Added application ID store; both trivial and distributed variants.

@@ -30,8 +30,8 @@ import org.apache.felix.scr.annotations.Modified;
 import org.apache.felix.scr.annotations.Property;
 import org.apache.felix.scr.annotations.Reference;
 import org.apache.felix.scr.annotations.ReferenceCardinality;
-import org.onlab.onos.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.Host;
 import org.onlab.onos.net.HostId;
 import org.onlab.onos.net.Path;

@@ -23,8 +23,8 @@ 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.onlab.onos.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.Host;
 import org.onlab.onos.net.HostId;
 import org.onlab.onos.net.PortNumber;

@@ -27,8 +27,8 @@ 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.onlab.onos.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.Host;
 import org.onlab.onos.net.device.DeviceService;

@@ -30,8 +30,8 @@ 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.onlab.onos.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.Path;

@@ -27,8 +27,8 @@ import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Deactivate;
 import org.apache.felix.scr.annotations.Reference;
 import org.apache.felix.scr.annotations.ReferenceCardinality;
-import org.onlab.onos.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.PortNumber;

@@ -25,8 +25,8 @@ 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.onlab.onos.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.packet.PacketContext;
 import org.onlab.onos.net.packet.PacketProcessor;
 import org.onlab.onos.net.packet.PacketService;

@@ -20,7 +20,7 @@ package org.onlab.onos.sdnip;
 
 import java.util.List;
 
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.DefaultTrafficSelector;
 import org.onlab.onos.net.flow.DefaultTrafficTreatment;

@@ -34,7 +34,7 @@ import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.Semaphore;
 
 import org.apache.commons.lang3.tuple.Pair;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.Host;
 import org.onlab.onos.net.flow.DefaultTrafficSelector;

@@ -28,8 +28,8 @@ 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.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.host.HostService;
 import org.onlab.onos.net.intent.IntentService;
 import org.onlab.onos.sdnip.bgp.BgpRouteEntry;

@@ -23,7 +23,7 @@ import org.easymock.IArgumentMatcher;
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.PortNumber;

@@ -37,7 +37,7 @@ import org.junit.Before;
 import org.junit.Test;
 import org.onlab.junit.TestUtils;
 import org.onlab.junit.TestUtils.TestUtilsException;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.DefaultHost;
 import org.onlab.onos.net.DeviceId;

@@ -19,7 +19,7 @@ import org.junit.Before;
 import org.junit.Test;
 import org.onlab.junit.TestUtils;
 import org.onlab.junit.TestUtils.TestUtilsException;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.DefaultHost;
 import org.onlab.onos.net.DeviceId;

@@ -22,8 +22,8 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import org.apache.karaf.shell.commands.Option;
 import org.apache.karaf.shell.console.OsgiCommandSupport;
-import org.onlab.onos.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.Annotations;
 import org.onlab.osgi.DefaultServiceDirectory;
 import org.onlab.osgi.ServiceNotFoundException;

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.onlab.onos.cli;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
+
+import java.util.Collections;
+import java.util.List;
+
+import static com.google.common.collect.Lists.newArrayList;
+
+/**
+ * Lists application ID information.
+ */
+@Command(scope = "onos", name = "apps",
+         description = "Lists application ID information")
+public class ApplicationIdListCommand extends AbstractShellCommand {
+
+    @Override
+    protected void execute() {
+        CoreService service = get(CoreService.class);
+        List<ApplicationId> ids = newArrayList(service.getAppIds());
+        Collections.sort(ids, Comparators.APP_ID_COMPARATOR);
+
+        if (outputJson()) {
+            print("%s", json(ids));
+        } else {
+            for (ApplicationId id : ids) {
+                print("id=%d, name=%s", id.id(), id.name());
+            }
+        }
+    }
+
+    // ApplicationId
+    private JsonNode json(List<ApplicationId> ids) {
+        ObjectMapper mapper = new ObjectMapper();
+        ArrayNode result = mapper.createArrayNode();
+        for (ApplicationId id : ids) {
+            result.add(mapper.createObjectNode()
+                               .put("id", id.id())
+                               .put("name", id.name()));
+        }
+        return result;
+    }
+
+}

