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

@@ -11,6 +11,9 @@ import org.onlab.onos.cluster.ClusterService;
 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.intent.IntentEvent;
+import org.onlab.onos.net.intent.IntentListener;
+import org.onlab.onos.net.intent.IntentService;
 import org.slf4j.Logger;
 
 import static org.slf4j.LoggerFactory.getLogger;
@@ -29,13 +32,18 @@ public class FooComponent {
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected DeviceService deviceService;
 
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected IntentService intentService;
+
     private final ClusterEventListener clusterListener = new InnerClusterListener();
     private final DeviceListener deviceListener = new InnerDeviceListener();
+    private final IntentListener intentListener = new InnerIntentListener();
 
     @Activate
     public void activate() {
         clusterService.addListener(clusterListener);
         deviceService.addListener(deviceListener);
+        intentService.addListener(intentListener);
         log.info("Started");
     }
 
@@ -43,6 +51,7 @@ public class FooComponent {
     public void deactivate() {
         clusterService.removeListener(clusterListener);
         deviceService.removeListener(deviceListener);
+        intentService.removeListener(intentListener);
         log.info("Stopped");
     }
 
@@ -59,6 +68,23 @@ public class FooComponent {
             log.info("YEEEEHAAAAW! {}", event);
         }
     }
+
+    private class InnerIntentListener implements IntentListener {
+        @Override
+        public void event(IntentEvent event) {
+            String message;
+            if (event.type() == IntentEvent.Type.SUBMITTED) {
+                message = "WOW! It looks like someone has some intentions: {}";
+            } else if (event.type() == IntentEvent.Type.INSTALLED) {
+                message = "AWESOME! So far things are going great: {}";
+            } else if (event.type() == IntentEvent.Type.WITHDRAWN) {
+                message = "HMMM! Ambitions are fading apparently: {}";
+            } else {
+                message = "CRAP!!! Things are not turning out as intended: {}";
+            }
+            log.info(message, event.subject());
+        }
+    }
 }
 
 

+package org.onlab.onos.cli;
+
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cluster.ClusterService;
+import org.onlab.onos.net.device.DeviceService;
+import org.onlab.onos.net.flow.FlowRuleService;
+import org.onlab.onos.net.host.HostService;
+import org.onlab.onos.net.intent.IntentService;
+import org.onlab.onos.net.link.LinkService;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyService;
+
+/**
+ * Provides summary of ONOS model.
+ */
+@Command(scope = "onos", name = "summary",
+         description = "Provides summary of ONOS model")
+public class SummaryCommand extends AbstractShellCommand {
+
+    @Override
+    protected void execute() {
+        TopologyService topologyService = get(TopologyService.class);
+        Topology topology = topologyService.currentTopology();
+        print("nodes=%d, devices=%d, links=%d, hosts=%d, clusters=%s, paths=%d, flows=%d, intents=%d",
+              get(ClusterService.class).getNodes().size(),
+              get(DeviceService.class).getDeviceCount(),
+              get(LinkService.class).getLinkCount(),
+              get(HostService.class).getHostCount(),
+              topologyService.getClusters(topology).size(),
+              topology.pathCount(),
+              get(FlowRuleService.class).getFlowRuleCount(),
+              get(IntentService.class).getIntentCount());
+    }
+
+}

@@ -35,7 +35,7 @@ public class DevicesListCommand extends AbstractShellCommand {
      * @param service device service
      * @return sorted device list
      */
-    protected List<Device> getSortedDevices(DeviceService service) {
+    protected static List<Device> getSortedDevices(DeviceService service) {
         List<Device> devices = newArrayList(service.getDevices());
         Collections.sort(devices, Comparators.ELEMENT_COMPARATOR);
         return devices;

 package org.onlab.onos.cli.net;
 
 import static com.google.common.collect.Lists.newArrayList;
+import static org.onlab.onos.cli.net.DevicesListCommand.getSortedDevices;
 
 import java.util.Collections;
 import java.util.List;
@@ -46,7 +47,7 @@ public class FlowsListCommand extends AbstractShellCommand {
         DeviceService deviceService = get(DeviceService.class);
         FlowRuleService service = get(FlowRuleService.class);
         Map<Device, List<FlowEntry>> flows = getSortedFlows(deviceService, service);
-        for (Device d : flows.keySet()) {
+        for (Device d : getSortedDevices(deviceService)) {
             printFlows(d, flows.get(d));
         }
     }
@@ -57,7 +58,8 @@ public class FlowsListCommand extends AbstractShellCommand {
      * @param service device service
      * @return sorted device list
      */
-    protected Map<Device, List<FlowEntry>> getSortedFlows(DeviceService deviceService, FlowRuleService service) {
+    protected Map<Device, List<FlowEntry>> getSortedFlows(DeviceService deviceService,
+                                                          FlowRuleService service) {
         Map<Device, List<FlowEntry>> flows = Maps.newHashMap();
         List<FlowEntry> rules;
         FlowEntryState s = null;
@@ -89,18 +91,16 @@ public class FlowsListCommand extends AbstractShellCommand {
      * @param flows the set of flows for that device.
      */
     protected void printFlows(Device d, List<FlowEntry> flows) {
-        print("Device: " + d.id());
-        if (flows == null | flows.isEmpty()) {
-            print(" %s", "No flows.");
-            return;
-        }
+        boolean empty = flows == null || flows.isEmpty();
+        print("deviceId=%s, flowRuleCount=%d", d.id(), empty ? 0 : flows.size());
+        if (!empty) {
             for (FlowEntry f : flows) {
                 print(FMT, Long.toHexString(f.id().value()), f.state(), f.bytes(),
                       f.packets(), f.life(), f.priority());
                 print(SFMT, f.selector().criteria());
                 print(TFMT, f.treatment().instructions());
             }
-
+        }
     }
 
 }

@@ -24,7 +24,7 @@ public class IntentIdCompleter implements Completer {
         Iterator<Intent> it = service.getIntents().iterator();
         SortedSet<String> strings = delegate.getStrings();
         while (it.hasNext()) {
-            strings.add(it.next().getId().toString());
+            strings.add(it.next().id().toString());
         }
 
         // Now let the completer do the work for figuring out what to offer.

@@ -10,9 +10,9 @@ import org.onlab.onos.net.intent.IntentService;
 /**
  * Removes host-to-host connectivity intent.
  */
-@Command(scope = "onos", name = "remove-host-intent",
-         description = "Removes host-to-host connectivity intent")
-public class RemoveHostToHostIntentCommand extends AbstractShellCommand {
+@Command(scope = "onos", name = "remove-intent",
+         description = "Removes the specified intent")
+public class IntentRemoveCommand extends AbstractShellCommand {
 
     @Argument(index = 0, name = "id", description = "Intent ID",
               required = true, multiValued = false)

@@ -17,8 +17,8 @@ public class IntentsListCommand extends AbstractShellCommand {
     protected void execute() {
         IntentService service = get(IntentService.class);
         for (Intent intent : service.getIntents()) {
-            IntentState state = service.getIntentState(intent.getId());
-            print("%s %s %s", intent.getId(), state, intent);
+            IntentState state = service.getIntentState(intent.id());
+            print("%s %s %s", intent.id(), state, intent);
         }
     }
 

 package org.onlab.onos.cli.net;
 
+import org.apache.karaf.shell.commands.Argument;
 import org.apache.karaf.shell.commands.Command;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.Host;
@@ -18,8 +19,22 @@ import org.onlab.onos.net.intent.IntentState;
          description = "Wipes-out the entire network information base, i.e. devices, links, hosts")
 public class WipeOutCommand extends ClustersListCommand {
 
+
+    private static final String DISCLAIMER = "Yes, I know it will delete everything!";
+
+    @Argument(index = 0, name = "disclaimer", description = "Device ID",
+              required = true, multiValued = false)
+    String disclaimer = null;
+
     @Override
     protected void execute() {
+        if (!disclaimer.equals(DISCLAIMER)) {
+            print("I'm afraid I can't do that...");
+            print("You have to acknowledge by: " + DISCLAIMER);
+            return;
+        }
+
+        print("Good bye...");
         DeviceAdminService deviceAdminService = get(DeviceAdminService.class);
         DeviceService deviceService = get(DeviceService.class);
         for (Device device : deviceService.getDevices()) {
@@ -34,7 +49,7 @@ public class WipeOutCommand extends ClustersListCommand {
 
         IntentService intentService = get(IntentService.class);
         for (Intent intent : intentService.getIntents()) {
-            if (intentService.getIntentState(intent.getId()) == IntentState.INSTALLED) {
+            if (intentService.getIntentState(intent.id()) == IntentState.INSTALLED) {
                 intentService.withdraw(intent);
             }
         }

@@ -2,6 +2,9 @@
 
     <command-bundle xmlns="http://karaf.apache.org/xmlns/shell/v1.1.0">
         <command>
+            <action class="org.onlab.onos.cli.SummaryCommand"/>
+        </command>
+        <command>
             <action class="org.onlab.onos.cli.NodesListCommand"/>
         </command>
         <command>
@@ -61,15 +64,15 @@
             <action class="org.onlab.onos.cli.net.IntentsListCommand"/>
         </command>
         <command>
-            <action class="org.onlab.onos.cli.net.AddHostToHostIntentCommand"/>
+            <action class="org.onlab.onos.cli.net.IntentRemoveCommand"/>
             <completers>
-                <ref component-id="hostIdCompleter"/>
+                <ref component-id="intentIdCompleter"/>
             </completers>
         </command>
         <command>
-            <action class="org.onlab.onos.cli.net.RemoveHostToHostIntentCommand"/>
+            <action class="org.onlab.onos.cli.net.AddHostToHostIntentCommand"/>
             <completers>
-                <ref component-id="intentIdCompleter"/>
+                <ref component-id="hostIdCompleter"/>
             </completers>
         </command>
 

@@ -115,7 +115,7 @@ public class DefaultFlowRule implements FlowRule {
     }
 
     public int hash() {
-        return Objects.hash(deviceId, selector, id);
+        return Objects.hash(deviceId, selector, treatment);
     }
 
     @Override
@@ -132,7 +132,7 @@ public class DefaultFlowRule implements FlowRule {
         if (obj instanceof DefaultFlowRule) {
             DefaultFlowRule that = (DefaultFlowRule) obj;
             return Objects.equals(deviceId, that.deviceId) &&
-                    //Objects.equals(id, that.id) &&
+                    Objects.equals(id, that.id) &&
                     Objects.equals(priority, that.priority) &&
                     Objects.equals(selector, that.selector);
 
@@ -143,7 +143,7 @@ public class DefaultFlowRule implements FlowRule {
     @Override
     public String toString() {
         return toStringHelper(this)
-                .add("id", id)
+                .add("id", Long.toHexString(id.value()))
                 .add("deviceId", deviceId)
                 .add("priority", priority)
                 .add("selector", selector.criteria())
@@ -154,7 +154,7 @@ public class DefaultFlowRule implements FlowRule {
 
     @Override
     public int timeout() {
-        return timeout > MAX_TIMEOUT ? MAX_TIMEOUT : this.timeout;
+        return timeout;
     }
 
 }

 package org.onlab.onos.net.flow;
 
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Objects;
+
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.flow.instructions.Instruction;
 import org.onlab.onos.net.flow.instructions.Instructions;
@@ -8,12 +15,6 @@ import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 import org.slf4j.Logger;
 
-import java.util.Collections;
-import java.util.LinkedList;
-import java.util.List;
-
-import static org.slf4j.LoggerFactory.getLogger;
-
 /**
  * Default traffic treatment implementation.
  */
@@ -44,6 +45,25 @@ public final class DefaultTrafficTreatment implements TrafficTreatment {
         return new Builder();
     }
 
+    //FIXME: Order of instructions may affect hashcode
+    @Override
+    public int hashCode() {
+        return Objects.hash(instructions);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof DefaultTrafficTreatment) {
+            DefaultTrafficTreatment that = (DefaultTrafficTreatment) obj;
+            return  Objects.equals(instructions, that.instructions);
+
+        }
+        return false;
+    }
+
     /**
      * Builds a list of treatments following the following order.
      * Modifications -> Group -> Output (including drop)
@@ -66,6 +86,7 @@ public final class DefaultTrafficTreatment implements TrafficTreatment {
         private Builder() {
         }
 
+        @Override
         public Builder add(Instruction instruction) {
             if (drop) {
                 return this;

@@ -13,6 +13,13 @@ import org.onlab.onos.net.DeviceId;
 public interface FlowRuleService {
 
     /**
+     * Returns the number of flow rules in the system.
+     *
+     * @return flow rule count
+     */
+    int getFlowRuleCount();
+
+    /**
      * Returns the collection of flow entries applied on the specified device.
      * This will include flow rules which may not yet have been applied to
      * the device.
@@ -59,6 +66,8 @@ public interface FlowRuleService {
      */
     Iterable<FlowRule> getFlowRulesById(ApplicationId id);
 
+    //Future<CompletedBatchOperation> applyBatch(BatchOperation<FlowRuleBatchEntry>)
+
     /**
      * Adds the specified flow rule listener.
      *
@@ -72,7 +81,4 @@ public interface FlowRuleService {
      * @param listener flow rule listener
      */
     void removeListener(FlowRuleListener listener);
-
-
-
 }

@@ -10,7 +10,15 @@ import org.onlab.onos.store.Store;
 public interface FlowRuleStore extends Store<FlowRuleEvent, FlowRuleStoreDelegate> {
 
     /**
+     * Returns the number of flow rule in the store.
+     *
+     * @return number of flow rules
+     */
+    int getFlowRuleCount();
+
+    /**
      * Returns the stored flow.
+     *
      * @param rule the rule to look for
      * @return a flow rule
      */
@@ -60,5 +68,4 @@ public interface FlowRuleStore extends Store<FlowRuleEvent, FlowRuleStoreDelegat
      * @return flow_removed event, or null if nothing removed
      */
     FlowRuleEvent removeFlowRule(FlowEntry rule);
-
 }

@@ -3,6 +3,8 @@ package org.onlab.onos.net.flow.instructions;
 import static com.google.common.base.MoreObjects.toStringHelper;
 import static com.google.common.base.Preconditions.checkNotNull;
 
+import java.util.Objects;
+
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.flow.instructions.L2ModificationInstruction.L2SubType;
 import org.onlab.onos.net.flow.instructions.L2ModificationInstruction.ModEtherInstruction;
@@ -117,6 +119,24 @@ public final class Instructions {
             return toStringHelper(type()).toString();
 
         }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(type());
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof DropInstruction) {
+                DropInstruction that = (DropInstruction) obj;
+                return Objects.equals(type(), that.type());
+
+            }
+            return false;
+        }
     }
 
 
@@ -140,6 +160,26 @@ public final class Instructions {
             return toStringHelper(type().toString())
                     .add("port", port).toString();
         }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(port, type());
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof OutputInstruction) {
+                OutputInstruction that = (OutputInstruction) obj;
+                        Objects.equals(port, that.port);
+
+            }
+            return false;
+        }
     }
 
 }
+
+

@@ -2,6 +2,8 @@ package org.onlab.onos.net.flow.instructions;
 
 import static com.google.common.base.MoreObjects.toStringHelper;
 
+import java.util.Objects;
+
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 
@@ -74,6 +76,25 @@ public abstract class L2ModificationInstruction implements Instruction {
                     .add("mac", mac).toString();
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(mac, subtype);
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof ModEtherInstruction) {
+                ModEtherInstruction that = (ModEtherInstruction) obj;
+                return  Objects.equals(mac, that.mac) &&
+                        Objects.equals(subtype, that.subtype);
+
+            }
+            return false;
+        }
+
 
     }
 
@@ -103,6 +124,25 @@ public abstract class L2ModificationInstruction implements Instruction {
                     .add("id", vlanId).toString();
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(vlanId, subtype());
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof ModVlanIdInstruction) {
+                ModVlanIdInstruction that = (ModVlanIdInstruction) obj;
+                return  Objects.equals(vlanId, that.vlanId);
+
+            }
+            return false;
+        }
+
+
     }
 
     /**
@@ -131,6 +171,24 @@ public abstract class L2ModificationInstruction implements Instruction {
                     .add("pcp", Long.toHexString(vlanPcp)).toString();
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(vlanPcp, subtype());
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof ModVlanPcpInstruction) {
+                ModVlanPcpInstruction that = (ModVlanPcpInstruction) obj;
+                return  Objects.equals(vlanPcp, that.vlanPcp);
+
+            }
+            return false;
+        }
+
     }
 
 

@@ -2,6 +2,8 @@ package org.onlab.onos.net.flow.instructions;
 
 import static com.google.common.base.MoreObjects.toStringHelper;
 
+import java.util.Objects;
+
 import org.onlab.packet.IpPrefix;
 
 /**
@@ -66,5 +68,23 @@ public abstract class L3ModificationInstruction implements Instruction {
                     .add("ip", ip).toString();
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(ip, subtype());
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof ModIPInstruction) {
+                ModIPInstruction that = (ModIPInstruction) obj;
+                return  Objects.equals(ip, that.ip);
+
+            }
+            return false;
+        }
+
     }
 }

@@ -24,7 +24,7 @@ public abstract class AbstractIntent implements Intent {
     }
 
     @Override
-    public IntentId getId() {
+    public IntentId id() {
         return id;
     }
 

@@ -53,7 +53,7 @@ public abstract class ConnectivityIntent extends AbstractIntent {
      *
      * @return traffic match
      */
-    public TrafficSelector getTrafficSelector() {
+    public TrafficSelector selector() {
         return selector;
     }
 
@@ -62,7 +62,7 @@ public abstract class ConnectivityIntent extends AbstractIntent {
      *
      * @return applied action
      */
-    public TrafficTreatment getTrafficTreatment() {
+    public TrafficTreatment treatment() {
         return treatment;
     }
 

