Added application ID store; both trivial and distributed variants.
diff --git a/apps/fwd/src/main/java/org/onlab/onos/fwd/ReactiveForwarding.java b/apps/fwd/src/main/java/org/onlab/onos/fwd/ReactiveForwarding.java
index 3578715..6d92ad8 100644
--- a/apps/fwd/src/main/java/org/onlab/onos/fwd/ReactiveForwarding.java
+++ b/apps/fwd/src/main/java/org/onlab/onos/fwd/ReactiveForwarding.java
@@ -30,8 +30,8 @@
 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;
diff --git a/apps/ifwd/src/main/java/org/onlab/onos/ifwd/IntentReactiveForwarding.java b/apps/ifwd/src/main/java/org/onlab/onos/ifwd/IntentReactiveForwarding.java
index 2078f29..b59d1ab 100644
--- a/apps/ifwd/src/main/java/org/onlab/onos/ifwd/IntentReactiveForwarding.java
+++ b/apps/ifwd/src/main/java/org/onlab/onos/ifwd/IntentReactiveForwarding.java
@@ -23,8 +23,8 @@
 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;
diff --git a/apps/mobility/src/main/java/org/onlab/onos/mobility/HostMobility.java b/apps/mobility/src/main/java/org/onlab/onos/mobility/HostMobility.java
index 13c765b..732caa9 100644
--- a/apps/mobility/src/main/java/org/onlab/onos/mobility/HostMobility.java
+++ b/apps/mobility/src/main/java/org/onlab/onos/mobility/HostMobility.java
@@ -27,8 +27,8 @@
 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;
diff --git a/apps/optical/src/main/java/org/onlab/onos/optical/provisioner/OpticalPathProvisioner.java b/apps/optical/src/main/java/org/onlab/onos/optical/provisioner/OpticalPathProvisioner.java
index 1bc6d99..dd6a8e2 100644
--- a/apps/optical/src/main/java/org/onlab/onos/optical/provisioner/OpticalPathProvisioner.java
+++ b/apps/optical/src/main/java/org/onlab/onos/optical/provisioner/OpticalPathProvisioner.java
@@ -30,8 +30,8 @@
 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;
diff --git a/apps/optical/src/main/java/org/onlab/onos/optical/testapp/LambdaForwarding.java b/apps/optical/src/main/java/org/onlab/onos/optical/testapp/LambdaForwarding.java
index 6878aa1..7230c44 100644
--- a/apps/optical/src/main/java/org/onlab/onos/optical/testapp/LambdaForwarding.java
+++ b/apps/optical/src/main/java/org/onlab/onos/optical/testapp/LambdaForwarding.java
@@ -27,8 +27,8 @@
 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;
diff --git a/apps/proxyarp/src/main/java/org/onlab/onos/proxyarp/ProxyArp.java b/apps/proxyarp/src/main/java/org/onlab/onos/proxyarp/ProxyArp.java
index 431c5d7..96e804f 100644
--- a/apps/proxyarp/src/main/java/org/onlab/onos/proxyarp/ProxyArp.java
+++ b/apps/proxyarp/src/main/java/org/onlab/onos/proxyarp/ProxyArp.java
@@ -25,8 +25,8 @@
 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;
diff --git a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/PeerConnectivityManager.java b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/PeerConnectivityManager.java
index 69a22b0..32f77fe 100644
--- a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/PeerConnectivityManager.java
+++ b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/PeerConnectivityManager.java
@@ -20,7 +20,7 @@
 
