Introducing concept of a physical or logical region to facilitate
support of geographically distributed cluster and to lay ground
for multiple/filtered topology layouts.

Added implementation of manager and store; unit-tests included.

Change-Id: Ia01673a0b711b8785c0ea68768552c2f61d7ea6d
diff --git a/core/api/src/main/java/org/onosproject/cluster/NodeId.java b/core/api/src/main/java/org/onosproject/cluster/NodeId.java
index e5ab9dc..8b7d540 100644
--- a/core/api/src/main/java/org/onosproject/cluster/NodeId.java
+++ b/core/api/src/main/java/org/onosproject/cluster/NodeId.java
@@ -15,14 +15,19 @@
  */
 package org.onosproject.cluster;
 
-import java.util.Objects;
+import org.onlab.util.Identifier;
 
 /**
  * Controller cluster identity.
  */
-public class NodeId implements Comparable<NodeId> {
+public final class NodeId extends Identifier<String> implements Comparable<NodeId> {
 
-    private final String id;
+    /**
+     * Constructor for serialization.
+     */
+    private NodeId() {
+        super("");
+    }
 
     /**
      * Creates a new cluster node identifier from the specified string.
@@ -30,34 +35,22 @@
      * @param id string identifier
      */
     public NodeId(String id) {
-        this.id = id;
+        super(id);
     }
 
-    @Override
-    public int hashCode() {
-        return id.hashCode();
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        if (this == obj) {
-            return true;
-        }
-        if (obj instanceof NodeId) {
-            final NodeId other = (NodeId) obj;
-            return Objects.equals(this.id, other.id);
-        }
-        return false;
-    }
-
-    @Override
-    public String toString() {
-        return id;
+    /**
+     * Creates a new cluster node identifier from the specified string.
+     *
+     * @param id string identifier
+     * @return node id
+     */
+    public static NodeId nodeId(String id) {
+        return new NodeId(id);
     }
 
     @Override
     public int compareTo(NodeId that) {
-        return this.id.compareTo(that.id);
+        return identifier.compareTo(that.identifier);
     }
 
 }
diff --git a/core/api/src/main/java/org/onosproject/net/key/DeviceKeyId.java b/core/api/src/main/java/org/onosproject/net/key/DeviceKeyId.java
index 12c1d95..d7cbdbe 100644
--- a/core/api/src/main/java/org/onosproject/net/key/DeviceKeyId.java
+++ b/core/api/src/main/java/org/onosproject/net/key/DeviceKeyId.java
@@ -16,21 +16,18 @@
 
 package org.onosproject.net.key;
 
-import java.util.Objects;
-
-import static com.google.common.base.Preconditions.checkNotNull;
+import org.onlab.util.Identifier;
 
 /**
- * Device key Id definition.
+ * Device key identifier backed by a string value.
  */
-public final class DeviceKeyId {
-    private final String identifier;
+public final class DeviceKeyId extends Identifier<String> {
 
     /**
      * Constructor for serialization.
      */
     private DeviceKeyId() {
-        this.identifier = null;
+        super();
     }
 
     /**
@@ -39,63 +36,17 @@
      * @param value the underlying value of this ID
      */
     private DeviceKeyId(String value) {
-        this.identifier = checkNotNull(value, "Device Key Id cannot be null.");
+        super(value);
     }
 
     /**
-     * Static  method to construct a device key identifier.
+     * Creates a new device key identifier.
      *
-     * @param id for the device key identifier
+     * @param id backing identifier value
      * @return device key identifier
      */
-    public static final DeviceKeyId deviceKeyId(String id) {
+    public static DeviceKeyId deviceKeyId(String id) {
         return new DeviceKeyId(id);
     }
 
