     }
     }
 }
 }

@@ -72,6 +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() {
@@ -83,20 +87,20 @@ public class DistributedDeviceStore
         // TODO decide on Map name scheme to avoid collision
         // TODO decide on Map name scheme to avoid collision
         rawDevices = theInstance.getMap("devices");
         rawDevices = theInstance.getMap("devices");
         final OptionalCacheLoader<DeviceId, DefaultDevice> deviceLoader
         final OptionalCacheLoader<DeviceId, DefaultDevice> deviceLoader
-                = new OptionalCacheLoader<>(storeService, rawDevices);
+                = new OptionalCacheLoader<>(kryoSerializationService, 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");
 
 
         rawDevicePorts = theInstance.getMap("devicePorts");
         rawDevicePorts = theInstance.getMap("devicePorts");
         final OptionalCacheLoader<DeviceId, Map<PortNumber, Port>> devicePortLoader
         final OptionalCacheLoader<DeviceId, Map<PortNumber, Port>> devicePortLoader
-                = new OptionalCacheLoader<>(storeService, rawDevicePorts);
+                = new OptionalCacheLoader<>(kryoSerializationService, 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();
@@ -106,6 +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");
     }
     }
 
 
@@ -354,7 +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);
         }
         }
@@ -375,7 +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);
         }
         }

@@ -58,6 +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() {
@@ -68,10 +70,10 @@ public class DistributedLinkStore
         // TODO decide on Map name scheme to avoid collision
         // TODO decide on Map name scheme to avoid collision
         rawLinks = theInstance.getMap("links");
         rawLinks = theInstance.getMap("links");
         final OptionalCacheLoader<LinkKey, DefaultLink> linkLoader
         final OptionalCacheLoader<LinkKey, DefaultLink> linkLoader
-                = new OptionalCacheLoader<>(storeService, rawLinks);
+                = new OptionalCacheLoader<>(kryoSerializationService, 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();
 
 
@@ -80,7 +82,7 @@ public class DistributedLinkStore
 
 
     @Deactivate
     @Deactivate
     public void deactivate() {
     public void deactivate() {
-        super.activate();
+        rawLinks.removeEntryListener(linksListener);
         log.info("Stopped");
         log.info("Stopped");
     }
     }
 
 
@@ -233,7 +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);
         }
         }

@@ -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;
@@ -35,12 +36,17 @@ import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.store.common.StoreManager;
 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.common.TestStoreManager;
 import org.onlab.onos.store.common.TestStoreManager;
+import org.onlab.onos.store.serializers.KryoSerializationManager;
+import org.onlab.onos.store.serializers.KryoSerializationService;
 
 
 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");
@@ -57,6 +63,7 @@ public class DistributedDeviceStoreTest {
     private static final PortNumber P3 = PortNumber.portNumber(3);
     private static final PortNumber P3 = PortNumber.portNumber(3);
 
 
     private DistributedDeviceStore deviceStore;
     private DistributedDeviceStore deviceStore;
+    private KryoSerializationManager serializationMgr;
 
 
     private StoreManager storeManager;
     private StoreManager storeManager;
 
 
@@ -78,7 +85,10 @@ public class DistributedDeviceStoreTest {
         storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
         storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
         storeManager.activate();
         storeManager.activate();
 
 
-        deviceStore = new TestDistributedDeviceStore(storeManager);
+        serializationMgr = new KryoSerializationManager();
+        serializationMgr.activate();
+
+        deviceStore = new TestDistributedDeviceStore(storeManager, serializationMgr);
         deviceStore.activate();
         deviceStore.activate();
     }
     }
 
 
@@ -86,6 +96,8 @@ public class DistributedDeviceStoreTest {
     public void tearDown() throws Exception {
     public void tearDown() throws Exception {
         deviceStore.deactivate();
         deviceStore.deactivate();
 
 
+        serializationMgr.deactivate();
+
         storeManager.deactivate();
         storeManager.deactivate();
     }
     }
 
 
@@ -326,6 +338,7 @@ 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);
@@ -379,8 +392,10 @@ public class DistributedDeviceStoreTest {
     }
     }
 
 
     private class TestDistributedDeviceStore extends DistributedDeviceStore {
     private class TestDistributedDeviceStore extends DistributedDeviceStore {
-        public TestDistributedDeviceStore(StoreService storeService) {
+        public TestDistributedDeviceStore(StoreService storeService,
+                                KryoSerializationService kryoSerializationService) {
             this.storeService = storeService;
             this.storeService = storeService;
+            this.kryoSerializationService = kryoSerializationService;
         }
         }
     }
     }
 }
 }