@@ -80,9 +80,9 @@ public class HostToHostIntent extends ConnectivityIntent {
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
-                .add("id", getId())
-                .add("selector", getTrafficSelector())
-                .add("treatment", getTrafficTreatment())
+                .add("id", id())
+                .add("selector", selector())
+                .add("treatment", treatment())
                 .add("one", one)
                 .add("two", two)
                 .toString();

@@ -11,5 +11,5 @@ public interface Intent extends BatchOperationTarget {
      *
      * @return intent identifier
      */
-    IntentId getId();
+    IntentId id();
 }

 package org.onlab.onos.net.intent;
 
-import com.google.common.base.MoreObjects;
 import org.onlab.onos.event.AbstractEvent;
 
-import java.util.Objects;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
 /**
  * A class to represent an intent related event.
  */
-public class IntentEvent extends AbstractEvent<IntentState, Intent> {
-
-    // TODO: determine a suitable parent class; if one does not exist, consider
-    // introducing one
+public class IntentEvent extends AbstractEvent<IntentEvent.Type, Intent> {
 
-    private final long time;
-    private final Intent intent;
-    private final IntentState state;
-    private final IntentState previous;
+    public enum Type {
+        /**
+         * Signifies that a new intent has been submitted to the system.
+         */
+        SUBMITTED,
 
         /**
-     * Creates an event describing a state change of an intent.
-     *
-     * @param intent   subject intent
-     * @param state    new intent state
-     * @param previous previous intent state
-     * @param time     time the event created in milliseconds since start of epoch
-     * @throws NullPointerException if the intent or state is null
+         * Signifies that an intent has been successfully installed.
          */
-    public IntentEvent(Intent intent, IntentState state, IntentState previous, long time) {
-        super(state, intent);
-        this.intent = checkNotNull(intent);
-        this.state = checkNotNull(state);
-        this.previous = previous;
-        this.time = time;
-    }
+        INSTALLED,
 
         /**
-     * Returns the state of the intent which caused the event.
-     *
-     * @return the state of the intent
+         * Signifies that an intent has failed compilation or installation.
          */
-    public IntentState getState() {
-        return state;
-    }
+        FAILED,
 
         /**
-     * Returns the previous state of the intent which caused the event.
-     *
-     * @return the previous state of the intent
+         * Signifies that an intent has been withdrawn from the system.
          */
-    public IntentState getPreviousState() {
-        return previous;
+        WITHDRAWN
     }
 
     /**
-     * Returns the intent associated with the event.
+     * Creates an event of a given type and for the specified intent and the
+     * current time.
      *
-     * @return the intent
+     * @param type   event type
+     * @param intent subject intent
+     * @param time   time the event created in milliseconds since start of epoch
      */
-    public Intent getIntent() {
-        return intent;
+    public IntentEvent(Type type, Intent intent, long time) {
+        super(type, intent, time);
     }
 
     /**
-     * Returns the time at which the event was created.
+     * Creates an event of a given type and for the specified intent and the
+     * current time.
      *
-     * @return the time in milliseconds since start of epoch
+     * @param type   event type
+     * @param intent subject intent
      */
-    public long getTime() {
-        return time;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) {
-            return true;
-        }
-        if (o == null || getClass() != o.getClass()) {
-            return false;
+    public IntentEvent(Type type, Intent intent) {
+        super(type, intent);
     }
 
-        IntentEvent that = (IntentEvent) o;
-        return Objects.equals(this.intent, that.intent)
-                && Objects.equals(this.state, that.state)
-                && Objects.equals(this.previous, that.previous)
-                && Objects.equals(this.time, that.time);
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(intent, state, previous, time);
-    }
-
-    @Override
-    public String toString() {
-        return MoreObjects.toStringHelper(getClass())
-                .add("intent", intent)
-                .add("state", state)
-                .add("previous", previous)
-                .add("time", time)
-                .toString();
-    }
 }

 package org.onlab.onos.net.intent;
 
 /**
- * This class represents the states of an intent.
- *
- * <p>
- * Note: The state is expressed as enum, but there is possibility
- * in the future that we define specific class instead of enum to improve
- * the extensibility of state definition.
- * </p>
+ * Representation of the phases an intent may attain during its lifecycle.
  */
 public enum IntentState {
-    // FIXME: requires discussion on State vs. EventType and a solid state-transition diagram
-    // TODO: consider the impact of conflict detection
-    // TODO: consider the impact that external events affect an installed intent
+
     /**
-     * The beginning state.
-     *
+     * Signifies that the intent has been submitted and will start compiling
+     * shortly. However, this compilation may not necessarily occur on the
+     * local controller instance.
+     * <p/>
      * All intent in the runtime take this state first.
      */
     SUBMITTED,
 
     /**
-     * The intent compilation has been completed.
-     *
-     * An intent translation graph (tree) is completely created.
-     * Leaves of the graph are installable intent type.
+     * Signifies that the intent is being compiled into installable intents.
+     * This is a transitional state after which the intent will enter either
+     * {@link #FAILED} state or {@link #INSTALLING} state.
+     */
+    COMPILING,
+
+    /**
+     * Signifies that the resulting installable intents are being installed
+     * into the network environment. This is a transitional state after which
+     * the intent will enter either {@link #INSTALLED} state or
+     * {@link #RECOMPILING} state.
      */
-    COMPILED,
+    INSTALLING,
 
     /**
-     * The intent has been successfully installed.
+     * The intent has been successfully installed. This is a state where the
+     * intent may remain parked until it is withdrawn by the application or
+     * until the network environment changes in some way to make the original
+     * set of installable intents untenable.
      */
     INSTALLED,
 
     /**
-     * The intent is being withdrawn.
-     *
-     * When {@link IntentService#withdraw(Intent)} is called,
-     * the intent takes this state first.
+     * Signifies that the intent is being recompiled into installable intents
+     * as an attempt to adapt to an anomaly in the network environment.
+     * This is a transitional state after which the intent will enter either
+     * {@link #FAILED} state or {@link #INSTALLING} state.
+     * <p/>
+     * Exit to the {@link #FAILED} state may be caused by failure to compile
+     * or by compiling into the same set of installable intents which have
+     * previously failed to be installed.
+     */
+    RECOMPILING,
+
+    /**
+     * Indicates that the intent is being withdrawn. This is a transitional
+     * state, triggered by invocation of the
+     * {@link IntentService#withdraw(Intent)} but one with only one outcome,
+     * which is the the intent being placed in the {@link #WITHDRAWN} state.
      */
     WITHDRAWING,
 
     /**
-     * The intent has been successfully withdrawn.
+     * Indicates that the intent has been successfully withdrawn.
      */
     WITHDRAWN,
 
     /**
-     * The intent has failed to be compiled, installed, or withdrawn.
-     *
-     * When the intent failed to be withdrawn, it is still, at least partially installed.
+     * Signifies that the intent has failed compiling, installing or
+     * recompiling states.
      */
-    FAILED,
+    FAILED
 }

@@ -10,10 +10,16 @@ import java.util.List;
 public interface IntentStore extends Store<IntentEvent, IntentStoreDelegate> {
 
     /**
-     * Creates a new intent.
+     * Submits a new intent into the store. If the returned event is not
+     * null, the manager is expected to dispatch the event and then to kick
+     * off intent compilation process. Otherwise, another node has been elected
+     * to perform the compilation process and the node will learn about
+     * the submittal and results of the intent compilation via the delegate
+     * mechanism.
      *
-     * @param intent intent
-     * @return appropriate event or null if no change resulted
+     * @param intent intent to be submitted
+     * @return event indicating the intent was submitted or null if no
+     * change resulted, e.g. duplicate intent
      */
     IntentEvent createIntent(Intent intent);
 
@@ -68,9 +74,8 @@ public interface IntentStore extends Store<IntentEvent, IntentStoreDelegate> {
      *
      * @param intentId           original intent identifier
      * @param installableIntents compiled installable intents
-     * @return compiled state transition event
      */
-    IntentEvent addInstallableIntents(IntentId intentId,
+    void addInstallableIntents(IntentId intentId,
                                List<InstallableIntent> installableIntents);
 
     /**

 package org.onlab.onos.net.intent;
 
-import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import java.util.Objects;
-import java.util.Set;
-
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.Sets;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
 
-import com.google.common.base.MoreObjects;
-import com.google.common.collect.Sets;
+import java.util.Objects;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Abstraction of multiple source to single destination connectivity intent.
  */
 public class MultiPointToSinglePointIntent extends ConnectivityIntent {
 
-    private final Set<ConnectPoint> ingressPorts;
-    private final ConnectPoint egressPort;
+    private final Set<ConnectPoint> ingressPoints;
+    private final ConnectPoint egressPoint;
 
     /**
      * Creates a new multi-to-single point connectivity intent for the specified
@@ -28,25 +27,25 @@ public class MultiPointToSinglePointIntent extends ConnectivityIntent {
      * @param id           intent identifier
      * @param match        traffic match
      * @param action       action
-     * @param ingressPorts set of ports from which ingress traffic originates
-     * @param egressPort   port to which traffic will egress
-     * @throws NullPointerException     if {@code ingressPorts} or
-     *                                  {@code egressPort} is null.
-     * @throws IllegalArgumentException if the size of {@code ingressPorts} is
+     * @param ingressPoints set of ports from which ingress traffic originates
+     * @param egressPoint   port to which traffic will egress
+     * @throws NullPointerException     if {@code ingressPoints} or
+     *                                  {@code egressPoint} is null.
+     * @throws IllegalArgumentException if the size of {@code ingressPoints} is
      *                                  not more than 1
      */
     public MultiPointToSinglePointIntent(IntentId id, TrafficSelector match,
                                          TrafficTreatment action,
-                                         Set<ConnectPoint> ingressPorts,
-                                         ConnectPoint egressPort) {
+                                         Set<ConnectPoint> ingressPoints,
+                                         ConnectPoint egressPoint) {
         super(id, match, action);
 
-        checkNotNull(ingressPorts);
-        checkArgument(!ingressPorts.isEmpty(),
+        checkNotNull(ingressPoints);
+        checkArgument(!ingressPoints.isEmpty(),
                       "there should be at least one ingress port");
 
-        this.ingressPorts = Sets.newHashSet(ingressPorts);
-        this.egressPort = checkNotNull(egressPort);
+        this.ingressPoints = Sets.newHashSet(ingressPoints);
+        this.egressPoint = checkNotNull(egressPoint);
     }
 
     /**
@@ -54,8 +53,8 @@ public class MultiPointToSinglePointIntent extends ConnectivityIntent {
      */
     protected MultiPointToSinglePointIntent() {
         super();
-        this.ingressPorts = null;
-        this.egressPort = null;
+        this.ingressPoints = null;
+        this.egressPoint = null;
     }
 
     /**
@@ -64,8 +63,8 @@ public class MultiPointToSinglePointIntent extends ConnectivityIntent {
      *
      * @return set of ingress ports
      */
-    public Set<ConnectPoint> getIngressPorts() {
-        return ingressPorts;
+    public Set<ConnectPoint> ingressPoints() {
+        return ingressPoints;
     }
 
     /**
@@ -73,8 +72,8 @@ public class MultiPointToSinglePointIntent extends ConnectivityIntent {
      *
      * @return egress port
      */
-    public ConnectPoint getEgressPort() {
-        return egressPort;
+    public ConnectPoint egressPoint() {
+        return egressPoint;
     }
 
     @Override
@@ -90,23 +89,23 @@ public class MultiPointToSinglePointIntent extends ConnectivityIntent {
         }
 
         MultiPointToSinglePointIntent that = (MultiPointToSinglePointIntent) o;
-        return Objects.equals(this.ingressPorts, that.ingressPorts)
-                && Objects.equals(this.egressPort, that.egressPort);
+        return Objects.equals(this.ingressPoints, that.ingressPoints)
+                && Objects.equals(this.egressPoint, that.egressPoint);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(super.hashCode(), ingressPorts, egressPort);
+        return Objects.hash(super.hashCode(), ingressPoints, egressPoint);
     }
 
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
-                .add("id", getId())
-                .add("match", getTrafficSelector())
-                .add("action", getTrafficTreatment())
-                .add("ingressPorts", getIngressPorts())
-                .add("egressPort", getEgressPort())
+                .add("id", id())
+                .add("match", selector())
+                .add("action", treatment())
+                .add("ingressPoints", ingressPoints())
+                .add("egressPoint", egressPoint())
                 .toString();
     }
 }

@@ -46,7 +46,7 @@ public class PathIntent extends PointToPointIntent implements InstallableIntent
      *
      * @return traversed links
      */
-    public Path getPath() {
+    public Path path() {
         return path;
     }
 
@@ -79,11 +79,11 @@ public class PathIntent extends PointToPointIntent implements InstallableIntent
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
-                .add("id", getId())
-                .add("match", getTrafficSelector())
-                .add("action", getTrafficTreatment())
-                .add("ingressPort", getIngressPort())
-                .add("egressPort", getEgressPort())
+                .add("id", id())
+                .add("match", selector())
+                .add("action", treatment())
+                .add("ingressPort", ingressPoint())
+                .add("egressPort", egressPoint())
                 .add("path", path)
                 .toString();
     }

@@ -14,8 +14,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
  */
 public class PointToPointIntent extends ConnectivityIntent {
 
-    private final ConnectPoint ingressPort;
-    private final ConnectPoint egressPort;
+    private final ConnectPoint ingressPoint;
+    private final ConnectPoint egressPoint;
 
     /**
      * Creates a new point-to-point intent with the supplied ingress/egress
@@ -24,17 +24,17 @@ public class PointToPointIntent extends ConnectivityIntent {
      * @param id           intent identifier
      * @param selector     traffic selector
      * @param treatment    treatment
-     * @param ingressPort ingress port
-     * @param egressPort  egress port
-     * @throws NullPointerException if {@code ingressPort} or {@code egressPort} is null.
+     * @param ingressPoint ingress port
+     * @param egressPoint  egress port
+     * @throws NullPointerException if {@code ingressPoint} or {@code egressPoints} is null.
      */
     public PointToPointIntent(IntentId id, TrafficSelector selector,
                               TrafficTreatment treatment,
-                              ConnectPoint ingressPort,
-                              ConnectPoint egressPort) {
+                              ConnectPoint ingressPoint,
+                              ConnectPoint egressPoint) {
         super(id, selector, treatment);
-        this.ingressPort = checkNotNull(ingressPort);
-        this.egressPort = checkNotNull(egressPort);
+        this.ingressPoint = checkNotNull(ingressPoint);
+        this.egressPoint = checkNotNull(egressPoint);
     }
 
     /**
@@ -42,8 +42,8 @@ public class PointToPointIntent extends ConnectivityIntent {
      */
     protected PointToPointIntent() {
         super();
-        this.ingressPort = null;
-        this.egressPort = null;
+        this.ingressPoint = null;
+        this.egressPoint = null;
     }
 
     /**
@@ -52,8 +52,8 @@ public class PointToPointIntent extends ConnectivityIntent {
      *
      * @return ingress port
      */
-    public ConnectPoint getIngressPort() {
-        return ingressPort;
+    public ConnectPoint ingressPoint() {
+        return ingressPoint;
     }
 
     /**
@@ -61,8 +61,8 @@ public class PointToPointIntent extends ConnectivityIntent {
      *
      * @return egress port
      */
-    public ConnectPoint getEgressPort() {
-        return egressPort;
+    public ConnectPoint egressPoint() {
+        return egressPoint;
     }
 
     @Override
@@ -78,23 +78,23 @@ public class PointToPointIntent extends ConnectivityIntent {
         }
 
         PointToPointIntent that = (PointToPointIntent) o;
-        return Objects.equals(this.ingressPort, that.ingressPort)
-                && Objects.equals(this.egressPort, that.egressPort);
+        return Objects.equals(this.ingressPoint, that.ingressPoint)
+                && Objects.equals(this.egressPoint, that.egressPoint);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(super.hashCode(), ingressPort, egressPort);
+        return Objects.hash(super.hashCode(), ingressPoint, egressPoint);
     }
 
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
-                .add("id", getId())
-                .add("match", getTrafficSelector())
-                .add("action", getTrafficTreatment())
-                .add("ingressPort", ingressPort)
-                .add("egressPort", egressPort)
+                .add("id", id())
+                .add("match", selector())
+                .add("action", treatment())
+                .add("ingressPoint", ingressPoint)
+                .add("egressPoints", egressPoint)
                 .toString();
     }
 

@@ -17,8 +17,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
  */
 public class SinglePointToMultiPointIntent extends ConnectivityIntent {
 
-    private final ConnectPoint ingressPort;
-    private final Set<ConnectPoint> egressPorts;
+    private final ConnectPoint ingressPoint;
+    private final Set<ConnectPoint> egressPoints;
 
     /**
      * Creates a new single-to-multi point connectivity intent.
@@ -26,25 +26,25 @@ public class SinglePointToMultiPointIntent extends ConnectivityIntent {
      * @param id           intent identifier
      * @param selector     traffic selector
      * @param treatment    treatment
-     * @param ingressPort port on which traffic will ingress
-     * @param egressPorts set of ports on which traffic will egress
-     * @throws NullPointerException     if {@code ingressPort} or
-     *                                  {@code egressPorts} is null
-     * @throws IllegalArgumentException if the size of {@code egressPorts} is
+     * @param ingressPoint port on which traffic will ingress
+     * @param egressPoints set of ports on which traffic will egress
+     * @throws NullPointerException     if {@code ingressPoint} or
+     *                                  {@code egressPoints} is null
+     * @throws IllegalArgumentException if the size of {@code egressPoints} is
      *                                  not more than 1
      */
     public SinglePointToMultiPointIntent(IntentId id, TrafficSelector selector,
                                          TrafficTreatment treatment,
-                                         ConnectPoint ingressPort,
-                                         Set<ConnectPoint> egressPorts) {
+                                         ConnectPoint ingressPoint,
+                                         Set<ConnectPoint> egressPoints) {
         super(id, selector, treatment);
 
-        checkNotNull(egressPorts);
-        checkArgument(!egressPorts.isEmpty(),
+        checkNotNull(egressPoints);
+        checkArgument(!egressPoints.isEmpty(),
                       "there should be at least one egress port");
 