-    /**
-     * Returns the identifier of the device key identifier.
-     *
-     * @return identifier
-     */
-    public String id() {
-        return identifier;
-    }
-
-    /**
-     * Returns the hashcode of the identifier.
-     *
-     * @return hashcode
-     */
-    @Override
-    public int hashCode() {
-        return identifier.hashCode();
-    }
-
-    /**
-     * Compares two device key identifiers for equality.
-     *
-     * @param obj to compare against
-     * @return true if the objects are equal, false otherwise.
-     */
-    @Override
-    public boolean equals(Object obj) {
-        if (this == obj) {
-            return true;
-        }
-        if (obj instanceof DeviceKeyId) {
-            final DeviceKeyId that = (DeviceKeyId) obj;
-            return this.getClass() == that.getClass() &&
-                    Objects.equals(this.identifier, that.identifier);
-        }
-        return false;
-    }
-
-    /**
-     * Returns a string representation of a DeviceKeyId.
-     *
-     * @return string
-     */
-    public String toString() {
-        return identifier;
-    }
 }
diff --git a/core/api/src/main/java/org/onosproject/net/region/DefaultRegion.java b/core/api/src/main/java/org/onosproject/net/region/DefaultRegion.java
new file mode 100644
index 0000000..d828880
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/region/DefaultRegion.java
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region;
+
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.ImmutableList;
+import org.onosproject.cluster.NodeId;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.Set;
+
+/**
+ * Default implementation of a region.
+ */
+public final class DefaultRegion implements Region {
+
+    private final RegionId id;
+    private final String name;
+    private final Type type;
+    private final List<Set<NodeId>> masters;
+
+    /**
+     * Creates a region using the supplied information.
+     *
+     * @param id      region identifier
+     * @param name    friendly name
+     * @param type    region type
+     * @param masters list of sets of cluster node identifiers; in order of mastership
+     */
+    public DefaultRegion(RegionId id, String name, Type type, List<Set<NodeId>> masters) {
+        this.id = id;
+        this.name = name;
+        this.type = type;
+        this.masters = masters != null ? ImmutableList.copyOf(masters) : ImmutableList.of();
+    }
+
+    @Override
+    public RegionId id() {
+        return id;
+    }
+
+    @Override
+    public String name() {
+        return name;
+    }
+
+    @Override
+    public Type type() {
+        return type;
+    }
+
+    @Override
+    public List<Set<NodeId>> masters() {
+        return masters;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, name, type, masters);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof DefaultRegion) {
+            final DefaultRegion that = (DefaultRegion) obj;
+            return Objects.equals(this.id, that.id)
+                    && Objects.equals(this.name, that.name)
+                    && Objects.equals(this.type, that.type)
+                    && Objects.equals(this.masters, that.masters);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(this)
+                .add("id", id)
+                .add("name", name)
+                .add("type", type)
+                .add("masters", masters)
+                .toString();
+    }
+
+}
diff --git a/core/api/src/main/java/org/onosproject/net/region/Region.java b/core/api/src/main/java/org/onosproject/net/region/Region.java
new file mode 100644
index 0000000..3a9f60a
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/region/Region.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region;
+
+import org.onosproject.cluster.NodeId;
+
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Representation of a group of devices located in a common physical or
+ * logical region. Optionally, devices in the region can share the same
+ * cluster nodes mastership affinities.
+ */
+public interface Region {
+
+    /**
+     * Coarse representation of the type of the region.
+     */
+    enum Type {
+        /**
+         * Region represents an entire continent.
+         */
+        CONTINENT,
+
+        /**
+         * Region represents an entire country.
+         */
+        COUNTRY,
+
+        /**
+         * Region represents a metropolitan area.
+         */
+        METRO,
+
+        /**
+         * Region represents a campus.
+         */
+        CAMPUS,
+
+        /**
+         * Region represents a building.
+         */
+        BUILDING,
+
+        /**
+         * Region represents a building floor.
+         */
+        FLOOR,
+
+        /**
+         * Region represents a room.
+         */
+        ROOM,
+
+        /**
+         * Region represents a rack.
+         */
+        RACK,
+
+        /**
+         * Region represents a logical grouping.
+         */
+        LOGICAL_GROUP
+    }
+
+    /**
+     * Returns the unique identifier of the region.
+     *
+     * @return region identifier
+     */
+    RegionId id();
+
+    /**
+     * Returns the friendly region name that can be used for display purposes.
+     *
+     * @return friendly name of the region
+     */
+    String name();
+
+    /**
+     * Returns the region type.
+     *
+     * @return region type
+     */
+    Type type();
+
+    /**
+     * Returns the list of master node sets. The sets of cluster node identifiers
+     * should be listed in the order of preferred mastership. Nodes specified
+     * in each sets should be considered with equally priority and devices in
+     * the region can be balanced between them based on other criteria, e.g. load.
+     *
+     * @return list of preferred master node sets
+     */
+    List<Set<NodeId>> masters();
+
+}
diff --git a/core/api/src/main/java/org/onosproject/net/region/RegionAdminService.java b/core/api/src/main/java/org/onosproject/net/region/RegionAdminService.java
new file mode 100644
index 0000000..e402a7d
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/region/RegionAdminService.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region;
+
+import org.onosproject.cluster.NodeId;
+import org.onosproject.net.DeviceId;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Service for interacting with inventory of network control regions.
+ */
+public interface RegionAdminService extends RegionService {
+
+    /**
+     * Creates a new region using the supplied data.
+     *
+     * @param regionId      region identifier
+     * @param name          friendly name
+     * @param type          region type
+     * @param masterNodeIds list of sets of master nodes; null implies empty list
+     * @return new region descriptor
+     * @throws IllegalArgumentException if region already exists
+     */
+    Region createRegion(RegionId regionId, String name, Region.Type type,
+                        List<Set<NodeId>> masterNodeIds);
+
+    /**
+     * Update the specified region using the new set of data.
+     *
+     * @param regionId      region identifier
+     * @param name          friendly name