@@ -18,6 +18,7 @@
  */
 package org.onlab.onos.cli;
 
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.cluster.ControllerNode;
 import org.onlab.onos.net.Element;
 import org.onlab.onos.net.ElementId;
@@ -36,6 +37,13 @@ public final class Comparators {
     private Comparators() {
     }
 
+    public static final Comparator<ApplicationId> APP_ID_COMPARATOR = new Comparator<ApplicationId>() {
+        @Override
+        public int compare(ApplicationId id1, ApplicationId id2) {
+            return id1.id() - id2.id();
+        }
+    };
+
     public static final Comparator<ElementId> ELEMENT_ID_COMPARATOR = new Comparator<ElementId>() {
         @Override
         public int compare(ElementId id1, ElementId id2) {

@@ -20,7 +20,7 @@ package org.onlab.onos.cli;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import org.apache.karaf.shell.commands.Command;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.cluster.ClusterService;
 import org.onlab.onos.net.device.DeviceService;
 import org.onlab.onos.net.flow.FlowRuleService;

@@ -25,7 +25,7 @@ import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.google.common.collect.Maps;
 import org.apache.karaf.shell.commands.Argument;
 import org.apache.karaf.shell.commands.Command;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.cli.AbstractShellCommand;
 import org.onlab.onos.cli.Comparators;
 import org.onlab.onos.net.Device;

@@ -37,9 +37,9 @@
         </command>
         <command>
             <action class="org.onlab.onos.cli.MastersListCommand"/>
-            <completers>
-                <ref component-id="clusterIdCompleter"/>
-            </completers>
+        </command>
+        <command>
+            <action class="org.onlab.onos.cli.ApplicationIdListCommand"/>
         </command>
 
         <command>

-package org.onlab.onos;
+package org.onlab.onos.core;
 
 
 /**

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.onlab.onos.core;
+
+import java.util.Set;
+
+/**
+ * Manages application IDs.
+ */
+public interface ApplicationIdStore {
+
+    /**
+     * Returns the set of currently registered application identifiers.
+     *
+     * @return set of application ids
+     */
+    Set<ApplicationId> getAppIds();
+
+    /**
+     * Returns an existing application id from a given id.
+     * @param id the short value of the id
+     * @return an application id
+     */
+    ApplicationId getAppId(Short id);
+
+    /**
+     * Registers a new application by its name, which is expected
+     * to follow the reverse DNS convention, e.g.
+     * {@code org.flying.circus.app}
+     *
+     * @param identifier string identifier
+     * @return the application id
+     */
+    ApplicationId registerApplication(String identifier);
+
+}

-package org.onlab.onos;
+package org.onlab.onos.core;
+
+import java.util.Set;
 
 /**
  * Service for interacting with the core system of the controller.
@@ -13,14 +15,11 @@ public interface CoreService {
     Version version();
 
     /**
-     * Registers a new application by its name, which is expected
-     * to follow the reverse DNS convention, e.g.
-     * {@code org.flying.circus.app}
+     * Returns the set of currently registered application identifiers.
      *
-     * @param identifier string identifier
-     * @return the application id
+     * @return set of application ids
      */
-    ApplicationId registerApplication(String identifier);
+    Set<ApplicationId> getAppIds();
 
     /**
      * Returns an existing application id from a given id.
@@ -29,4 +28,14 @@ public interface CoreService {
      */
     ApplicationId getAppId(Short id);
 
+    /**
+     * Registers a new application by its name, which is expected
+     * to follow the reverse DNS convention, e.g.
+     * {@code org.flying.circus.app}
+     *
+     * @param identifier string identifier
+     * @return the application id
+     */
+    ApplicationId registerApplication(String identifier);
+
 }

-package org.onlab.onos.impl;
-
-import org.onlab.onos.ApplicationId;
+package org.onlab.onos.core;
 
 import java.util.Objects;
 
 import static com.google.common.base.MoreObjects.toStringHelper;
 
