Bundle restructuring

Change-Id: I5a9efa7f4d03bd78dd17297731c5addea5cf0442
diff --git a/core/store/hz/pom.xml b/core/store/hz/pom.xml
new file mode 100644
index 0000000..d17bb4f
--- /dev/null
+++ b/core/store/hz/pom.xml
@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onlab.onos</groupId>
+        <artifactId>onos-core-store</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-core-hz</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>ONOS Hazelcast based distributed store subsystems</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onlab.onos</groupId>
+            <artifactId>onos-core-serializers</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.felix</groupId>
+            <artifactId>org.apache.felix.scr.annotations</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>com.hazelcast</groupId>
+          <artifactId>hazelcast</artifactId>
+        </dependency>
+        <dependency>
+          <groupId>de.javakaffee</groupId>
+          <artifactId>kryo-serializers</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-scr-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/cluster/impl/DistributedClusterStore.java b/core/store/hz/src/main/java/org/onlab/onos/store/cluster/impl/DistributedClusterStore.java
new file mode 100644
index 0000000..004f807
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/cluster/impl/DistributedClusterStore.java
@@ -0,0 +1,158 @@
+package org.onlab.onos.store.cluster.impl;
+
+import com.google.common.base.Optional;
+import com.google.common.cache.LoadingCache;
+import com.google.common.collect.ImmutableSet;
+import com.hazelcast.core.IMap;
+import com.hazelcast.core.Member;
+import com.hazelcast.core.MemberAttributeEvent;
+import com.hazelcast.core.MembershipEvent;
+import com.hazelcast.core.MembershipListener;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.cluster.ClusterEvent;
+import org.onlab.onos.cluster.ClusterStore;
+import org.onlab.onos.cluster.ClusterStoreDelegate;
+import org.onlab.onos.cluster.ControllerNode;
+import org.onlab.onos.cluster.DefaultControllerNode;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.store.impl.AbsentInvalidatingLoadingCache;
+import org.onlab.onos.store.impl.AbstractDistributedStore;
+import org.onlab.onos.store.impl.OptionalCacheLoader;
+import org.onlab.packet.IpPrefix;
+
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static com.google.common.cache.CacheBuilder.newBuilder;
+import static org.onlab.onos.cluster.ClusterEvent.Type.INSTANCE_ACTIVATED;
+import static org.onlab.onos.cluster.ClusterEvent.Type.INSTANCE_DEACTIVATED;
+import static org.onlab.onos.cluster.ControllerNode.State;
+
+/**
+ * Distributed implementation of the cluster nodes store.
+ */
+@Component(immediate = true)
+@Service
+public class DistributedClusterStore
+        extends AbstractDistributedStore<ClusterEvent, ClusterStoreDelegate>
+        implements ClusterStore {
+
+    private IMap<byte[], byte[]> rawNodes;
+    private LoadingCache<NodeId, Optional<DefaultControllerNode>> nodes;
+
+    private String listenerId;
+    private final MembershipListener listener = new InternalMembershipListener();
+    private final Map<NodeId, State> states = new ConcurrentHashMap<>();
+
+    @Activate
+    public void activate() {
+        super.activate();
+        listenerId = theInstance.getCluster().addMembershipListener(listener);
+
+        rawNodes = theInstance.getMap("nodes");
+        OptionalCacheLoader<NodeId, DefaultControllerNode> nodeLoader
+                = new OptionalCacheLoader<>(storeService, rawNodes);
+        nodes = new AbsentInvalidatingLoadingCache<>(newBuilder().build(nodeLoader));
+        rawNodes.addEntryListener(new RemoteEventHandler<>(nodes), true);
+
+        loadClusterNodes();
+
+        log.info("Started");
+    }
+
+    // Loads the initial set of cluster nodes
+    private void loadClusterNodes() {
+        for (Member member : theInstance.getCluster().getMembers()) {
+            addMember(member);
+        }
+    }
+
+    @Deactivate
+    public void deactivate() {
+        theInstance.getCluster().removeMembershipListener(listenerId);
+        log.info("Stopped");
+    }
+
+    @Override
+    public ControllerNode getLocalNode() {
+        return node(theInstance.getCluster().getLocalMember());
+    }
+
+    @Override
+    public Set<ControllerNode> getNodes() {
+        ImmutableSet.Builder<ControllerNode> builder = ImmutableSet.builder();
+        for (Optional<DefaultControllerNode> optional : nodes.asMap().values()) {
+            builder.add(optional.get());
+        }
+        return builder.build();
+    }
+
+    @Override
+    public ControllerNode getNode(NodeId nodeId) {
+        return nodes.getUnchecked(nodeId).orNull();
+    }
+
+    @Override
+    public State getState(NodeId nodeId) {
+        State state = states.get(nodeId);
+        return state == null ? State.INACTIVE : state;
+    }
+
+    @Override
+    public void removeNode(NodeId nodeId) {
+        synchronized (this) {
+            rawNodes.remove(serialize(nodeId));
+            nodes.invalidate(nodeId);
+        }
+    }
+
+    // Adds a new node based on the specified member
+    private synchronized ControllerNode addMember(Member member) {
+        DefaultControllerNode node = node(member);
+        rawNodes.put(serialize(node.id()), serialize(node));
+        nodes.put(node.id(), Optional.of(node));
+        states.put(node.id(), State.ACTIVE);
+        return node;
+    }
+
+    // Creates a controller node descriptor from the Hazelcast member.
+    private DefaultControllerNode node(Member member) {
+        IpPrefix ip = memberAddress(member);
+        return new DefaultControllerNode(new NodeId(ip.toString()), ip);
+    }
+
+    private IpPrefix memberAddress(Member member) {
+        byte[] address = member.getSocketAddress().getAddress().getAddress();
+        return IpPrefix.valueOf(address);
+    }
+
+    // Interceptor for membership events.
+    private class InternalMembershipListener implements MembershipListener {
+        @Override
+        public void memberAdded(MembershipEvent membershipEvent) {
+            log.info("Member {} added", membershipEvent.getMember());
+            ControllerNode node = addMember(membershipEvent.getMember());
+            notifyDelegate(new ClusterEvent(INSTANCE_ACTIVATED, node));
+        }
+
+        @Override
+        public void memberRemoved(MembershipEvent membershipEvent) {
+            log.info("Member {} removed", membershipEvent.getMember());
+            NodeId nodeId = new NodeId(memberAddress(membershipEvent.getMember()).toString());
+            states.put(nodeId, State.INACTIVE);
+            notifyDelegate(new ClusterEvent(INSTANCE_DEACTIVATED, getNode(nodeId)));
+        }
+
+        @Override
+        public void memberAttributeChanged(MemberAttributeEvent memberAttributeEvent) {
+            log.info("Member {} attribute {} changed to {}",
+                     memberAttributeEvent.getMember(),
+                     memberAttributeEvent.getKey(),
+                     memberAttributeEvent.getValue());
+        }
+    }
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/cluster/impl/DistributedMastershipStore.java b/core/store/hz/src/main/java/org/onlab/onos/store/cluster/impl/DistributedMastershipStore.java
new file mode 100644
index 0000000..989cc83
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/cluster/impl/DistributedMastershipStore.java
@@ -0,0 +1,147 @@
+package org.onlab.onos.store.cluster.impl;
+
+import static com.google.common.cache.CacheBuilder.newBuilder;
+import static org.onlab.onos.cluster.MastershipEvent.Type.MASTER_CHANGED;
+
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.cluster.ClusterService;
+import org.onlab.onos.cluster.MastershipEvent;
+import org.onlab.onos.cluster.MastershipStore;
+import org.onlab.onos.cluster.MastershipStoreDelegate;
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.MastershipRole;
+import org.onlab.onos.store.impl.AbsentInvalidatingLoadingCache;
+import org.onlab.onos.store.impl.AbstractDistributedStore;
+import org.onlab.onos.store.impl.OptionalCacheLoader;
+
+import com.google.common.base.Optional;
+import com.google.common.cache.LoadingCache;
+import com.google.common.collect.ImmutableSet;
+import com.hazelcast.core.IMap;
+
+/**
+ * Distributed implementation of the cluster nodes store.
+ */
+@Component(immediate = true)
+@Service
+public class DistributedMastershipStore
+extends AbstractDistributedStore<MastershipEvent, MastershipStoreDelegate>
+implements MastershipStore {
+
+    private IMap<byte[], byte[]> rawMasters;
+    private LoadingCache<DeviceId, Optional<NodeId>> masters;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClusterService clusterService;
+
+    @Override
+    @Activate
+    public void activate() {
+        super.activate();
+
+        rawMasters = theInstance.getMap("masters");
+        OptionalCacheLoader<DeviceId, NodeId> nodeLoader
+        = new OptionalCacheLoader<>(storeService, rawMasters);
+        masters = new AbsentInvalidatingLoadingCache<>(newBuilder().build(nodeLoader));
+        rawMasters.addEntryListener(new RemoteMasterShipEventHandler(masters), true);
+
+        loadMasters();
+
+        log.info("Started");
+    }
+
+    private void loadMasters() {
+        for (byte[] keyBytes : rawMasters.keySet()) {
+            final DeviceId id = deserialize(keyBytes);
+            masters.refresh(id);
+        }
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public MastershipEvent setMaster(NodeId nodeId, DeviceId deviceId) {
+        synchronized (this) {
+            NodeId currentMaster = getMaster(deviceId);
+            if (Objects.equals(currentMaster, nodeId)) {
+                return null;
+            }
+
+            // FIXME: for now implementing semantics of setMaster
+            rawMasters.put(serialize(deviceId), serialize(nodeId));
+            masters.put(deviceId, Optional.of(nodeId));
+            return new MastershipEvent(MastershipEvent.Type.MASTER_CHANGED, deviceId, nodeId);
+        }
+    }
+
+    @Override
+    public NodeId getMaster(DeviceId deviceId) {
+        return masters.getUnchecked(deviceId).orNull();
+    }
+
+    @Override
+    public Set<DeviceId> getDevices(NodeId nodeId) {
+        ImmutableSet.Builder<DeviceId> builder = ImmutableSet.builder();
+        for (Map.Entry<DeviceId, Optional<NodeId>> entry : masters.asMap().entrySet()) {
+            if (nodeId.equals(entry.getValue().get())) {
+                builder.add(entry.getKey());
+            }
+        }
+        return builder.build();
+    }
+
+    @Override
+    public MastershipRole requestRole(DeviceId deviceId) {
+        // FIXME: for now we are 'selecting' as master whoever asks
+        setMaster(clusterService.getLocalNode().id(), deviceId);
+        return MastershipRole.MASTER;
+    }
+
+    @Override
+    public MastershipRole getRole(NodeId nodeId, DeviceId deviceId) {
+        NodeId master = masters.getUnchecked(deviceId).orNull();
+        return nodeId.equals(master) ? MastershipRole.MASTER : MastershipRole.STANDBY;
+    }
+
+    @Override
+    public MastershipTerm getTermFor(DeviceId deviceId) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    private class RemoteMasterShipEventHandler extends RemoteEventHandler<DeviceId, NodeId> {
+        public RemoteMasterShipEventHandler(LoadingCache<DeviceId, Optional<NodeId>> cache) {
+            super(cache);
+        }
+
+        @Override
+        protected void onAdd(DeviceId deviceId, NodeId nodeId) {
+            notifyDelegate(new MastershipEvent(MASTER_CHANGED, deviceId, nodeId));
+        }
+
+        @Override
+        protected void onRemove(DeviceId deviceId, NodeId nodeId) {
+            notifyDelegate(new MastershipEvent(MASTER_CHANGED, deviceId, nodeId));
+        }
+
+        @Override
+        protected void onUpdate(DeviceId deviceId, NodeId oldNodeId, NodeId nodeId) {
+            notifyDelegate(new MastershipEvent(MASTER_CHANGED, deviceId, nodeId));
+        }
+    }
+
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/cluster/impl/package-info.java b/core/store/hz/src/main/java/org/onlab/onos/store/cluster/impl/package-info.java
new file mode 100644
index 0000000..9f36b88
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/cluster/impl/package-info.java
@@ -0,0 +1,4 @@
+/**
+ * Implementation of a distributed cluster node store using Hazelcast.