-        this.ingressPort = checkNotNull(ingressPort);
-        this.egressPorts = Sets.newHashSet(egressPorts);
+        this.ingressPoint = checkNotNull(ingressPoint);
+        this.egressPoints = Sets.newHashSet(egressPoints);
     }
 
     /**
@@ -52,8 +52,8 @@ public class SinglePointToMultiPointIntent extends ConnectivityIntent {
      */
     protected SinglePointToMultiPointIntent() {
         super();
-        this.ingressPort = null;
-        this.egressPorts = null;
+        this.ingressPoint = null;
+        this.egressPoints = null;
     }
 
     /**
@@ -61,8 +61,8 @@ public class SinglePointToMultiPointIntent extends ConnectivityIntent {
      *
      * @return ingress port
      */
-    public ConnectPoint getIngressPort() {
-        return ingressPort;
+    public ConnectPoint ingressPoint() {
+        return ingressPoint;
     }
 
     /**
@@ -70,8 +70,8 @@ public class SinglePointToMultiPointIntent extends ConnectivityIntent {
      *
      * @return set of egress ports
      */
-    public Set<ConnectPoint> getEgressPorts() {
-        return egressPorts;
+    public Set<ConnectPoint> egressPoints() {
+        return egressPoints;
     }
 
     @Override
@@ -87,23 +87,23 @@ public class SinglePointToMultiPointIntent extends ConnectivityIntent {
         }
 
         SinglePointToMultiPointIntent that = (SinglePointToMultiPointIntent) o;
-        return Objects.equals(this.ingressPort, that.ingressPort)
-                && Objects.equals(this.egressPorts, that.egressPorts);
+        return Objects.equals(this.ingressPoint, that.ingressPoint)
+                && Objects.equals(this.egressPoints, that.egressPoints);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(super.hashCode(), ingressPort, egressPorts);
+        return Objects.hash(super.hashCode(), ingressPoint, egressPoints);
     }
 
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
-                .add("id", getId())
-                .add("match", getTrafficSelector())
-                .add("action", getTrafficTreatment())
-                .add("ingressPort", ingressPort)
-                .add("egressPort", egressPorts)
+                .add("id", id())
+                .add("match", selector())
+                .add("action", treatment())
+                .add("ingressPoint", ingressPoint)
+                .add("egressPort", egressPoints)
                 .toString();
     }
 

@@ -4,5 +4,53 @@
  * <em>what</em> rather than the <em>how</em>. This makes such instructions
  * largely independent of topology and device specifics, thus allowing them to
  * survive topology mutations.
+ * <p/>
+ * The controller core provides a suite of built-in intents and their compilers
+ * and installers. However, the intent framework is extensible in that it allows
+ * additional intents and their compilers or installers to be added
+ * dynamically at run-time. This allows others to enhance the initial arsenal of
+ * connectivity and policy-based intents available in base controller software.
+ * <p/>
+ * The following diagram depicts the state transition diagram for each top-level intent:<br>
+ * <img src="doc-files/intent-states.png" alt="ONOS intent states">
+ * <p/>
+ * The controller core accepts the intent specifications and translates them, via a
+ * process referred to as intent compilation, to installable intents, which are
+ * essentially actionable operations on the network environment.
+ * These actions are carried out by intent installation process, which results
+ * in some changes to the environment, e.g. tunnel links being provisioned,
+ * flow rules being installed on the data-plane, optical lambdas being reserved.
+ * <p/>
+ * After an intent is submitted by an application, it will be sent immediately
+ * (but asynchronously) into a compiling phase, then to installing phase and if
+ * all goes according to plan into installed state. Once an application decides
+ * it no longer wishes the intent to hold, it can withdraw it. This describes
+ * the nominal flow. However, it may happen that some issue is encountered.
+ * For example, an application may ask for an objective that is not currently
+ * achievable, e.g. connectivity across to unconnected network segments.
+ * If this is the case, the compiling phase may fail to produce a set of
+ * installable intents and instead result in a failed compile. If this occurs,
+ * only a change in the environment can trigger a transition back to the
+ * compiling state.
+ * <p/>
+ * Similarly, an issue may be encountered during the installation phase in
+ * which case the framework will attempt to recompile the intent to see if an
+ * alternate approach is available. If so, the intent will be sent back to
+ * installing phase. Otherwise, it will be parked in the failed state. Another
+ * scenario that’s very likely to be encountered is where the intent is
+ * successfully compiled and installed, but due to some topology event, such
+ * as a downed or downgraded link, loss of throughput may occur or connectivity
+ * may be lost altogether, thus impacting the viability of a previously
+ * satisfied intent. If this occurs, the framework will attempt to recompile
+ * the intent, and if an alternate approach is available, its installation
+ * will be attempted. Otherwise, the original top-level intent will be parked
+ * in the failed state.
+ * <p/>
+ * Please note that all *ing states, depicted in orange, are transitional and
+ * are expected to last only a brief amount of time. The rest of the states
+ * are parking states where the intent may spent some time; except for the
+ * submitted state of course. There, the intent may pause, but only briefly,
+ * while the system determines where to perform the compilation or while it
+ * performs global recomputation/optimization across all prior intents.
  */
 package org.onlab.onos.net.intent;
\ No newline at end of file

@@ -40,8 +40,7 @@ public class FakeIntentManager implements TestableIntentService {
             @Override
             public void run() {
                 try {
-                    List<InstallableIntent> installable = compileIntent(intent);
-                    installIntents(intent, installable);
+                    executeCompilingPhase(intent);
                 } catch (IntentException e) {
                     exceptions.add(e);
                 }
@@ -55,8 +54,8 @@ public class FakeIntentManager implements TestableIntentService {
             @Override
             public void run() {
                 try {
-                    List<InstallableIntent> installable = getInstallable(intent.getId());
-                    uninstallIntents(intent, installable);
+                    List<InstallableIntent> installable = getInstallable(intent.id());
+                    executeWithdrawingPhase(intent, installable);
                 } catch (IntentException e) {
                     exceptions.add(e);
                 }
@@ -84,53 +83,60 @@ public class FakeIntentManager implements TestableIntentService {
         return installer;
     }
 
-    private <T extends Intent> List<InstallableIntent> compileIntent(T intent) {
+    private <T extends Intent> void executeCompilingPhase(T intent) {
+        setState(intent, IntentState.COMPILING);
         try {
             // For the fake, we compile using a single level pass
             List<InstallableIntent> installable = new ArrayList<>();
             for (Intent compiled : getCompiler(intent).compile(intent)) {
                 installable.add((InstallableIntent) compiled);
             }
-            setState(intent, IntentState.COMPILED);
-            return installable;
+            executeInstallingPhase(intent, installable);
+
         } catch (IntentException e) {
             setState(intent, IntentState.FAILED);
-            throw e;
+            dispatch(new IntentEvent(IntentEvent.Type.FAILED, intent));
         }
     }
 
-    private void installIntents(Intent intent, List<InstallableIntent> installable) {
+    private void executeInstallingPhase(Intent intent,
+                                        List<InstallableIntent> installable) {
+        setState(intent, IntentState.INSTALLING);
         try {
             for (InstallableIntent ii : installable) {
                 registerSubclassInstallerIfNeeded(ii);
                 getInstaller(ii).install(ii);
             }
             setState(intent, IntentState.INSTALLED);
-            putInstallable(intent.getId(), installable);
+            putInstallable(intent.id(), installable);
+            dispatch(new IntentEvent(IntentEvent.Type.INSTALLED, intent));
+
         } catch (IntentException e) {
             setState(intent, IntentState.FAILED);
-            throw e;
+            dispatch(new IntentEvent(IntentEvent.Type.FAILED, intent));
         }
     }
 
-    private void uninstallIntents(Intent intent, List<InstallableIntent> installable) {
+    private void executeWithdrawingPhase(Intent intent,
+                                         List<InstallableIntent> installable) {
+        setState(intent, IntentState.WITHDRAWING);
         try {
             for (InstallableIntent ii : installable) {
                 getInstaller(ii).uninstall(ii);
             }
+            removeInstallable(intent.id());
             setState(intent, IntentState.WITHDRAWN);
-            removeInstallable(intent.getId());
+            dispatch(new IntentEvent(IntentEvent.Type.WITHDRAWN, intent));
         } catch (IntentException e) {
+            // FIXME: Rework this to always go from WITHDRAWING to WITHDRAWN!
             setState(intent, IntentState.FAILED);
-            throw e;
+            dispatch(new IntentEvent(IntentEvent.Type.FAILED, intent));
         }
     }
 
     // Sets the internal state for the given intent and dispatches an event
     private void setState(Intent intent, IntentState state) {
-        IntentState previous = intentStates.get(intent.getId());
-        intentStates.put(intent.getId(), state);
-        dispatch(new IntentEvent(intent, state, previous, System.currentTimeMillis()));
+        intentStates.put(intent.id(), state);
     }
 
     private void putInstallable(IntentId id, List<InstallableIntent> installable) {
@@ -152,15 +158,15 @@ public class FakeIntentManager implements TestableIntentService {
 
     @Override
     public void submit(Intent intent) {
-        intents.put(intent.getId(), intent);
+        intents.put(intent.id(), intent);
         setState(intent, IntentState.SUBMITTED);
+        dispatch(new IntentEvent(IntentEvent.Type.SUBMITTED, intent));
         executeSubmit(intent);
     }
 
     @Override
     public void withdraw(Intent intent) {
-        intents.remove(intent.getId());
-        setState(intent, IntentState.WITHDRAWING);
+        intents.remove(intent.id());
         executeWithdraw(intent);
     }
 

@@ -10,11 +10,9 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 
-import static org.onlab.onos.net.intent.IntentState.*;
 import static org.junit.Assert.*;
+import static org.onlab.onos.net.intent.IntentEvent.Type.*;
 
-// TODO: consider make it categorized as integration test when it become
-//   slow test or fragile test
 /**
  * Suite of tests for the intent service contract.
  */
@@ -64,13 +62,13 @@ public class IntentServiceTest {
         TestTools.assertAfter(GRACE_MS, new Runnable() {
             @Override
             public void run() {
-                assertEquals("incorrect intent state", INSTALLED,
-                             service.getIntentState(intent.getId()));
+                assertEquals("incorrect intent state", IntentState.INSTALLED,
+                             service.getIntentState(intent.id()));
             }
         });
 
         // Make sure that all expected events have been emitted
-        validateEvents(intent, SUBMITTED, COMPILED, INSTALLED);
+        validateEvents(intent, SUBMITTED, INSTALLED);
 
         // Make sure there is just one intent (and is ours)
         assertEquals("incorrect intent count", 1, service.getIntentCount());
@@ -85,19 +83,19 @@ public class IntentServiceTest {
         TestTools.assertAfter(GRACE_MS, new Runnable() {
             @Override
             public void run() {
-                assertEquals("incorrect intent state", WITHDRAWN,
-                             service.getIntentState(intent.getId()));
+                assertEquals("incorrect intent state", IntentState.WITHDRAWN,
+                             service.getIntentState(intent.id()));
             }
         });
 
         // Make sure that all expected events have been emitted
-        validateEvents(intent, WITHDRAWING, WITHDRAWN);
+        validateEvents(intent, WITHDRAWN);
 
         // TODO: discuss what is the fate of intents after they have been withdrawn
         // Make sure that the intent is no longer in the system
 //        assertEquals("incorrect intent count", 0, service.getIntents().size());
-//        assertNull("intent should not be found", service.getIntent(intent.getId()));
-//        assertNull("intent state should not be found", service.getIntentState(intent.getId()));
+//        assertNull("intent should not be found", service.getIntent(intent.id()));
+//        assertNull("intent state should not be found", service.getIntentState(intent.id()));
     }
 
     @Test
@@ -113,8 +111,8 @@ public class IntentServiceTest {
         TestTools.assertAfter(GRACE_MS, new Runnable() {
             @Override
             public void run() {
-                assertEquals("incorrect intent state", FAILED,
-                             service.getIntentState(intent.getId()));
+                assertEquals("incorrect intent state", IntentState.FAILED,
+                             service.getIntentState(intent.id()));
             }
         });
 
@@ -136,13 +134,13 @@ public class IntentServiceTest {
         TestTools.assertAfter(GRACE_MS, new Runnable() {
             @Override
             public void run() {
-                assertEquals("incorrect intent state", FAILED,
-                             service.getIntentState(intent.getId()));
+                assertEquals("incorrect intent state", IntentState.FAILED,
+                             service.getIntentState(intent.id()));
             }
         });
 
         // Make sure that all expected events have been emitted
-        validateEvents(intent, SUBMITTED, COMPILED, FAILED);
+        validateEvents(intent, SUBMITTED, FAILED);
     }
 
     /**
@@ -151,23 +149,23 @@ public class IntentServiceTest {
      * considered.
      *
      * @param intent intent subject
-     * @param states list of states for which events are expected
+     * @param types  list of event types for which events are expected
      */
-    protected void validateEvents(Intent intent, IntentState... states) {
+    protected void validateEvents(Intent intent, IntentEvent.Type... types) {
         Iterator<IntentEvent> events = listener.events.iterator();
-        for (IntentState state : states) {
+        for (IntentEvent.Type type : types) {
             IntentEvent event = events.hasNext() ? events.next() : null;
             if (event == null) {
-                fail("expected event not found: " + state);
-            } else if (intent.equals(event.getIntent())) {
-                assertEquals("incorrect state", state, event.getState());
+                fail("expected event not found: " + type);
+            } else if (intent.equals(event.subject())) {
+                assertEquals("incorrect state", type, event.type());
             }
         }
 
         // Remainder of events should not apply to this intent; make sure.
         while (events.hasNext()) {
             assertFalse("unexpected event for intent",
-                        intent.equals(events.next().getIntent()));
+                        intent.equals(events.next().subject()));
         }
     }
 
@@ -228,8 +226,8 @@ public class IntentServiceTest {
         TestTools.assertAfter(GRACE_MS, new Runnable() {
             @Override
             public void run() {
-                assertEquals("incorrect intent state", INSTALLED,
-                             service.getIntentState(intent.getId()));
+                assertEquals("incorrect intent state", IntentState.INSTALLED,
+                             service.getIntentState(intent.id()));
             }
         });
 

@@ -12,10 +12,10 @@ public class MultiPointToSinglePointIntentTest extends ConnectivityIntentTest {
     @Test
     public void basics() {
         MultiPointToSinglePointIntent intent = createOne();
-        assertEquals("incorrect id", IID, intent.getId());
-        assertEquals("incorrect match", MATCH, intent.getTrafficSelector());
-        assertEquals("incorrect ingress", PS1, intent.getIngressPorts());
-        assertEquals("incorrect egress", P2, intent.getEgressPort());
+        assertEquals("incorrect id", IID, intent.id());
+        assertEquals("incorrect match", MATCH, intent.selector());
+        assertEquals("incorrect ingress", PS1, intent.ingressPoints());
+        assertEquals("incorrect egress", P2, intent.egressPoint());
     }
 
     @Override

@@ -16,12 +16,12 @@ public class PathIntentTest extends ConnectivityIntentTest {
     @Test
     public void basics() {
         PathIntent intent = createOne();
-        assertEquals("incorrect id", IID, intent.getId());
-        assertEquals("incorrect match", MATCH, intent.getTrafficSelector());
-        assertEquals("incorrect action", NOP, intent.getTrafficTreatment());
-        assertEquals("incorrect ingress", P1, intent.getIngressPort());
-        assertEquals("incorrect egress", P2, intent.getEgressPort());
-        assertEquals("incorrect path", PATH1, intent.getPath());
+        assertEquals("incorrect id", IID, intent.id());
+        assertEquals("incorrect match", MATCH, intent.selector());
+        assertEquals("incorrect action", NOP, intent.treatment());
+        assertEquals("incorrect ingress", P1, intent.ingressPoint());
+        assertEquals("incorrect egress", P2, intent.egressPoint());
+        assertEquals("incorrect path", PATH1, intent.path());
     }
 
     @Override

@@ -12,10 +12,10 @@ public class PointToPointIntentTest extends ConnectivityIntentTest {
     @Test
     public void basics() {
         PointToPointIntent intent = createOne();
-        assertEquals("incorrect id", IID, intent.getId());
-        assertEquals("incorrect match", MATCH, intent.getTrafficSelector());
-        assertEquals("incorrect ingress", P1, intent.getIngressPort());
-        assertEquals("incorrect egress", P2, intent.getEgressPort());
+        assertEquals("incorrect id", IID, intent.id());
+        assertEquals("incorrect match", MATCH, intent.selector());
+        assertEquals("incorrect ingress", P1, intent.ingressPoint());
+        assertEquals("incorrect egress", P2, intent.egressPoint());
     }
 
     @Override

@@ -12,10 +12,10 @@ public class SinglePointToMultiPointIntentTest extends ConnectivityIntentTest {
     @Test
     public void basics() {
         SinglePointToMultiPointIntent intent = createOne();
-        assertEquals("incorrect id", IID, intent.getId());
-        assertEquals("incorrect match", MATCH, intent.getTrafficSelector());
-        assertEquals("incorrect ingress", P1, intent.getIngressPort());
-        assertEquals("incorrect egress", PS2, intent.getEgressPorts());
+        assertEquals("incorrect id", IID, intent.id());
+        assertEquals("incorrect match", MATCH, intent.selector());
+        assertEquals("incorrect ingress", P1, intent.ingressPoint());
+        assertEquals("incorrect egress", PS2, intent.egressPoints());
     }
 
     @Override

@@ -40,8 +40,8 @@ import com.google.common.collect.Lists;
 @Component(immediate = true)
 @Service
 public class FlowRuleManager
-extends AbstractProviderRegistry<FlowRuleProvider, FlowRuleProviderService>
-implements FlowRuleService, FlowRuleProviderRegistry {
+        extends AbstractProviderRegistry<FlowRuleProvider, FlowRuleProviderService>
+        implements FlowRuleService, FlowRuleProviderRegistry {
 
     public static final String FLOW_RULE_NULL = "FlowRule cannot be null";
     private final Logger log = getLogger(getClass());
@@ -75,6 +75,11 @@ implements FlowRuleService, FlowRuleProviderRegistry {
     }
 