+     * @param type          region type
+     * @param masterNodeIds list of sets of master nodes; null implies empty list
+     * @return new region descriptor
+     */
+    Region updateRegion(RegionId regionId, String name, Region.Type type,
+                        List<Set<NodeId>> masterNodeIds);
+
+    /**
+     * Removes the specified region using the new set of data.
+     *
+     * @param regionId region identifier
+     */
+    void removeRegion(RegionId regionId);
+
+    /**
+     * Adds the specified collection of devices to the region.
+     *
+     * @param regionId  region identifier
+     * @param deviceIds list of device identifiers
+     */
+    void addDevices(RegionId regionId, Collection<DeviceId> deviceIds);
+
+    /**
+     * Removes the specified collection of devices from the region.
+     *
+     * @param regionId  region identifier
+     * @param deviceIds list of device identifiers
+     */
+    void removeDevices(RegionId regionId, Collection<DeviceId> deviceIds);
+
+}
diff --git a/core/api/src/main/java/org/onosproject/net/region/RegionEvent.java b/core/api/src/main/java/org/onosproject/net/region/RegionEvent.java
new file mode 100644
index 0000000..6f0abd8
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/region/RegionEvent.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region;
+
+import com.google.common.collect.ImmutableSet;
+import org.onosproject.event.AbstractEvent;
+import org.onosproject.net.DeviceId;
+
+import java.util.Set;
+
+/**
+ * Describes region event.
+ */
+public class RegionEvent extends AbstractEvent<RegionEvent.Type, Region> {
+
+    private final Set<DeviceId> deviceIds;
+
+    public enum Type {
+        /**
+         * Signifies that a new region was created.
+         */
+        REGION_ADDED,
+
+        /**
+         * Signifies that a region was updated.
+         */
+        REGION_REMOVED,
+
+        /**
+         * Signifies that a region was removed.
+         */
+        REGION_UPDATED,
+
+        /**
+         * Signifies that a region device membership has changed.
+         */
+        REGION_MEMBERSHIP_CHANGED
+    }
+
+    /**
+     * Creates an event of a given type and for the specified region and the
+     * current time.
+     *
+     * @param type   device event type
+     * @param region event region subject
+     */
+    public RegionEvent(Type type, Region region) {
+        this(type, region, null);
+    }
+
+    /**
+     * Creates an event of a given type and for the specified region, device
+     * id list and the current time.
+     *
+     * @param type      device event type
+     * @param region    event region subject
+     * @param deviceIds optional set of device ids
+     */
+    public RegionEvent(Type type, Region region, Set<DeviceId> deviceIds) {
+        super(type, region);
+        this.deviceIds = deviceIds != null ? ImmutableSet.copyOf(deviceIds) : ImmutableSet.of();
+    }
+
+    /**
+     * Creates an event of a given type and for the specified device and time.
+     *
+     * @param type      device event type
+     * @param region    event region subject
+     * @param deviceIds optional set of device ids
+     * @param time      occurrence time
+     */
+    public RegionEvent(Type type, Region region, Set<DeviceId> deviceIds, long time) {
+        super(type, region, time);
+        this.deviceIds = deviceIds != null ? ImmutableSet.copyOf(deviceIds) : ImmutableSet.of();
+    }
+
+}
diff --git a/core/api/src/main/java/org/onosproject/net/region/RegionId.java b/core/api/src/main/java/org/onosproject/net/region/RegionId.java
new file mode 100644
index 0000000..0754f6e
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/region/RegionId.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region;
+
+import org.onlab.util.Identifier;
+
+/**
+ * Region identifier backed by a string value.
+ */
+public final class RegionId extends Identifier<String> {
+
+    /**
+     * Constructor for serialization.
+     */
+    private RegionId() {
+        super();
+    }
+
+    /**
+     * Constructs the ID corresponding to a given string value.
+     *
+     * @param value the underlying value of this ID
+     */
+    private RegionId(String value) {
+        super(value);
+    }
+
+    /**
+     * Creates a new region identifier.
+     *
+     * @param id backing identifier value
+     * @return region identifier
+     */
+    public static RegionId regionId(String id) {
+        return new RegionId(id);
+    }
+
+}
diff --git a/core/api/src/main/java/org/onosproject/net/region/RegionListener.java b/core/api/src/main/java/org/onosproject/net/region/RegionListener.java
new file mode 100644
index 0000000..1a41c76
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/region/RegionListener.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region;
+
+import org.onosproject.event.EventListener;
+
+/**
+ * Entity capable of receiving region related events.
+ */
+public interface RegionListener extends EventListener<RegionEvent> {
+}
diff --git a/core/api/src/main/java/org/onosproject/net/region/RegionService.java b/core/api/src/main/java/org/onosproject/net/region/RegionService.java
new file mode 100644
index 0000000..9f16aff
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/region/RegionService.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region;
+
+import org.onosproject.net.DeviceId;
+
+import java.util.Set;
+
+/**
+ * Service for interacting with inventory of network control regions.
+ */
+public interface RegionService {
+
+    /**
+     * Returns set of all regions.
+     *
+     * @return set of regions
+     */
+    Set<Region> getRegions();
+
+    /**
+     * Returns the region with the specified identifier.
+     *
+     * @param regionId region identifier
+     * @return region
+     * @throws org.onlab.util.ItemNotFoundException if region with given
+     *                                              id does not exist
+     */
+    Region getRegion(RegionId regionId);
+
+    /**
+     * Returns the region to which the specified device belongs.
+     *
+     * @param deviceId device identifier
+     * @return region or null if device does not belong to any region
+     */
+    Region getRegionForDevice(DeviceId deviceId);
+
+    /**
+     * Returns the set of devices that belong to the specified region.
+     *
+     * @param regionId region identifier
+     * @return set of identifiers for devices in the given region
+     */
+    Set<DeviceId> getRegionDevices(RegionId regionId);
+
+}
diff --git a/core/api/src/main/java/org/onosproject/net/region/RegionStore.java b/core/api/src/main/java/org/onosproject/net/region/RegionStore.java
new file mode 100644
index 0000000..6ba1354
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/region/RegionStore.java
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region;
+
+import org.onosproject.cluster.NodeId;
+import org.onosproject.net.DeviceId;
+import org.onosproject.store.Store;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Manages inventory of regions of devices; not intended for direct use.
+ */
+public interface RegionStore extends Store<RegionEvent, RegionStoreDelegate> {