+ */
+package org.onlab.onos.store.cluster.impl;
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/common/StoreService.java b/core/store/hz/src/main/java/org/onlab/onos/store/common/StoreService.java
new file mode 100644
index 0000000..490183f
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/common/StoreService.java
@@ -0,0 +1,36 @@
+package org.onlab.onos.store.common;
+
+import com.hazelcast.core.HazelcastInstance;
+
+/**
+ * Bootstrap service to get a handle on a share Hazelcast instance.
+ */
+public interface StoreService {
+
+    /**
+     * Returns the shared Hazelcast instance for use as a distributed store
+     * backing.
+     *
+     * @return shared Hazelcast instance
+     */
+    HazelcastInstance getHazelcastInstance();
+
+    /**
+     * Serializes the specified object into bytes using one of the
+     * pre-registered serializers.
+     *
+     * @param obj object to be serialized
+     * @return serialized bytes
+     */
+    public byte[] serialize(final Object obj);
+
+    /**
+     * Deserializes the specified bytes into an object using one of the
+     * pre-registered serializers.
+     *
+     * @param bytes bytes to be deserialized
+     * @return deserialized object
+     */
+    public <T> T deserialize(final byte[] bytes);
+
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/common/package-info.java b/core/store/hz/src/main/java/org/onlab/onos/store/common/package-info.java
new file mode 100644
index 0000000..cf19812
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/common/package-info.java
@@ -0,0 +1,5 @@
+/**
+ * Common abstractions and facilities for implementing distributed store
+ * using Hazelcast.
+ */
+package org.onlab.onos.store.common;
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/device/impl/DistributedDeviceStore.java b/core/store/hz/src/main/java/org/onlab/onos/store/device/impl/DistributedDeviceStore.java
new file mode 100644
index 0000000..3186578
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/device/impl/DistributedDeviceStore.java
@@ -0,0 +1,400 @@
+package org.onlab.onos.store.device.impl;
+
+import static com.google.common.base.Predicates.notNull;
+import com.google.common.base.Optional;
+import com.google.common.cache.LoadingCache;
+import com.google.common.collect.FluentIterable;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSet.Builder;
+import com.hazelcast.core.IMap;
+import com.hazelcast.core.ISet;
+
+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.net.DefaultDevice;
+import org.onlab.onos.net.DefaultPort;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.device.DeviceDescription;
+import org.onlab.onos.net.device.DeviceEvent;
+import org.onlab.onos.net.device.DeviceStore;
+import org.onlab.onos.net.device.DeviceStoreDelegate;
+import org.onlab.onos.net.device.PortDescription;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.impl.AbsentInvalidatingLoadingCache;
+import org.onlab.onos.store.impl.AbstractDistributedStore;
+import org.onlab.onos.store.impl.OptionalCacheLoader;
+import org.slf4j.Logger;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.cache.CacheBuilder.newBuilder;
+import static org.onlab.onos.net.device.DeviceEvent.Type.*;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Manages inventory of infrastructure devices using Hazelcast-backed map.
+ */
+@Component(immediate = true)
+@Service
+public class DistributedDeviceStore
+        extends AbstractDistributedStore<DeviceEvent, DeviceStoreDelegate>
+        implements DeviceStore {
+
+    private final Logger log = getLogger(getClass());
+
+    public static final String DEVICE_NOT_FOUND = "Device with ID %s not found";
+
+    // private IMap<DeviceId, DefaultDevice> cache;
+    private IMap<byte[], byte[]> rawDevices;
+    private LoadingCache<DeviceId, Optional<DefaultDevice>> devices;
+
+    // private ISet<DeviceId> availableDevices;
+    private ISet<byte[]> availableDevices;
+
+    // TODO DevicePorts is very inefficient consider restructuring.
+    // private IMap<DeviceId, Map<PortNumber, Port>> devicePorts;
+    private IMap<byte[], byte[]> rawDevicePorts;
+    private LoadingCache<DeviceId, Optional<Map<PortNumber, Port>>> devicePorts;
+
+    @Override
+    @Activate
+    public void activate() {
+        super.activate();
+
+        // IMap event handler needs value
+        final boolean includeValue = true;
+
+        // TODO decide on Map name scheme to avoid collision
+        rawDevices = theInstance.getMap("devices");
+        final OptionalCacheLoader<DeviceId, DefaultDevice> deviceLoader
+                = new OptionalCacheLoader<>(storeService, rawDevices);
+        devices = new AbsentInvalidatingLoadingCache<>(newBuilder().build(deviceLoader));
+        // refresh/populate cache based on notification from other instance
+        rawDevices.addEntryListener(new RemoteDeviceEventHandler(devices), includeValue);
+
+        // TODO cache availableDevices
+        availableDevices = theInstance.getSet("availableDevices");
+
+        rawDevicePorts = theInstance.getMap("devicePorts");
+        final OptionalCacheLoader<DeviceId, Map<PortNumber, Port>> devicePortLoader
+                = new OptionalCacheLoader<>(storeService, rawDevicePorts);
+        devicePorts = new AbsentInvalidatingLoadingCache<>(newBuilder().build(devicePortLoader));
+        // refresh/populate cache based on notification from other instance
+        rawDevicePorts.addEntryListener(new RemotePortEventHandler(devicePorts), includeValue);
+
+        loadDeviceCache();
+        loadDevicePortsCache();
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public int getDeviceCount() {
+        return devices.asMap().size();
+    }
+
+    @Override
+    public Iterable<Device> getDevices() {
+        // TODO builder v.s. copyOf. Guava semms to be using copyOf?
+        Builder<Device> builder = ImmutableSet.builder();
+        for (Optional<DefaultDevice> e : devices.asMap().values()) {
+            if (e.isPresent()) {
+                builder.add(e.get());
+            }
+        }
+        return builder.build();
+    }
+
+    private void loadDeviceCache() {
+        for (byte[] keyBytes : rawDevices.keySet()) {
+            final DeviceId id = deserialize(keyBytes);
+            devices.refresh(id);
+        }
+    }
+
+    private void loadDevicePortsCache() {
+        for (byte[] keyBytes : rawDevicePorts.keySet()) {
+            final DeviceId id = deserialize(keyBytes);
+            devicePorts.refresh(id);
+        }
+    }
+
+    @Override
+    public Device getDevice(DeviceId deviceId) {
+        // TODO revisit if ignoring exception is safe.
+        return devices.getUnchecked(deviceId).orNull();
+    }
+
+    @Override
+    public DeviceEvent createOrUpdateDevice(ProviderId providerId, DeviceId deviceId,
+                                            DeviceDescription deviceDescription) {
+        DefaultDevice device = devices.getUnchecked(deviceId).orNull();
+        if (device == null) {
+            return createDevice(providerId, deviceId, deviceDescription);
+        }
+        return updateDevice(providerId, device, deviceDescription);
+    }
+
+    // Creates the device and returns the appropriate event if necessary.
+    private DeviceEvent createDevice(ProviderId providerId, DeviceId deviceId,
+                                     DeviceDescription desc) {
+        DefaultDevice device = new DefaultDevice(providerId, deviceId, desc.type(),
+                                                 desc.manufacturer(),
+                                                 desc.hwVersion(), desc.swVersion(),
+                                                 desc.serialNumber());
+
+        synchronized (this) {
+            final byte[] deviceIdBytes = serialize(deviceId);
+            rawDevices.put(deviceIdBytes, serialize(device));
+            devices.put(deviceId, Optional.of(device));
+
+            availableDevices.add(deviceIdBytes);
+        }
+        return new DeviceEvent(DEVICE_ADDED, device, null);
+    }
+
+    // Updates the device and returns the appropriate event if necessary.