 /**
- * Application id generator class.
+ * Application identifier.
  */
 public class DefaultApplicationId implements ApplicationId {
 
     private final short id;
     private final String name;
 
-    // Ban public construction
-    protected DefaultApplicationId(Short id, String identifier) {
+    /**
+     * Creates a new application ID.
+     *
+     * @param id   application identifier
+     * @param name application name
+     */
+    public DefaultApplicationId(Short id, String name) {
         this.id = id;
-        this.name = identifier;
+        this.name = name;
+    }
+
+    // Constructor for serializers.
+    private DefaultApplicationId() {
+        this.id = 0;
+        this.name = null;
     }
 
     @Override

-package org.onlab.onos;
+package org.onlab.onos.core;
 
 import java.util.Objects;
 

 /**
  * ONOS Core API definitions.
  */
-package org.onlab.onos;
+package org.onlab.onos.core;

@@ -23,7 +23,7 @@ import static org.slf4j.LoggerFactory.getLogger;
 
 import java.util.Objects;
 
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.DeviceId;
 import org.slf4j.Logger;
 

@@ -18,7 +18,7 @@
  */
 package org.onlab.onos.net.flow;
 
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.provider.Provider;
 
 import com.google.common.util.concurrent.ListenableFuture;

@@ -20,7 +20,7 @@ package org.onlab.onos.net.flow;
 
 import java.util.concurrent.Future;
 
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.DeviceId;
 
 /**

@@ -19,7 +19,7 @@
 package org.onlab.onos.net.intent;
 
 import com.google.common.collect.ImmutableSet;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.NetworkResource;
 import org.onlab.onos.net.flow.TrafficSelector;

@@ -19,7 +19,7 @@
 package org.onlab.onos.net.intent;
 
 import com.google.common.base.MoreObjects;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.HostId;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;

@@ -18,7 +18,7 @@
  */
 package org.onlab.onos.net.intent;
 
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.NetworkResource;
 import org.onlab.onos.net.flow.BatchOperationTarget;
 

@@ -19,7 +19,7 @@
 package org.onlab.onos.net.intent;
 
 import com.google.common.base.MoreObjects;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.flow.TrafficSelector;

@@ -20,7 +20,7 @@ package org.onlab.onos.net.intent;
 
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.Sets;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;

 package org.onlab.onos.net.intent;
 
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 
 /**

@@ -2,7 +2,7 @@ package org.onlab.onos.net.intent;
 
 import java.util.Collection;
 
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.NetworkResource;

@@ -19,7 +19,7 @@
 package org.onlab.onos.net.intent;
 
 import com.google.common.base.MoreObjects;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.Path;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;

@@ -19,7 +19,7 @@
 package org.onlab.onos.net.intent;
 
 import com.google.common.base.MoreObjects;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;

@@ -20,7 +20,7 @@ package org.onlab.onos.net.intent;
 
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.Sets;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;

 package org.onlab.onos;
 
+import org.onlab.onos.core.ApplicationId;
+
 import java.util.Objects;
 
 /**

@@ -2,9 +2,10 @@ package org.onlab.onos;
 
 import com.google.common.testing.EqualsTester;
 import org.junit.Test;
+import org.onlab.onos.core.Version;
 
 import static org.junit.Assert.*;
-import static org.onlab.onos.Version.version;
+import static org.onlab.onos.core.Version.version;
 
 /**
  * Tests of the version descriptor.