@@ -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;
@@ -29,27 +30,28 @@ import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.store.common.StoreManager;
 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.common.TestStoreManager;
 import org.onlab.onos.store.common.TestStoreManager;
+import org.onlab.onos.store.serializers.KryoSerializationManager;
+import org.onlab.onos.store.serializers.KryoSerializationService;
 
 
 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);
     private static final PortNumber P3 = PortNumber.portNumber(3);
     private static final PortNumber P3 = PortNumber.portNumber(3);
 
 
     private StoreManager storeManager;
     private StoreManager storeManager;
+    private KryoSerializationManager serializationMgr;
 
 
     private DistributedLinkStore linkStore;
     private DistributedLinkStore linkStore;
 
 
@@ -69,13 +71,17 @@ public class DistributedLinkStoreTest {
         storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
         storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
         storeManager.activate();
         storeManager.activate();
 
 
-        linkStore = new TestDistributedLinkStore(storeManager);
+        serializationMgr = new KryoSerializationManager();
+        serializationMgr.activate();
+
+        linkStore = new TestDistributedLinkStore(storeManager, serializationMgr);
         linkStore.activate();
         linkStore.activate();
     }
     }
 
 
     @After
     @After
     public void tearDown() throws Exception {
     public void tearDown() throws Exception {
         linkStore.deactivate();
         linkStore.deactivate();
+        serializationMgr.deactivate();
         storeManager.deactivate();
         storeManager.deactivate();
     }
     }
 
 
@@ -302,6 +308,7 @@ 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 {
 
 
@@ -354,8 +361,10 @@ public class DistributedLinkStoreTest {
 
 
 
 
     class TestDistributedLinkStore extends DistributedLinkStore {
     class TestDistributedLinkStore extends DistributedLinkStore {
-        TestDistributedLinkStore(StoreService storeService) {
+        TestDistributedLinkStore(StoreService storeService,
+                            KryoSerializationService kryoSerializationService) {
             this.storeService = storeService;
             this.storeService = storeService;
+            this.kryoSerializationService = kryoSerializationService;
         }
         }
     }
     }
 }
 }

+package org.onlab.onos.store.serializers;
+
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.HashMap;
+
+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.ControllerNode;
+import org.onlab.onos.cluster.DefaultControllerNode;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultDevice;
+import org.onlab.onos.net.DefaultLink;
+import org.onlab.onos.net.DefaultPort;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Element;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.LinkKey;
+import org.onlab.onos.net.MastershipRole;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.packet.IpPrefix;
+import org.onlab.util.KryoPool;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import de.javakaffee.kryoserializers.URISerializer;
+
+/**
+ * Serialization service using Kryo.
+ */
+@Component(immediate = true)
+@Service
+public class KryoSerializationManager implements KryoSerializationService {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+    private KryoPool serializerPool;
+
+
+    @Activate
+    public void activate() {
+        setupKryoPool();
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    /**
+     * Sets up the common serialzers pool.
+     */
+    protected void setupKryoPool() {
+        // FIXME Slice out types used in common to separate pool/namespace.
+        serializerPool = KryoPool.newBuilder()
+                .register(ArrayList.class,
+                          HashMap.class,
+
+                          ControllerNode.State.class,
+                          Device.Type.class,
+
+                          DefaultControllerNode.class,
+                          DefaultDevice.class,
+                          MastershipRole.class,
+                          Port.class,
+                          Element.class,
+
+                          Link.Type.class
+                )
+                .register(IpPrefix.class, new IpPrefixSerializer())
+                .register(URI.class, new URISerializer())
+                .register(NodeId.class, new NodeIdSerializer())
+                .register(ProviderId.class, new ProviderIdSerializer())
+                .register(DeviceId.class, new DeviceIdSerializer())
+                .register(PortNumber.class, new PortNumberSerializer())
+                .register(DefaultPort.class, new DefaultPortSerializer())
+                .register(LinkKey.class, new LinkKeySerializer())
+                .register(ConnectPoint.class, new ConnectPointSerializer())
+                .register(DefaultLink.class, new DefaultLinkSerializer())
+                .build()
+                .populate(1);
+    }
+
+    @Override
+    public byte[] serialize(final Object obj) {
+        return serializerPool.serialize(obj);
+    }
+
+    @Override
+    public <T> T deserialize(final byte[] bytes) {
+        if (bytes == null) {
+            return null;
+        }
+        return serializerPool.deserialize(bytes);
+    }
+
+}