+
+    /**
+     * Returns set of all regions.
+     *
+     * @return set of regions
+     */
+    Set<Region> getRegions();
+
+    /**
+     * Returns the region with the specified identifier.
+     *
+     * @param regionId region identifier
+     * @return region
+     * @throws org.onlab.util.ItemNotFoundException if region with given
+     *                                              id does not exist
+     */
+    Region getRegion(RegionId regionId);
+
+    /**
+     * Returns the region to which the specified device belongs.
+     *
+     * @param deviceId device identifier
+     * @return region or null if device does not belong to any region
+     */
+    Region getRegionForDevice(DeviceId deviceId);
+
+    /**
+     * Returns the set of devices that belong to the specified region.
+     *
+     * @param regionId region identifier
+     * @return set of identifiers for devices in the given region
+     */
+    Set<DeviceId> getRegionDevices(RegionId regionId);
+
+    /**
+     * Creates a new region using the supplied data.
+     *
+     * @param regionId      region identifier
+     * @param name          friendly name
+     * @param type          region type
+     * @param masterNodeIds list of master nodes; null implies empty list
+     * @return new region descriptor
+     * @throws IllegalArgumentException if item already exists
+     */
+    Region createRegion(RegionId regionId, String name, Region.Type type,
+                        List<Set<NodeId>> masterNodeIds);
+
+    /**
+     * Updates the specified new region using the supplied data.
+     *
+     * @param regionId      region identifier
+     * @param name          friendly name
+     * @param type          region type
+     * @param masterNodeIds list of master nodes; null implies empty list
+     * @return new region descriptor
+     * @throws IllegalArgumentException if item already exists
+     */
+    Region updateRegion(RegionId regionId, String name, Region.Type type,
+                        List<Set<NodeId>> masterNodeIds);
+
+    /**
+     * Removes the specified region using the new set of data.
+     *
+     * @param regionId region identifier
+     */
+    void removeRegion(RegionId regionId);
+
+    /**
+     * Adds the specified collection of devices to the region.
+     *
+     * @param regionId  region identifier
+     * @param deviceIds list of device identifiers
+     */
+    void addDevices(RegionId regionId, Collection<DeviceId> deviceIds);
+
+    /**
+     * Removes the specified collection of devices from the region.
+     *
+     * @param regionId  region identifier
+     * @param deviceIds list of device identifiers
+     */
+    void removeDevices(RegionId regionId, Collection<DeviceId> deviceIds);
+
+}
diff --git a/core/api/src/main/java/org/onosproject/net/region/RegionStoreDelegate.java b/core/api/src/main/java/org/onosproject/net/region/RegionStoreDelegate.java
new file mode 100644
index 0000000..be0c0bb
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/region/RegionStoreDelegate.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region;
+
+import org.onosproject.store.StoreDelegate;
+
+/**
+ * Region store delegate abstraction.
+ */
+public interface RegionStoreDelegate extends StoreDelegate<RegionEvent> {
+}
diff --git a/core/api/src/main/java/org/onosproject/net/region/package-info.java b/core/api/src/main/java/org/onosproject/net/region/package-info.java
new file mode 100644
index 0000000..9f6bafd
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/region/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.
+ */
+
+/**
+ * Subsystem for tracking inventory of network control regions.
+ */
+package org.onosproject.net.region;
\ No newline at end of file
diff --git a/core/api/src/test/java/org/onosproject/net/region/DefaultRegionTest.java b/core/api/src/test/java/org/onosproject/net/region/DefaultRegionTest.java
new file mode 100644
index 0000000..8268857
--- /dev/null
+++ b/core/api/src/test/java/org/onosproject/net/region/DefaultRegionTest.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2014-2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.testing.EqualsTester;
+import org.junit.Test;
+import org.onosproject.cluster.NodeId;
+
+import java.util.Set;
+
+import static org.junit.Assert.assertEquals;
+import static org.onosproject.cluster.NodeId.nodeId;
+import static org.onosproject.net.region.Region.Type.METRO;
+
+/**
+ * Suite of tests of the default region implementation.
+ */
+public class DefaultRegionTest {
+
+    private static final RegionId ID1 = RegionId.regionId("r1");
+
+    @Test
+    public void basics() {
+        ImmutableList<Set<NodeId>> masters = ImmutableList
+                .of(ImmutableSet.of(nodeId("n1"), nodeId("n2")),
+                    ImmutableSet.of(nodeId("n3"), nodeId("n4")));
+        Region r = new DefaultRegion(ID1, "R1", METRO, masters);
+        assertEquals("incorrect id", ID1, r.id());
+        assertEquals("incorrect name", "R1", r.name());
+        assertEquals("incorrect type", METRO, r.type());
+        assertEquals("incorrect masters", masters, r.masters());
+    }
+
+    @Test
+    public void equality() {
+        Region a = new DefaultRegion(ID1, "R1", METRO, null);
+        Region b = new DefaultRegion(ID1, "R1", METRO, null);
+        Region c = new DefaultRegion(ID1, "R2", METRO, null);
+
+        new EqualsTester().addEqualityGroup(a, b).addEqualityGroup(c).testEquals();
+    }
+
+}
\ No newline at end of file
diff --git a/core/net/src/main/java/org/onosproject/net/region/impl/RegionManager.java b/core/net/src/main/java/org/onosproject/net/region/impl/RegionManager.java
new file mode 100644
index 0000000..fcb1d6a
--- /dev/null
+++ b/core/net/src/main/java/org/onosproject/net/region/impl/RegionManager.java
@@ -0,0 +1,142 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region.impl;
+
+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.onosproject.cluster.NodeId;
+import org.onosproject.event.AbstractListenerManager;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.region.Region;
+import org.onosproject.net.region.RegionAdminService;
+import org.onosproject.net.region.RegionEvent;
+import org.onosproject.net.region.RegionId;
+import org.onosproject.net.region.RegionListener;
+import org.onosproject.net.region.RegionService;
+import org.onosproject.net.region.RegionStore;
+import org.onosproject.net.region.RegionStoreDelegate;
+import org.slf4j.Logger;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
+import static com.google.common.collect.ImmutableList.of;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Provides implementation of the region service APIs.
+ */
+public class RegionManager extends AbstractListenerManager<RegionEvent, RegionListener>
+        implements RegionAdminService, RegionService {
+
+    private static final String REGION_ID_NULL = "Region ID cannot be null";
+    private static final String REGION_TYPE_NULL = "Region type cannot be null";
+    private static final String DEVICE_ID_NULL = "Device ID cannot be null";
+    private static final String DEVICE_IDS_NULL = "Device IDs cannot be null";