@@ -2,7 +2,7 @@ package org.onlab.onos.net.intent;
 
 import java.util.Set;
 
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.TestApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.DeviceId;

-package org.onlab.onos.impl;
+package org.onlab.onos.core.impl;
 
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
+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.ApplicationId;
-import org.onlab.onos.CoreService;
-import org.onlab.onos.Version;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.ApplicationIdStore;
+import org.onlab.onos.core.CoreService;
+import org.onlab.onos.core.Version;
 import org.onlab.util.Tools;
 
 import java.io.File;
 import java.util.List;
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.atomic.AtomicInteger;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Core service implementation.
@@ -21,15 +24,11 @@ import java.util.concurrent.atomic.AtomicInteger;
 @Service
 public class CoreManager implements CoreService {
 
-    private static final AtomicInteger ID_DISPENSER = new AtomicInteger(1);
-
     private static final File VERSION_FILE = new File("../VERSION");
     private static Version version = Version.version("1.0.0-SNAPSHOT");
 
-    private final Map<Short, DefaultApplicationId> appIds = new ConcurrentHashMap<>();
-    private final Map<String, DefaultApplicationId> appIdsByName = new ConcurrentHashMap<>();
-
-    // TODO: work in progress
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ApplicationIdStore applicationIdStore;
 
     @Activate
     public void activate() {
@@ -45,20 +44,19 @@ public class CoreManager implements CoreService {
     }
 
     @Override
+    public Set<ApplicationId> getAppIds() {
+        return applicationIdStore.getAppIds();
+    }
+
+    @Override
     public ApplicationId getAppId(Short id) {
-        return appIds.get(id);
+        return applicationIdStore.getAppId(id);
     }
 
     @Override
     public ApplicationId registerApplication(String name) {
-        DefaultApplicationId appId = appIdsByName.get(name);
-        if (appId == null) {
-            short id = (short) ID_DISPENSER.getAndIncrement();
-            appId = new DefaultApplicationId(id, name);
-            appIds.put(id, appId);
-            appIdsByName.put(name, appId);
-        }
-        return appId;
+        checkNotNull(name, "Application ID cannot be null");
+        return applicationIdStore.registerApplication(name);
     }
 
 }

-package org.onlab.onos.impl;
+package org.onlab.onos.core.impl;
 
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;

 /**
  * Miscellaneous core system implementations.
  */
-package org.onlab.onos.impl;
\ No newline at end of file
+package org.onlab.onos.core.impl;
\ No newline at end of file

@@ -22,7 +22,7 @@ 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.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.event.AbstractListenerRegistry;
 import org.onlab.onos.event.EventDeliveryService;
 import org.onlab.onos.net.Device;

@@ -9,8 +9,8 @@ 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.onlab.onos.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.PortNumber;

@@ -12,7 +12,7 @@ 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.onlab.onos.CoreService;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.Path;

@@ -10,8 +10,8 @@ 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.onlab.onos.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.flow.DefaultFlowRule;

@@ -11,8 +11,8 @@ 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.onlab.onos.ApplicationId;
-import org.onlab.onos.CoreService;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.CoreService;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.flow.DefaultFlowRule;

 package org.onlab.onos.net.flow.impl;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
-import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_ADDED;
-import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_ADD_REQUESTED;
-import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_REMOVED;
-import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_REMOVE_REQUESTED;
-import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_UPDATED;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Executor;
-import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+import com.google.common.util.concurrent.ListenableFuture;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.DefaultApplicationId;
 import org.onlab.onos.event.impl.TestEventDispatcher;
-import org.onlab.onos.impl.DefaultApplicationId;
 import org.onlab.onos.net.DefaultDevice;
 import org.onlab.onos.net.Device;
 import org.onlab.onos.net.Device.Type;
@@ -63,11 +44,21 @@ import org.onlab.onos.net.provider.AbstractProvider;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.store.trivial.impl.SimpleFlowRuleStore;
 
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.Lists;
-import com.google.common.collect.Sets;
-import com.google.common.util.concurrent.ListenableFuture;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+import static org.junit.Assert.*;
+import static org.onlab.onos.net.flow.FlowRuleEvent.Type.*;
 
 /**
  * Test codifying the flow rule service & flow rule provider service contracts.
@@ -75,7 +66,6 @@ import com.google.common.util.concurrent.ListenableFuture;
 public class FlowRuleManagerTest {
 