     @Override
+    public int getFlowRuleCount() {
+        return store.getFlowRuleCount();
+    }
+
+    @Override
     public Iterable<FlowEntry> getFlowEntries(DeviceId deviceId) {
         return store.getFlowEntries(deviceId);
     }
@@ -98,11 +103,13 @@ implements FlowRuleService, FlowRuleProviderRegistry {
         for (int i = 0; i < flowRules.length; i++) {
             f = flowRules[i];
             device = deviceService.getDevice(f.deviceId());
-            frp = getProvider(device.providerId());
             store.deleteFlowRule(f);
+            if (device != null) {
+                frp = getProvider(device.providerId());
                 frp.removeFlowRule(f);
             }
         }
+    }
 
     @Override
     public void removeFlowRulesById(ApplicationId id) {

@@ -71,11 +71,11 @@ public class HostToHostIntentCompiler
     private Intent createPathIntent(Path path, Host src, Host dst,
                                     HostToHostIntent intent) {
 
-        TrafficSelector selector = builder(intent.getTrafficSelector())
+        TrafficSelector selector = builder(intent.selector())
                 .matchEthSrc(src.mac()).matchEthDst(dst.mac()).build();
 
         return new PathIntent(intentIdGenerator.getNewId(),
-                              selector, intent.getTrafficTreatment(),
+                              selector, intent.treatment(),
                               path.src(), path.dst(), path);
     }
 

 package org.onlab.onos.net.intent.impl;
 
-import com.google.common.collect.ImmutableMap;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static java.util.concurrent.Executors.newSingleThreadExecutor;
+import static org.onlab.onos.net.intent.IntentState.COMPILING;
+import static org.onlab.onos.net.intent.IntentState.FAILED;
+import static org.onlab.onos.net.intent.IntentState.INSTALLED;
+import static org.onlab.onos.net.intent.IntentState.INSTALLING;
+import static org.onlab.onos.net.intent.IntentState.RECOMPILING;
+import static org.onlab.onos.net.intent.IntentState.WITHDRAWING;
+import static org.onlab.onos.net.intent.IntentState.WITHDRAWN;
+import static org.onlab.util.Tools.namedThreads;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.ExecutorService;
+
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
@@ -25,15 +44,7 @@ import org.onlab.onos.net.intent.IntentStore;
 import org.onlab.onos.net.intent.IntentStoreDelegate;
 import org.slf4j.Logger;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-import static org.onlab.onos.net.intent.IntentState.*;
-import static org.slf4j.LoggerFactory.getLogger;
+import com.google.common.collect.ImmutableMap;
 
 /**
  * An implementation of Intent Manager.
@@ -56,6 +67,8 @@ public class IntentManager
     private final AbstractListenerRegistry<IntentEvent, IntentListener>
             listenerRegistry = new AbstractListenerRegistry<>();
 
+    private final ExecutorService executor = newSingleThreadExecutor(namedThreads("onos-intents"));
+
     private final IntentStoreDelegate delegate = new InternalStoreDelegate();
     private final TopologyChangeDelegate topoDelegate = new InternalTopoChangeDelegate();
 
@@ -63,7 +76,7 @@ public class IntentManager
     protected IntentStore store;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    protected FlowTrackerService trackerService;
+    protected ObjectiveTrackerService trackerService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected EventDeliveryService eventDispatcher;
@@ -89,21 +102,16 @@ public class IntentManager
         checkNotNull(intent, INTENT_NULL);
         registerSubclassCompilerIfNeeded(intent);
         IntentEvent event = store.createIntent(intent);
-        processStoreEvent(event);
+        if (event != null) {
+            eventDispatcher.post(event);
+            executor.execute(new IntentTask(COMPILING, intent));
+        }
     }
 
     @Override
     public void withdraw(Intent intent) {
         checkNotNull(intent, INTENT_NULL);
-        IntentEvent event = store.setState(intent, WITHDRAWING);
-        List<InstallableIntent> installables = store.getInstallableIntents(intent.getId());
-        if (installables != null) {
-            for (InstallableIntent installable : installables) {
-                trackerService.removeTrackedResources(intent.getId(),
-                                                      installable.requiredLinks());
-            }
-        }
-        processStoreEvent(event);
+        executor.execute(new IntentTask(WITHDRAWING, intent));
     }
 
     // FIXME: implement this method
@@ -207,56 +215,142 @@ public class IntentManager
     }
 
     /**
-     * Compiles an intent.
+     * Compiles the specified intent.
      *
-     * @param intent intent
+     * @param intent intent to be compiled
      */
-    private void compileIntent(Intent intent) {
+    private void executeCompilingPhase(Intent intent) {
+        // Indicate that the intent is entering the compiling phase.
+        store.setState(intent, COMPILING);
+
+        try {
+            // Compile the intent into installable derivatives.
+            List<InstallableIntent> installable = compileIntent(intent);
+
+            // If all went well, associate the resulting list of installable
+            // intents with the top-level intent and proceed to install.
+            store.addInstallableIntents(intent.id(), installable);
+            executeInstallingPhase(intent);
+
+        } catch (Exception e) {
+            log.warn("Unable to compile intent {} due to: {}", intent.id(), e);
+
+            // If compilation failed, mark the intent as failed.
+            store.setState(intent, FAILED);
+        }
+    }
+
     // FIXME: To make SDN-IP workable ASAP, only single level compilation is implemented
     // TODO: implement compilation traversing tree structure
+    private List<InstallableIntent> compileIntent(Intent intent) {
         List<InstallableIntent> installable = new ArrayList<>();
         for (Intent compiled : getCompiler(intent).compile(intent)) {
             InstallableIntent installableIntent = (InstallableIntent) compiled;
             installable.add(installableIntent);
-            trackerService.addTrackedResources(intent.getId(),
-                                               installableIntent.requiredLinks());
         }
-        IntentEvent event = store.addInstallableIntents(intent.getId(), installable);
-        processStoreEvent(event);
+        return installable;
     }
 
     /**
-     * Installs an intent.
+     * Installs all installable intents associated with the specified top-level
+     * intent.
      *
-     * @param intent intent
+     * @param intent intent to be installed
      */
-    private void installIntent(Intent intent) {
-        List<InstallableIntent> installables = store.getInstallableIntents(intent.getId());
+    private void executeInstallingPhase(Intent intent) {
+        // Indicate that the intent is entering the installing phase.
+        store.setState(intent, INSTALLING);
+
+        try {
+            List<InstallableIntent> installables = store.getInstallableIntents(intent.id());
             if (installables != null) {
                 for (InstallableIntent installable : installables) {
                     registerSubclassInstallerIfNeeded(installable);
+                    trackerService.addTrackedResources(intent.id(),
+                                                       installable.requiredLinks());
                     getInstaller(installable).install(installable);
                 }
             }
-        IntentEvent event = store.setState(intent, INSTALLED);
-        processStoreEvent(event);
+            eventDispatcher.post(store.setState(intent, INSTALLED));
+
+        } catch (Exception e) {
+            log.warn("Unable to install intent {} due to: {}", intent.id(), e);
+            uninstallIntent(intent);
 
+            // If compilation failed, kick off the recompiling phase.
+            executeRecompilingPhase(intent);
+        }
     }
 
     /**
-     * Uninstalls an intent.
+     * Recompiles the specified intent.
      *
-     * @param intent intent
+     * @param intent intent to be recompiled
+     */
+    private void executeRecompilingPhase(Intent intent) {
+        // Indicate that the intent is entering the recompiling phase.
+        store.setState(intent, RECOMPILING);
+
+        try {
+            // Compile the intent into installable derivatives.
+            List<InstallableIntent> installable = compileIntent(intent);
+
+            // If all went well, compare the existing list of installable
+            // intents with the newly compiled list. If they are the same,
+            // bail, out since the previous approach was determined not to
+            // be viable.
+            List<InstallableIntent> originalInstallable =
+                    store.getInstallableIntents(intent.id());
+
+            if (Objects.equals(originalInstallable, installable)) {
+                eventDispatcher.post(store.setState(intent, FAILED));
+            } else {
+                // Otherwise, re-associate the newly compiled installable intents
+                // with the top-level intent and kick off installing phase.
+                store.addInstallableIntents(intent.id(), installable);
+                executeInstallingPhase(intent);
+            }
+        } catch (Exception e) {
+            log.warn("Unable to recompile intent {} due to: {}", intent.id(), e);
+
+            // If compilation failed, mark the intent as failed.
+            eventDispatcher.post(store.setState(intent, FAILED));
+        }
+    }
+
+    /**
+     * Uninstalls the specified intent by uninstalling all of its associated
+     * installable derivatives.
+     *
+     * @param intent intent to be installed
+     */
+    private void executeWithdrawingPhase(Intent intent) {
+        // Indicate that the intent is being withdrawn.
+        store.setState(intent, WITHDRAWING);
+        uninstallIntent(intent);
+
+        // If all went well, disassociate the top-level intent with its
+        // installable derivatives and mark it as withdrawn.
+        store.removeInstalledIntents(intent.id());
+        eventDispatcher.post(store.setState(intent, WITHDRAWN));
+    }
+
+    /**
+     * Uninstalls all installable intents associated with the given intent.
+     *
+     * @param intent intent to be uninstalled
      */
     private void uninstallIntent(Intent intent) {
-        List<InstallableIntent> installables = store.getInstallableIntents(intent.getId());
+        try {
+            List<InstallableIntent> installables = store.getInstallableIntents(intent.id());
             if (installables != null) {
                 for (InstallableIntent installable : installables) {
                     getInstaller(installable).uninstall(installable);
                 }
             }
-        store.removeInstalledIntents(intent.getId());
-        store.setState(intent, WITHDRAWN);
+        } catch (IntentException e) {
+            log.warn("Unable to uninstall intent {} due to: {}", intent.id(), e);
+        }
     }
 
     /**
@@ -309,63 +403,61 @@ public class IntentManager
         }
     }
 
-    /**
-     * Handles state transition of submitted intents.
-     */
-    private void processStoreEvent(IntentEvent event) {
-        eventDispatcher.post(event);
-        Intent intent = event.getIntent();
-        try {
-            switch (event.getState()) {
-                case SUBMITTED:
-                    compileIntent(intent);
-                    break;
-                case COMPILED:
-                    installIntent(intent);
-                    break;
-                case INSTALLED:
-                    break;
-                case WITHDRAWING:
-                    uninstallIntent(intent);
-                    break;
-                case WITHDRAWN:
-                    break;
-                case FAILED:
-                    break;
-                default:
-                    throw new IllegalStateException("the state of IntentEvent is illegal: " +
-                                                            event.getState());
-            }
-        } catch (IntentException e) {
-            store.setState(intent, FAILED);
-        }
-
-    }
-
     // Store delegate to re-post events emitted from the store.
     private class InternalStoreDelegate implements IntentStoreDelegate {
         @Override
         public void notify(IntentEvent event) {
-            processStoreEvent(event);
+            eventDispatcher.post(event);
+            if (event.type() == IntentEvent.Type.SUBMITTED) {
+                executor.execute(new IntentTask(COMPILING, event.subject()));
+            }
         }
     }
 
     // Topology change delegate
     private class InternalTopoChangeDelegate implements TopologyChangeDelegate {
         @Override
-        public void bumpIntents(Iterable<IntentId> intentIds) {
+        public void triggerCompile(Iterable<IntentId> intentIds,
+                                   boolean compileAllFailed) {
+            // Attempt recompilation of the specified intents first.
             for (IntentId intentId : intentIds) {
-                compileIntent(getIntent(intentId));
+                Intent intent = getIntent(intentId);
+                uninstallIntent(intent);
+
+                executeRecompilingPhase(intent);
             }
+
+            if (compileAllFailed) {
+                // If required, compile all currently failed intents.
+                for (Intent intent : getIntents()) {
+                    if (getIntentState(intent.id()) == FAILED) {
+                        executeCompilingPhase(intent);
+                    }
+                }
+            }
+        }
+    }
+
+    // Auxiliary runnable to perform asynchronous tasks.
+    private class IntentTask implements Runnable {
+        private final IntentState state;
+        private final Intent intent;
+
+        public IntentTask(IntentState state, Intent intent) {
+            this.state = state;
+            this.intent = intent;
         }
 
         @Override
-        public void failIntents(Iterable<IntentId> intentIds) {
-            for (IntentId intentId : intentIds) {
-                Intent intent = getIntent(intentId);
-                uninstallIntent(intent);
-                compileIntent(intent);
+        public void run() {
+            if (state == COMPILING) {
+                executeCompilingPhase(intent);
+            } else if (state == RECOMPILING) {
+                executeRecompilingPhase(intent);
+            } else if (state == WITHDRAWING) {
+                executeWithdrawingPhase(intent);
             }
         }
     }
+
 }

@@ -19,12 +19,15 @@ import org.onlab.onos.net.topology.TopologyService;
 import org.slf4j.Logger;
 
 import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
 import java.util.concurrent.ExecutorService;
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.collect.Multimaps.synchronizedSetMultimap;
 import static java.util.concurrent.Executors.newSingleThreadExecutor;
+import static org.onlab.onos.net.link.LinkEvent.Type.LINK_REMOVED;
 import static org.onlab.util.Tools.namedThreads;
 import static org.slf4j.LoggerFactory.getLogger;
 
@@ -34,7 +37,7 @@ import static org.slf4j.LoggerFactory.getLogger;
  */
 @Component
 @Service
-public class FlowTracker implements FlowTrackerService {
+public class ObjectiveTracker implements ObjectiveTrackerService {
 
     private final Logger log = getLogger(getClass());
 
@@ -110,19 +113,26 @@ public class FlowTracker implements FlowTrackerService {
         @Override
         public void run() {
             if (event.reasons() == null) {
-                delegate.bumpIntents(intentsByLink.values());
+                delegate.triggerCompile(new HashSet<IntentId>(), true);
+
             } else {
+                Set<IntentId> toBeRecompiled = new HashSet<>();
+                boolean recompileOnly = true;
+
+                // Scan through the list of reasons and keep accruing all
+                // intents that need to be recompiled.
                 for (Event reason : event.reasons()) {
                     if (reason instanceof LinkEvent) {
                         LinkEvent linkEvent = (LinkEvent) reason;
-                        if (linkEvent.type() == LinkEvent.Type.LINK_ADDED ||
-                                linkEvent.type() == LinkEvent.Type.LINK_UPDATED) {
-                            delegate.bumpIntents(intentsByLink.get(new LinkKey(linkEvent.subject())));
-                        } else if (linkEvent.type() == LinkEvent.Type.LINK_REMOVED) {
-                            delegate.failIntents(intentsByLink.get(new LinkKey(linkEvent.subject())));
+                        if (linkEvent.type() == LINK_REMOVED) {
+                            Set<IntentId> intentIds = intentsByLink.get(new LinkKey(linkEvent.subject()));
+                            toBeRecompiled.addAll(intentIds);
                         }
+                        recompileOnly = recompileOnly && linkEvent.type() == LINK_REMOVED;
                     }
                 }
+
+                delegate.triggerCompile(toBeRecompiled, !recompileOnly);
             }
         }
     }

@@ -9,7 +9,7 @@ import java.util.Collection;
  * Auxiliary service for tracking intent path flows and for notifying the
  * intent service of environment changes via topology change delegate.
  */
-public interface FlowTrackerService {
+public interface ObjectiveTrackerService {
 
     /**
      * Sets a topology change delegate.

 package org.onlab.onos.net.intent.impl;
 
 import static org.onlab.onos.net.flow.DefaultTrafficTreatment.builder;
+import static org.slf4j.LoggerFactory.getLogger;
 
 import java.util.Iterator;
 
@@ -21,6 +22,7 @@ import org.onlab.onos.net.flow.TrafficTreatment;
 import org.onlab.onos.net.intent.IntentExtensionService;
 import org.onlab.onos.net.intent.IntentInstaller;
 import org.onlab.onos.net.intent.PathIntent;
+import org.slf4j.Logger;
 
 /**
  * Installer for {@link PathIntent path connectivity intents}.
@@ -28,6 +30,8 @@ import org.onlab.onos.net.intent.PathIntent;
 @Component(immediate = true)
 public class PathIntentInstaller implements IntentInstaller<PathIntent> {
 
+    private final Logger log = getLogger(getClass());
+
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected IntentExtensionService intentManager;
 
@@ -49,8 +53,8 @@ public class PathIntentInstaller implements IntentInstaller<PathIntent> {
     @Override
     public void install(PathIntent intent) {
         TrafficSelector.Builder builder =
-                DefaultTrafficSelector.builder(intent.getTrafficSelector());
-        Iterator<Link> links = intent.getPath().links().iterator();
+                DefaultTrafficSelector.builder(intent.selector());
+        Iterator<Link> links = intent.path().links().iterator();
         ConnectPoint prev = links.next().dst();
 
         while (links.hasNext()) {
@@ -70,8 +74,8 @@ public class PathIntentInstaller implements IntentInstaller<PathIntent> {
     @Override
     public void uninstall(PathIntent intent) {
         TrafficSelector.Builder builder =
-                DefaultTrafficSelector.builder(intent.getTrafficSelector());
-        Iterator<Link> links = intent.getPath().links().iterator();
+                DefaultTrafficSelector.builder(intent.selector());
+        Iterator<Link> links = intent.path().links().iterator();
         ConnectPoint prev = links.next().dst();
 
         while (links.hasNext()) {
@@ -82,6 +86,7 @@ public class PathIntentInstaller implements IntentInstaller<PathIntent> {
             FlowRule rule = new DefaultFlowRule(link.src().deviceId(),
                     builder.build(), treatment,
                     123, appId, 600);
+
             flowRuleService.removeFlowRules(rule);
             prev = link.dst();
         }