+    private static final String DEVICE_IDS_EMPTY = "Device IDs cannot be empty";
+    private static final String NAME_NULL = "Name cannot be null";
+
+    private final Logger log = getLogger(getClass());
+
+    private RegionStoreDelegate delegate = this::post;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected RegionStore store;
+
+    @Activate
+    public void activate() {
+        store.setDelegate(delegate);
+        eventDispatcher.addSink(RegionEvent.class, listenerRegistry);
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        store.unsetDelegate(delegate);
+        eventDispatcher.removeSink(RegionEvent.class);
+        log.info("Stopped");
+    }
+
+    @Override
+    public Region createRegion(RegionId regionId, String name, Region.Type type,
+                               List<Set<NodeId>> masterNodeIds) {
+        checkNotNull(regionId, REGION_ID_NULL);
+        checkNotNull(name, NAME_NULL);
+        checkNotNull(name, REGION_TYPE_NULL);
+        return store.createRegion(regionId, name, type, masterNodeIds == null ? of() : masterNodeIds);
+    }
+
+    @Override
+    public Region updateRegion(RegionId regionId, String name, Region.Type type,
+                               List<Set<NodeId>> masterNodeIds) {
+        checkNotNull(regionId, REGION_ID_NULL);
+        checkNotNull(name, NAME_NULL);
+        checkNotNull(name, REGION_TYPE_NULL);
+        return store.updateRegion(regionId, name, type, masterNodeIds == null ? of() : masterNodeIds);
+    }
+
+    @Override
+    public void removeRegion(RegionId regionId) {
+        checkNotNull(regionId, REGION_ID_NULL);
+        store.removeRegion(regionId);
+    }
+
+    @Override
+    public void addDevices(RegionId regionId, Collection<DeviceId> deviceIds) {
+        checkNotNull(regionId, REGION_ID_NULL);
+        checkNotNull(deviceIds, DEVICE_IDS_NULL);
+        checkState(!deviceIds.isEmpty(), DEVICE_IDS_EMPTY);
+        store.addDevices(regionId, deviceIds);
+    }
+
+    @Override
+    public void removeDevices(RegionId regionId, Collection<DeviceId> deviceIds) {
+        checkNotNull(regionId, REGION_ID_NULL);
+        checkNotNull(deviceIds, DEVICE_IDS_NULL);
+        checkState(!deviceIds.isEmpty(), DEVICE_IDS_EMPTY);
+        store.removeDevices(regionId, deviceIds);
+    }
+
+    @Override
+    public Set<Region> getRegions() {
+        return store.getRegions();
+    }
+
+    @Override
+    public Region getRegion(RegionId regionId) {
+        checkNotNull(regionId, REGION_ID_NULL);
+        return store.getRegion(regionId);
+    }
+
+    @Override
+    public Region getRegionForDevice(DeviceId deviceId) {
+        checkNotNull(deviceId, DEVICE_ID_NULL);
+        return store.getRegionForDevice(deviceId);
+    }
+
+    @Override
+    public Set<DeviceId> getRegionDevices(RegionId regionId) {
+        checkNotNull(regionId, REGION_ID_NULL);
+        return store.getRegionDevices(regionId);
+    }
+
+}
diff --git a/core/net/src/main/java/org/onosproject/net/region/impl/package-info.java b/core/net/src/main/java/org/onosproject/net/region/impl/package-info.java
new file mode 100644
index 0000000..ce41213
--- /dev/null
+++ b/core/net/src/main/java/org/onosproject/net/region/impl/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.
+ */
+
+/**
+ * Core subsystem for managing region definitions.
+ */
+package org.onosproject.net.region.impl;
\ No newline at end of file
diff --git a/core/net/src/test/java/org/onosproject/net/region/impl/RegionManagerTest.java b/core/net/src/test/java/org/onosproject/net/region/impl/RegionManagerTest.java
new file mode 100644
index 0000000..01c5911
--- /dev/null
+++ b/core/net/src/test/java/org/onosproject/net/region/impl/RegionManagerTest.java
@@ -0,0 +1,189 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.net.region.impl;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.junit.TestUtils;
+import org.onlab.util.ItemNotFoundException;
+import org.onosproject.cluster.NodeId;
+import org.onosproject.common.event.impl.TestEventDispatcher;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.NetTestTools;
+import org.onosproject.net.region.Region;
+import org.onosproject.net.region.RegionAdminService;
+import org.onosproject.net.region.RegionEvent;
+import org.onosproject.net.region.RegionId;
+import org.onosproject.net.region.RegionListener;
+import org.onosproject.store.region.impl.DistributedRegionStore;
+import org.onosproject.store.service.TestStorageService;
+
+import java.util.List;
+import java.util.Set;
+
+import static org.junit.Assert.*;
+import static org.onosproject.net.region.Region.Type.*;
+import static org.onosproject.net.region.RegionEvent.Type.*;
+
+/**
+ * Tests of the region service implementation.
+ */
+public class RegionManagerTest {
+
+    private static final RegionId RID1 = RegionId.regionId("r1");
+    private static final RegionId RID2 = RegionId.regionId("r2");
+
+    private static final DeviceId DID1 = DeviceId.deviceId("foo:d1");
+    private static final DeviceId DID2 = DeviceId.deviceId("foo:d2");
+    private static final DeviceId DID3 = DeviceId.deviceId("foo:d3");
+
+    private static final NodeId NID1 = NodeId.nodeId("n1");
+
+    private static final List<Set<NodeId>> MASTERS = ImmutableList.of(ImmutableSet.of(NID1));
+
+    private TestManager manager = new TestManager();
+    private RegionAdminService service;
+    private TestStore store = new TestStore();
+    private TestListener listener = new TestListener();
+
+    @Before
+    public void setUp() throws Exception {
+        TestUtils.setField(store, "storageService", new TestStorageService());
+        store.activate();
+
+        manager.store = store;
+        manager.addListener(listener);
+        NetTestTools.injectEventDispatcher(manager, new TestEventDispatcher());
+        manager.activate();
+        service = manager;
+    }
+
+    @After
+    public void tearDown() {
+        store.deactivate();
+        manager.removeListener(listener);
+        manager.deactivate();
+        NetTestTools.injectEventDispatcher(manager, null);
+    }
+
+    @Test
+    public void basics() {
+        Region r1 = service.createRegion(RID1, "R1", METRO, MASTERS);
+        assertEquals("incorrect id", RID1, r1.id());
+        assertEquals("incorrect event", REGION_ADDED, listener.event.type());
+
+        Region r2 = service.createRegion(RID2, "R2", CAMPUS, MASTERS);
+        assertEquals("incorrect id", RID2, r2.id());
+        assertEquals("incorrect type", CAMPUS, r2.type());
+        assertEquals("incorrect event", REGION_ADDED, listener.event.type());
+
+        r2 = service.updateRegion(RID2, "R2", COUNTRY, MASTERS);
+        assertEquals("incorrect type", COUNTRY, r2.type());
+        assertEquals("incorrect event", REGION_UPDATED, listener.event.type());
+
+        Set<Region> regions = service.getRegions();
+        assertEquals("incorrect size", 2, regions.size());
+        assertTrue("missing r1", regions.contains(r1));
+        assertTrue("missing r2", regions.contains(r2));
+
+        r1 = service.getRegion(RID1);
+        assertEquals("incorrect id", RID1, r1.id());
+