 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;
diff --git a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/Router.java b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/Router.java
index 4e3415b..faf31f6 100644
--- a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/Router.java
+++ b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/Router.java
@@ -34,7 +34,7 @@
 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;
diff --git a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/SdnIp.java b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/SdnIp.java
index fedf582..a6669ab 100644
--- a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/SdnIp.java
+++ b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/SdnIp.java
@@ -28,8 +28,8 @@
 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;
diff --git a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/PeerConnectivityManagerTest.java b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/PeerConnectivityManagerTest.java
index 832989f..118a04e 100644
--- a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/PeerConnectivityManagerTest.java
+++ b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/PeerConnectivityManagerTest.java
@@ -23,7 +23,7 @@
 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;
diff --git a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTest.java b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTest.java
index 7bc9473..581144e 100644
--- a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTest.java
+++ b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTest.java
@@ -37,7 +37,7 @@
 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;
diff --git a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTestWithAsyncArp.java b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTestWithAsyncArp.java
index d1c8b2a..e4854f3 100644
--- a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTestWithAsyncArp.java
+++ b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTestWithAsyncArp.java
@@ -19,7 +19,7 @@
 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;
diff --git a/cli/src/main/java/org/onlab/onos/cli/AbstractShellCommand.java b/cli/src/main/java/org/onlab/onos/cli/AbstractShellCommand.java
index 68b3244..b121dcb 100644
--- a/cli/src/main/java/org/onlab/onos/cli/AbstractShellCommand.java
+++ b/cli/src/main/java/org/onlab/onos/cli/AbstractShellCommand.java
@@ -22,8 +22,8 @@
 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;
diff --git a/cli/src/main/java/org/onlab/onos/cli/ApplicationIdListCommand.java b/cli/src/main/java/org/onlab/onos/cli/ApplicationIdListCommand.java
new file mode 100644
index 0000000..8acc3d2
--- /dev/null
+++ b/cli/src/main/java/org/onlab/onos/cli/ApplicationIdListCommand.java
@@ -0,0 +1,67 @@
+/*
+ * 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;
+    }
+
+}
diff --git a/cli/src/main/java/org/onlab/onos/cli/Comparators.java b/cli/src/main/java/org/onlab/onos/cli/Comparators.java
index 807af27..80b31d5 100644
--- a/cli/src/main/java/org/onlab/onos/cli/Comparators.java
+++ b/cli/src/main/java/org/onlab/onos/cli/Comparators.java
@@ -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 @@
     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) {
diff --git a/cli/src/main/java/org/onlab/onos/cli/SummaryCommand.java b/cli/src/main/java/org/onlab/onos/cli/SummaryCommand.java
index 60b9ded..b4b3e98 100644
--- a/cli/src/main/java/org/onlab/onos/cli/SummaryCommand.java
+++ b/cli/src/main/java/org/onlab/onos/cli/SummaryCommand.java
@@ -20,7 +20,7 @@
 
 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;
diff --git a/cli/src/main/java/org/onlab/onos/cli/net/FlowsListCommand.java b/cli/src/main/java/org/onlab/onos/cli/net/FlowsListCommand.java
index 9a1c085..6918c93 100644
--- a/cli/src/main/java/org/onlab/onos/cli/net/FlowsListCommand.java
+++ b/cli/src/main/java/org/onlab/onos/cli/net/FlowsListCommand.java
@@ -25,7 +25,7 @@
 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;
diff --git a/cli/src/main/resources/OSGI-INF/blueprint/shell-config.xml b/cli/src/main/resources/OSGI-INF/blueprint/shell-config.xml
index 610646b..b5752b6 100644
--- a/cli/src/main/resources/OSGI-INF/blueprint/shell-config.xml
+++ b/cli/src/main/resources/OSGI-INF/blueprint/shell-config.xml
@@ -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>
diff --git a/core/api/src/main/java/org/onlab/onos/ApplicationId.java b/core/api/src/main/java/org/onlab/onos/core/ApplicationId.java
similarity index 90%
rename from core/api/src/main/java/org/onlab/onos/ApplicationId.java
rename to core/api/src/main/java/org/onlab/onos/core/ApplicationId.java
index 3fab53f..10c0c75 100644
--- a/core/api/src/main/java/org/onlab/onos/ApplicationId.java
+++ b/core/api/src/main/java/org/onlab/onos/core/ApplicationId.java
@@ -1,4 +1,4 @@
-package org.onlab.onos;
+package org.onlab.onos.core;
 