+    private DeviceEvent updateDevice(ProviderId providerId, DefaultDevice device,
+                                     DeviceDescription desc) {
+        // We allow only certain attributes to trigger update
+        if (!Objects.equals(device.hwVersion(), desc.hwVersion()) ||
+                !Objects.equals(device.swVersion(), desc.swVersion())) {
+
+            DefaultDevice updated = new DefaultDevice(providerId, device.id(),
+                                                      desc.type(),
+                                                      desc.manufacturer(),
+                                                      desc.hwVersion(),
+                                                      desc.swVersion(),
+                                                      desc.serialNumber());
+            synchronized (this) {
+                final byte[] deviceIdBytes = serialize(device.id());
+                rawDevices.put(deviceIdBytes, serialize(updated));
+                devices.put(device.id(), Optional.of(updated));
+                availableDevices.add(serialize(device.id()));
+            }
+            return new DeviceEvent(DeviceEvent.Type.DEVICE_UPDATED, updated, null);
+        }
+
+        // Otherwise merely attempt to change availability
+        synchronized (this) {
+            boolean added = availableDevices.add(serialize(device.id()));
+            return !added ? null :
+                    new DeviceEvent(DEVICE_AVAILABILITY_CHANGED, device, null);
+        }
+    }
+
+    @Override
+    public DeviceEvent markOffline(DeviceId deviceId) {
+        synchronized (this) {
+            Device device = devices.getUnchecked(deviceId).orNull();
+            boolean removed = device != null && availableDevices.remove(serialize(deviceId));
+            return !removed ? null :
+                    new DeviceEvent(DEVICE_AVAILABILITY_CHANGED, device, null);
+        }
+    }
+
+    @Override
+    public List<DeviceEvent> updatePorts(DeviceId deviceId,
+                                         List<PortDescription> portDescriptions) {
+        List<DeviceEvent> events = new ArrayList<>();
+        synchronized (this) {
+            Device device = devices.getUnchecked(deviceId).orNull();
+            checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+            Map<PortNumber, Port> ports = getPortMap(deviceId);
+
+            // Add new ports
+            Set<PortNumber> processed = new HashSet<>();
+            for (PortDescription portDescription : portDescriptions) {
+                Port port = ports.get(portDescription.portNumber());
+                events.add(port == null ?
+                                   createPort(device, portDescription, ports) :
+                                   updatePort(device, port, portDescription, ports));
+                processed.add(portDescription.portNumber());
+            }
+
+            updatePortMap(deviceId, ports);
+
+            events.addAll(pruneOldPorts(device, ports, processed));
+        }
+        return FluentIterable.from(events).filter(notNull()).toList();
+    }
+
+    // Creates a new port based on the port description adds it to the map and
+    // Returns corresponding event.
+    //@GuardedBy("this")
+    private DeviceEvent createPort(Device device, PortDescription portDescription,
+                                   Map<PortNumber, Port> ports) {
+        DefaultPort port = new DefaultPort(device, portDescription.portNumber(),
+                                           portDescription.isEnabled());
+        ports.put(port.number(), port);
+        updatePortMap(device.id(), ports);
+        return new DeviceEvent(PORT_ADDED, device, port);
+    }
+
+    // Checks if the specified port requires update and if so, it replaces the
+    // existing entry in the map and returns corresponding event.
+    //@GuardedBy("this")
+    private DeviceEvent updatePort(Device device, Port port,
+                                   PortDescription portDescription,
+                                   Map<PortNumber, Port> ports) {
+        if (port.isEnabled() != portDescription.isEnabled()) {
+            DefaultPort updatedPort =
+                    new DefaultPort(device, portDescription.portNumber(),
+                                    portDescription.isEnabled());
+            ports.put(port.number(), updatedPort);
+            updatePortMap(device.id(), ports);
+            return new DeviceEvent(PORT_UPDATED, device, updatedPort);
+        }
+        return null;
+    }
+
+    // Prunes the specified list of ports based on which ports are in the
+    // processed list and returns list of corresponding events.
+    //@GuardedBy("this")
+    private List<DeviceEvent> pruneOldPorts(Device device,
+                                            Map<PortNumber, Port> ports,
+                                            Set<PortNumber> processed) {
+        List<DeviceEvent> events = new ArrayList<>();
+        Iterator<PortNumber> iterator = ports.keySet().iterator();
+        while (iterator.hasNext()) {
+            PortNumber portNumber = iterator.next();
+            if (!processed.contains(portNumber)) {
+                events.add(new DeviceEvent(PORT_REMOVED, device,
+                                           ports.get(portNumber)));
+                iterator.remove();
+            }
+        }
+        if (!events.isEmpty()) {
+            updatePortMap(device.id(), ports);
+        }
+        return events;
+    }
+
+    // Gets the map of ports for the specified device; if one does not already
+    // exist, it creates and registers a new one.
+    // WARN: returned value is a copy, changes made to the Map
+    //       needs to be written back using updatePortMap
+    //@GuardedBy("this")
+    private Map<PortNumber, Port> getPortMap(DeviceId deviceId) {
+        Map<PortNumber, Port> ports = devicePorts.getUnchecked(deviceId).orNull();
+        if (ports == null) {
+            ports = new HashMap<>();
+            // this probably is waste of time in most cases.
+            updatePortMap(deviceId, ports);
+        }
+        return ports;
+    }
+
+    //@GuardedBy("this")
+    private void updatePortMap(DeviceId deviceId, Map<PortNumber, Port> ports) {
+        rawDevicePorts.put(serialize(deviceId), serialize(ports));
+        devicePorts.put(deviceId, Optional.of(ports));
+    }
+
+    @Override
+    public DeviceEvent updatePortStatus(DeviceId deviceId,
+                                        PortDescription portDescription) {
+        synchronized (this) {
+            Device device = devices.getUnchecked(deviceId).orNull();
+            checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+            Map<PortNumber, Port> ports = getPortMap(deviceId);
+            Port port = ports.get(portDescription.portNumber());
+            return updatePort(device, port, portDescription, ports);
+        }
+    }
+
+    @Override
+    public List<Port> getPorts(DeviceId deviceId) {
+        Map<PortNumber, Port> ports = devicePorts.getUnchecked(deviceId).orNull();
+        return ports == null ? Collections.<Port>emptyList() : ImmutableList.copyOf(ports.values());
+    }
+
+    @Override
+    public Port getPort(DeviceId deviceId, PortNumber portNumber) {
+        Map<PortNumber, Port> ports = devicePorts.getUnchecked(deviceId).orNull();
+        return ports == null ? null : ports.get(portNumber);
+    }
+
+    @Override
+    public boolean isAvailable(DeviceId deviceId) {
+        return availableDevices.contains(serialize(deviceId));
+    }
+
+    @Override
+    public DeviceEvent removeDevice(DeviceId deviceId) {
+        synchronized (this) {
+            byte[] deviceIdBytes = serialize(deviceId);
+
+            // TODO conditional remove?
+            Device device = deserialize(rawDevices.remove(deviceIdBytes));
+            devices.invalidate(deviceId);
+            return device == null ? null :
+                    new DeviceEvent(DEVICE_REMOVED, device, null);
+        }
+    }
+
+    private class RemoteDeviceEventHandler extends RemoteEventHandler<DeviceId, DefaultDevice> {
+        public RemoteDeviceEventHandler(LoadingCache<DeviceId, Optional<DefaultDevice>> cache) {
+            super(cache);
+        }
+
+        @Override
+        protected void onAdd(DeviceId deviceId, DefaultDevice device) {
+            notifyDelegate(new DeviceEvent(DEVICE_ADDED, device));
+        }
+
+        @Override
+        protected void onRemove(DeviceId deviceId, DefaultDevice device) {
+            notifyDelegate(new DeviceEvent(DEVICE_REMOVED, device));
+        }
+
+        @Override
+        protected void onUpdate(DeviceId deviceId, DefaultDevice oldDevice, DefaultDevice device) {
+            notifyDelegate(new DeviceEvent(DEVICE_UPDATED, device));
+        }
+    }
+
+    private class RemotePortEventHandler extends RemoteEventHandler<DeviceId, Map<PortNumber, Port>> {
+        public RemotePortEventHandler(LoadingCache<DeviceId, Optional<Map<PortNumber, Port>>> cache) {
+            super(cache);
+        }
+
+        @Override
+        protected void onAdd(DeviceId deviceId, Map<PortNumber, Port> ports) {
+//            notifyDelegate(new DeviceEvent(PORT_ADDED, getDevice(deviceId)));
+        }
+
+        @Override
+        protected void onRemove(DeviceId deviceId, Map<PortNumber, Port> ports) {
+//            notifyDelegate(new DeviceEvent(PORT_REMOVED, getDevice(deviceId)));
+        }
+
+        @Override
+        protected void onUpdate(DeviceId deviceId, Map<PortNumber, Port> oldPorts, Map<PortNumber, Port> ports) {
+//            notifyDelegate(new DeviceEvent(PORT_UPDATED, getDevice(deviceId)));
+        }
+    }
+
+
+    // TODO cache serialized DeviceID if we suffer from serialization cost
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/device/impl/package-info.java b/core/store/hz/src/main/java/org/onlab/onos/store/device/impl/package-info.java
new file mode 100644
index 0000000..2fd9f27
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/device/impl/package-info.java
@@ -0,0 +1,4 @@
+/**
+ * Implementation of device store using Hazelcast distributed structures.
+ */
+package org.onlab.onos.store.device.impl;
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/flow/impl/DistributedFlowRuleStore.java b/core/store/hz/src/main/java/org/onlab/onos/store/flow/impl/DistributedFlowRuleStore.java
new file mode 100644
index 0000000..5a5592a
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/flow/impl/DistributedFlowRuleStore.java
@@ -0,0 +1,153 @@
+package org.onlab.onos.store.flow.impl;
+
+import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_ADDED;
+import static org.onlab.onos.net.flow.FlowRuleEvent.Type.RULE_REMOVED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Collection;
+import java.util.Collections;
+
+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.ApplicationId;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.flow.DefaultFlowRule;
+import org.onlab.onos.net.flow.FlowRule;
+import org.onlab.onos.net.flow.FlowRule.FlowRuleState;
+import org.onlab.onos.net.flow.FlowRuleEvent;
+import org.onlab.onos.net.flow.FlowRuleEvent.Type;
+import org.onlab.onos.net.flow.FlowRuleStore;
+import org.onlab.onos.net.flow.FlowRuleStoreDelegate;
+import org.onlab.onos.store.AbstractStore;
+import org.slf4j.Logger;
+
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Multimap;
+
+/**
+ * Manages inventory of flow rules using trivial in-memory implementation.