@@ -9,18 +9,14 @@ public interface TopologyChangeDelegate {
 
     /**
      * Notifies that topology has changed in such a way that the specified
-     * intents should be recompiled.
+     * intents should be recompiled. If the {@code compileAllFailed} parameter
+     * is true, then all intents in {@link org.onlab.onos.net.intent.IntentState#FAILED}
+     * state should be compiled as well.
      *
      * @param intentIds intents that should be recompiled
+     * @param compileAllFailed true implies full compile of all failed intents
+     *                         is required; false for selective recompile only
      */
-    void bumpIntents(Iterable<IntentId> intentIds);
-
-    /**
-     * Notifies that topology has changed in such a way that the specified
-     * intents should be marked failed and then recompiled.
-     *
-     * @param intentIds intents that should be failed and recompiled
-     */
-    void failIntents(Iterable<IntentId> intentIds);
+    void triggerCompile(Iterable<IntentId> intentIds, boolean compileAllFailed);
 
 }

@@ -36,8 +36,6 @@ 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.device.impl.DistributedDeviceStore;
-import org.onlab.onos.store.serializers.KryoSerializationManager;
-import org.onlab.onos.store.serializers.KryoSerializationService;
 import org.onlab.packet.IpPrefix;
 
 import java.util.ArrayList;
@@ -95,7 +93,6 @@ public class DistributedDeviceManagerTest {
     private DistributedDeviceStore dstore;
     private TestMastershipManager masterManager;
     private EventDeliveryService eventService;
-    private KryoSerializationManager serializationMgr;
 
     @Before
     public void setUp() {
@@ -111,10 +108,7 @@ public class DistributedDeviceManagerTest {
         storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
         storeManager.activate();
 
-        serializationMgr = new KryoSerializationManager();
-        serializationMgr.activate();
-
-        dstore = new TestDistributedDeviceStore(storeManager, serializationMgr);
+        dstore = new TestDistributedDeviceStore(storeManager);
         dstore.activate();
 
         mgr.store = dstore;
@@ -140,7 +134,6 @@ public class DistributedDeviceManagerTest {
         mgr.deactivate();
 
         dstore.deactivate();
-        serializationMgr.deactivate();
         storeManager.deactivate();
     }
 
@@ -306,10 +299,8 @@ public class DistributedDeviceManagerTest {
 
     private class TestDistributedDeviceStore extends DistributedDeviceStore {
 
-        public TestDistributedDeviceStore(StoreService storeService,
-                                    KryoSerializationService kryoSerializationService) {
+        public TestDistributedDeviceStore(StoreService storeService) {
             this.storeService = storeService;
-            this.kryoSerializationService = kryoSerializationService;
         }
     }
 

-package org.onlab.onos.store.cluster.messaging.impl;
+package org.onlab.onos.store.cluster.impl;
 
 import org.onlab.onos.store.cluster.messaging.MessageSubject;
 
-public final class ClusterMessageSubjects {
+public final class ClusterManagementMessageSubjects {
     // avoid instantiation
-    private ClusterMessageSubjects() {}
+    private ClusterManagementMessageSubjects() {}
 
     public static final MessageSubject CLUSTER_MEMBERSHIP_EVENT = new MessageSubject("CLUSTER_MEMBERSHIP_EVENT");
 }

-package org.onlab.onos.store.cluster.messaging.impl;
+package org.onlab.onos.store.cluster.impl;
 
 import org.onlab.onos.cluster.ControllerNode;
 

-package org.onlab.onos.store.cluster.messaging.impl;
+package org.onlab.onos.store.cluster.impl;
 
 public enum ClusterMembershipEventType {
     NEW_MEMBER,

@@ -11,14 +11,15 @@ public class ClusterMessage {
 
     private final NodeId sender;
     private final MessageSubject subject;
-    private final Object payload;
+    private final byte[] payload;
+    // TODO: add field specifying Serializer for payload
 
     /**
      * Creates a cluster message.
      *
      * @param subject message subject
      */
-    public ClusterMessage(NodeId sender, MessageSubject subject, Object payload) {
+    public ClusterMessage(NodeId sender, MessageSubject subject, byte[] payload) {
         this.sender = sender;
         this.subject = subject;
         this.payload = payload;
@@ -47,7 +48,7 @@ public class ClusterMessage {
      *
      * @return message payload.
      */
-    public Object payload() {
+    public byte[] payload() {
         return payload;
     }
 }

 package org.onlab.onos.store.cluster.messaging;
 
 /**
- * Service for encoding & decoding intra-cluster messages.
+ * Service for encoding & decoding intra-cluster message payload.
  */
 public interface SerializationService {
 
@@ -11,7 +11,7 @@ public interface SerializationService {
      * @param buffer byte buffer with message(s)
      * @return parsed message
      */
-    Object decode(byte[] data);
+    <T> T decode(byte[] data);
 
     /**
      * Encodes the specified message into the given byte buffer.

@@ -12,17 +12,20 @@ import java.util.TimerTask;
 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.ControllerNode;
 import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.store.cluster.impl.ClusterMembershipEvent;
+import org.onlab.onos.store.cluster.impl.ClusterMembershipEventType;
 import org.onlab.onos.store.cluster.impl.ClusterNodesDelegate;
 import org.onlab.onos.store.cluster.messaging.ClusterCommunicationAdminService;
 import org.onlab.onos.store.cluster.messaging.ClusterCommunicationService;
 import org.onlab.onos.store.cluster.messaging.ClusterMessage;
 import org.onlab.onos.store.cluster.messaging.ClusterMessageHandler;
 import org.onlab.onos.store.cluster.messaging.MessageSubject;
+import org.onlab.onos.store.serializers.KryoPoolUtil;
+import org.onlab.onos.store.serializers.KryoSerializer;
+import org.onlab.util.KryoPool;
 import org.onlab.netty.Endpoint;
 import org.onlab.netty.Message;
 import org.onlab.netty.MessageHandler;
@@ -44,16 +47,35 @@ public class ClusterCommunicationManager
     private final Timer timer = new Timer("onos-controller-heatbeats");
     public static final long HEART_BEAT_INTERVAL_MILLIS = 1000L;
 
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    // TODO: This probably should not be a OSGi service.
+    //@Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     private MessagingService messagingService;
 
+    private static final KryoSerializer SERIALIZER = new KryoSerializer() {
+        protected void setupKryoPool() {
+            serializerPool = KryoPool.newBuilder()
+                    .register(KryoPoolUtil.API)
+                    .register(ClusterMessage.class)
+                    .register(ClusterMembershipEvent.class)
+                    .build()
+                    .populate(1);
+        }
+
+    };
+
     @Activate
     public void activate() {
+        // TODO: initialize messagingService
+        // TODO: setPayloadSerializer, which is capable of
+        //  (1) serialize ClusterMessage - ClusterMessage.payload
+        //  (2) serialize ClusterMessage.payload using user specified serializer
+//        messagingService.setPayloadSerializer(...);
         log.info("Started");
     }
 
     @Deactivate
     public void deactivate() {
+        // TODO: cleanup messageingService if needed.
         log.info("Stopped");
     }
 
@@ -85,7 +107,7 @@ public class ClusterCommunicationManager
         checkArgument(node != null, "Unknown nodeId: %s", toNodeId);
         Endpoint nodeEp = new Endpoint(node.ip().toString(), node.tcpPort());
         try {
-            messagingService.sendAsync(nodeEp, message.subject().value(), message);
+            messagingService.sendAsync(nodeEp, message.subject().value(), SERIALIZER.encode(message));
             return true;
         } catch (IOException e) {
             log.error("Failed to send cluster message to nodeId: " + toNodeId, e);
@@ -119,7 +141,7 @@ public class ClusterCommunicationManager
         broadcast(new ClusterMessage(
                 localNode.id(),
                 new MessageSubject("CLUSTER_MEMBERSHIP_EVENT"),
-                new ClusterMembershipEvent(ClusterMembershipEventType.LEAVING_MEMBER, node)));
+                SERIALIZER.encode(new ClusterMembershipEvent(ClusterMembershipEventType.LEAVING_MEMBER, node))));
         members.remove(node.id());
     }
 
@@ -131,7 +153,7 @@ public class ClusterCommunicationManager
             broadcast(new ClusterMessage(
                 localNode.id(),
                 new MessageSubject("CLUSTER_MEMBERSHIP_EVENT"),
-                new ClusterMembershipEvent(ClusterMembershipEventType.HEART_BEAT, localNode)));
+                SERIALIZER.encode(new ClusterMembershipEvent(ClusterMembershipEventType.HEART_BEAT, localNode))));
         }
     }
 
@@ -140,7 +162,7 @@ public class ClusterCommunicationManager
         @Override
         public void handle(ClusterMessage message) {
 
-            ClusterMembershipEvent event = (ClusterMembershipEvent) message.payload();
+            ClusterMembershipEvent event = SERIALIZER.decode(message.payload());
             ControllerNode node = event.node();
             if (event.type() == ClusterMembershipEventType.HEART_BEAT) {
                 log.info("Node {} sent a hearbeat", node.id());
@@ -165,7 +187,8 @@ public class ClusterCommunicationManager
 
         @Override
         public void handle(Message message) {
-            handler.handle((ClusterMessage) message.payload());
+            ClusterMessage clusterMessage = SERIALIZER.decode(message.payload());
+            handler.handle(clusterMessage);
         }
     }
 }

-package org.onlab.onos.store.cluster.impl;
+package org.onlab.onos.store.cluster.messaging.impl;
 
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
@@ -52,7 +52,7 @@ public class MessageSerializer implements SerializationService {
 
 
     @Override
-    public Object decode(byte[] data) {
+    public <T> T decode(byte[] data) {
         return serializerPool.deserialize(data);
     }
 

-package org.onlab.onos.store.cluster.messaging;
+package org.onlab.onos.store.common.impl;
 
 import java.util.Map;
 

-package org.onlab.onos.store.cluster.messaging;
+package org.onlab.onos.store.common.impl;
 
 import java.util.Map;
 import java.util.Set;

@@ -8,7 +8,7 @@ import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.store.Timestamp;
-import org.onlab.onos.store.cluster.messaging.AntiEntropyAdvertisement;
+import org.onlab.onos.store.common.impl.AntiEntropyAdvertisement;
 
 // TODO DeviceID needs to be changed to something like (ProviderID, DeviceID)
 // TODO: Handle Port as part of these messages, or separate messages for Ports?

@@ -10,7 +10,7 @@ import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.store.Timestamp;
-import org.onlab.onos.store.cluster.messaging.AntiEntropyReply;
+import org.onlab.onos.store.common.impl.AntiEntropyReply;
 
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;

@@ -4,6 +4,7 @@ import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
+
 import org.apache.commons.lang3.concurrent.ConcurrentException;
 import org.apache.commons.lang3.concurrent.ConcurrentInitializer;
 import org.apache.felix.scr.annotations.Activate;
@@ -12,6 +13,7 @@ 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.ClusterService;
 import org.onlab.onos.net.AnnotationsUtil;
 import org.onlab.onos.net.DefaultAnnotations;
 import org.onlab.onos.net.DefaultDevice;
@@ -33,10 +35,18 @@ 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.cluster.messaging.ClusterCommunicationService;
+import org.onlab.onos.store.cluster.messaging.ClusterMessage;
+import org.onlab.onos.store.cluster.messaging.ClusterMessageHandler;
+import org.onlab.onos.store.common.impl.MastershipBasedTimestamp;
 import org.onlab.onos.store.common.impl.Timestamped;
+import org.onlab.onos.store.serializers.KryoPoolUtil;
+import org.onlab.onos.store.serializers.KryoSerializer;
+import org.onlab.util.KryoPool;
 import org.onlab.util.NewConcurrentHashMap;
 import org.slf4j.Logger;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
@@ -96,8 +106,35 @@ public class GossipDeviceStore
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected ClockService clockService;
 
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClusterCommunicationService clusterCommunicator;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClusterService clusterService;
+
+    private static final KryoSerializer SERIALIZER = new KryoSerializer() {
+        protected void setupKryoPool() {
+            serializerPool = KryoPool.newBuilder()
+                    .register(KryoPoolUtil.API)
+                    .register(InternalDeviceEvent.class)
+                    .register(InternalPortEvent.class)
+                    .register(InternalPortStatusEvent.class)
+                    .register(Timestamped.class)
+                    .register(MastershipBasedTimestamp.class)
+                    .build()
+                    .populate(1);
+        }
+
+    };
+
     @Activate
     public void activate() {
+        clusterCommunicator.addSubscriber(
+                GossipDeviceStoreMessageSubjects.DEVICE_UPDATE, new InternalDeviceEventListener());
+        clusterCommunicator.addSubscriber(
+                GossipDeviceStoreMessageSubjects.PORT_UPDATE, new InternalPortEventListener());
+        clusterCommunicator.addSubscriber(
+                GossipDeviceStoreMessageSubjects.PORT_STATUS_UPDATE, new InternalPortStatusEventListener());
         log.info("Started");
     }
 
@@ -133,8 +170,14 @@ public class GossipDeviceStore
         final Timestamped<DeviceDescription> deltaDesc = new Timestamped<>(deviceDescription, newTimestamp);
         DeviceEvent event = createOrUpdateDeviceInternal(providerId, deviceId, deltaDesc);
         if (event != null) {
-            // FIXME: broadcast deltaDesc, UP
-            log.debug("broadcast deltaDesc");
+            log.info("Notifying peers of a device update topology event for providerId: {} and deviceId: {}",
+                providerId, deviceId);
+            try {
+                notifyPeers(new InternalDeviceEvent(providerId, deviceId, deltaDesc));
+            } catch (IOException e) {
+                log.error("Failed to notify peers of a device update topology event or providerId: "
+                        + providerId + " and deviceId: " + deviceId, e);
+            }
         }
         return event;
     }
@@ -298,19 +341,21 @@ public class GossipDeviceStore
                                        List<PortDescription> portDescriptions) {
         Timestamp newTimestamp = clockService.getTimestamp(deviceId);
 
-        List<Timestamped<PortDescription>> deltaDescs = new ArrayList<>(portDescriptions.size());
-        for (PortDescription e : portDescriptions) {
-            deltaDescs.add(new Timestamped<PortDescription>(e, newTimestamp));
-        }
+        Timestamped<List<PortDescription>> timestampedPortDescriptions =
+            new Timestamped<>(portDescriptions, newTimestamp);
 
-        List<DeviceEvent> events = updatePortsInternal(providerId, deviceId,
-                          new Timestamped<>(portDescriptions, newTimestamp));
+        List<DeviceEvent> events = updatePortsInternal(providerId, deviceId, timestampedPortDescriptions);
         if (!events.isEmpty()) {
-            // FIXME: broadcast deltaDesc, UP
-            log.debug("broadcast deltaDesc");
+            log.info("Notifying peers of a port update topology event for providerId: {} and deviceId: {}",
+                    providerId, deviceId);
+            try {
+                notifyPeers(new InternalPortEvent(providerId, deviceId, timestampedPortDescriptions));
+            } catch (IOException e) {
+                log.error("Failed to notify peers of a port update topology event or providerId: "
+                    + providerId + " and deviceId: " + deviceId, e);
+            }
         }
         return events;
-
     }
 
     private List<DeviceEvent> updatePortsInternal(ProviderId providerId,
@@ -437,8 +482,14 @@ public class GossipDeviceStore
         final Timestamped<PortDescription> deltaDesc = new Timestamped<>(portDescription, newTimestamp);
         DeviceEvent event = updatePortStatusInternal(providerId, deviceId, deltaDesc);
         if (event != null) {
-            // FIXME: broadcast deltaDesc
-            log.debug("broadcast deltaDesc");
+            log.info("Notifying peers of a port status update topology event for providerId: {} and deviceId: {}",
+                        providerId, deviceId);
+            try {
+                notifyPeers(new InternalPortStatusEvent(providerId, deviceId, deltaDesc));
+            } catch (IOException e) {
+                log.error("Failed to notify peers of a port status update topology event or providerId: "
+                        + providerId + " and deviceId: " + deviceId, e);
+            }
         }
         return event;
     }
@@ -749,4 +800,70 @@ public class GossipDeviceStore
             return portDescs.put(newOne.value().portNumber(), newOne);
         }
     }
+
+    private void notifyPeers(InternalDeviceEvent event) throws IOException {
+        ClusterMessage message = new ClusterMessage(
+                clusterService.getLocalNode().id(),
+                GossipDeviceStoreMessageSubjects.DEVICE_UPDATE,
+                SERIALIZER.encode(event));
+        clusterCommunicator.broadcast(message);
+    }
+
+    private void notifyPeers(InternalPortEvent event) throws IOException {
+        ClusterMessage message = new ClusterMessage(
+                clusterService.getLocalNode().id(),
+                GossipDeviceStoreMessageSubjects.PORT_UPDATE,
+                SERIALIZER.encode(event));
+        clusterCommunicator.broadcast(message);
+    }
+
+    private void notifyPeers(InternalPortStatusEvent event) throws IOException {
+        ClusterMessage message = new ClusterMessage(
+                clusterService.getLocalNode().id(),
+                GossipDeviceStoreMessageSubjects.PORT_STATUS_UPDATE,
+                SERIALIZER.encode(event));
+        clusterCommunicator.broadcast(message);
+    }
+
+    private class InternalDeviceEventListener implements ClusterMessageHandler {
+        @Override
+        public void handle(ClusterMessage message) {
+            log.info("Received device update event from peer: {}", message.sender());
+            InternalDeviceEvent event = (InternalDeviceEvent) SERIALIZER.decode(message.payload());
+            ProviderId providerId = event.providerId();
+            DeviceId deviceId = event.deviceId();
+            Timestamped<DeviceDescription> deviceDescription = event.deviceDescription();
+            createOrUpdateDeviceInternal(providerId, deviceId, deviceDescription);
+        }
+    }
+
+    private class InternalPortEventListener implements ClusterMessageHandler {
+        @Override
+        public void handle(ClusterMessage message) {
+
+            log.info("Received port update event from peer: {}", message.sender());
+            InternalPortEvent event = (InternalPortEvent) SERIALIZER.decode(message.payload());
+
+            ProviderId providerId = event.providerId();
+            DeviceId deviceId = event.deviceId();
+            Timestamped<List<PortDescription>> portDescriptions = event.portDescriptions();
+
+            updatePortsInternal(providerId, deviceId, portDescriptions);
+        }
+    }
+
+    private class InternalPortStatusEventListener implements ClusterMessageHandler {
+        @Override
+        public void handle(ClusterMessage message) {
+
+            log.info("Received port status update event from peer: {}", message.sender());
+            InternalPortStatusEvent event = (InternalPortStatusEvent) SERIALIZER.decode(message.payload());
+
+            ProviderId providerId = event.providerId();
+            DeviceId deviceId = event.deviceId();
+            Timestamped<PortDescription> portDescription = event.portDescription();
+
+            updatePortStatusInternal(providerId, deviceId, portDescription);
+        }
+    }
 }