+        service.removeRegion(RID1);
+        regions = service.getRegions();
+        assertEquals("incorrect size", 1, regions.size());
+        assertTrue("missing r2", regions.contains(r2));
+        assertEquals("incorrect event", REGION_REMOVED, listener.event.type());
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void duplicateCreate() {
+        service.createRegion(RID1, "R1", METRO, MASTERS);
+        service.createRegion(RID1, "R2", CAMPUS, MASTERS);
+    }
+
+    @Test(expected = ItemNotFoundException.class)
+    public void missingUpdate() {
+        service.updateRegion(RID1, "R1", METRO, MASTERS);
+    }
+
+    @Test
+    public void membership() {
+        Region r = service.createRegion(RID1, "R1", METRO, MASTERS);
+        assertTrue("no devices expected", service.getRegionDevices(RID1).isEmpty());
+        assertNull("no region expected", service.getRegionForDevice(DID1));
+
+        service.addDevices(RID1, ImmutableSet.of(DID1, DID2));
+        Set<DeviceId> deviceIds = service.getRegionDevices(RID1);
+        assertEquals("incorrect device count", 2, deviceIds.size());
+        assertTrue("missing d1", deviceIds.contains(DID1));
+        assertTrue("missing d2", deviceIds.contains(DID2));
+        assertEquals("wrong region", r, service.getRegionForDevice(DID1));
+        assertEquals("incorrect event", REGION_MEMBERSHIP_CHANGED, listener.event.type());
+
+        service.addDevices(RID1, ImmutableSet.of(DID3));
+        deviceIds = service.getRegionDevices(RID1);
+        assertEquals("incorrect device count", 3, deviceIds.size());
+        assertTrue("missing d3", deviceIds.contains(DID3));
+        assertEquals("incorrect event", REGION_MEMBERSHIP_CHANGED, listener.event.type());
+
+        service.addDevices(RID1, ImmutableSet.of(DID3, DID1));
+        deviceIds = service.getRegionDevices(RID1);
+        assertEquals("incorrect device count", 3, deviceIds.size());
+
+        service.removeDevices(RID1, ImmutableSet.of(DID2, DID3));
+        deviceIds = service.getRegionDevices(RID1);
+        assertEquals("incorrect device count", 1, deviceIds.size());
+        assertTrue("missing d1", deviceIds.contains(DID1));
+
+        service.removeDevices(RID1, ImmutableSet.of(DID1, DID3));
+        assertTrue("no devices expected", service.getRegionDevices(RID1).isEmpty());
+
+        service.removeDevices(RID1, ImmutableSet.of(DID2));
+        assertTrue("no devices expected", service.getRegionDevices(RID1).isEmpty());
+    }
+
+    private class TestStore extends DistributedRegionStore {
+        @Override
+        protected void activate() {
+            super.activate();
+        }
+
+        @Override
+        protected void deactivate() {
+            super.deactivate();
+        }
+    }
+
+    private class TestManager extends RegionManager {
+        TestManager() {
+            eventDispatcher = new TestEventDispatcher();
+        }
+    }
+
+    private class TestListener implements RegionListener {
+        RegionEvent event;
+
+        @Override
+        public void event(RegionEvent event) {
+            this.event = event;
+        }
+    }
+}
\ No newline at end of file
diff --git a/core/store/dist/src/main/java/org/onosproject/store/region/impl/DistributedRegionStore.java b/core/store/dist/src/main/java/org/onosproject/store/region/impl/DistributedRegionStore.java
new file mode 100644
index 0000000..6243dac
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onosproject/store/region/impl/DistributedRegionStore.java
@@ -0,0 +1,246 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.store.region.impl;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Sets;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.util.Identifier;
+import org.onosproject.cluster.NodeId;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.region.DefaultRegion;
+import org.onosproject.net.region.Region;
+import org.onosproject.net.region.RegionEvent;
+import org.onosproject.net.region.RegionId;
+import org.onosproject.net.region.RegionStore;
+import org.onosproject.net.region.RegionStoreDelegate;
+import org.onosproject.store.AbstractStore;
+import org.onosproject.store.serializers.KryoNamespaces;
+import org.onosproject.store.service.ConsistentMap;
+import org.onosproject.store.service.MapEvent;
+import org.onosproject.store.service.MapEventListener;
+import org.onosproject.store.service.Serializer;
+import org.onosproject.store.service.StorageService;
+import org.slf4j.Logger;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onlab.util.Tools.nullIsNotFound;
+import static org.onosproject.net.region.RegionEvent.Type.REGION_MEMBERSHIP_CHANGED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Consistent store implementation for tracking region definitions and device
+ * region affiliation.
+ */
+@Component(immediate = true)
+@Service
+public class DistributedRegionStore
+        extends AbstractStore<RegionEvent, RegionStoreDelegate>
+        implements RegionStore {
+
+    private static final String NO_REGION = "Region does not exist";
+    private static final String DUPLICATE_REGION = "Region already exists";
+
+    private final Logger log = getLogger(getClass());
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected StorageService storageService;
+
+    private ConsistentMap<RegionId, Region> regionsRepo;
+    private Map<RegionId, Region> regionsById;
+
+    private ConsistentMap<RegionId, Set<DeviceId>> membershipRepo;
+    private Map<RegionId, Set<DeviceId>> regionDevices;
+
+    private Map<DeviceId, Region> regionsByDevice = new HashMap<>();
+
+    private final MapEventListener<RegionId, Region> listener =
+            new InternalRegionListener();
+    private final MapEventListener<RegionId, Set<DeviceId>> membershipListener =
+            new InternalMembershipListener();
+
+    @Activate
+    protected void activate() {
+        Serializer serializer =
+                Serializer.using(Arrays.asList(KryoNamespaces.API),
+                                 Identifier.class,
+                                 RegionId.class,
+                                 Region.class,
+                                 DefaultRegion.class,
+                                 Region.Type.class);
+
+        regionsRepo = storageService.<RegionId, Region>consistentMapBuilder()
+                .withSerializer(serializer)
+                .withName("onos-regions")
+                .withRelaxedReadConsistency()
+                .build();
+        regionsRepo.addListener(listener);
+        regionsById = regionsRepo.asJavaMap();
+
+        membershipRepo = storageService.<RegionId, Set<DeviceId>>consistentMapBuilder()
+                .withSerializer(serializer)
+                .withName("onos-region-devices")
+                .withRelaxedReadConsistency()
+                .build();
+        membershipRepo.addListener(membershipListener);
+        regionDevices = membershipRepo.asJavaMap();
+        log.info("Started");
+    }
+
+    @Deactivate
+    protected void deactivate() {
+        regionsRepo.removeListener(listener);
+        membershipRepo.removeListener(membershipListener);
+        regionsByDevice.clear();