+package org.onlab.onos.store.serializers;
+
+// TODO: To be replaced with SerializationService from IOLoop activity
+/**
+ * Service to serialize Objects into byte array.
+ */
+public interface KryoSerializationService {
+
+    /**
+     * Serializes the specified object into bytes using one of the
+     * pre-registered serializers.
+     *
+     * @param obj object to be serialized
+     * @return serialized bytes
+     */
+    public byte[] serialize(final Object obj);
+
+    /**
+     * Deserializes the specified bytes into an object using one of the
+     * pre-registered serializers.
+     *
+     * @param bytes bytes to be deserialized
+     * @return deserialized object
+     */
+    public <T> T deserialize(final byte[] bytes);
+
+}

@@ -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)

@@ -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));
+    }
+}

@@ -9,7 +9,6 @@
         <bundle>mvn:org.apache.commons/commons-lang3/3.3.2</bundle>
         <bundle>mvn:org.apache.commons/commons-lang3/3.3.2</bundle>
         <bundle>mvn:com.google.guava/guava/18.0</bundle>
         <bundle>mvn:com.google.guava/guava/18.0</bundle>
         <bundle>mvn:io.netty/netty/3.9.2.Final</bundle>
         <bundle>mvn:io.netty/netty/3.9.2.Final</bundle>
-        <bundle>mvn:org.livetribe.slp/livetribe-slp-osgi/2.2.1</bundle>
 
 
         <bundle>mvn:com.hazelcast/hazelcast/3.3</bundle>
         <bundle>mvn:com.hazelcast/hazelcast/3.3</bundle>
         <bundle>mvn:com.eclipsesource.minimal-json/minimal-json/0.9.1</bundle>
         <bundle>mvn:com.eclipsesource.minimal-json/minimal-json/0.9.1</bundle>
@@ -20,6 +19,9 @@
         <bundle>mvn:de.javakaffee/kryo-serializers/0.27</bundle>
         <bundle>mvn:de.javakaffee/kryo-serializers/0.27</bundle>
 
 
         <bundle>mvn:org.onlab.onos/onlab-nio/1.0.0-SNAPSHOT</bundle>
         <bundle>mvn:org.onlab.onos/onlab-nio/1.0.0-SNAPSHOT</bundle>
+
+	<bundle>mvn:org.codehaus.jackson/jackson-core-asl/1.9.13</bundle>
+	<bundle>mvn:org.codehaus.jackson/jackson-mapper-asl/1.9.13</bundle>
     </feature>
     </feature>
 
 
     <feature name="onos-thirdparty-web" version="1.0.0"
     <feature name="onos-thirdparty-web" version="1.0.0"
@@ -49,20 +51,17 @@
              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-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>
+        <bundle>mvn:org.onlab.onos/onos-core-dist/1.0.0-SNAPSHOT</bundle>
     </feature>
     </feature>
 
 
-    <feature name="onos-core-dist" version="1.0.0"
-             description="ONOS core components">
+    <feature name="onos-core-hazelcast" version="1.0.0"
+             description="ONOS core components built on hazelcast">
         <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-hz-common/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-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-cluster/1.0.0-SNAPSHOT</bundle>
-        <bundle>mvn:org.onlab.onos/onos-core-dist/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"
@@ -126,4 +125,10 @@
         <bundle>mvn:org.onlab.onos/onos-app-foo/1.0.0-SNAPSHOT</bundle>
         <bundle>mvn:org.onlab.onos/onos-app-foo/1.0.0-SNAPSHOT</bundle>
     </feature>
     </feature>
 
 
+    <feature name="onos-app-config" version="1.0.0"
+             description="ONOS network config reader">
+        <feature>onos-api</feature>
+        <bundle>mvn:org.onlab.onos/onos-app-config/1.0.0-SNAPSHOT</bundle>
+    </feature>
+
 </features>
 </features>

@@ -92,6 +92,17 @@
                 <version>3.3.2</version>
                 <version>3.3.2</version>
             </dependency>
             </dependency>
 