 
 /**
diff --git a/core/api/src/main/java/org/onlab/onos/core/ApplicationIdStore.java b/core/api/src/main/java/org/onlab/onos/core/ApplicationIdStore.java
new file mode 100644
index 0000000..ccb1414
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/core/ApplicationIdStore.java
@@ -0,0 +1,52 @@
+/*
+ * 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);
+
+}
diff --git a/core/api/src/main/java/org/onlab/onos/CoreService.java b/core/api/src/main/java/org/onlab/onos/core/CoreService.java
similarity index 76%
rename from core/api/src/main/java/org/onlab/onos/CoreService.java
rename to core/api/src/main/java/org/onlab/onos/core/CoreService.java
index 3302888..0de33b3 100644
--- a/core/api/src/main/java/org/onlab/onos/CoreService.java
+++ b/core/api/src/main/java/org/onlab/onos/core/CoreService.java
@@ -1,4 +1,6 @@
-package org.onlab.onos;
+package org.onlab.onos.core;
+
+import java.util.Set;
 
 /**
  * Service for interacting with the core system of the controller.
@@ -13,6 +15,20 @@
     Version version();
 
     /**
+     * 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}
@@ -22,11 +38,4 @@
      */
     ApplicationId registerApplication(String identifier);
 
-    /**
-     * 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);
-
 }
diff --git a/core/net/src/main/java/org/onlab/onos/impl/DefaultApplicationId.java b/core/api/src/main/java/org/onlab/onos/core/DefaultApplicationId.java
similarity index 69%
rename from core/net/src/main/java/org/onlab/onos/impl/DefaultApplicationId.java
rename to core/api/src/main/java/org/onlab/onos/core/DefaultApplicationId.java
index eed5fb0..b5ecccc 100644
--- a/core/net/src/main/java/org/onlab/onos/impl/DefaultApplicationId.java
+++ b/core/api/src/main/java/org/onlab/onos/core/DefaultApplicationId.java
@@ -1,23 +1,32 @@
-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
diff --git a/core/api/src/main/java/org/onlab/onos/Version.java b/core/api/src/main/java/org/onlab/onos/core/Version.java
similarity index 98%
rename from core/api/src/main/java/org/onlab/onos/Version.java
rename to core/api/src/main/java/org/onlab/onos/core/Version.java
index 5d071b7..72fd509 100644
--- a/core/api/src/main/java/org/onlab/onos/Version.java
+++ b/core/api/src/main/java/org/onlab/onos/core/Version.java
@@ -1,4 +1,4 @@
-package org.onlab.onos;
+package org.onlab.onos.core;
 
 import java.util.Objects;
 
diff --git a/core/api/src/main/java/org/onlab/onos/core/package-info.java b/core/api/src/main/java/org/onlab/onos/core/package-info.java
new file mode 100644
index 0000000..fb97734
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/core/package-info.java
@@ -0,0 +1,4 @@
+/**
+ * ONOS Core API definitions.
+ */
+package org.onlab.onos.core;
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/DefaultFlowRule.java b/core/api/src/main/java/org/onlab/onos/net/flow/DefaultFlowRule.java
index 53a94bb..deb654e 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/DefaultFlowRule.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/DefaultFlowRule.java
@@ -23,7 +23,7 @@
 
 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;
 
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleProvider.java b/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleProvider.java
index ae74ac5..8748fe8 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleProvider.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleProvider.java
@@ -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;
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleService.java b/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleService.java
index 0b6f6c7..6fbc053 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleService.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleService.java
@@ -20,7 +20,7 @@
 
 import java.util.concurrent.Future;
 
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.DeviceId;
 