 
-
     private static final ProviderId PID = new ProviderId("of", "foo");
     private static final DeviceId DID = DeviceId.deviceId("of:001");
     private static final int TIMEOUT = 10;
@@ -106,14 +96,14 @@ public class FlowRuleManagerTest {
         providerService = registry.register(provider);
         appId = new TestApplicationId((short) 0, "FlowRuleManagerTest");
         assertTrue("provider should be registered",
-                registry.getProviders().contains(provider.id()));
+                   registry.getProviders().contains(provider.id()));
     }
 
     @After
     public void tearDown() {
         registry.unregister(provider);
         assertFalse("provider should not be registered",
-                registry.getProviders().contains(provider.id()));
+                    registry.getProviders().contains(provider.id()));
         service.removeListener(listener);
         mgr.deactivate();
         mgr.eventDispatcher = null;
@@ -135,7 +125,7 @@ public class FlowRuleManagerTest {
         return rule;
     }
 
-    private void validateEvents(FlowRuleEvent.Type ... events) {
+    private void validateEvents(FlowRuleEvent.Type... events) {
         if (events == null) {
             assertTrue("events generated", listener.events.isEmpty());
         }
@@ -148,7 +138,7 @@ public class FlowRuleManagerTest {
         }
 
         assertEquals("mispredicted number of events",
-                events.length, listener.events.size());
+                     events.length, listener.events.size());
 
         listener.events.clear();
     }
@@ -156,10 +146,11 @@ public class FlowRuleManagerTest {
     private int flowCount() {
         return Sets.newHashSet(service.getFlowEntries(DID)).size();
     }
+
     @Test
     public void getFlowEntries() {
         assertTrue("store should be empty",
-                Sets.newHashSet(service.getFlowEntries(DID)).isEmpty());
+                   Sets.newHashSet(service.getFlowEntries(DID)).isEmpty());
         FlowRule f1 = addFlowRule(1);
         FlowRule f2 = addFlowRule(2);
 
@@ -206,9 +197,9 @@ public class FlowRuleManagerTest {
         assertEquals("3 rules should exist", 3, flowCount());
         assertTrue("Entries should be pending add.",
                    validateState(ImmutableMap.of(
-                                   r1, FlowEntryState.PENDING_ADD,
-                                   r2, FlowEntryState.PENDING_ADD,
-                                   r3, FlowEntryState.PENDING_ADD)));
+                           r1, FlowEntryState.PENDING_ADD,
+                           r2, FlowEntryState.PENDING_ADD,
+                           r3, FlowEntryState.PENDING_ADD)));
     }
 
     @Test
@@ -231,9 +222,9 @@ public class FlowRuleManagerTest {
         assertEquals("3 rule should exist", 3, flowCount());
         assertTrue("Entries should be pending remove.",
                    validateState(ImmutableMap.of(
-                                 f1, FlowEntryState.PENDING_REMOVE,
-                                 f2, FlowEntryState.PENDING_REMOVE,
-                                 f3, FlowEntryState.ADDED)));
+                           f1, FlowEntryState.PENDING_REMOVE,
+                           f2, FlowEntryState.PENDING_REMOVE,
+                           f3, FlowEntryState.ADDED)));
 
         mgr.removeFlowRules(f1);
         assertEquals("3 rule should still exist", 3, flowCount());
@@ -283,10 +274,10 @@ public class FlowRuleManagerTest {
         providerService.pushFlowMetrics(DID, Lists.newArrayList(fe1, fe2));
 
         assertTrue("Entries should be added.",
-                validateState(ImmutableMap.of(
-                        f1, FlowEntryState.ADDED,
-                        f2, FlowEntryState.ADDED,
-                        f3, FlowEntryState.PENDING_ADD)));
+                   validateState(ImmutableMap.of(
+                           f1, FlowEntryState.ADDED,
+                           f2, FlowEntryState.ADDED,
+                           f3, FlowEntryState.PENDING_ADD)));
 
         validateEvents(RULE_ADD_REQUESTED, RULE_ADD_REQUESTED, RULE_ADD_REQUESTED,
                        RULE_ADDED, RULE_ADDED);
@@ -361,8 +352,8 @@ public class FlowRuleManagerTest {
         //only check that we are in pending remove. Events and actual remove state will
         // be set by flowRemoved call.
         validateState(ImmutableMap.of(
-                    f1, FlowEntryState.PENDING_REMOVE,
-                    f2, FlowEntryState.PENDING_REMOVE));
+                f1, FlowEntryState.PENDING_REMOVE,
+                f2, FlowEntryState.PENDING_REMOVE));
     }
 