+        log.info("Stopped");
+    }
+
+    @Override
+    public Set<Region> getRegions() {
+        return ImmutableSet.copyOf(regionsById.values());
+    }
+
+    @Override
+    public Region getRegion(RegionId regionId) {
+        return nullIsNotFound(regionsById.get(regionId), NO_REGION);
+    }
+
+    @Override
+    public Region getRegionForDevice(DeviceId deviceId) {
+        return regionsByDevice.get(deviceId);
+    }
+
+    @Override
+    public Set<DeviceId> getRegionDevices(RegionId regionId) {
+        Set<DeviceId> deviceIds = regionDevices.get(regionId);
+        return deviceIds != null ? ImmutableSet.copyOf(deviceIds) : ImmutableSet.of();
+    }
+
+    @Override
+    public Region createRegion(RegionId regionId, String name, Region.Type type,
+                               List<Set<NodeId>> masterNodeIds) {
+        return regionsRepo.compute(regionId, (id, region) -> {
+            checkArgument(region == null, DUPLICATE_REGION);
+            return new DefaultRegion(regionId, name, type, masterNodeIds);
+        }).value();
+    }
+
+    @Override
+    public Region updateRegion(RegionId regionId, String name, Region.Type type,
+                               List<Set<NodeId>> masterNodeIds) {
+        return regionsRepo.compute(regionId, (id, region) -> {
+            nullIsNotFound(region, NO_REGION);
+            return new DefaultRegion(regionId, name, type, masterNodeIds);
+        }).value();
+    }
+
+    @Override
+    public void removeRegion(RegionId regionId) {
+        membershipRepo.remove(regionId);
+        regionsRepo.remove(regionId);
+    }
+
+    @Override
+    public void addDevices(RegionId regionId, Collection<DeviceId> deviceIds) {
+        membershipRepo.compute(regionId, (id, existingDevices) -> {
+            if (existingDevices == null) {
+                return ImmutableSet.copyOf(deviceIds);
+            } else if (!existingDevices.containsAll(deviceIds)) {
+                return ImmutableSet.<DeviceId>builder()
+                        .addAll(existingDevices)
+                        .addAll(deviceIds)
+                        .build();
+            } else {
+                return existingDevices;
+            }
+        });
+
+        Region region = regionsById.get(regionId);
+        deviceIds.forEach(deviceId -> regionsByDevice.put(deviceId, region));
+    }
+
+    @Override
+    public void removeDevices(RegionId regionId, Collection<DeviceId> deviceIds) {
+        membershipRepo.compute(regionId, (id, existingDevices) -> {
+            if (existingDevices == null || existingDevices.isEmpty()) {
+                return ImmutableSet.of();
+            } else {
+                return ImmutableSet.<DeviceId>builder()
+                        .addAll(Sets.difference(existingDevices,
+                                                ImmutableSet.copyOf(deviceIds)))
+                        .build();
+            }
+        });
+
+        deviceIds.forEach(deviceId -> regionsByDevice.remove(deviceId));
+    }
+
+    /**
+     * Listener class to map listener events to the region inventory events.
+     */
+    private class InternalRegionListener implements MapEventListener<RegionId, Region> {
+        @Override
+        public void event(MapEvent<RegionId, Region> event) {
+            Region region = null;
+            RegionEvent.Type type = null;
+            switch (event.type()) {
+                case INSERT:
+                    type = RegionEvent.Type.REGION_ADDED;
+                    region = checkNotNull(event.newValue().value());
+                    break;
+                case UPDATE:
+                    type = RegionEvent.Type.REGION_UPDATED;
+                    region = checkNotNull(event.newValue().value());
+                    break;
+                case REMOVE:
+                    type = RegionEvent.Type.REGION_REMOVED;
+                    region = checkNotNull(event.oldValue().value());
+                    break;
+                default:
+                    log.error("Unsupported event type: " + event.type());
+            }
+            notifyDelegate(new RegionEvent(type, region));
+        }
+    }
+
+    /**
+     * Listener class to map listener events to the region membership events.
+     */
+    private class InternalMembershipListener implements MapEventListener<RegionId, Set<DeviceId>> {
+        @Override
+        public void event(MapEvent<RegionId, Set<DeviceId>> event) {
+            if (event.type() != MapEvent.Type.REMOVE) {
+                notifyDelegate(new RegionEvent(REGION_MEMBERSHIP_CHANGED,
+                                               regionsById.get(event.key()),
+                                               event.newValue().value()));
+            }
+        }
+    }
+}
diff --git a/core/store/dist/src/main/java/org/onosproject/store/region/impl/package-info.java b/core/store/dist/src/main/java/org/onosproject/store/region/impl/package-info.java
new file mode 100644
index 0000000..32d8c90
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onosproject/store/region/impl/package-info.java
@@ -0,0 +1,21 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.
+ */
+
+/**
+ * A distributed store implementation for tracking region definitions
+ *  consistently across the cluster.
+ */
+package org.onosproject.store.region.impl;
\ No newline at end of file
diff --git a/core/store/dist/src/test/java/org/onosproject/store/region/impl/DistributedRegionStoreTest.java b/core/store/dist/src/test/java/org/onosproject/store/region/impl/DistributedRegionStoreTest.java
new file mode 100644
index 0000000..df3f048
--- /dev/null
+++ b/core/store/dist/src/test/java/org/onosproject/store/region/impl/DistributedRegionStoreTest.java
@@ -0,0 +1,154 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.store.region.impl;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.util.ItemNotFoundException;
+import org.onosproject.cluster.NodeId;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.region.Region;
+import org.onosproject.net.region.RegionEvent;
+import org.onosproject.net.region.RegionId;
+import org.onosproject.store.service.TestStorageService;
+
+import java.util.List;
+import java.util.Set;
+
+import static org.junit.Assert.*;
+import static org.onosproject.net.region.Region.Type.*;
+import static org.onosproject.net.region.RegionEvent.Type.*;
+
+/**
+ * Test of the distributed region store implementation.
+ */
+public class DistributedRegionStoreTest {
+
+    private static final RegionId RID1 = RegionId.regionId("r1");
+    private static final RegionId RID2 = RegionId.regionId("r2");
+
+    private static final DeviceId DID1 = DeviceId.deviceId("foo:d1");
+    private static final DeviceId DID2 = DeviceId.deviceId("foo:d2");
+    private static final DeviceId DID3 = DeviceId.deviceId("foo:d3");
+
+    private static final NodeId NID1 = NodeId.nodeId("n1");
+
+    private static final List<Set<NodeId>> MASTERS = ImmutableList.of(ImmutableSet.of(NID1));
+
+    private TestStore store;
+    private RegionEvent event;
+
+    /**
+     * Sets up the device key store and the storage service test harness.
+     */
+    @Before