+package org.onlab.onos.store.device.impl;
+
+import org.onlab.onos.store.cluster.messaging.MessageSubject;
+
+/**
+ * MessageSubjects used by GossipDeviceStore.
+ */
+public final class GossipDeviceStoreMessageSubjects {
+
+    private GossipDeviceStoreMessageSubjects() {}
+
+    public static final MessageSubject DEVICE_UPDATE = new MessageSubject("peer-device-update");
+    public static final MessageSubject PORT_UPDATE = new MessageSubject("peer-port-update");
+    public static final MessageSubject PORT_STATUS_UPDATE = new MessageSubject("peer-port-status-update");
+}

+package org.onlab.onos.store.device.impl;
+
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.device.DeviceDescription;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.common.impl.Timestamped;
+
+/**
+ * Information published by GossipDeviceStore to notify peers of a device
+ * change event.
+ */
+public class InternalDeviceEvent {
+
+    private final ProviderId providerId;
+    private final DeviceId deviceId;
+    private final Timestamped<DeviceDescription> deviceDescription;
+
+    protected InternalDeviceEvent(
+            ProviderId providerId,
+            DeviceId deviceId,
+            Timestamped<DeviceDescription> deviceDescription) {
+        this.providerId = providerId;
+        this.deviceId = deviceId;
+        this.deviceDescription = deviceDescription;
+    }
+
+    public DeviceId deviceId() {
+        return deviceId;
+    }
+
+    public ProviderId providerId() {
+        return providerId;
+    }
+
+    public Timestamped<DeviceDescription> deviceDescription() {
+        return deviceDescription;
+    }
+}

+package org.onlab.onos.store.device.impl;
+
+import java.util.List;
+
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.device.PortDescription;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.common.impl.Timestamped;
+
+/**
+ * Information published by GossipDeviceStore to notify peers of a port
+ * change event.
+ */
+public class InternalPortEvent {
+
+    private final ProviderId providerId;
+    private final DeviceId deviceId;
+    private final Timestamped<List<PortDescription>> portDescriptions;
+
+    protected InternalPortEvent(
+            ProviderId providerId,
+            DeviceId deviceId,
+            Timestamped<List<PortDescription>> portDescriptions) {
+        this.providerId = providerId;
+        this.deviceId = deviceId;
+        this.portDescriptions = portDescriptions;
+    }
+
+    public DeviceId deviceId() {
+        return deviceId;
+    }
+
+    public ProviderId providerId() {
+        return providerId;
+    }
+
+    public Timestamped<List<PortDescription>> portDescriptions() {
+        return portDescriptions;
+    }
+}

+package org.onlab.onos.store.device.impl;
+
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.device.PortDescription;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.common.impl.Timestamped;
+
+/**
+ * Information published by GossipDeviceStore to notify peers of a port
+ * status change event.
+ */
+public class InternalPortStatusEvent {
+
+    private final ProviderId providerId;
+    private final DeviceId deviceId;
+    private final Timestamped<PortDescription> portDescription;
+
+    protected InternalPortStatusEvent(
+            ProviderId providerId,
+            DeviceId deviceId,
+            Timestamped<PortDescription> portDescription) {
+        this.providerId = providerId;
+        this.deviceId = deviceId;
+        this.portDescription = portDescription;
+    }
+
+    public DeviceId deviceId() {
+        return deviceId;
+    }
+
+    public ProviderId providerId() {
+        return providerId;
+    }
+
+    public Timestamped<PortDescription> portDescription() {
+        return portDescription;
+    }
+}

@@ -58,6 +58,11 @@ public class DistributedFlowRuleStore
 
 
     @Override
+    public int getFlowRuleCount() {
+        return flowEntries.size();
+    }
+
+    @Override
     public synchronized FlowEntry getFlowEntry(FlowRule rule) {
         for (FlowEntry f : flowEntries.get(rule.deviceId())) {
             if (f.equals(rule)) {

+package org.onlab.onos.store.serializers;
+
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.store.cluster.messaging.ClusterMessage;
+import org.onlab.onos.store.cluster.messaging.MessageSubject;
+
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.io.Input;
+import com.esotericsoftware.kryo.io.Output;
+
+public final class ClusterMessageSerializer extends Serializer<ClusterMessage> {
+
+    public ClusterMessageSerializer() {
+        // does not accept null
+        super(false);
+    }
+
+    @Override
+    public void write(Kryo kryo, Output output, ClusterMessage message) {
+        kryo.writeClassAndObject(output, message.sender());
+        kryo.writeClassAndObject(output, message.subject());
+        output.writeInt(message.payload().length);
+        output.writeBytes(message.payload());
+    }
+
+    @Override
+    public ClusterMessage read(Kryo kryo, Input input,
+                               Class<ClusterMessage> type) {
+        NodeId sender = (NodeId) kryo.readClassAndObject(input);
+        MessageSubject subject = (MessageSubject) kryo.readClassAndObject(input);
+        int payloadSize = input.readInt();
+        byte[] payload = input.readBytes(payloadSize);
+        return new ClusterMessage(sender, subject, payload);
+    }
+}
\ No newline at end of file

@@ -7,6 +7,7 @@ import org.junit.Test;
 import org.onlab.onos.cluster.DefaultControllerNode;
 import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.store.cluster.messaging.impl.ClusterCommunicationManager;
+import org.onlab.onos.store.cluster.messaging.impl.MessageSerializer;
 import org.onlab.netty.NettyMessagingService;
 import org.onlab.packet.IpPrefix;
 

@@ -5,6 +5,7 @@ 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.io.IOException;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
@@ -19,6 +20,11 @@ import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Ignore;
 import org.junit.Test;
+import org.onlab.onos.cluster.ClusterEventListener;
+import org.onlab.onos.cluster.ClusterService;
+import org.onlab.onos.cluster.ControllerNode;
+import org.onlab.onos.cluster.ControllerNode.State;
+import org.onlab.onos.cluster.DefaultControllerNode;
 import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.net.Annotations;
@@ -37,6 +43,11 @@ import org.onlab.onos.net.device.DeviceStoreDelegate;
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.store.ClockService;
+import org.onlab.onos.store.cluster.messaging.ClusterCommunicationService;
+import org.onlab.onos.store.cluster.messaging.ClusterMessage;
+import org.onlab.onos.store.cluster.messaging.ClusterMessageHandler;
+import org.onlab.onos.store.cluster.messaging.MessageSubject;
+import org.onlab.packet.IpPrefix;
 
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Sets;
@@ -105,7 +116,10 @@ public class GossipDeviceStoreTest {
         deviceClockManager.setMastershipTerm(DID1, MastershipTerm.of(MYSELF, 1));
         deviceClockManager.setMastershipTerm(DID2, MastershipTerm.of(MYSELF, 2));
 
-        gossipDeviceStore = new TestGossipDeviceStore(clockService);
+        ClusterCommunicationService clusterCommunicator = new TestClusterCommunicationService();
+        ClusterService clusterService = new TestClusterService();
+
+        gossipDeviceStore = new TestGossipDeviceStore(clockService, clusterService, clusterCommunicator);
         gossipDeviceStore.activate();
         deviceStore = gossipDeviceStore;
     }
@@ -541,8 +555,65 @@ public class GossipDeviceStoreTest {
 
     private static final class TestGossipDeviceStore extends GossipDeviceStore {
 
-        public TestGossipDeviceStore(ClockService clockService) {
+        public TestGossipDeviceStore(
+                ClockService clockService,
+                ClusterService clusterService,
+                ClusterCommunicationService clusterCommunicator) {
             this.clockService = clockService;
+            this.clusterService = clusterService;
+            this.clusterCommunicator = clusterCommunicator;
+        }
+    }
+
+    private static final class TestClusterCommunicationService implements ClusterCommunicationService {
+        @Override
+        public boolean broadcast(ClusterMessage message) throws IOException { return true; }
+        @Override
+        public boolean unicast(ClusterMessage message, NodeId nodeId) throws IOException { return true; }
+        @Override
+        public boolean multicast(ClusterMessage message, Set<NodeId> nodeIds) throws IOException { return true; }
+        @Override
+        public void addSubscriber(MessageSubject subject, ClusterMessageHandler subscriber) {}
+    }
+
+    private static final class TestClusterService implements ClusterService {
+
+        private static final ControllerNode ONOS1 =
+            new DefaultControllerNode(new NodeId("N1"), IpPrefix.valueOf("127.0.0.1"));
+        private final Map<NodeId, ControllerNode> nodes = new HashMap<>();
+        private final Map<NodeId, ControllerNode.State> nodeStates = new HashMap<>();
+
+        public TestClusterService() {
+            nodes.put(new NodeId("N1"), ONOS1);
+            nodeStates.put(new NodeId("N1"), ControllerNode.State.ACTIVE);
+        }
+
+        @Override
+        public ControllerNode getLocalNode() {
+            return ONOS1;
+        }
+
+        @Override
+        public Set<ControllerNode> getNodes() {
+            return Sets.newHashSet(nodes.values());
+        }
+
+        @Override
+        public ControllerNode getNode(NodeId nodeId) {
+            return nodes.get(nodeId);
+        }
+
+        @Override
+        public State getState(NodeId nodeId) {
+            return nodeStates.get(nodeId);
+        }
+
+        @Override
+        public void addListener(ClusterEventListener listener) {
+        }
+
+        @Override
+        public void removeListener(ClusterEventListener listener) {
         }
     }
 }

@@ -57,7 +57,7 @@ public class DistributedClusterStore
 
         rawNodes = theInstance.getMap("nodes");
         OptionalCacheLoader<NodeId, DefaultControllerNode> nodeLoader
-                = new OptionalCacheLoader<>(kryoSerializationService, rawNodes);
+                = new OptionalCacheLoader<>(serializer, rawNodes);
         nodes = new AbsentInvalidatingLoadingCache<>(newBuilder().build(nodeLoader));
         rawNodes.addEntryListener(new RemoteCacheEventHandler<>(nodes), true);
 

@@ -52,7 +52,7 @@ implements MastershipStore {
 
         rawMasters = theInstance.getMap("masters");
         OptionalCacheLoader<DeviceId, NodeId> nodeLoader
-        = new OptionalCacheLoader<>(kryoSerializationService, rawMasters);
+        = new OptionalCacheLoader<>(serializer, rawMasters);
         masters = new AbsentInvalidatingLoadingCache<>(newBuilder().build(nodeLoader));
         rawMasters.addEntryListener(new RemoteMasterShipEventHandler(masters), true);
 

@@ -15,7 +15,8 @@ import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.onlab.onos.event.Event;
 import org.onlab.onos.store.AbstractStore;
 import org.onlab.onos.store.StoreDelegate;
-import org.onlab.onos.store.serializers.KryoSerializationService;
+import org.onlab.onos.store.serializers.KryoSerializer;
+import org.onlab.onos.store.serializers.Serializer;
 import org.slf4j.Logger;
 
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -24,7 +25,7 @@ import static org.slf4j.LoggerFactory.getLogger;
 /**
  * Abstraction of a distributed store based on Hazelcast.
  */
-@Component(componentAbstract = true)
+@Component
 public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDelegate<E>>
         extends AbstractStore<E, D> {
 
@@ -33,13 +34,13 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected StoreService storeService;
 
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    protected KryoSerializationService kryoSerializationService;
+    protected Serializer serializer;
 
     protected HazelcastInstance theInstance;
 
     @Activate
     public void activate() {
+        serializer = new KryoSerializer();
         theInstance = storeService.getHazelcastInstance();
     }
 
@@ -50,7 +51,7 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
      * @return serialized object
      */
     protected byte[] serialize(Object obj) {
-        return kryoSerializationService.serialize(obj);
+        return serializer.encode(obj);
     }
 
     /**
@@ -61,7 +62,7 @@ public abstract class AbstractHazelcastStore<E extends Event, D extends StoreDel
      * @return deserialized object
      */
     protected <T> T deserialize(byte[] bytes) {
-        return kryoSerializationService.deserialize(bytes);
+        return serializer.decode(bytes);
     }
 
 

@@ -2,7 +2,7 @@ package org.onlab.onos.store.common;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
-import org.onlab.onos.store.serializers.KryoSerializationService;
+import org.onlab.onos.store.serializers.Serializer;
 
 import com.google.common.base.Optional;
 import com.google.common.cache.CacheLoader;
@@ -18,28 +18,28 @@ import com.hazelcast.core.IMap;
 public final class OptionalCacheLoader<K, V> extends
         CacheLoader<K, Optional<V>> {
 
-    private final KryoSerializationService kryoSerializationService;
+    private final Serializer serializer;
     private IMap<byte[], byte[]> rawMap;
 
     /**
      * Constructor.
      *
-     * @param kryoSerializationService to use for serialization
+     * @param serializer to use for serialization
      * @param rawMap underlying IMap
      */
-    public OptionalCacheLoader(KryoSerializationService kryoSerializationService, IMap<byte[], byte[]> rawMap) {
-        this.kryoSerializationService = checkNotNull(kryoSerializationService);
+    public OptionalCacheLoader(Serializer serializer, IMap<byte[], byte[]> rawMap) {
+        this.serializer = checkNotNull(serializer);
         this.rawMap = checkNotNull(rawMap);
     }
 
     @Override
     public Optional<V> load(K key) throws Exception {
-        byte[] keyBytes = kryoSerializationService.serialize(key);
+        byte[] keyBytes = serializer.encode(key);
         byte[] valBytes = rawMap.get(keyBytes);
         if (valBytes == null) {
             return Optional.absent();
         }
-        V dev = kryoSerializationService.deserialize(valBytes);
+        V dev = serializer.decode(valBytes);
         return Optional.of(dev);
     }
 }

@@ -88,7 +88,7 @@ public class DistributedDeviceStore
         // TODO decide on Map name scheme to avoid collision
         rawDevices = theInstance.getMap("devices");
         final OptionalCacheLoader<DeviceId, DefaultDevice> deviceLoader
-                = new OptionalCacheLoader<>(kryoSerializationService, rawDevices);
+                = new OptionalCacheLoader<>(serializer, rawDevices);
         devices = new AbsentInvalidatingLoadingCache<>(newBuilder().build(deviceLoader));
         // refresh/populate cache based on notification from other instance
         devicesListener = rawDevices.addEntryListener(new RemoteDeviceEventHandler(devices), includeValue);
@@ -98,7 +98,7 @@ public class DistributedDeviceStore
 
         rawDevicePorts = theInstance.getMap("devicePorts");
         final OptionalCacheLoader<DeviceId, Map<PortNumber, Port>> devicePortLoader
-                = new OptionalCacheLoader<>(kryoSerializationService, rawDevicePorts);
+                = new OptionalCacheLoader<>(serializer, rawDevicePorts);
         devicePorts = new AbsentInvalidatingLoadingCache<>(newBuilder().build(devicePortLoader));
         // refresh/populate cache based on notification from other instance
         portsListener = rawDevicePorts.addEntryListener(new RemotePortEventHandler(devicePorts), includeValue);

@@ -58,6 +58,11 @@ public class DistributedFlowRuleStore
 
 
     @Override
+    public int getFlowRuleCount() {
+        return flowEntries.size();
+    }
+
+    @Override
     public synchronized FlowEntry getFlowEntry(FlowRule rule) {
         for (FlowEntry f : flowEntries.get(rule.deviceId())) {
             if (f.equals(rule)) {

@@ -71,7 +71,7 @@ public class DistributedLinkStore
         // TODO decide on Map name scheme to avoid collision
         rawLinks = theInstance.getMap("links");
         final OptionalCacheLoader<LinkKey, DefaultLink> linkLoader
-                = new OptionalCacheLoader<>(kryoSerializationService, rawLinks);
+                = new OptionalCacheLoader<>(serializer, rawLinks);
         links = new AbsentInvalidatingLoadingCache<>(newBuilder().build(linkLoader));
         // refresh/populate cache based on notification from other instance
         linksListener = rawLinks.addEntryListener(new RemoteLinkEventHandler(links), includeValue);

@@ -36,9 +36,6 @@ import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.store.common.StoreManager;
 import org.onlab.onos.store.common.StoreService;
 import org.onlab.onos.store.common.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.Sets;
 import com.hazelcast.config.Config;
@@ -63,7 +60,6 @@ public class DistributedDeviceStoreTest {
     private static final PortNumber P3 = PortNumber.portNumber(3);
 
     private DistributedDeviceStore deviceStore;
-    private KryoSerializationManager serializationMgr;
 
     private StoreManager storeManager;
 
@@ -85,10 +81,7 @@ public class DistributedDeviceStoreTest {
         storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
         storeManager.activate();
 
-        serializationMgr = new KryoSerializationManager();
-        serializationMgr.activate();
-
-        deviceStore = new TestDistributedDeviceStore(storeManager, serializationMgr);
+        deviceStore = new TestDistributedDeviceStore(storeManager);
         deviceStore.activate();
     }
 
@@ -96,8 +89,6 @@ public class DistributedDeviceStoreTest {
     public void tearDown() throws Exception {
         deviceStore.deactivate();
 