+ */
+//FIXME: I LIE I AM NOT DISTRIBUTED
+@Component(immediate = true)
+@Service
+public class DistributedFlowRuleStore
+extends AbstractStore<FlowRuleEvent, FlowRuleStoreDelegate>
+implements FlowRuleStore {
+
+    private final Logger log = getLogger(getClass());
+
+    // store entries as a pile of rules, no info about device tables
+    private final Multimap<DeviceId, FlowRule> flowEntries =
+            ArrayListMultimap.<DeviceId, FlowRule>create();
+
+    private final Multimap<ApplicationId, FlowRule> flowEntriesById =
+            ArrayListMultimap.<ApplicationId, FlowRule>create();
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+
+    @Override
+    public synchronized FlowRule getFlowRule(FlowRule rule) {
+        for (FlowRule f : flowEntries.get(rule.deviceId())) {
+            if (f.equals(rule)) {
+                return f;
+            }
+        }
+        return null;
+    }
+
+    @Override
+    public synchronized Iterable<FlowRule> getFlowEntries(DeviceId deviceId) {
+        Collection<FlowRule> rules = flowEntries.get(deviceId);
+        if (rules == null) {
+            return Collections.emptyList();
+        }
+        return ImmutableSet.copyOf(rules);
+    }
+
+    @Override
+    public synchronized Iterable<FlowRule> getFlowEntriesByAppId(ApplicationId appId) {
+        Collection<FlowRule> rules = flowEntriesById.get(appId);
+        if (rules == null) {
+            return Collections.emptyList();
+        }
+        return ImmutableSet.copyOf(rules);
+    }
+
+    @Override
+    public synchronized void storeFlowRule(FlowRule rule) {
+        FlowRule f = new DefaultFlowRule(rule, FlowRuleState.PENDING_ADD);
+        DeviceId did = f.deviceId();
+        if (!flowEntries.containsEntry(did, f)) {
+            flowEntries.put(did, f);
+            flowEntriesById.put(rule.appId(), f);
+        }
+    }
+
+    @Override
+    public synchronized void deleteFlowRule(FlowRule rule) {
+        FlowRule f = new DefaultFlowRule(rule, FlowRuleState.PENDING_REMOVE);
+        DeviceId did = f.deviceId();
+
+        /*
+         *  find the rule and mark it for deletion.
+         *  Ultimately a flow removed will come remove it.
+         */
+
+        if (flowEntries.containsEntry(did, f)) {
+            //synchronized (flowEntries) {
+            flowEntries.remove(did, f);
+            flowEntries.put(did, f);
+            flowEntriesById.remove(rule.appId(), rule);
+            //}
+        }
+    }
+
+    @Override
+    public synchronized FlowRuleEvent addOrUpdateFlowRule(FlowRule rule) {
+        DeviceId did = rule.deviceId();
+
+        // check if this new rule is an update to an existing entry
+        if (flowEntries.containsEntry(did, rule)) {
+            //synchronized (flowEntries) {
+            // Multimaps support duplicates so we have to remove our rule
+            // and replace it with the current version.
+            flowEntries.remove(did, rule);
+            flowEntries.put(did, rule);
+            //}
+            return new FlowRuleEvent(Type.RULE_UPDATED, rule);
+        }
+
+        flowEntries.put(did, rule);
+        return new FlowRuleEvent(RULE_ADDED, rule);
+    }
+
+    @Override
+    public synchronized FlowRuleEvent removeFlowRule(FlowRule rule) {
+        //synchronized (this) {
+        if (flowEntries.remove(rule.deviceId(), rule)) {
+            return new FlowRuleEvent(RULE_REMOVED, rule);
+        } else {
+            return null;
+        }
+        //}
+    }
+
+
+
+
+
+
+
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/host/impl/DistributedHostStore.java b/core/store/hz/src/main/java/org/onlab/onos/store/host/impl/DistributedHostStore.java
new file mode 100644
index 0000000..09820f4
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/host/impl/DistributedHostStore.java
@@ -0,0 +1,278 @@
+package org.onlab.onos.store.host.impl;
+
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_ADDED;
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_MOVED;
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_REMOVED;
+import static org.onlab.onos.net.host.HostEvent.Type.HOST_UPDATED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+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.net.ConnectPoint;
+import org.onlab.onos.net.DefaultHost;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Host;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.host.HostDescription;
+import org.onlab.onos.net.host.HostEvent;
+import org.onlab.onos.net.host.HostStore;
+import org.onlab.onos.net.host.HostStoreDelegate;
+import org.onlab.onos.net.host.PortAddresses;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.AbstractStore;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.VlanId;
+import org.slf4j.Logger;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Sets;
+
+/**
+ * Manages inventory of end-station hosts using trivial in-memory
+ * implementation.
+ */
+//FIXME: I LIE I AM NOT DISTRIBUTED
+@Component(immediate = true)
+@Service
+public class DistributedHostStore
+extends AbstractStore<HostEvent, HostStoreDelegate>
+implements HostStore {
+
+    private final Logger log = getLogger(getClass());
+
+    // Host inventory
+    private final Map<HostId, Host> hosts = new ConcurrentHashMap<>();
+
+    // Hosts tracked by their location
+    private final Multimap<ConnectPoint, Host> locations = HashMultimap.create();
+
+    private final Map<ConnectPoint, PortAddresses> portAddresses =
+            new ConcurrentHashMap<>();
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public HostEvent createOrUpdateHost(ProviderId providerId, HostId hostId,
+            HostDescription hostDescription) {
+        Host host = hosts.get(hostId);
+        if (host == null) {
+            return createHost(providerId, hostId, hostDescription);
+        }
+        return updateHost(providerId, host, hostDescription);
+    }
+
+    // creates a new host and sends HOST_ADDED
+    private HostEvent createHost(ProviderId providerId, HostId hostId,
+            HostDescription descr) {
+        DefaultHost newhost = new DefaultHost(providerId, hostId,
+                descr.hwAddress(),
+                descr.vlan(),
+                descr.location(),
+                descr.ipAddresses());
+        synchronized (this) {
+            hosts.put(hostId, newhost);
+            locations.put(descr.location(), newhost);
+        }
+        return new HostEvent(HOST_ADDED, newhost);
+    }
+
+    // checks for type of update to host, sends appropriate event
+    private HostEvent updateHost(ProviderId providerId, Host host,
+            HostDescription descr) {
+        DefaultHost updated;
+        HostEvent event;
+        if (!host.location().equals(descr.location())) {
+            updated = new DefaultHost(providerId, host.id(),
+                    host.mac(),
+                    host.vlan(),
+                    descr.location(),
+                    host.ipAddresses());
+            event = new HostEvent(HOST_MOVED, updated);
+
+        } else if (!(host.ipAddresses().equals(descr.ipAddresses()))) {
+            updated = new DefaultHost(providerId, host.id(),
+                    host.mac(),
+                    host.vlan(),
+                    descr.location(),
+                    descr.ipAddresses());
+            event = new HostEvent(HOST_UPDATED, updated);
+        } else {
+            return null;
+        }
+        synchronized (this) {
+            hosts.put(host.id(), updated);
+            locations.remove(host.location(), host);
+            locations.put(updated.location(), updated);
+        }
+        return event;
+    }
+
+    @Override
+    public HostEvent removeHost(HostId hostId) {
+        synchronized (this) {
+            Host host = hosts.remove(hostId);
+            if (host != null) {
+                locations.remove((host.location()), host);
+                return new HostEvent(HOST_REMOVED, host);
+            }
+            return null;
+        }
+    }
+
+    @Override
+    public int getHostCount() {
+        return hosts.size();
+    }
+
+    @Override
+    public Iterable<Host> getHosts() {
+        return Collections.unmodifiableSet(new HashSet<>(hosts.values()));
+    }
+
+    @Override
+    public Host getHost(HostId hostId) {
+        return hosts.get(hostId);
+    }
+
+    @Override
+    public Set<Host> getHosts(VlanId vlanId) {
+        Set<Host> vlanset = new HashSet<>();
+        for (Host h : hosts.values()) {
+            if (h.vlan().equals(vlanId)) {
+                vlanset.add(h);
+            }
+        }
+        return vlanset;
+    }
+
+    @Override
+    public Set<Host> getHosts(MacAddress mac) {
+        Set<Host> macset = new HashSet<>();
+        for (Host h : hosts.values()) {
+            if (h.mac().equals(mac)) {
+                macset.add(h);
+            }
+        }
+        return macset;
+    }
+
+    @Override
+    public Set<Host> getHosts(IpPrefix ip) {
+        Set<Host> ipset = new HashSet<>();
+        for (Host h : hosts.values()) {
+            if (h.ipAddresses().contains(ip)) {
+                ipset.add(h);
+            }
+        }
+        return ipset;
+    }
+
+    @Override
+    public Set<Host> getConnectedHosts(ConnectPoint connectPoint) {
+        return ImmutableSet.copyOf(locations.get(connectPoint));
+    }
+
+    @Override
+    public Set<Host> getConnectedHosts(DeviceId deviceId) {
+        Set<Host> hostset = new HashSet<>();
+        for (ConnectPoint p : locations.keySet()) {
+            if (p.deviceId().equals(deviceId)) {
+                hostset.addAll(locations.get(p));
+            }
+        }
+        return hostset;
+    }
+
+    @Override
+    public void updateAddressBindings(PortAddresses addresses) {
+        synchronized (portAddresses) {
+            PortAddresses existing = portAddresses.get(addresses.connectPoint());
+            if (existing == null) {
+                portAddresses.put(addresses.connectPoint(), addresses);
+            } else {
+                Set<IpPrefix> union = Sets.union(existing.ips(), addresses.ips())
+                        .immutableCopy();
+
+                MacAddress newMac = (addresses.mac() == null) ? existing.mac()
+                        : addresses.mac();
+
+                PortAddresses newAddresses =
+                        new PortAddresses(addresses.connectPoint(), union, newMac);
+
+                portAddresses.put(newAddresses.connectPoint(), newAddresses);
+            }
+        }
+    }
+
+    @Override
+    public void removeAddressBindings(PortAddresses addresses) {
+        synchronized (portAddresses) {
+            PortAddresses existing = portAddresses.get(addresses.connectPoint());
+            if (existing != null) {
+                Set<IpPrefix> difference =
+                        Sets.difference(existing.ips(), addresses.ips()).immutableCopy();
+
+                // If they removed the existing mac, set the new mac to null.
+                // Otherwise, keep the existing mac.