     @Test
@@ -387,8 +378,8 @@ public class FlowRuleManagerTest {
         Future<CompletedBatchOperation> future = mgr.applyBatch(fbo);
         assertTrue("Entries in wrong state",
                    validateState(ImmutableMap.of(
-                               f1, FlowEntryState.PENDING_REMOVE,
-                               f2, FlowEntryState.PENDING_ADD)));
+                           f1, FlowEntryState.PENDING_REMOVE,
+                           f2, FlowEntryState.PENDING_ADD)));
         CompletedBatchOperation completed = null;
         try {
             completed = future.get();
@@ -410,15 +401,15 @@ public class FlowRuleManagerTest {
         mgr.applyFlowRules(f1);
 
         assertTrue("Entries in wrong state",
-                validateState(ImmutableMap.of(
-                            f1, FlowEntryState.PENDING_ADD)));
+                   validateState(ImmutableMap.of(
+                           f1, FlowEntryState.PENDING_ADD)));
 
         FlowEntry fe1 = new DefaultFlowEntry(f1);
         providerService.pushFlowMetrics(DID, Collections.<FlowEntry>singletonList(fe1));
 
         assertTrue("Entries in wrong state",
-                validateState(ImmutableMap.of(
-                            f1, FlowEntryState.ADDED)));
+                   validateState(ImmutableMap.of(
+                           f1, FlowEntryState.ADDED)));
 
 
         FlowRuleBatchEntry fbe1 = new FlowRuleBatchEntry(
@@ -441,14 +432,13 @@ public class FlowRuleManagerTest {
          */
         assertTrue("Entries in wrong state",
                    validateState(ImmutableMap.of(
-                               f2, FlowEntryState.PENDING_REMOVE,
-                               f1, FlowEntryState.PENDING_ADD)));
+                           f2, FlowEntryState.PENDING_REMOVE,
+                           f1, FlowEntryState.PENDING_ADD)));
 
 
     }
 
 
-
     private static class TestListener implements FlowRuleListener {
         final List<FlowRuleEvent> events = new ArrayList<>();
 

 package org.onlab.onos.net.intent;
 
 import org.junit.Test;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.TestApplicationId;
 import org.onlab.onos.net.HostId;
 import org.onlab.onos.net.flow.TrafficSelector;

@@ -12,7 +12,7 @@ import java.util.Set;
 
 import org.junit.Before;
 import org.junit.Test;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.TestApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.DeviceId;

@@ -2,7 +2,7 @@ package org.onlab.onos.net.intent;
 
 import org.junit.Before;
 import org.junit.Test;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.TestApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;

 package org.onlab.onos.net.intent;
 
 import org.junit.Test;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.TestApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;

@@ -3,7 +3,7 @@ package org.onlab.onos.net.intent.impl;
 import org.hamcrest.Matchers;
 import org.junit.Before;
 import org.junit.Test;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.TestApplicationId;
 import org.onlab.onos.net.Host;
 import org.onlab.onos.net.HostId;

@@ -2,7 +2,7 @@ package org.onlab.onos.net.intent.impl;
 
 import org.hamcrest.Matchers;
 import org.junit.Test;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.TestApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.ElementId;

@@ -2,7 +2,7 @@ package org.onlab.onos.net.intent.impl;
 
 import org.hamcrest.Matchers;
 //import org.junit.Test;
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.TestApplicationId;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.onlab.onos.store.core.impl;
+
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.event.AbstractEvent;
+
+/**
+ * Application ID event.
+ */
+public class AppIdEvent extends AbstractEvent<AppIdEvent.Type, ApplicationId> {
+
+    public enum Type {
+        APP_REGISTERED
+    }
+
+    protected AppIdEvent(Type type, ApplicationId subject) {
+        super(type, subject);
+    }
+
+}