+    public void setUp() {
+        store = new TestStore();
+        store.storageService = new TestStorageService();
+        store.setDelegate(e -> this.event = e);
+        store.activate();
+    }
+
+    /**
+     * Tears down the device key store.
+     */
+    @After
+    public void tearDown() {
+        store.deactivate();
+    }
+
+    @Test
+    public void basics() {
+        Region r1 = store.createRegion(RID1, "R1", METRO, MASTERS);
+        assertEquals("incorrect id", RID1, r1.id());
+        assertEquals("incorrect event", REGION_ADDED, event.type());
+
+        Region r2 = store.createRegion(RID2, "R2", CAMPUS, MASTERS);
+        assertEquals("incorrect id", RID2, r2.id());
+        assertEquals("incorrect type", CAMPUS, r2.type());
+        assertEquals("incorrect event", REGION_ADDED, event.type());
+
+        r2 = store.updateRegion(RID2, "R2", COUNTRY, MASTERS);
+        assertEquals("incorrect type", COUNTRY, r2.type());
+        assertEquals("incorrect event", REGION_UPDATED, event.type());
+
+        Set<Region> regions = store.getRegions();
+        assertEquals("incorrect size", 2, regions.size());
+        assertTrue("missing r1", regions.contains(r1));
+        assertTrue("missing r2", regions.contains(r2));
+
+        r1 = store.getRegion(RID1);
+        assertEquals("incorrect id", RID1, r1.id());
+
+        store.removeRegion(RID1);
+        regions = store.getRegions();
+        assertEquals("incorrect size", 1, regions.size());
+        assertTrue("missing r2", regions.contains(r2));
+        assertEquals("incorrect event", REGION_REMOVED, event.type());
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void duplicateCreate() {
+        store.createRegion(RID1, "R1", METRO, MASTERS);
+        store.createRegion(RID1, "R2", CAMPUS, MASTERS);
+    }
+
+    @Test(expected = ItemNotFoundException.class)
+    public void missingUpdate() {
+        store.updateRegion(RID1, "R1", METRO, MASTERS);
+    }
+
+    @Test
+    public void membership() {
+        Region r = store.createRegion(RID1, "R1", METRO, MASTERS);
+        assertTrue("no devices expected", store.getRegionDevices(RID1).isEmpty());
+        assertNull("no region expected", store.getRegionForDevice(DID1));
+
+        store.addDevices(RID1, ImmutableSet.of(DID1, DID2));
+        Set<DeviceId> deviceIds = store.getRegionDevices(RID1);
+        assertEquals("incorrect device count", 2, deviceIds.size());
+        assertTrue("missing d1", deviceIds.contains(DID1));
+        assertTrue("missing d2", deviceIds.contains(DID2));
+        assertEquals("wrong region", r, store.getRegionForDevice(DID1));
+
+        store.addDevices(RID1, ImmutableSet.of(DID3));
+        deviceIds = store.getRegionDevices(RID1);
+        assertEquals("incorrect device count", 3, deviceIds.size());
+        assertTrue("missing d3", deviceIds.contains(DID3));
+
+        store.addDevices(RID1, ImmutableSet.of(DID3, DID1));
+        deviceIds = store.getRegionDevices(RID1);
+        assertEquals("incorrect device count", 3, deviceIds.size());
+
+        store.removeDevices(RID1, ImmutableSet.of(DID2, DID3));
+        deviceIds = store.getRegionDevices(RID1);
+        assertEquals("incorrect device count", 1, deviceIds.size());
+        assertTrue("missing d1", deviceIds.contains(DID1));
+
+        store.removeDevices(RID1, ImmutableSet.of(DID1, DID3));
+        assertTrue("no devices expected", store.getRegionDevices(RID1).isEmpty());
+
+        store.removeDevices(RID1, ImmutableSet.of(DID2));
+        assertTrue("no devices expected", store.getRegionDevices(RID1).isEmpty());
+    }
+
+    class TestStore extends DistributedRegionStore {
+    }
+}
\ No newline at end of file
diff --git a/tools/dev/header.txt b/tools/dev/header.txt
index 5b9dcb8..6c18c92 100644
--- a/tools/dev/header.txt
+++ b/tools/dev/header.txt
@@ -1,4 +1,4 @@
-Copyright 2014-$today.year Open Networking Laboratory
+Copyright $today.year Open Networking Laboratory
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
diff --git a/utils/misc/src/main/java/org/onlab/util/Identifier.java b/utils/misc/src/main/java/org/onlab/util/Identifier.java
new file mode 100644
index 0000000..7fcfcfe
--- /dev/null
+++ b/utils/misc/src/main/java/org/onlab/util/Identifier.java
@@ -0,0 +1,93 @@
+/*
+ * Copyright 2014-2016 Open Networking Laboratory
+ *
+ * Licensed 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.util;
+
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Abstract identifier backed by another value, e.g. string, int.
+ */
+public class Identifier<T> {
+
+    protected final T identifier; // backing identifier value
+
+    /**
+     * Constructor for serialization.
+     */
+    protected Identifier() {
+        this.identifier = null;
+    }
+
+    /**
+     * Constructs an identifier backed by the specified value.
+     *
+     * @param value the backing value
+     */
+    protected Identifier(T value) {
+        this.identifier = checkNotNull(value, "Identifier cannot be null.");
+    }
+
+    /**
+     * Returns the backing identifier value.
+     *
+     * @return identifier
+     */
+    public T id() {
+        return identifier;
+    }
+
+    /**
+     * Returns the hashcode of the identifier.
+     *
+     * @return hashcode
+     */
+    @Override
+    public int hashCode() {
+        return identifier.hashCode();
+    }
+
+    /**
+     * Compares two device key identifiers for equality.
+     *
+     * @param obj to compare against
+     * @return true if the objects are equal, false otherwise.
+     */
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof Identifier) {
+            Identifier that = (Identifier) obj;
+            return this.getClass() == that.getClass() &&
+                    Objects.equals(this.identifier, that.identifier);
+        }
+        return false;
+    }
+
+    /**
+     * Returns a string representation of a DeviceKeyId.
+     *
+     * @return string
+     */
+    public String toString() {
+        return identifier.toString();
+    }
+
+}
diff --git a/utils/misc/src/test/java/org/onlab/util/IdentifierTest.java b/utils/misc/src/test/java/org/onlab/util/IdentifierTest.java
new file mode 100644
index 0000000..dda556e
--- /dev/null
+++ b/utils/misc/src/test/java/org/onlab/util/IdentifierTest.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2014-2016 Open Networking Laboratory
+ *
+ * Licensed 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.util;
+
+import com.google.common.testing.EqualsTester;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Test of the base identifier.
+ */
+public class IdentifierTest {
+
+    @Test
+    public void basics() {
+        FooId id = new FooId(123);
+        assertEquals("incorrect value", 123, (int) id.id());
+    }
+
+    @Test
+    public void equality() {
+        FooId a = new FooId(1);
+        FooId b = new FooId(1);
+        FooId c = new FooId(2);
+        new EqualsTester().addEqualityGroup(a, b).addEqualityGroup(c).testEquals();
+    }
+
+    static class FooId extends Identifier<Integer> {
+        FooId(int id) {
+            super(id);
+        }
+    }
+
+}
\ No newline at end of file