+                MacAddress newMac = existing.mac();
+                if (addresses.mac() != null && addresses.mac().equals(existing.mac())) {
+                    newMac = null;
+                }
+
+                PortAddresses newAddresses =
+                        new PortAddresses(addresses.connectPoint(), difference, newMac);
+
+                portAddresses.put(newAddresses.connectPoint(), newAddresses);
+            }
+        }
+    }
+
+    @Override
+    public void clearAddressBindings(ConnectPoint connectPoint) {
+        synchronized (portAddresses) {
+            portAddresses.remove(connectPoint);
+        }
+    }
+
+    @Override
+    public Set<PortAddresses> getAddressBindings() {
+        synchronized (portAddresses) {
+            return new HashSet<>(portAddresses.values());
+        }
+    }
+
+    @Override
+    public PortAddresses getAddressBindingsForPort(ConnectPoint connectPoint) {
+        PortAddresses addresses;
+
+        synchronized (portAddresses) {
+            addresses = portAddresses.get(connectPoint);
+        }
+
+        if (addresses == null) {
+            addresses = new PortAddresses(connectPoint, null, null);
+        }
+
+        return addresses;
+    }
+
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/impl/AbsentInvalidatingLoadingCache.java b/core/store/hz/src/main/java/org/onlab/onos/store/impl/AbsentInvalidatingLoadingCache.java
new file mode 100644
index 0000000..df4e70a
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/impl/AbsentInvalidatingLoadingCache.java
@@ -0,0 +1,76 @@
+package org.onlab.onos.store.impl;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+
+import com.google.common.base.Optional;
+import com.google.common.cache.ForwardingLoadingCache.SimpleForwardingLoadingCache;
+import com.google.common.cache.LoadingCache;
+
+/**
+ * Wrapper around LoadingCache to handle negative hit scenario.
+ * <p>
+ * When the LoadingCache returned Absent,
+ * this implementation will invalidate the entry immediately to avoid
+ * caching negative hits.
+ *
+ * @param <K> Cache key type
+ * @param <V> Cache value type. (Optional{@literal <V>})
+ */
+public class AbsentInvalidatingLoadingCache<K, V> extends
+        SimpleForwardingLoadingCache<K, Optional<V>> {
+
+    /**
+     * Constructor.
+     *
+     * @param delegate actual {@link LoadingCache} to delegate loading.
+     */
+    public AbsentInvalidatingLoadingCache(LoadingCache<K, Optional<V>> delegate) {
+        super(delegate);
+    }
+
+    @Override
+    public Optional<V> get(K key) throws ExecutionException {
+        Optional<V> v = super.get(key);
+        if (!v.isPresent()) {
+            invalidate(key);
+        }
+        return v;
+    }
+
+    @Override
+    public Optional<V> getUnchecked(K key) {
+        Optional<V> v = super.getUnchecked(key);
+        if (!v.isPresent()) {
+            invalidate(key);
+        }
+        return v;
+    }
+
+    @Override
+    public Optional<V> apply(K key) {
+        return getUnchecked(key);
+    }
+
+    @Override
+    public Optional<V> getIfPresent(Object key) {
+        Optional<V> v = super.getIfPresent(key);
+        if (!v.isPresent()) {
+            invalidate(key);
+        }
+        return v;
+    }
+
+    @Override
+    public Optional<V> get(K key, Callable<? extends Optional<V>> valueLoader)
+            throws ExecutionException {
+
+        Optional<V> v = super.get(key, valueLoader);
+        if (!v.isPresent()) {
+            invalidate(key);
+        }
+        return v;
+    }
+
+    // TODO should we be also checking getAll, etc.
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/impl/AbstractDistributedStore.java b/core/store/hz/src/main/java/org/onlab/onos/store/impl/AbstractDistributedStore.java
new file mode 100644
index 0000000..eb795a8
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/impl/AbstractDistributedStore.java
@@ -0,0 +1,144 @@
+package org.onlab.onos.store.impl;
+
+import com.google.common.base.Optional;
+import com.google.common.cache.LoadingCache;
+import com.hazelcast.core.EntryAdapter;
+import com.hazelcast.core.EntryEvent;
+import com.hazelcast.core.HazelcastInstance;
+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.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onlab.onos.event.Event;
+import org.onlab.onos.store.AbstractStore;
+import org.onlab.onos.store.StoreDelegate;
+import org.onlab.onos.store.common.StoreService;
+import org.slf4j.Logger;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Abstraction of a distributed store based on Hazelcast.
+ */
+@Component(componentAbstract = true)
+public abstract class AbstractDistributedStore<E extends Event, D extends StoreDelegate<E>>
+        extends AbstractStore<E, D> {
+
+    protected final Logger log = getLogger(getClass());
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected StoreService storeService;
+
+    protected HazelcastInstance theInstance;
+
+    @Activate
+    public void activate() {
+        theInstance = storeService.getHazelcastInstance();
+    }
+
+    /**
+     * Serializes the specified object using the backing store service.
+     *
+     * @param obj object to be serialized
+     * @return serialized object
+     */
+    protected byte[] serialize(Object obj) {
+        return storeService.serialize(obj);
+    }
+
+    /**
+     * Deserializes the specified object using the backing store service.
+     *
+     * @param bytes bytes to be deserialized
+     * @param <T>   type of object
+     * @return deserialized object
+     */
+    protected <T> T deserialize(byte[] bytes) {
+        return storeService.deserialize(bytes);
+    }
+
+
+    /**
+     * An IMap entry listener, which reflects each remote event to the cache.
+     *
+     * @param <K> IMap key type after deserialization
+     * @param <V> IMap value type after deserialization
+     */
+    public class RemoteEventHandler<K, V> extends EntryAdapter<byte[], byte[]> {
+
+        private LoadingCache<K, Optional<V>> cache;
+
+        /**
+         * Constructor.
+         *
+         * @param cache cache to update
+         */
+        public RemoteEventHandler(LoadingCache<K, Optional<V>> cache) {
+            this.cache = checkNotNull(cache);
+        }
+
+        @Override
+        public void mapCleared(MapEvent event) {
+            cache.invalidateAll();
+        }
+
+        @Override
+        public void entryAdded(EntryEvent<byte[], byte[]> event) {
+            K key = deserialize(event.getKey());
+            V newVal = deserialize(event.getValue());
+            Optional<V> newValue = Optional.of(newVal);
+            cache.asMap().putIfAbsent(key, newValue);
+            onAdd(key, newVal);
+        }
+
+        @Override
+        public void entryUpdated(EntryEvent<byte[], byte[]> event) {
+            K key = deserialize(event.getKey());
+            V oldVal = deserialize(event.getOldValue());
+            Optional<V> oldValue = Optional.fromNullable(oldVal);
+            V newVal = deserialize(event.getValue());
+            Optional<V> newValue = Optional.of(newVal);
+            cache.asMap().replace(key, oldValue, newValue);
+            onUpdate(key, oldVal, newVal);
+        }
+
+        @Override
+        public void entryRemoved(EntryEvent<byte[], byte[]> event) {
+            K key = deserialize(event.getKey());
+            V val = deserialize(event.getOldValue());
+            cache.invalidate(key);
+            onRemove(key, val);
+        }
+
+        /**
+         * Cache entry addition hook.
+         *
+         * @param key    new key
+         * @param newVal new value
+         */
+        protected void onAdd(K key, V newVal) {
+        }
+
+        /**
+         * Cache entry update hook.
+         *
+         * @param key    new key
+         * @param oldValue old value
+         * @param newVal new value
+         */
+        protected void onUpdate(K key, V oldValue, V newVal) {
+        }
+
+        /**
+         * Cache entry remove hook.
+         *
+         * @param key new key
+         * @param val old value
+         */
+        protected void onRemove(K key, V val) {
+        }
+    }
+
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/impl/OptionalCacheLoader.java b/core/store/hz/src/main/java/org/onlab/onos/store/impl/OptionalCacheLoader.java
new file mode 100644
index 0000000..dddd128
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/impl/OptionalCacheLoader.java
@@ -0,0 +1,45 @@
+package org.onlab.onos.store.impl;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import org.onlab.onos.store.common.StoreService;
+
+import com.google.common.base.Optional;
+import com.google.common.cache.CacheLoader;
+import com.hazelcast.core.IMap;
+
+/**
+ * CacheLoader to wrap Map value with Optional,
+ * to handle negative hit on underlying IMap.
+ *
+ * @param <K> IMap key type after deserialization
+ * @param <V> IMap value type after deserialization
+ */
+public final class OptionalCacheLoader<K, V> extends
+        CacheLoader<K, Optional<V>> {
+
+    private final StoreService storeService;
+    private IMap<byte[], byte[]> rawMap;
+
+    /**
+     * Constructor.
+     *
+     * @param storeService to use for serialization
+     * @param rawMap underlying IMap
+     */
+    public OptionalCacheLoader(StoreService storeService, IMap<byte[], byte[]> rawMap) {
+        this.storeService = checkNotNull(storeService);
+        this.rawMap = checkNotNull(rawMap);
+    }
+
+    @Override
+    public Optional<V> load(K key) throws Exception {
+        byte[] keyBytes = storeService.serialize(key);
+        byte[] valBytes = rawMap.get(keyBytes);
+        if (valBytes == null) {
+            return Optional.absent();
+        }
+        V dev = storeService.deserialize(valBytes);
+        return Optional.of(dev);
+    }
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/impl/StoreManager.java b/core/store/hz/src/main/java/org/onlab/onos/store/impl/StoreManager.java
new file mode 100644
index 0000000..7d542a8
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/impl/StoreManager.java
@@ -0,0 +1,136 @@
+package org.onlab.onos.store.impl;
+
+import com.hazelcast.config.Config;
+import com.hazelcast.config.FileSystemXmlConfig;
+import com.hazelcast.core.Hazelcast;
+import com.hazelcast.core.HazelcastInstance;
+
+import de.javakaffee.kryoserializers.URISerializer;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.cluster.ControllerNode;
+import org.onlab.onos.cluster.DefaultControllerNode;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultDevice;
+import org.onlab.onos.net.DefaultLink;
+import org.onlab.onos.net.DefaultPort;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Element;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.LinkKey;
+import org.onlab.onos.net.MastershipRole;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.common.StoreService;
+import org.onlab.onos.store.serializers.ConnectPointSerializer;
+import org.onlab.onos.store.serializers.DefaultLinkSerializer;
+import org.onlab.onos.store.serializers.DefaultPortSerializer;
+import org.onlab.onos.store.serializers.DeviceIdSerializer;
+import org.onlab.onos.store.serializers.IpPrefixSerializer;
+import org.onlab.onos.store.serializers.LinkKeySerializer;
+import org.onlab.onos.store.serializers.NodeIdSerializer;
+import org.onlab.onos.store.serializers.PortNumberSerializer;
+import org.onlab.onos.store.serializers.ProviderIdSerializer;
+import org.onlab.packet.IpPrefix;
+import org.onlab.util.KryoPool;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.FileNotFoundException;
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.HashMap;
+
+/**
+ * Auxiliary bootstrap of distributed store.