 /**
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/ConnectivityIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/ConnectivityIntent.java
index 710ae4e..d15a15a 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/ConnectivityIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/ConnectivityIntent.java
@@ -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;
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/HostToHostIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/HostToHostIntent.java
index 795f681..3bf5e4e 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/HostToHostIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/HostToHostIntent.java
@@ -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;
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/Intent.java b/core/api/src/main/java/org/onlab/onos/net/intent/Intent.java
index b5fefb2..32ed36f 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/Intent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/Intent.java
@@ -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;
 
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/LinkCollectionIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/LinkCollectionIntent.java
index 65d1ba8..c328a4e 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/LinkCollectionIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/LinkCollectionIntent.java
@@ -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;
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/MultiPointToSinglePointIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/MultiPointToSinglePointIntent.java
index 13324d0..9766f8f 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/MultiPointToSinglePointIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/MultiPointToSinglePointIntent.java
@@ -20,7 +20,7 @@
 
 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;
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/OpticalConnectivityIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/OpticalConnectivityIntent.java
index 6e595c5..d22700b 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/OpticalConnectivityIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/OpticalConnectivityIntent.java
@@ -1,6 +1,6 @@
 package org.onlab.onos.net.intent;
 
-import org.onlab.onos.ApplicationId;
+import org.onlab.onos.core.ApplicationId;
 import org.onlab.onos.net.ConnectPoint;
 
 /**
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/OpticalPathIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/OpticalPathIntent.java
index edf3d5c..e9bf826 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/OpticalPathIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/OpticalPathIntent.java
@@ -2,7 +2,7 @@
 
 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;
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/PathIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/PathIntent.java
index d7996c9..639e68b 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/PathIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/PathIntent.java
@@ -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;
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/PointToPointIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/PointToPointIntent.java
index 7b91cdf..7c69887 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/PointToPointIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/PointToPointIntent.java
@@ -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;
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/SinglePointToMultiPointIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/SinglePointToMultiPointIntent.java
index e5790d0..f08c1d7 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/SinglePointToMultiPointIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/SinglePointToMultiPointIntent.java
@@ -20,7 +20,7 @@
 
 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;
diff --git a/core/api/src/main/java/org/onlab/onos/package-info.java b/core/api/src/main/java/org/onlab/onos/package-info.java
deleted file mode 100644
index 65ef461..0000000
--- a/core/api/src/main/java/org/onlab/onos/package-info.java
+++ /dev/null
@@ -1,4 +0,0 @@
-/**
- * ONOS Core API definitions.
- */
-package org.onlab.onos;
diff --git a/core/api/src/test/java/org/onlab/onos/TestApplicationId.java b/core/api/src/test/java/org/onlab/onos/TestApplicationId.java
index e8c0304..cb16219 100644
--- a/core/api/src/test/java/org/onlab/onos/TestApplicationId.java
+++ b/core/api/src/test/java/org/onlab/onos/TestApplicationId.java
@@ -1,5 +1,7 @@
 package org.onlab.onos;
 
+import org.onlab.onos.core.ApplicationId;
+
 import java.util.Objects;
 
 /**
diff --git a/core/api/src/test/java/org/onlab/onos/VersionTest.java b/core/api/src/test/java/org/onlab/onos/VersionTest.java
index e357f9d..14b69d7 100644
--- a/core/api/src/test/java/org/onlab/onos/VersionTest.java
+++ b/core/api/src/test/java/org/onlab/onos/VersionTest.java
@@ -2,9 +2,10 @@
 
 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.
diff --git a/core/api/src/test/java/org/onlab/onos/net/intent/ConnectivityIntentTest.java b/core/api/src/test/java/org/onlab/onos/net/intent/ConnectivityIntentTest.java
index 03b101a..3d92e87 100644
--- a/core/api/src/test/java/org/onlab/onos/net/intent/ConnectivityIntentTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/intent/ConnectivityIntentTest.java
@@ -2,7 +2,7 @@
 