 
+	    <dependency>
+	      <groupId>org.codehaus.jackson</groupId>
+	      <artifactId>jackson-core-asl</artifactId>
+	      <version>1.9.13</version>
+	    </dependency>
+	    <dependency>
+	      <groupId>org.codehaus.jackson</groupId>
+	      <artifactId>jackson-mapper-asl</artifactId>
+	      <version>1.9.13</version>
+	    </dependency>
+
 
 
             <!-- Web related -->
             <!-- Web related -->
             <dependency>
             <dependency>

@@ -106,10 +106,10 @@ public class OpenFlowPacketProvider extends AbstractProvider implements PacketPr
         for (Instruction inst : packet.treatment().instructions()) {
         for (Instruction inst : packet.treatment().instructions()) {
             if (inst.type().equals(Instruction.Type.OUTPUT)) {
             if (inst.type().equals(Instruction.Type.OUTPUT)) {
                 p = portDesc(((OutputInstruction) inst).port());
                 p = portDesc(((OutputInstruction) inst).port());
-                if (!sw.getPorts().contains(p)) {
-                    log.warn("Tried to write out non-existint port {}", p.getPortNo());
+                /*if (!sw.getPorts().contains(p)) {
+                    log.warn("Tried to write out non-existent port {}", p.getPortNo());
                     continue;
                     continue;
-                }
+                }*/
                 OFPacketOut po = packetOut(sw, eth, p.getPortNo());
                 OFPacketOut po = packetOut(sw, eth, p.getPortNo());
                 sw.sendMsg(po);
                 sw.sendMsg(po);
             }
             }

@@ -154,9 +154,9 @@ public class OpenFlowPacketProviderTest {
         assertEquals("message sent incorrectly", 0, sw.sent.size());
         assertEquals("message sent incorrectly", 0, sw.sent.size());
 
 
         //to missing port
         //to missing port
-        OutboundPacket portFailPkt = outPacket(DID, TR_MISSING, eth);
-        provider.emit(portFailPkt);
-        assertEquals("extra message sent", 1, sw.sent.size());
+        //OutboundPacket portFailPkt = outPacket(DID, TR_MISSING, eth);
+        //provider.emit(portFailPkt);
+        //assertEquals("extra message sent", 1, sw.sent.size());
 
 
     }
     }
 
 

@@ -9,5 +9,5 @@
 nodes=$(env | sort | egrep "OC[0-9]+" | cut -d= -f2)
 nodes=$(env | sort | egrep "OC[0-9]+" | cut -d= -f2)
 
 
 onos-package
 onos-package
-for node in $nodes; do printf "%s: " $node; onos-install -f $node; done
+for node in $nodes; do (printf "%s: %s\n" "$node" "`onos-install -f $node`")& done
 for node in $nodes; do onos-wait-for-start $node; done
 for node in $nodes; do onos-wait-for-start $node; done

@@ -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

@@ -8,8 +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
-    echo \"onos.ip=\$(ifconfig  | grep $ONOS_NIC | cut -d: -f2 | cut -d\\  -f1)\" >> $ONOS_INSTALL_DIR/$KARAF_DIST/etc/system.properties
+
+    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

 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.

@@ -54,9 +54,9 @@ public abstract class IOLoop<M extends Message, S extends MessageStream<M>>
     }
     }
 
 
     /**
     /**
-     * Returns the number of streams in custody of the IO loop.
+     * Returns the number of message stream in custody of the loop.
      *
      *
-     * @return number of message streams using this loop
+     * @return number of message streams
      */
      */
     public int streamCount() {
     public int streamCount() {
         return streams.size();
         return streams.size();
@@ -93,14 +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 {
+    protected void connect(SelectionKey key) throws IOException {
         SocketChannel ch = (SocketChannel) key.channel();
         SocketChannel ch = (SocketChannel) key.channel();
         ch.finishConnect();
         ch.finishConnect();
-        } catch (IOException | IllegalStateException e) {
-            log.warn("Unable to complete connection", e);
-        }
-
         if (key.isValid()) {
         if (key.isValid()) {
             key.interestOps(SelectionKey.OP_READ);
             key.interestOps(SelectionKey.OP_READ);
         }
         }
@@ -124,7 +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()) {
+                try {
                     connect(key);
                     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.

@@ -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;
                     }
                     }

@@ -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;