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.onlab.onos.store.core.impl;
+
+import org.onlab.onos.store.StoreDelegate;
+
+/**
+ * Application ID store delegate.
+ */
+public interface AppIdStoreDelegate extends StoreDelegate<AppIdEvent> {
+}

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.onlab.onos.store.core.impl;
+
+import com.google.common.collect.ImmutableSet;
+import com.hazelcast.core.EntryEvent;
+import com.hazelcast.core.EntryListener;
+import com.hazelcast.core.IAtomicLong;
+import com.hazelcast.core.MapEvent;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.ApplicationIdStore;
+import org.onlab.onos.core.DefaultApplicationId;
+import org.onlab.onos.store.hz.AbstractHazelcastStore;
+import org.onlab.onos.store.hz.SMap;
+import org.onlab.onos.store.serializers.KryoNamespaces;
+import org.onlab.onos.store.serializers.KryoSerializer;
+import org.onlab.util.KryoNamespace;
+
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Simple implementation of the application ID registry using in-memory
+ * structures.
+ */
+@Component(immediate = true)
+@Service
+public class DistributedApplicationIdStore
+        extends AbstractHazelcastStore<AppIdEvent, AppIdStoreDelegate>
+        implements ApplicationIdStore {
+
+    protected IAtomicLong lastAppId;
+    protected SMap<String, DefaultApplicationId> appIdsByName;
+
+    protected Map<Short, DefaultApplicationId> appIds = new ConcurrentHashMap<>();
+
+
+    @Override
+    @Activate
+    public void activate() {
+        super.activate();
+
+        this.serializer = new KryoSerializer() {
+            @Override
+            protected void setupKryoPool() {
+                serializerPool = KryoNamespace.newBuilder()
+                        .register(KryoNamespaces.API)
+                        .build()
+                        .populate(1);
+            }
+        };
+
+        lastAppId = theInstance.getAtomicLong("applicationId");
+
+        appIdsByName = new SMap<>(theInstance.<byte[], byte[]>getMap("appIdsByName"), this.serializer);
+        appIdsByName.addEntryListener((new RemoteAppIdEventHandler()), true);
+
+        primeAppIds();
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public Set<ApplicationId> getAppIds() {
+        return ImmutableSet.<ApplicationId>copyOf(appIds.values());
+    }
+
+    @Override
+    public ApplicationId getAppId(Short id) {
+        ApplicationId appId = appIds.get(id);
+        if (appId == null) {
+            primeAppIds();
+        }
+        return appId;
+    }
+
+    private synchronized void primeAppIds() {
+        for (DefaultApplicationId appId : appIdsByName.values()) {
+            appIds.put(appId.id(), appId);
+        }
+    }
+
+    @Override
+    public synchronized ApplicationId registerApplication(String name) {
+        DefaultApplicationId appId = appIdsByName.get(name);
+        if (appId == null) {
+            short id = (short) lastAppId.getAndIncrement();
+            appId = new DefaultApplicationId(id, name);
+            appIds.put(id, appId);
+            appIdsByName.put(name, appId);
+        }
+        return appId;
+    }
+
+    private class RemoteAppIdEventHandler implements EntryListener<String, DefaultApplicationId> {
+        @Override
+        public void entryAdded(EntryEvent<String, DefaultApplicationId> event) {
+            DefaultApplicationId appId = event.getValue();
+            appIds.put(appId.id(), appId);
+        }
+
+        @Override
+        public void entryRemoved(EntryEvent<String, DefaultApplicationId> event) {
+        }
+
+        @Override
+        public void entryUpdated(EntryEvent<String, DefaultApplicationId> event) {
+            entryAdded(event);
+        }
+
+        @Override
+        public void entryEvicted(EntryEvent<String, DefaultApplicationId> event) {
+        }
+
+        @Override
+        public void mapEvicted(MapEvent event) {
+        }
+
+        @Override
+        public void mapCleared(MapEvent event) {
+        }
+    }
+}