 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;
diff --git a/core/net/src/main/java/org/onlab/onos/core/impl/CoreManager.java b/core/net/src/main/java/org/onlab/onos/core/impl/CoreManager.java
new file mode 100644
index 0000000..907466f
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/core/impl/CoreManager.java
@@ -0,0 +1,62 @@
+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.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.Set;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Core service implementation.
+ */
+@Component
+@Service
+public class CoreManager implements CoreService {
+
+    private static final File VERSION_FILE = new File("../VERSION");
+    private static Version version = Version.version("1.0.0-SNAPSHOT");
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ApplicationIdStore applicationIdStore;
+
+    @Activate
+    public void activate() {
+        List<String> versionLines = Tools.slurp(VERSION_FILE);
+        if (versionLines != null && !versionLines.isEmpty()) {
+            version = Version.version(versionLines.get(0));
+        }
+    }
+
+    @Override
+    public Version version() {
+        return version;
+    }
+
+    @Override
+    public Set<ApplicationId> getAppIds() {
+        return applicationIdStore.getAppIds();
+    }
+
+    @Override
+    public ApplicationId getAppId(Short id) {
+        return applicationIdStore.getAppId(id);
+    }
+
+    @Override
+    public ApplicationId registerApplication(String name) {
+        checkNotNull(name, "Application ID cannot be null");
+        return applicationIdStore.registerApplication(name);
+    }
+
+}
diff --git a/core/net/src/main/java/org/onlab/onos/impl/MetricsManagerComponent.java b/core/net/src/main/java/org/onlab/onos/core/impl/MetricsManagerComponent.java
similarity index 93%
rename from core/net/src/main/java/org/onlab/onos/impl/MetricsManagerComponent.java
rename to core/net/src/main/java/org/onlab/onos/core/impl/MetricsManagerComponent.java
index de47635..66608f2 100644
--- a/core/net/src/main/java/org/onlab/onos/impl/MetricsManagerComponent.java
+++ b/core/net/src/main/java/org/onlab/onos/core/impl/MetricsManagerComponent.java
@@ -1,4 +1,4 @@
-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;
diff --git a/core/net/src/main/java/org/onlab/onos/impl/package-info.java b/core/net/src/main/java/org/onlab/onos/core/impl/package-info.java
similarity index 62%
rename from core/net/src/main/java/org/onlab/onos/impl/package-info.java
rename to core/net/src/main/java/org/onlab/onos/core/impl/package-info.java
index 2bf17b3..8a501e3 100644
--- a/core/net/src/main/java/org/onlab/onos/impl/package-info.java
+++ b/core/net/src/main/java/org/onlab/onos/core/impl/package-info.java
@@ -1,4 +1,4 @@
 /**
  * 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
diff --git a/core/net/src/main/java/org/onlab/onos/impl/CoreManager.java b/core/net/src/main/java/org/onlab/onos/impl/CoreManager.java
deleted file mode 100644
index da1f8c9..0000000
--- a/core/net/src/main/java/org/onlab/onos/impl/CoreManager.java
+++ /dev/null
@@ -1,64 +0,0 @@
-package org.onlab.onos.impl;
-
-import org.apache.felix.scr.annotations.Activate;
-import org.apache.felix.scr.annotations.Component;
-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.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;
-
-/**
- * Core service implementation.
- */
-@Component
-@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
-
-    @Activate
-    public void activate() {
-        List<String> versionLines = Tools.slurp(VERSION_FILE);
-        if (versionLines != null && !versionLines.isEmpty()) {
-            version = Version.version(versionLines.get(0));
-        }
-    }
-
-    @Override
-    public Version version() {
-        return version;
-    }
-
-    @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;
-    }
-
-}
diff --git a/core/net/src/main/java/org/onlab/onos/net/flow/impl/FlowRuleManager.java b/core/net/src/main/java/org/onlab/onos/net/flow/impl/FlowRuleManager.java
index 0c07bab..aef5831 100644
--- a/core/net/src/main/java/org/onlab/onos/net/flow/impl/FlowRuleManager.java
+++ b/core/net/src/main/java/org/onlab/onos/net/flow/impl/FlowRuleManager.java
@@ -22,7 +22,7 @@
 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;
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/LinkCollectionIntentInstaller.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/LinkCollectionIntentInstaller.java
index 2983a68..93c6345 100644
--- a/core/net/src/main/java/org/onlab/onos/net/intent/impl/LinkCollectionIntentInstaller.java
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/LinkCollectionIntentInstaller.java
@@ -9,8 +9,8 @@
 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;
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/OpticalConnectivityIntentCompiler.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/OpticalConnectivityIntentCompiler.java
index 8fcf75b..c19bba0 100644
--- a/core/net/src/main/java/org/onlab/onos/net/intent/impl/OpticalConnectivityIntentCompiler.java
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/OpticalConnectivityIntentCompiler.java
@@ -12,7 +12,7 @@
 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;
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/OpticalPathIntentInstaller.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/OpticalPathIntentInstaller.java
index 5557b05..a504992 100644
--- a/core/net/src/main/java/org/onlab/onos/net/intent/impl/OpticalPathIntentInstaller.java
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/OpticalPathIntentInstaller.java
@@ -10,8 +10,8 @@
 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;
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/PathIntentInstaller.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/PathIntentInstaller.java
index a7381b7..84e2c7c 100644
--- a/core/net/src/main/java/org/onlab/onos/net/intent/impl/PathIntentInstaller.java
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/PathIntentInstaller.java
@@ -11,8 +11,8 @@
 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;
diff --git a/core/net/src/test/java/org/onlab/onos/net/flow/impl/FlowRuleManagerTest.java b/core/net/src/test/java/org/onlab/onos/net/flow/impl/FlowRuleManagerTest.java
index 85ceb3f..59f0595 100644
--- a/core/net/src/test/java/org/onlab/onos/net/flow/impl/FlowRuleManagerTest.java
+++ b/core/net/src/test/java/org/onlab/onos/net/flow/impl/FlowRuleManagerTest.java
@@ -1,35 +1,16 @@
 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.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 @@
 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 @@
         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 @@
         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 @@
         }
 