+ */
+@Component(immediate = true)
+@Service
+public class StoreManager implements StoreService {
+
+    protected static final String HAZELCAST_XML_FILE = "etc/hazelcast.xml";
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    protected HazelcastInstance instance;
+    private KryoPool serializerPool;
+
+
+    @Activate
+    public void activate() {
+        try {
+            Config config = new FileSystemXmlConfig(HAZELCAST_XML_FILE);
+            instance = Hazelcast.newHazelcastInstance(config);
+            setupKryoPool();
+            log.info("Started");
+        } catch (FileNotFoundException e) {
+            log.error("Unable to configure Hazelcast", e);
+        }
+    }
+
+    /**
+     * Sets up the common serialzers pool.
+     */
+    protected void setupKryoPool() {
+        // FIXME Slice out types used in common to separate pool/namespace.
+        serializerPool = KryoPool.newBuilder()
+                .register(ArrayList.class,
+                          HashMap.class,
+
+                          ControllerNode.State.class,
+                          Device.Type.class,
+
+                          DefaultControllerNode.class,
+                          DefaultDevice.class,
+                          MastershipRole.class,
+                          Port.class,
+                          Element.class,
+
+                          Link.Type.class
+                )
+                .register(IpPrefix.class, new IpPrefixSerializer())
+                .register(URI.class, new URISerializer())
+                .register(NodeId.class, new NodeIdSerializer())
+                .register(ProviderId.class, new ProviderIdSerializer())
+                .register(DeviceId.class, new DeviceIdSerializer())
+                .register(PortNumber.class, new PortNumberSerializer())
+                .register(DefaultPort.class, new DefaultPortSerializer())
+                .register(LinkKey.class, new LinkKeySerializer())
+                .register(ConnectPoint.class, new ConnectPointSerializer())
+                .register(DefaultLink.class, new DefaultLinkSerializer())
+                .build()
+                .populate(10);
+    }
+
+    @Deactivate
+    public void deactivate() {
+        instance.shutdown();
+        log.info("Stopped");
+    }
+
+    @Override
+    public HazelcastInstance getHazelcastInstance() {
+        return instance;
+    }
+
+
+    @Override
+    public byte[] serialize(final Object obj) {
+        return serializerPool.serialize(obj);
+    }
+
+    @Override
+    public <T> T deserialize(final byte[] bytes) {
+        if (bytes == null) {
+            return null;
+        }
+        return serializerPool.deserialize(bytes);
+    }
+
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/impl/package-info.java b/core/store/hz/src/main/java/org/onlab/onos/store/impl/package-info.java
new file mode 100644
index 0000000..5b3ec30
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/impl/package-info.java
@@ -0,0 +1,4 @@
+/**
+ * Common facilities for use by various distributed stores.
+ */
+package org.onlab.onos.store.impl;
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/link/impl/DistributedLinkStore.java b/core/store/hz/src/main/java/org/onlab/onos/store/link/impl/DistributedLinkStore.java
new file mode 100644
index 0000000..6db9695
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/link/impl/DistributedLinkStore.java
@@ -0,0 +1,258 @@
+package org.onlab.onos.store.link.impl;
+
+import static com.google.common.cache.CacheBuilder.newBuilder;
+import static org.onlab.onos.net.Link.Type.DIRECT;
+import static org.onlab.onos.net.Link.Type.INDIRECT;
+import static org.onlab.onos.net.link.LinkEvent.Type.LINK_ADDED;
+import static org.onlab.onos.net.link.LinkEvent.Type.LINK_REMOVED;
+import static org.onlab.onos.net.link.LinkEvent.Type.LINK_UPDATED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.HashSet;
+import java.util.Set;
+import 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.net.ConnectPoint;
+import org.onlab.onos.net.DefaultLink;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.LinkKey;
+import org.onlab.onos.net.link.LinkDescription;
+import org.onlab.onos.net.link.LinkEvent;
+import org.onlab.onos.net.link.LinkStore;
+import org.onlab.onos.net.link.LinkStoreDelegate;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.impl.AbsentInvalidatingLoadingCache;
+import org.onlab.onos.store.impl.AbstractDistributedStore;
+import org.onlab.onos.store.impl.OptionalCacheLoader;
+import org.slf4j.Logger;
+
+import com.google.common.base.Optional;
+import com.google.common.cache.LoadingCache;
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.ImmutableSet.Builder;
+import com.hazelcast.core.IMap;
+
+/**
+ * Manages inventory of infrastructure links using Hazelcast-backed map.
+ */
+@Component(immediate = true)
+@Service
+public class DistributedLinkStore
+    extends AbstractDistributedStore<LinkEvent, LinkStoreDelegate>
+    implements LinkStore {
+
+    private final Logger log = getLogger(getClass());
+
+    // Link inventory
+    private IMap<byte[], byte[]> rawLinks;
+    private LoadingCache<LinkKey, Optional<DefaultLink>> links;
+
+    // TODO synchronize?
+    // Egress and ingress link sets
+    private final Multimap<DeviceId, Link> srcLinks = HashMultimap.create();
+    private final Multimap<DeviceId, Link> dstLinks = HashMultimap.create();
+
+    @Override
+    @Activate
+    public void activate() {
+        super.activate();
+
+        boolean includeValue = true;
+
+        // TODO decide on Map name scheme to avoid collision
+        rawLinks = theInstance.getMap("links");
+        final OptionalCacheLoader<LinkKey, DefaultLink> linkLoader
+                = new OptionalCacheLoader<>(storeService, rawLinks);
+        links = new AbsentInvalidatingLoadingCache<>(newBuilder().build(linkLoader));
+        // refresh/populate cache based on notification from other instance
+        rawLinks.addEntryListener(new RemoteLinkEventHandler(links), includeValue);
+
+        loadLinkCache();
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        super.activate();
+        log.info("Stopped");
+    }
+
+    private void loadLinkCache() {
+        for (byte[] keyBytes : rawLinks.keySet()) {
+            final LinkKey id = deserialize(keyBytes);
+            links.refresh(id);
+        }
+    }
+
+    @Override
+    public int getLinkCount() {
+        return links.asMap().size();
+    }
+
+    @Override
+    public Iterable<Link> getLinks() {
+        Builder<Link> builder = ImmutableSet.builder();
+        for (Optional<DefaultLink> e : links.asMap().values()) {
+            if (e.isPresent()) {
+                builder.add(e.get());
+            }
+        }
+        return builder.build();
+    }
+
+    @Override
+    public Set<Link> getDeviceEgressLinks(DeviceId deviceId) {
+        return ImmutableSet.copyOf(srcLinks.get(deviceId));
+    }
+
+    @Override
+    public Set<Link> getDeviceIngressLinks(DeviceId deviceId) {
+        return ImmutableSet.copyOf(dstLinks.get(deviceId));
+    }
+
+    @Override
+    public Link getLink(ConnectPoint src, ConnectPoint dst) {
+        return links.getUnchecked(new LinkKey(src, dst)).orNull();
+    }
+
+    @Override
+    public Set<Link> getEgressLinks(ConnectPoint src) {
+        Set<Link> egress = new HashSet<>();
+        for (Link link : srcLinks.get(src.deviceId())) {
+            if (link.src().equals(src)) {
+                egress.add(link);
+            }
+        }
+        return egress;
+    }
+
+    @Override
+    public Set<Link> getIngressLinks(ConnectPoint dst) {
+        Set<Link> ingress = new HashSet<>();
+        for (Link link : dstLinks.get(dst.deviceId())) {
+            if (link.dst().equals(dst)) {
+                ingress.add(link);
+            }
+        }
+        return ingress;
+    }
+
+    @Override
+    public LinkEvent createOrUpdateLink(ProviderId providerId,
+                                        LinkDescription linkDescription) {
+        LinkKey key = new LinkKey(linkDescription.src(), linkDescription.dst());
+        Optional<DefaultLink> link = links.getUnchecked(key);
+        if (!link.isPresent()) {
+            return createLink(providerId, key, linkDescription);
+        }
+        return updateLink(providerId, link.get(), key, linkDescription);
+    }
+
+    // Creates and stores the link and returns the appropriate event.
+    private LinkEvent createLink(ProviderId providerId, LinkKey key,
+                                 LinkDescription linkDescription) {
+        DefaultLink link = new DefaultLink(providerId, key.src(), key.dst(),
+                                           linkDescription.type());
+        synchronized (this) {
+            final byte[] keyBytes = serialize(key);
+            rawLinks.put(keyBytes, serialize(link));
+            links.asMap().putIfAbsent(key, Optional.of(link));
+
+            addNewLink(link);
+        }
+        return new LinkEvent(LINK_ADDED, link);
+    }
+
+    // update Egress and ingress link sets
+    private void addNewLink(DefaultLink link) {
+        synchronized (this) {
+            srcLinks.put(link.src().deviceId(), link);
+            dstLinks.put(link.dst().deviceId(), link);
+        }
+    }
+
+    // Updates, if necessary the specified link and returns the appropriate event.