-        serializationMgr.deactivate();
-
         storeManager.deactivate();
     }
 
@@ -392,10 +383,8 @@ public class DistributedDeviceStoreTest {
     }
 
     private class TestDistributedDeviceStore extends DistributedDeviceStore {
-        public TestDistributedDeviceStore(StoreService storeService,
-                                KryoSerializationService kryoSerializationService) {
+        public TestDistributedDeviceStore(StoreService storeService) {
             this.storeService = storeService;
-            this.kryoSerializationService = kryoSerializationService;
         }
     }
 }

@@ -30,9 +30,6 @@ import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.store.common.StoreManager;
 import org.onlab.onos.store.common.StoreService;
 import org.onlab.onos.store.common.TestStoreManager;
-import org.onlab.onos.store.serializers.KryoSerializationManager;
-import org.onlab.onos.store.serializers.KryoSerializationService;
-
 import com.google.common.collect.Iterables;
 import com.hazelcast.config.Config;
 import com.hazelcast.core.Hazelcast;
@@ -51,7 +48,6 @@ public class DistributedLinkStoreTest {
     private static final PortNumber P3 = PortNumber.portNumber(3);
 
     private StoreManager storeManager;
-    private KryoSerializationManager serializationMgr;
 
     private DistributedLinkStore linkStore;
 
@@ -71,17 +67,13 @@ public class DistributedLinkStoreTest {
         storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
         storeManager.activate();
 
-        serializationMgr = new KryoSerializationManager();
-        serializationMgr.activate();
-
-        linkStore = new TestDistributedLinkStore(storeManager, serializationMgr);
+        linkStore = new TestDistributedLinkStore(storeManager);
         linkStore.activate();
     }
 
     @After
     public void tearDown() throws Exception {
         linkStore.deactivate();
-        serializationMgr.deactivate();
         storeManager.deactivate();
     }
 
@@ -361,10 +353,8 @@ public class DistributedLinkStoreTest {
 
 
     class TestDistributedLinkStore extends DistributedLinkStore {
-        TestDistributedLinkStore(StoreService storeService,
-                            KryoSerializationService kryoSerializationService) {
+        TestDistributedLinkStore(StoreService storeService) {
             this.storeService = storeService;
-            this.kryoSerializationService = kryoSerializationService;
         }
     }
 }

@@ -2,6 +2,7 @@ package org.onlab.onos.store.serializers;
 
 import java.net.URI;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 
 import org.onlab.onos.cluster.ControllerNode;
@@ -21,6 +22,8 @@ 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.device.DefaultDeviceDescription;
+import org.onlab.onos.net.device.DefaultPortDescription;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.packet.IpAddress;
 import org.onlab.packet.IpPrefix;
@@ -47,6 +50,7 @@ public final class KryoPoolUtil {
             .register(
                     //
                     ArrayList.class,
+                    Arrays.asList().getClass(),
                     HashMap.class,
                     //
                     ControllerNode.State.class,
@@ -54,8 +58,10 @@ public final class KryoPoolUtil {
                     DefaultAnnotations.class,
                     DefaultControllerNode.class,
                     DefaultDevice.class,
+                    DefaultDeviceDescription.class,
                     MastershipRole.class,
                     Port.class,
+                    DefaultPortDescription.class,
                     Element.class,
                     Link.Type.class
                     )

 package org.onlab.onos.store.serializers;
 
-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.util.KryoPool;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -11,25 +7,16 @@ import org.slf4j.LoggerFactory;
 import java.nio.ByteBuffer;
 
 /**
- * Serialization service using Kryo.
+ * Serializer implementation using Kryo.
  */
-@Component(immediate = true)
-@Service
-public class KryoSerializationManager implements KryoSerializationService {
+public class KryoSerializer implements Serializer {
 
     private final Logger log = LoggerFactory.getLogger(getClass());
-    private KryoPool serializerPool;
+    protected KryoPool serializerPool;
 
 
-    @Activate
-    public void activate() {
+    public KryoSerializer() {
         setupKryoPool();
-        log.info("Started");
-    }
-
-    @Deactivate
-    public void deactivate() {
-        log.info("Stopped");
     }
 
     /**
@@ -43,12 +30,12 @@ public class KryoSerializationManager implements KryoSerializationService {
     }
 
     @Override
-    public byte[] serialize(final Object obj) {
+    public byte[] encode(final Object obj) {
         return serializerPool.serialize(obj);
     }
 
     @Override
-    public <T> T deserialize(final byte[] bytes) {
+    public <T> T decode(final byte[] bytes) {
         if (bytes == null) {
             return null;
         }
@@ -56,12 +43,12 @@ public class KryoSerializationManager implements KryoSerializationService {
     }
 
     @Override
-    public void serialize(Object obj, ByteBuffer buffer) {
+    public void encode(Object obj, ByteBuffer buffer) {
         serializerPool.serialize(obj, buffer);
     }
 
     @Override
-    public <T> T deserialize(ByteBuffer buffer) {
+    public <T> T decode(ByteBuffer buffer) {
         return serializerPool.deserialize(buffer);
     }
 

@@ -6,41 +6,37 @@ import java.nio.ByteBuffer;
 /**
  * Service to serialize Objects into byte array.
  */
-public interface KryoSerializationService {
+public interface Serializer {
 
     /**
-     * Serializes the specified object into bytes using one of the
-     * pre-registered serializers.
+     * Serializes the specified object into bytes.
      *
      * @param obj object to be serialized
      * @return serialized bytes
      */
-    public byte[] serialize(final Object obj);
+    public byte[] encode(final Object obj);
 
     /**
-     * Serializes the specified object into bytes using one of the
-     * pre-registered serializers.
+     * Serializes the specified object into bytes.
      *
      * @param obj object to be serialized
      * @param buffer to write serialized bytes
      */
-    public void serialize(final Object obj, ByteBuffer buffer);
+    public void encode(final Object obj, ByteBuffer buffer);
 
     /**
-     * Deserializes the specified bytes into an object using one of the
-     * pre-registered serializers.
+     * Deserializes the specified bytes into an object.
      *
      * @param bytes bytes to be deserialized
      * @return deserialized object
      */
-    public <T> T deserialize(final byte[] bytes);
+    public <T> T decode(final byte[] bytes);
 
     /**
-     * Deserializes the specified bytes into an object using one of the
-     * pre-registered serializers.
+     * Deserializes the specified bytes into an object.
      *
      * @param buffer bytes to be deserialized
      * @return deserialized object
      */
-    public <T> T deserialize(final ByteBuffer buffer);
+    public <T> T decode(final ByteBuffer buffer);
 }

@@ -57,6 +57,11 @@ public class SimpleFlowRuleStore
 
 
     @Override
+    public int getFlowRuleCount() {
+        return flowEntries.size();
+    }
+
+    @Override
     public synchronized FlowEntry getFlowEntry(FlowRule rule) {
         for (FlowEntry f : flowEntries.get(rule.deviceId())) {
             if (f.equals(rule)) {
@@ -98,6 +103,7 @@ public class SimpleFlowRuleStore
     public synchronized void deleteFlowRule(FlowRule rule) {
         FlowEntry entry = getFlowEntry(rule);
         if (entry == null) {
+            //log.warn("Cannot find rule {}", rule);
             return;
         }
         entry.setState(FlowEntryState.PENDING_REMOVE);
@@ -120,7 +126,7 @@ public class SimpleFlowRuleStore
             return new FlowRuleEvent(Type.RULE_UPDATED, rule);
         }
 
-        flowEntries.put(did, rule);
+        //flowEntries.put(did, rule);
         return null;
     }
 

 package org.onlab.onos.store.trivial.impl;
 
-import static org.onlab.onos.net.intent.IntentState.COMPILED;
-import static org.slf4j.LoggerFactory.getLogger;
-
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
+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;
@@ -21,7 +15,12 @@ import org.onlab.onos.net.intent.IntentStoreDelegate;
 import org.onlab.onos.store.AbstractStore;
 import org.slf4j.Logger;
 
-import com.google.common.collect.ImmutableSet;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.onlab.onos.net.intent.IntentState.*;
+import static org.slf4j.LoggerFactory.getLogger;
 
 @Component(immediate = true)
 @Service
@@ -46,7 +45,7 @@ public class SimpleIntentStore
 
     @Override
     public IntentEvent createIntent(Intent intent) {
-        intents.put(intent.getId(), intent);
+        intents.put(intent.id(), intent);
         return this.setState(intent, IntentState.SUBMITTED);
     }
 
@@ -54,7 +53,7 @@ public class SimpleIntentStore
     public IntentEvent removeIntent(IntentId intentId) {
         Intent intent = intents.remove(intentId);
         installable.remove(intentId);
-        IntentEvent event = this.setState(intent, IntentState.WITHDRAWN);
+        IntentEvent event = this.setState(intent, WITHDRAWN);
         states.remove(intentId);
         return event;
     }
@@ -79,19 +78,21 @@ public class SimpleIntentStore
         return states.get(id);
     }
 
-    // TODO return dispatch event here... replace with state transition methods
     @Override
-    public IntentEvent setState(Intent intent, IntentState newState) {
-        IntentId id = intent.getId();
-        IntentState oldState = states.get(id);
-        states.put(id, newState);
-        return new IntentEvent(intent, newState, oldState, System.currentTimeMillis());
+    public IntentEvent setState(Intent intent, IntentState state) {
+        IntentId id = intent.id();
+        states.put(id, state);
+        IntentEvent.Type type = (state == SUBMITTED ? IntentEvent.Type.SUBMITTED :
+                (state == INSTALLED ? IntentEvent.Type.INSTALLED :
+                        (state == FAILED ? IntentEvent.Type.FAILED :
+                                state == WITHDRAWN ? IntentEvent.Type.WITHDRAWN :
+                                        null)));
+        return type == null ? null : new IntentEvent(type, intent);
     }
 
     @Override
-    public IntentEvent addInstallableIntents(IntentId intentId, List<InstallableIntent> result) {
+    public void addInstallableIntents(IntentId intentId, List<InstallableIntent> result) {
         installable.put(intentId, result);
-        return this.setState(intents.get(intentId), COMPILED);
     }
 
     @Override

@@ -53,6 +53,8 @@
         <feature>onos-api</feature>
         <bundle>mvn:org.onlab.onos/onos-core-net/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-serializers/1.0.0-SNAPSHOT</bundle>
+        <bundle>mvn:org.onlab.onos/onlab-netty/1.0.0-SNAPSHOT</bundle>
     </feature>
 
     <feature name="onos-core-hazelcast" version="1.0.0"

@@ -33,6 +33,7 @@ alias obs='onos-build-selective'
 alias op='onos-package'
 alias ot='onos-test'
 alias ol='onos-log'
+alias pub='onos-push-update-bundle'
 
 # Short-hand for tailing the ONOS (karaf) log 
 alias tl='$ONOS_ROOT/tools/dev/bin/onos-local-log'
@@ -89,5 +90,5 @@ function spy {
 }
 
 function nuke {
-    spy | cut -c7-11 | xargs kill
+    spy "$@" | cut -c7-11 | xargs kill
 }

@@ -32,6 +32,10 @@ ssh $remote "
 
     # Remove any previous ON.Lab bits from ~/.m2 repo
     rm -fr ~/.m2/repository/org/onlab
+
+    # Drop log level for the console
+    echo "log4j.logger.org.apache.sshd = WARN" >> $ONOS_INSTALL_DIR/$KARAF_DIST/etc/org.ops4j.pax.logging.cfg
+
 "
 
 # Configure the ONOS installation

@@ -15,7 +15,7 @@ name=${2:-onos-1}
 
 ssh $remote "
     sudo perl -pi.bak -e \"s/127.0.1.1.*/127.0.1.1       $name/g\" /etc/hosts
-    sudo perl -pi.bak -e \"local \$/ = ''; s/.*/$name/g\" /etc/hostname
+    sudo bash -c \"echo $name >/etc/hostname\"
     sudo hostname $name
 " 2>/dev/null
 

@@ -9,5 +9,9 @@
 remote=$ONOS_USER@${1:-$OCI}
 
 scp -q ~/.ssh/id_rsa.pub $remote:/tmp
-ssh $remote "cat /tmp/id_rsa.pub >> ~/.ssh/authorized_keys"
+ssh $remote "
+    cat /tmp/id_rsa.pub >> ~/.ssh/authorized_keys
+    sort -u ~/.ssh/authorized_keys > ~/.ssh/authorized_keys.bak
+    mv ~/.ssh/authorized_keys.bak ~/.ssh/authorized_keys
+"
 ssh -n -o PasswordAuthentication=no $remote true

+#!/bin/bash
+#-------------------------------------------------------------------------------
+# Pushes the specified bundle to the remote ONOS cell machines and updates it.
+#-------------------------------------------------------------------------------
+
+[ ! -d "$ONOS_ROOT" ] && echo "ONOS_ROOT is not defined" >&2 && exit 1
+. $ONOS_ROOT/tools/build/envDefaults
+
+cd ~/.m2/repository
+jar=$(find org/onlab -type f -name '*.jar' | grep $1 | grep -v -e -tests | head -n 1)
+
+[ -z "$jar" ] && echo "No bundle $1 found for" && exit 1
+
+bundle=$(echo $(basename $jar .jar) | sed 's/-[0-9].*//g')
+
+nodes=$(env | sort | egrep "OC[0-9]+" | cut -d= -f2)
+for node in $nodes; do
+    scp -q $jar $ONOS_USER@$node:$ONOS_INSTALL_DIR/$KARAF_DIST/system/$jar
+    ssh $ONOS_USER@$node "ls -l $ONOS_INSTALL_DIR/$KARAF_DIST/system/$jar"
+    ssh $ONOS_USER@$node "$ONOS_INSTALL_DIR/bin/onos \"bundle:update -f $bundle\"" 2>/dev/null
+done

+#!/usr/bin/env python
+from mininet.cli import CLI
+from mininet.net import Mininet
+from mininet.node import RemoteController, OVSKernelSwitch
+
+MAC = 12
+DPID = 16
+
+def string_to_hex(s, length):
+    """ Convert a string like 00:00 in to hex 0x0000 format"""
+    tmp = '{0:#x}'.format(int(s.replace(':', '').lstrip('0'),length))
+    return tmp
+
+def hex_to_string(h, length):
+    """Convert a hex number from 0x0000 to 00:00 format"""
+    tmp = h.lstrip('0x').zfill(length)
+    tmp = ':'.join(a+b for a,b in zip(tmp[::2], tmp[1::2]))
+    return tmp
+
+class Tower(object):
+    """ Create a tower topology from semi-scratch in Mininet """
+
+    def __init__(self, cname='flare', cip='15.255.126.183', k=4, h=6, 
+                 proto=None):
+        """Create tower topology for mininet
+            cname: controller name
+            cip: controller ip
+            k: number of leaf switches
+            h: number of hosts perl leaf switch
+        """
+
+        # We are creating the controller with local-loopback on purpose to avoid
+        # having the switches connect immediately. Instead, we'll set controller
+        # explicitly for each switch after configuring it as we want.
+        self.flare = RemoteController(cname, '127.0.0.1', 6633)
+        self.net = Mininet(controller=self.flare, switch = OVSKernelSwitch, 
+                           build=False)
+
+        self.cip = cip
+        self.spines = []
+        self.leaves = []
+        self.hosts = []
+        self.proto = proto
+
+        # Create the two spine switches
+        self.spines.append(self.net.addSwitch('s1'))
+        self.spines.append(self.net.addSwitch('s2'))
+
+        # Create two links between the spine switches
+        self.net.addLink(self.spines[0], self.spines[1])
+        self.net.addLink(self.spines[1], self.spines[0])
+        
+        # Now create the leaf switches, their hosts and connect them together
+        i = 1
+        c = 0
+        while i <= k:
+            self.leaves.append(self.net.addSwitch('s1%d' % i))
+            for spine in self.spines:
+                self.net.addLink(self.leaves[i-1], spine)
+
+            j = 1
+            while j <= h:
+                self.hosts.append(self.net.addHost('h%d%d' % (i, j)))
+                self.net.addLink(self.hosts[c], self.leaves[i-1])
+                j+=1
+                c+=1
+
+            i+=1
+
+    def run(self):
+        """ Runs the created network topology and launches mininet cli"""
+        self.run_silent()
+        CLI(self.net)
+        self.net.stop()
+
+    def run_silent(self):
+        """ Runs silently - for unit testing """
+        self.net.build()
+
+        # Start the switches, configure them with desired protocols and only 
+        # then set the controller
+        for sw in self.spines:
+            sw.start([self.flare])
+            if self.proto:
+                sw.cmd('ovs-vsctl set bridge %(sw)s protocols=%(proto)s' % \
+                           { 'sw': sw.name, 'proto': self.proto})
+            sw.cmdPrint('ovs-vsctl set-controller %(sw)s tcp:%(ctl)s:6633' % \
+                            {'sw': sw.name, 'ctl': self.cip})
+
+        for sw in self.leaves:
+            sw.start([self.flare])
+            sw.cmdPrint('ovs-vsctl set-controller %(sw)s tcp:%(ctl)s:6633' % \
+                            {'sw': sw.name, 'ctl': self.cip})
+
+    def pingAll(self):
+        """ PingAll to create flows - for unit testing """
+        self.net.pingAll()
+
+    def stop(self):
+        "Stops the topology. You should call this after run_silent"
+        self.net.stop()

@@ -28,8 +28,9 @@ public final class Timer {
 
     private static synchronized  void initTimer() {
         if (Timer.timer == null) {
-            Timer.timer = new HashedWheelTimer();
-            Timer.timer.start();
+            HashedWheelTimer hwTimer = new HashedWheelTimer();
+            hwTimer.start();
+            Timer.timer = hwTimer;
         }
     }
 

@@ -8,16 +8,15 @@ import java.util.concurrent.TimeoutException;
  * This class provides a base implementation of Response, with methods to retrieve the
  * result and query to see if the result is ready. The result can only be retrieved when
  * it is ready and the get methods will block if the result is not ready yet.
- * @param <T> type of response.
  */
-public class AsyncResponse<T> implements Response<T> {
+public class AsyncResponse implements Response {
 