         assertEquals("mispredicted number of events",
-                events.length, listener.events.size());
+                     events.length, listener.events.size());
 
         listener.events.clear();
     }
@@ -156,10 +146,11 @@
     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 @@
         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 @@
         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 @@
         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 @@
         //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 @@
         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 @@
         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 @@
          */
         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<>();
 
diff --git a/core/net/src/test/java/org/onlab/onos/net/intent/TestHostToHostIntent.java b/core/net/src/test/java/org/onlab/onos/net/intent/TestHostToHostIntent.java
index 2b56e88..270ffd6 100644
--- a/core/net/src/test/java/org/onlab/onos/net/intent/TestHostToHostIntent.java
+++ b/core/net/src/test/java/org/onlab/onos/net/intent/TestHostToHostIntent.java
@@ -1,7 +1,7 @@
 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;
diff --git a/core/net/src/test/java/org/onlab/onos/net/intent/TestLinkCollectionIntent.java b/core/net/src/test/java/org/onlab/onos/net/intent/TestLinkCollectionIntent.java
index 42b5b28..8618aa0 100644
--- a/core/net/src/test/java/org/onlab/onos/net/intent/TestLinkCollectionIntent.java
+++ b/core/net/src/test/java/org/onlab/onos/net/intent/TestLinkCollectionIntent.java
@@ -12,7 +12,7 @@
 
 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;
diff --git a/core/net/src/test/java/org/onlab/onos/net/intent/TestMultiPointToSinglePointIntent.java b/core/net/src/test/java/org/onlab/onos/net/intent/TestMultiPointToSinglePointIntent.java
index 0e4f706..4420578 100644
--- a/core/net/src/test/java/org/onlab/onos/net/intent/TestMultiPointToSinglePointIntent.java
+++ b/core/net/src/test/java/org/onlab/onos/net/intent/TestMultiPointToSinglePointIntent.java
@@ -2,7 +2,7 @@
 