+    private LinkEvent updateLink(ProviderId providerId, DefaultLink link,
+                                 LinkKey key, LinkDescription linkDescription) {
+        // FIXME confirm Link update condition is OK
+        if (link.type() == INDIRECT && linkDescription.type() == DIRECT) {
+            synchronized (this) {
+
+                DefaultLink updated =
+                        new DefaultLink(providerId, link.src(), link.dst(),
+                                        linkDescription.type());
+                final byte[] keyBytes = serialize(key);
+                rawLinks.put(keyBytes, serialize(updated));
+                links.asMap().replace(key, Optional.of(link), Optional.of(updated));
+
+                replaceLink(link, updated);
+                return new LinkEvent(LINK_UPDATED, updated);
+            }
+        }
+        return null;
+    }
+
+    // update Egress and ingress link sets
+    private void replaceLink(DefaultLink link, DefaultLink updated) {
+        synchronized (this) {
+            srcLinks.remove(link.src().deviceId(), link);
+            dstLinks.remove(link.dst().deviceId(), link);
+
+            srcLinks.put(link.src().deviceId(), updated);
+            dstLinks.put(link.dst().deviceId(), updated);
+        }
+    }
+
+    @Override
+    public LinkEvent removeLink(ConnectPoint src, ConnectPoint dst) {
+        synchronized (this) {
+            LinkKey key = new LinkKey(src, dst);
+            byte[] keyBytes = serialize(key);
+            Link link = deserialize(rawLinks.remove(keyBytes));
+            links.invalidate(key);
+            if (link != null) {
+                removeLink(link);
+                return new LinkEvent(LINK_REMOVED, link);
+            }
+            return null;
+        }
+    }
+
+    // update Egress and ingress link sets
+    private void removeLink(Link link) {
+        synchronized (this) {
+            srcLinks.remove(link.src().deviceId(), link);
+            dstLinks.remove(link.dst().deviceId(), link);
+        }
+    }
+
+    private class RemoteLinkEventHandler extends RemoteEventHandler<LinkKey, DefaultLink> {
+        public RemoteLinkEventHandler(LoadingCache<LinkKey, Optional<DefaultLink>> cache) {
+            super(cache);
+        }
+
+        @Override
+        protected void onAdd(LinkKey key, DefaultLink newVal) {
+            addNewLink(newVal);
+            notifyDelegate(new LinkEvent(LINK_ADDED, newVal));
+        }
+
+        @Override
+        protected void onUpdate(LinkKey key, DefaultLink oldVal, DefaultLink newVal) {
+            replaceLink(oldVal, newVal);
+            notifyDelegate(new LinkEvent(LINK_UPDATED, newVal));
+        }
+
+        @Override
+        protected void onRemove(LinkKey key, DefaultLink val) {
+            removeLink(val);
+            notifyDelegate(new LinkEvent(LINK_REMOVED, val));
+        }
+    }
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/link/impl/package-info.java b/core/store/hz/src/main/java/org/onlab/onos/store/link/impl/package-info.java
new file mode 100644
index 0000000..53b6f33
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/link/impl/package-info.java
@@ -0,0 +1,4 @@
+/**
+ * Implementation of link store using Hazelcast distributed structures.
+ */
+package org.onlab.onos.store.link.impl;
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopology.java b/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopology.java
new file mode 100644
index 0000000..5574d27
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopology.java
@@ -0,0 +1,444 @@
+package org.onlab.onos.store.topology.impl;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSetMultimap;
+import org.onlab.graph.DijkstraGraphSearch;
+import org.onlab.graph.GraphPathSearch;
+import org.onlab.graph.TarjanGraphSearch;
+import org.onlab.onos.net.AbstractModel;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultPath;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.net.topology.ClusterId;
+import org.onlab.onos.net.topology.DefaultTopologyCluster;
+import org.onlab.onos.net.topology.DefaultTopologyVertex;
+import org.onlab.onos.net.topology.GraphDescription;
+import org.onlab.onos.net.topology.LinkWeight;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyCluster;
+import org.onlab.onos.net.topology.TopologyEdge;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyVertex;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.collect.ImmutableSetMultimap.Builder;
+import static org.onlab.graph.GraphPathSearch.Result;
+import static org.onlab.graph.TarjanGraphSearch.SCCResult;
+import static org.onlab.onos.net.Link.Type.INDIRECT;
+
+/**
+ * Default implementation of the topology descriptor. This carries the
+ * backing topology data.
+ */
+public class DefaultTopology extends AbstractModel implements Topology {
+
+    private static final DijkstraGraphSearch<TopologyVertex, TopologyEdge> DIJKSTRA =
+            new DijkstraGraphSearch<>();
+    private static final TarjanGraphSearch<TopologyVertex, TopologyEdge> TARJAN =
+            new TarjanGraphSearch<>();
+
+    private static final ProviderId PID = new ProviderId("core", "org.onlab.onos.net");
+
+    private final long time;
+    private final TopologyGraph graph;
+
+    private final SCCResult<TopologyVertex, TopologyEdge> clusterResults;
+    private final ImmutableMap<DeviceId, Result<TopologyVertex, TopologyEdge>> results;
+    private final ImmutableSetMultimap<PathKey, Path> paths;
+
+    private final ImmutableMap<ClusterId, TopologyCluster> clusters;
+    private final ImmutableSet<ConnectPoint> infrastructurePoints;
+    private final ImmutableSetMultimap<ClusterId, ConnectPoint> broadcastSets;
+
+    private ImmutableMap<DeviceId, TopologyCluster> clustersByDevice;
+    private ImmutableSetMultimap<TopologyCluster, DeviceId> devicesByCluster;
+    private ImmutableSetMultimap<TopologyCluster, Link> linksByCluster;
+
+
+    /**
+     * Creates a topology descriptor attributed to the specified provider.
+     *
+     * @param providerId  identity of the provider
+     * @param description data describing the new topology
+     */
+    DefaultTopology(ProviderId providerId, GraphDescription description) {
+        super(providerId);
+        this.time = description.timestamp();
+
+        // Build the graph
+        this.graph = new DefaultTopologyGraph(description.vertexes(),
+                                              description.edges());
+
+        this.results = searchForShortestPaths();
+        this.paths = buildPaths();
+
+        this.clusterResults = searchForClusters();
+        this.clusters = buildTopologyClusters();
+
+        buildIndexes();
+
+        this.broadcastSets = buildBroadcastSets();
+        this.infrastructurePoints = findInfrastructurePoints();
+    }
+
+    @Override
+    public long time() {
+        return time;
+    }
+
+    @Override
+    public int clusterCount() {
+        return clusters.size();
+    }
+
+    @Override
+    public int deviceCount() {
+        return graph.getVertexes().size();
+    }
+
+    @Override
+    public int linkCount() {
+        return graph.getEdges().size();
+    }
+
+    @Override
+    public int pathCount() {
+        return paths.size();
+    }
+
+    /**
+     * Returns the backing topology graph.
+     *
+     * @return topology graph
+     */
+    TopologyGraph getGraph() {
+        return graph;
+    }
+
+    /**
+     * Returns the set of topology clusters.
+     *
+     * @return set of clusters
+     */
+    Set<TopologyCluster> getClusters() {
+        return ImmutableSet.copyOf(clusters.values());
+    }
+
+    /**
+     * Returns the specified topology cluster.
+     *
+     * @param clusterId cluster identifier
+     * @return topology cluster
+     */
+    TopologyCluster getCluster(ClusterId clusterId) {
+        return clusters.get(clusterId);
+    }
+
+    /**
+     * Returns the topology cluster that contains the given device.
+     *
+     * @param deviceId device identifier
+     * @return topology cluster
+     */
+    TopologyCluster getCluster(DeviceId deviceId) {
+        return clustersByDevice.get(deviceId);
+    }
+
+    /**
+     * Returns the set of cluster devices.
+     *
+     * @param cluster topology cluster
+     * @return cluster devices
+     */
+    Set<DeviceId> getClusterDevices(TopologyCluster cluster) {
+        return devicesByCluster.get(cluster);
+    }
+
+    /**
+     * Returns the set of cluster links.
+     *
+     * @param cluster topology cluster
+     * @return cluster links
+     */
+    Set<Link> getClusterLinks(TopologyCluster cluster) {
+        return linksByCluster.get(cluster);
+    }
+
+    /**
+     * Indicates whether the given point is an infrastructure link end-point.
+     *
+     * @param connectPoint connection point
+     * @return true if infrastructure
+     */
+    boolean isInfrastructure(ConnectPoint connectPoint) {
+        return infrastructurePoints.contains(connectPoint);
+    }
+
+    /**
+     * Indicates whether the given point is part of a broadcast set.
+     *
+     * @param connectPoint connection point
+     * @return true if in broadcast set
+     */
+    boolean isBroadcastPoint(ConnectPoint connectPoint) {
+        // Any non-infrastructure, i.e. edge points are assumed to be OK.
+        if (!isInfrastructure(connectPoint)) {
+            return true;
+        }
+
+        // Find the cluster to which the device belongs.
+        TopologyCluster cluster = clustersByDevice.get(connectPoint.deviceId());
+        if (cluster == null) {
+            throw new IllegalArgumentException("No cluster found for device " + connectPoint.deviceId());
+        }
+
+        // If the broadcast set is null or empty, or if the point explicitly
+        // belongs to it, return true;
+        Set<ConnectPoint> points = broadcastSets.get(cluster.id());
+        return points == null || points.isEmpty() || points.contains(connectPoint);
+    }
+
+    /**
+     * Returns the size of the cluster broadcast set.
+     *
+     * @param clusterId cluster identifier
+     * @return size of the cluster broadcast set
+     */
+    int broadcastSetSize(ClusterId clusterId) {
+        return broadcastSets.get(clusterId).size();
+    }
+
+    /**
+     * Returns the set of pre-computed shortest paths between source and
+     * destination devices.
+     *
+     * @param src source device
+     * @param dst destination device
+     * @return set of shortest paths
+     */
+    Set<Path> getPaths(DeviceId src, DeviceId dst) {
+        return paths.get(new PathKey(src, dst));
+    }
+
+    /**
+     * Computes on-demand the set of shortest paths between source and
+     * destination devices.
+     *
+     * @param src source device
+     * @param dst destination device
+     * @return set of shortest paths
+     */
+    Set<Path> getPaths(DeviceId src, DeviceId dst, LinkWeight weight) {
+        GraphPathSearch.Result<TopologyVertex, TopologyEdge> result =
+                DIJKSTRA.search(graph, new DefaultTopologyVertex(src),
+                                new DefaultTopologyVertex(dst), weight);
+        ImmutableSet.Builder<Path> builder = ImmutableSet.builder();
+        for (org.onlab.graph.Path<TopologyVertex, TopologyEdge> path : result.paths()) {
+            builder.add(networkPath(path));
+        }
+        return builder.build();
+    }
+
+
+    // Searches the graph for all shortest paths and returns the search results.
+    private ImmutableMap<DeviceId, Result<TopologyVertex, TopologyEdge>> searchForShortestPaths() {
+        ImmutableMap.Builder<DeviceId, Result<TopologyVertex, TopologyEdge>> builder = ImmutableMap.builder();
+
+        // Search graph paths for each source to all destinations.