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/**
+ * Implementation of a distributed application ID registry store using Hazelcast.
+ */
+package org.onlab.onos.store.core.impl;

@@ -15,7 +15,7 @@ import com.google.common.base.MoreObjects.ToStringHelper;
 
 /**
  * A structure that holds node mastership roles associated with a
- * {@link DeviceId}. This structure needs to be locked through IMap.
+ * {@link org.onlab.onos.net.DeviceId}. This structure needs to be locked through IMap.
  */
 final class RoleValue {
 

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.onlab.onos.store.serializers;
+
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.io.Input;
+import com.esotericsoftware.kryo.io.Output;
+import org.onlab.onos.core.DefaultApplicationId;
+
+/**
+ * Kryo Serializer for {@link org.onlab.onos.core.DefaultApplicationId}.
+ */
+public final class DefaultApplicationIdSerializer extends Serializer<DefaultApplicationId> {
+
+    /**
+     * Creates {@link org.onlab.onos.core.DefaultApplicationId} serializer instance.
+     */
+    public DefaultApplicationIdSerializer() {
+        // non-null, immutable
+        super(false, true);
+    }
+
+    @Override
+    public void write(Kryo kryo, Output output, DefaultApplicationId object) {
+        kryo.writeObject(output, object.id());
+        kryo.writeObject(output, object.name());
+    }
+
+    @Override
+    public DefaultApplicationId read(Kryo kryo, Input input, Class<DefaultApplicationId> type) {
+        short id = kryo.readObject(input, Short.class);
+        String name = kryo.readObject(input, String.class);
+        return new DefaultApplicationId(id, name);
+    }
+}

@@ -7,6 +7,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedList;
 
+import org.onlab.onos.core.DefaultApplicationId;
 import org.onlab.onos.cluster.ControllerNode;
 import org.onlab.onos.cluster.DefaultControllerNode;
 import org.onlab.onos.cluster.NodeId;
@@ -129,6 +130,7 @@ public final class KryoNamespaces {
                     FlowRuleBatchEntry.class,
                     FlowRuleBatchEntry.FlowRuleOperation.class
                     )
+            .register(DefaultApplicationId.class, new DefaultApplicationIdSerializer())
             .register(URI.class, new URISerializer())
             .register(NodeId.class, new NodeIdSerializer())
             .register(ProviderId.class, new ProviderIdSerializer())

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.onlab.onos.store.trivial.impl;
+
+import com.google.common.collect.ImmutableSet;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.core.ApplicationId;
+import org.onlab.onos.core.ApplicationIdStore;
+import org.onlab.onos.core.DefaultApplicationId;
+
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Simple implementation of the application ID registry using in-memory
+ * structures.
+ */
+@Component(immediate = true)
+@Service
+public class SimpleApplicationIdStore implements ApplicationIdStore {
+
+    private static final AtomicInteger ID_DISPENSER = new AtomicInteger(1);
+
+    private final Map<Short, DefaultApplicationId> appIds = new ConcurrentHashMap<>();
+    private final Map<String, DefaultApplicationId> appIdsByName = new ConcurrentHashMap<>();
+
+    @Override
+    public Set<ApplicationId> getAppIds() {
+        return ImmutableSet.<ApplicationId>copyOf(appIds.values());
+    }
+
+    @Override
+    public ApplicationId getAppId(Short id) {
+        return appIds.get(id);
+    }
+
+    @Override
+    public ApplicationId registerApplication(String name) {
+        DefaultApplicationId appId = appIdsByName.get(name);
+        if (appId == null) {
+            short id = (short) ID_DISPENSER.getAndIncrement();
+            appId = new DefaultApplicationId(id, name);
+            appIds.put(id, appId);
+            appIdsByName.put(name, appId);
+        }
+        return appId;
+    }
+
+}

@@ -38,7 +38,7 @@ 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.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.flow.BatchOperation;
 import org.onlab.onos.net.flow.CompletedBatchOperation;