 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;
diff --git a/core/net/src/test/java/org/onlab/onos/net/intent/TestPointToPointIntent.java b/core/net/src/test/java/org/onlab/onos/net/intent/TestPointToPointIntent.java
index e34d7ce..904e013 100644
--- a/core/net/src/test/java/org/onlab/onos/net/intent/TestPointToPointIntent.java
+++ b/core/net/src/test/java/org/onlab/onos/net/intent/TestPointToPointIntent.java
@@ -1,7 +1,7 @@
 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;
diff --git a/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestHostToHostIntentCompiler.java b/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestHostToHostIntentCompiler.java
index e853a29..06d0f11 100644
--- a/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestHostToHostIntentCompiler.java
+++ b/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestHostToHostIntentCompiler.java
@@ -3,7 +3,7 @@
 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;
diff --git a/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestMultiPointToSinglePointIntentCompiler.java b/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestMultiPointToSinglePointIntentCompiler.java
index 1c78e26..276d07f 100644
--- a/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestMultiPointToSinglePointIntentCompiler.java
+++ b/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestMultiPointToSinglePointIntentCompiler.java
@@ -2,7 +2,7 @@
 
 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;
diff --git a/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestPointToPointIntentCompiler.java b/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestPointToPointIntentCompiler.java
index 90b7155..b04bc29 100644
--- a/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestPointToPointIntentCompiler.java
+++ b/core/net/src/test/java/org/onlab/onos/net/intent/impl/TestPointToPointIntentCompiler.java
@@ -2,7 +2,7 @@
 
 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;
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/AppIdEvent.java b/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/AppIdEvent.java
new file mode 100644
index 0000000..3dd626c
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/AppIdEvent.java
@@ -0,0 +1,37 @@
+/*
+ * 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);
+    }
+
+}
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/AppIdStoreDelegate.java b/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/AppIdStoreDelegate.java
new file mode 100644
index 0000000..e05daf2
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/AppIdStoreDelegate.java
@@ -0,0 +1,27 @@
+/*
+ * 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> {
+}
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/DistributedApplicationIdStore.java b/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/DistributedApplicationIdStore.java
new file mode 100644
index 0000000..354ef49
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/DistributedApplicationIdStore.java
@@ -0,0 +1,149 @@
+/*
+ * 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) {
+        }
+    }
+}
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/package-info.java b/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/package-info.java
new file mode 100644
index 0000000..7613a4f
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/core/impl/package-info.java
@@ -0,0 +1,23 @@
+/*
+ * 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;
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/mastership/impl/RoleValue.java b/core/store/dist/src/main/java/org/onlab/onos/store/mastership/impl/RoleValue.java
index 7447161..0a3de50 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/mastership/impl/RoleValue.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/mastership/impl/RoleValue.java
@@ -15,7 +15,7 @@
 
 /**
  * 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 {
 
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultApplicationIdSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultApplicationIdSerializer.java
new file mode 100644
index 0000000..87e9ba4
--- /dev/null
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultApplicationIdSerializer.java
@@ -0,0 +1,52 @@
+/*
+ * 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);
+    }
+}
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoNamespaces.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoNamespaces.java
index 0e9e19c..c554372 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoNamespaces.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoNamespaces.java
@@ -7,6 +7,7 @@
 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 @@
                     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())
diff --git a/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/SimpleApplicationIdStore.java b/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/SimpleApplicationIdStore.java
new file mode 100644
index 0000000..a242822
--- /dev/null
+++ b/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/SimpleApplicationIdStore.java
@@ -0,0 +1,68 @@
+/*
+ * 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;
+    }
+
+}
diff --git a/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/OpenFlowRuleProvider.java b/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/OpenFlowRuleProvider.java
index a3d2bfe..05860f6 100644
--- a/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/OpenFlowRuleProvider.java
+++ b/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/OpenFlowRuleProvider.java
@@ -38,7 +38,7 @@
 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;