-    private T value;
+    private byte[] value;
     private boolean done = false;
     private final long start = System.nanoTime();
 
     @Override
-    public T get(long timeout, TimeUnit timeUnit) throws TimeoutException {
+    public byte[] get(long timeout, TimeUnit timeUnit) throws TimeoutException {
         timeout = timeUnit.toNanos(timeout);
         boolean interrupted = false;
         try {
@@ -43,7 +42,7 @@ public class AsyncResponse<T> implements Response<T> {
     }
 
     @Override
-    public T get() throws InterruptedException {
+    public byte[] get() throws InterruptedException {
         throw new UnsupportedOperationException();
     }
 
@@ -57,11 +56,10 @@ public class AsyncResponse<T> implements Response<T> {
      * available.
      * @param data response data.
      */
-    @SuppressWarnings("unchecked")
-    public synchronized void setResponse(Object data) {
+    public synchronized void setResponse(byte[] data) {
         if (!done) {
             done = true;
-            value = (T) data;
+            value = data;
             this.notifyAll();
         }
     }

@@ -5,6 +5,7 @@ import java.io.IOException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+//FIXME: Should be move out to test or app
 /**
  * Message handler that echos the message back to the sender.
  */

 package org.onlab.netty;
 
+import java.util.Objects;
+
+import com.google.common.base.MoreObjects;
+
 /**
  * Representation of a TCP/UDP communication end point.
  */
@@ -32,16 +36,15 @@ public class Endpoint {
 
     @Override
     public String toString() {
-        return "Endpoint [port=" + port + ", host=" + host + "]";
+        return MoreObjects.toStringHelper(getClass())
+                .add("port", port)
+                .add("host", host)
+                .toString();
     }
 
     @Override
     public int hashCode() {
-        final int prime = 31;
-        int result = 1;
-        result = prime * result + ((host == null) ? 0 : host.hashCode());
-        result = prime * result + port;
-        return result;
+        return Objects.hash(host, port);
     }
 
     @Override
@@ -55,17 +58,8 @@ public class Endpoint {
         if (getClass() != obj.getClass()) {
             return false;
         }
-        Endpoint other = (Endpoint) obj;
-        if (host == null) {
-            if (other.host != null) {
-                return false;
-            }
-        } else if (!host.equals(other.host)) {
-            return false;
-        }
-        if (port != other.port) {
-            return false;
-        }
-        return true;
+        Endpoint that = (Endpoint) obj;
+        return Objects.equals(this.port, that.port) &&
+               Objects.equals(this.host, that.host);
     }
 }

@@ -8,12 +8,13 @@ import java.io.IOException;
  */
 public final class InternalMessage implements Message {
 
+    public static final String REPLY_MESSAGE_TYPE = "NETTY_MESSAGIG_REQUEST_REPLY";
+
     private long id;
     private Endpoint sender;
     private String type;
-    private Object payload;
+    private byte[] payload;
     private transient NettyMessagingService messagingService;
-    public static final String REPLY_MESSAGE_TYPE = "NETTY_MESSAGIG_REQUEST_REPLY";
 
     // Must be created using the Builder.
     private InternalMessage() {}
@@ -31,7 +32,7 @@ public final class InternalMessage implements Message {
     }
 
     @Override
-    public Object payload() {
+    public byte[] payload() {
         return payload;
     }
 
@@ -40,7 +41,7 @@ public final class InternalMessage implements Message {
     }
 
     @Override
-    public void respond(Object data) throws IOException {
+    public void respond(byte[] data) throws IOException {
         Builder builder = new Builder(messagingService);
         InternalMessage message = builder.withId(this.id)
              // FIXME: Sender should be messagingService.localEp.
@@ -55,7 +56,7 @@ public final class InternalMessage implements Message {
     /**
      * Builder for InternalMessages.
      */
-    public static class Builder {
+    public static final class Builder {
         private InternalMessage message;
 
         public Builder(NettyMessagingService messagingService) {
@@ -77,7 +78,7 @@ public final class InternalMessage implements Message {
             message.sender = sender;
             return this;
         }
-        public Builder withPayload(Object payload) {
+        public Builder withPayload(byte[] payload) {
             message.payload = payload;
             return this;
         }

@@ -6,10 +6,11 @@ import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.HashMap;
 
+//FIXME: Should be move out to test or app
 /**
  * Kryo Serializer.
  */
-public class KryoSerializer implements Serializer {
+public class KryoSerializer {
 
     private KryoPool serializerPool;
 
@@ -27,29 +28,26 @@ public class KryoSerializer implements Serializer {
                           HashMap.class,
                           ArrayList.class,
                           InternalMessage.class,
-                          Endpoint.class
+                          Endpoint.class,
+                          byte[].class
                 )
                 .build()
                 .populate(1);
     }
 
 
-    @Override
     public <T> T decode(byte[] data) {
         return serializerPool.deserialize(data);
     }
 
-    @Override
     public byte[] encode(Object payload) {
         return serializerPool.serialize(payload);
     }
 
-    @Override
     public <T> T decode(ByteBuffer buffer) {
         return serializerPool.deserialize(buffer);
     }
 
-    @Override
     public void encode(Object obj, ByteBuffer buffer) {
         serializerPool.serialize(obj, buffer);
     }

@@ -12,6 +12,6 @@ public class LoggingHandler implements MessageHandler {
 
     @Override
     public void handle(Message message) {
-        log.info("Received message. Payload: " + message.payload());
+        log.info("Received message. Payload has {} bytes", message.payload().length);
     }
 }

@@ -12,12 +12,12 @@ public interface Message {
      * Returns the payload of this message.
      * @return message payload.
      */
-    public Object payload();
+    public byte[] payload();
 
     /**
-     * Sends a reply back to the sender of this messge.
+     * Sends a reply back to the sender of this message.
      * @param data payload of the response.
      * @throws IOException if there is a communication error.
      */
-    public void respond(Object data) throws IOException;
+    public void respond(byte[] data) throws IOException;
 }

@@ -14,14 +14,14 @@ import java.util.List;
 public class MessageDecoder extends ReplayingDecoder<DecoderState> {
 
     private final NettyMessagingService messagingService;
-    private final Serializer serializer;
+
+    private static final KryoSerializer SERIALIZER = new KryoSerializer();
 
     private int contentLength;
 
-    public MessageDecoder(NettyMessagingService messagingService, Serializer serializer) {
+    public MessageDecoder(NettyMessagingService messagingService) {
         super(DecoderState.READ_HEADER_VERSION);
         this.messagingService = messagingService;
-        this.serializer = serializer;
     }
 
     @Override
@@ -48,7 +48,7 @@ public class MessageDecoder extends ReplayingDecoder<DecoderState> {
             checkState(serializerVersion == MessageEncoder.SERIALIZER_VERSION, "Unexpected serializer version");
             checkpoint(DecoderState.READ_CONTENT);
         case READ_CONTENT:
-            InternalMessage message = serializer.decode(buffer.readBytes(contentLength).nioBuffer());
+            InternalMessage message = SERIALIZER.decode(buffer.readBytes(contentLength).nioBuffer());
             message.setMessagingService(messagingService);
             out.add(message);
             checkpoint(DecoderState.READ_HEADER_VERSION);

@@ -17,11 +17,7 @@ public class MessageEncoder extends MessageToByteEncoder<InternalMessage> {
     public static final int SERIALIZER_VERSION = 1;
 
 
-    private final Serializer serializer;
-
-    public MessageEncoder(Serializer serializer) {
-        this.serializer = serializer;
-    }
+    private static final KryoSerializer SERIALIZER = new KryoSerializer();
 
     @Override
     protected void encode(
@@ -35,12 +31,17 @@ public class MessageEncoder extends MessageToByteEncoder<InternalMessage> {
         // write preamble
         out.writeBytes(PREAMBLE);
 
-        byte[] payload = serializer.encode(message);
+        try {
+            SERIALIZER.encode(message);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        byte[] payload = SERIALIZER.encode(message);
 
         // write payload length
         out.writeInt(payload.length);
 
-        // write serializer version
+        // write payloadSerializer version
         out.writeInt(SERIALIZER_VERSION);
 
         // write payload.

@@ -11,10 +11,10 @@ public interface MessagingService {
      * The message is specified using the type and payload.
      * @param ep end point to send the message to.
      * @param type type of message.
-     * @param payload message payload.
+     * @param payload message payload bytes.
      * @throws IOException
      */
-    public void sendAsync(Endpoint ep, String type, Object payload) throws IOException;
+    public void sendAsync(Endpoint ep, String type, byte[] payload) throws IOException;
 
     /**
      * Sends a message synchronously and waits for a response.
@@ -24,7 +24,7 @@ public interface MessagingService {
      * @return a response future
      * @throws IOException
      */
-    public <T> Response<T> sendAndReceive(Endpoint ep, String type, Object payload) throws IOException;
+    public Response sendAndReceive(Endpoint ep, String type, byte[] payload) throws IOException;
 
     /**
      * Registers a new message handler for message type.

@@ -43,7 +43,7 @@ public class NettyMessagingService implements MessagingService {
     private final EventLoopGroup bossGroup = new NioEventLoopGroup();
     private final EventLoopGroup workerGroup = new NioEventLoopGroup();
     private final ConcurrentMap<String, MessageHandler> handlers = new ConcurrentHashMap<>();
-    private final Cache<Long, AsyncResponse<?>> responseFutures = CacheBuilder.newBuilder()
+    private final Cache<Long, AsyncResponse> responseFutures = CacheBuilder.newBuilder()
             .maximumSize(100000)
             .weakValues()
             // TODO: Once the entry expires, notify blocking threads (if any).
@@ -52,8 +52,6 @@ public class NettyMessagingService implements MessagingService {
     private final GenericKeyedObjectPool<Endpoint, Channel> channels
             = new GenericKeyedObjectPool<Endpoint, Channel>(new OnosCommunicationChannelFactory());
 
-    protected Serializer serializer;
-
     public NettyMessagingService() {
         // TODO: Default port should be configurable.
         this(8080);
@@ -83,7 +81,7 @@ public class NettyMessagingService implements MessagingService {
     }
 
     @Override
-    public void sendAsync(Endpoint ep, String type, Object payload) throws IOException {
+    public void sendAsync(Endpoint ep, String type, byte[] payload) throws IOException {
         InternalMessage message = new InternalMessage.Builder(this)
             .withId(RandomUtils.nextLong())
             .withSender(localEp)
@@ -108,9 +106,9 @@ public class NettyMessagingService implements MessagingService {
     }
 
     @Override
-    public <T> Response<T> sendAndReceive(Endpoint ep, String type, Object payload)
+    public Response sendAndReceive(Endpoint ep, String type, byte[] payload)
             throws IOException {
-        AsyncResponse<T> futureResponse = new AsyncResponse<T>();
+        AsyncResponse futureResponse = new AsyncResponse();
         Long messageId = RandomUtils.nextLong();
         responseFutures.put(messageId, futureResponse);
         InternalMessage message = new InternalMessage.Builder(this)
@@ -133,10 +131,6 @@ public class NettyMessagingService implements MessagingService {
         handlers.remove(type);
     }
 
-    public void setSerializer(Serializer serializer) {
-        this.serializer = serializer;
-    }
-
     private MessageHandler getMessageHandler(String type) {
         return handlers.get(type);
     }
@@ -201,13 +195,13 @@ public class NettyMessagingService implements MessagingService {
     private class OnosCommunicationChannelInitializer extends ChannelInitializer<SocketChannel> {
 
         private final ChannelHandler dispatcher = new InboundMessageDispatcher();
-        private final ChannelHandler encoder = new MessageEncoder(serializer);
+        private final ChannelHandler encoder = new MessageEncoder();
 
         @Override
         protected void initChannel(SocketChannel channel) throws Exception {
             channel.pipeline()
                 .addLast("encoder", encoder)
-                .addLast("decoder", new MessageDecoder(NettyMessagingService.this, serializer))
+                .addLast("decoder", new MessageDecoder(NettyMessagingService.this))
                 .addLast("handler", dispatcher);
         }
     }
@@ -236,12 +230,13 @@ public class NettyMessagingService implements MessagingService {
             String type = message.type();
             if (type.equals(InternalMessage.REPLY_MESSAGE_TYPE)) {
                 try {
-                    AsyncResponse<?> futureResponse =
+                    AsyncResponse futureResponse =
                         NettyMessagingService.this.responseFutures.getIfPresent(message.id());
                     if (futureResponse != null) {
                         futureResponse.setResponse(message.payload());
-                    }
+                    } else {
                         log.warn("Received a reply. But was unable to locate the request handle");
+                    }
                 } finally {
                     NettyMessagingService.this.responseFutures.invalidate(message.id());
                 }

@@ -7,26 +7,24 @@ import java.util.concurrent.TimeoutException;
  * Response object returned when making synchronous requests.
  * Can you used to check is a response is ready and/or wait for a response
  * to become available.
- *
- * @param <T> type of response.
  */
-public interface Response<T> {
+public interface Response {
 
     /**
      * Gets the response waiting for a designated timeout period.
      * @param timeout timeout period (since request was sent out)
      * @param tu unit of time.
-     * @return response
+     * @return response payload
      * @throws TimeoutException if the timeout expires before the response arrives.
      */
-    public T get(long timeout, TimeUnit tu) throws TimeoutException;
+    public byte[] get(long timeout, TimeUnit tu) throws TimeoutException;
 
     /**
      * Gets the response waiting for indefinite timeout period.
-     * @return response
+     * @return response payload
      * @throws InterruptedException if the thread is interrupted before the response arrives.
      */
-    public T get() throws InterruptedException;
+    public byte[] get() throws InterruptedException;
 
     /**
      * Checks if the response is ready without blocking.

-package org.onlab.netty;
-
-import java.nio.ByteBuffer;
-
-/**
- * Interface for encoding/decoding message payloads.
- */
-public interface Serializer {
-
-    /**
-     * Decodes the specified byte array to a POJO.
-     *
-     * @param data byte array.
-     * @return POJO
-     */
-    public <T> T decode(byte[] data);
-
-    /**
-     * Encodes the specified POJO into a byte array.
-     *
-     * @param data POJO to be encoded
-     * @return byte array.
-     */
-    public byte[] encode(Object data);
-
-    /**
-     * Encodes the specified POJO into a byte buffer.
-     *
-     * @param data POJO to be encoded
-     * @param buffer to write serialized bytes
-     */
-    public void encode(final Object data, ByteBuffer buffer);
-
-    /**
-     * Decodes the specified byte buffer to a POJO.
-     *
-     * @param buffer bytes to be decoded
-     * @return POJO
-     */
-    public <T> T decode(final ByteBuffer buffer);
-}

@@ -8,6 +8,7 @@ import org.onlab.metrics.MetricsManager;
 
 import com.codahale.metrics.Timer;
 
+// FIXME: Should be move out to test or app
 public final class SimpleClient {
     private SimpleClient() {
     }
@@ -23,7 +24,7 @@ public final class SimpleClient {
         final int warmup = 100;
         for (int i = 0; i < warmup; i++) {
             Timer.Context context = sendAsyncTimer.time();
-            messaging.sendAsync(new Endpoint("localhost", 8080), "simple", "Hello World");
+            messaging.sendAsync(new Endpoint("localhost", 8080), "simple", "Hello World".getBytes());
             context.stop();
         }
         metrics.registerMetric(component, feature, "AsyncTimer", sendAsyncTimer);
@@ -32,10 +33,10 @@ public final class SimpleClient {
         final int iterations = 1000000;
         for (int i = 0; i < iterations; i++) {
             Timer.Context context = sendAndReceiveTimer.time();
-            Response<String> response = messaging
+            Response response = messaging
                     .sendAndReceive(new Endpoint("localhost", 8080), "echo",
-                                    "Hello World");
-            System.out.println("Got back:" + response.get(2, TimeUnit.SECONDS));
+                                    "Hello World".getBytes());
+            System.out.println("Got back:" + new String(response.get(2, TimeUnit.SECONDS)));
             context.stop();
         }
         metrics.registerMetric(component, feature, "AsyncTimer", sendAndReceiveTimer);
@@ -44,8 +45,6 @@ public final class SimpleClient {
     public static class TestNettyMessagingService extends NettyMessagingService {
         public TestNettyMessagingService(int port) throws Exception {
             super(port);
-            Serializer serializer = new KryoSerializer();
-            this.serializer = serializer;
         }
     }
 }

 package org.onlab.netty;
 
+//FIXME: Should be move out to test or app
 public final class SimpleServer {
     private SimpleServer() {}
 
     public static void main(String... args) throws Exception {
         NettyMessagingService server = new NettyMessagingService(8080);
         server.activate();
-        server.setSerializer(new KryoSerializer());
         server.registerHandler("simple", new LoggingHandler());
         server.registerHandler("echo", new EchoHandler());
     }

+package org.onlab.netty;
+
+import java.util.concurrent.TimeUnit;
+
+import org.apache.commons.lang3.RandomUtils;
+import static org.junit.Assert.*;
+import org.junit.Test;
+
+/**
+ * Simple ping-pong test that exercises NettyMessagingService.
+ */
+public class PingPongTest {
+
+    @Test
+    public void testPingPong() throws Exception {
+        NettyMessagingService pinger = new NettyMessagingService(8085);
+        NettyMessagingService ponger = new NettyMessagingService(9086);
+        try {
+            pinger.activate();
+            ponger.activate();
+            ponger.registerHandler("echo", new EchoHandler());
+            byte[] payload = RandomUtils.nextBytes(100);
+            Response response = pinger.sendAndReceive(new Endpoint("localhost", 9086), "echo", payload);
+            assertArrayEquals(payload, response.get(10000, TimeUnit.MILLISECONDS));
+        } finally {
+            pinger.deactivate();
+            ponger.deactivate();
+        }
+    }
+}