+        LinkWeight weight = new HopCountLinkWeight(graph.getVertexes().size());
+        for (TopologyVertex src : graph.getVertexes()) {
+            builder.put(src.deviceId(), DIJKSTRA.search(graph, src, null, weight));
+        }
+        return builder.build();
+    }
+
+    // Builds network paths from the graph path search results
+    private ImmutableSetMultimap<PathKey, Path> buildPaths() {
+        Builder<PathKey, Path> builder = ImmutableSetMultimap.builder();
+        for (DeviceId deviceId : results.keySet()) {
+            Result<TopologyVertex, TopologyEdge> result = results.get(deviceId);
+            for (org.onlab.graph.Path<TopologyVertex, TopologyEdge> path : result.paths()) {
+                builder.put(new PathKey(path.src().deviceId(), path.dst().deviceId()),
+                            networkPath(path));
+            }
+        }
+        return builder.build();
+    }
+
+    // Converts graph path to a network path with the same cost.
+    private Path networkPath(org.onlab.graph.Path<TopologyVertex, TopologyEdge> path) {
+        List<Link> links = new ArrayList<>();
+        for (TopologyEdge edge : path.edges()) {
+            links.add(edge.link());
+        }
+        return new DefaultPath(PID, links, path.cost());
+    }
+
+
+    // Searches for SCC clusters in the network topology graph using Tarjan
+    // algorithm.
+    private SCCResult<TopologyVertex, TopologyEdge> searchForClusters() {
+        return TARJAN.search(graph, new NoIndirectLinksWeight());
+    }
+
+    // Builds the topology clusters and returns the id-cluster bindings.
+    private ImmutableMap<ClusterId, TopologyCluster> buildTopologyClusters() {
+        ImmutableMap.Builder<ClusterId, TopologyCluster> clusterBuilder = ImmutableMap.builder();
+        SCCResult<TopologyVertex, TopologyEdge> result =
+                TARJAN.search(graph, new NoIndirectLinksWeight());
+
+        // Extract both vertexes and edges from the results; the lists form
+        // pairs along the same index.
+        List<Set<TopologyVertex>> clusterVertexes = result.clusterVertexes();
+        List<Set<TopologyEdge>> clusterEdges = result.clusterEdges();
+
+        // Scan over the lists and create a cluster from the results.
+        for (int i = 0, n = result.clusterCount(); i < n; i++) {
+            Set<TopologyVertex> vertexSet = clusterVertexes.get(i);
+            Set<TopologyEdge> edgeSet = clusterEdges.get(i);
+
+            ClusterId cid = ClusterId.clusterId(i);
+            DefaultTopologyCluster cluster =
+                    new DefaultTopologyCluster(cid, vertexSet.size(), edgeSet.size(),
+                                               findRoot(vertexSet).deviceId());
+            clusterBuilder.put(cid, cluster);
+        }
+        return clusterBuilder.build();
+    }
+
+    // Finds the vertex whose device id is the lexicographical minimum in the
+    // specified set.
+    private TopologyVertex findRoot(Set<TopologyVertex> vertexSet) {
+        TopologyVertex minVertex = null;
+        for (TopologyVertex vertex : vertexSet) {
+            if (minVertex == null ||
+                    minVertex.deviceId().toString()
+                            .compareTo(minVertex.deviceId().toString()) < 0) {
+                minVertex = vertex;
+            }
+        }
+        return minVertex;
+    }
+
+    // Processes a map of broadcast sets for each cluster.
+    private ImmutableSetMultimap<ClusterId, ConnectPoint> buildBroadcastSets() {
+        Builder<ClusterId, ConnectPoint> builder = ImmutableSetMultimap.builder();
+        for (TopologyCluster cluster : clusters.values()) {
+            addClusterBroadcastSet(cluster, builder);
+        }
+        return builder.build();
+    }
+
+    // Finds all broadcast points for the cluster. These are those connection
+    // points which lie along the shortest paths between the cluster root and
+    // all other devices within the cluster.
+    private void addClusterBroadcastSet(TopologyCluster cluster,
+                                        Builder<ClusterId, ConnectPoint> builder) {
+        // Use the graph root search results to build the broadcast set.
+        Result<TopologyVertex, TopologyEdge> result = results.get(cluster.root());
+        for (Map.Entry<TopologyVertex, Set<TopologyEdge>> entry : result.parents().entrySet()) {
+            TopologyVertex vertex = entry.getKey();
+
+            // Ignore any parents that lead outside the cluster.
+            if (clustersByDevice.get(vertex.deviceId()) != cluster) {
+                continue;
+            }
+
+            // Ignore any back-link sets that are empty.
+            Set<TopologyEdge> parents = entry.getValue();
+            if (parents.isEmpty()) {
+                continue;
+            }
+
+            // Use the first back-link source and destinations to add to the
+            // broadcast set.
+            Link link = parents.iterator().next().link();
+            builder.put(cluster.id(), link.src());
+            builder.put(cluster.id(), link.dst());
+        }
+    }
+
+    // Collects and returns an set of all infrastructure link end-points.
+    private ImmutableSet<ConnectPoint> findInfrastructurePoints() {
+        ImmutableSet.Builder<ConnectPoint> builder = ImmutableSet.builder();
+        for (TopologyEdge edge : graph.getEdges()) {
+            builder.add(edge.link().src());
+            builder.add(edge.link().dst());
+        }
+        return builder.build();
+    }
+
+    // Builds cluster-devices, cluster-links and device-cluster indexes.
+    private void buildIndexes() {
+        // Prepare the index builders
+        ImmutableMap.Builder<DeviceId, TopologyCluster> clusterBuilder = ImmutableMap.builder();
+        ImmutableSetMultimap.Builder<TopologyCluster, DeviceId> devicesBuilder = ImmutableSetMultimap.builder();
+        ImmutableSetMultimap.Builder<TopologyCluster, Link> linksBuilder = ImmutableSetMultimap.builder();
+
+        // Now scan through all the clusters
+        for (TopologyCluster cluster : clusters.values()) {
+            int i = cluster.id().index();
+
+            // Scan through all the cluster vertexes.
+            for (TopologyVertex vertex : clusterResults.clusterVertexes().get(i)) {
+                devicesBuilder.put(cluster, vertex.deviceId());
+                clusterBuilder.put(vertex.deviceId(), cluster);
+            }
+
+            // Scan through all the cluster edges.
+            for (TopologyEdge edge : clusterResults.clusterEdges().get(i)) {
+                linksBuilder.put(cluster, edge.link());
+            }
+        }
+
+        // Finalize all indexes.
+        clustersByDevice = clusterBuilder.build();
+        devicesByCluster = devicesBuilder.build();
+        linksByCluster = linksBuilder.build();
+    }
+
+    // Link weight for measuring link cost as hop count with indirect links
+    // being as expensive as traversing the entire graph to assume the worst.
+    private static class HopCountLinkWeight implements LinkWeight {
+        private final int indirectLinkCost;
+
+        HopCountLinkWeight(int indirectLinkCost) {
+            this.indirectLinkCost = indirectLinkCost;
+        }
+
+        @Override
+        public double weight(TopologyEdge edge) {
+            // To force preference to use direct paths first, make indirect
+            // links as expensive as the linear vertex traversal.
+            return edge.link().type() == INDIRECT ? indirectLinkCost : 1;
+        }
+    }
+
+    // Link weight for preventing traversal over indirect links.
+    private static class NoIndirectLinksWeight implements LinkWeight {
+        @Override
+        public double weight(TopologyEdge edge) {
+            return edge.link().type() == INDIRECT ? -1 : 1;
+        }
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("time", time)
+                .add("clusters", clusterCount())
+                .add("devices", deviceCount())
+                .add("links", linkCount())
+                .add("pathCount", pathCount())
+                .toString();
+    }
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopologyGraph.java b/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopologyGraph.java
new file mode 100644
index 0000000..945ba05
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopologyGraph.java
@@ -0,0 +1,28 @@
+package org.onlab.onos.store.topology.impl;
+
+import org.onlab.graph.AdjacencyListsGraph;
+import org.onlab.onos.net.topology.TopologyEdge;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyVertex;
+
+import java.util.Set;
+
+/**
+ * Default implementation of an immutable topology graph based on a generic
+ * implementation of adjacency lists graph.
+ */
+public class DefaultTopologyGraph
+        extends AdjacencyListsGraph<TopologyVertex, TopologyEdge>
+        implements TopologyGraph {
+
+    /**
+     * Creates a topology graph comprising of the specified vertexes and edges.
+     *
+     * @param vertexes set of graph vertexes
+     * @param edges    set of graph edges
+     */
+    public DefaultTopologyGraph(Set<TopologyVertex> vertexes, Set<TopologyEdge> edges) {
+        super(vertexes, edges);
+    }
+
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/DistributedTopologyStore.java b/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/DistributedTopologyStore.java
new file mode 100644
index 0000000..567861e
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/DistributedTopologyStore.java
@@ -0,0 +1,141 @@
+package org.onlab.onos.store.topology.impl;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.List;
+import java.util.Set;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.event.Event;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.net.topology.ClusterId;
+import org.onlab.onos.net.topology.GraphDescription;
+import org.onlab.onos.net.topology.LinkWeight;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyCluster;
+import org.onlab.onos.net.topology.TopologyEvent;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyStore;
+import org.onlab.onos.net.topology.TopologyStoreDelegate;
+import org.onlab.onos.store.AbstractStore;
+import org.slf4j.Logger;
+
+/**
+ * Manages inventory of topology snapshots using trivial in-memory
+ * structures implementation.
+ */
+//FIXME: I LIE I AM NOT DISTRIBUTED
+@Component(immediate = true)
+@Service
+public class DistributedTopologyStore
+extends AbstractStore<TopologyEvent, TopologyStoreDelegate>
+implements TopologyStore {
+
+    private final Logger log = getLogger(getClass());
+
+    private volatile DefaultTopology current;
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+    @Override
+    public Topology currentTopology() {
+        return current;
+    }
+
+    @Override
+    public boolean isLatest(Topology topology) {
+        // Topology is current only if it is the same as our current topology
+        return topology == current;
+    }
+
+    @Override
+    public TopologyGraph getGraph(Topology topology) {
+        return defaultTopology(topology).getGraph();
+    }
+
+    @Override
+    public Set<TopologyCluster> getClusters(Topology topology) {
+        return defaultTopology(topology).getClusters();
+    }
+
+    @Override
+    public TopologyCluster getCluster(Topology topology, ClusterId clusterId) {
+        return defaultTopology(topology).getCluster(clusterId);
+    }
+
+    @Override
+    public Set<DeviceId> getClusterDevices(Topology topology, TopologyCluster cluster) {
+        return defaultTopology(topology).getClusterDevices(cluster);
+    }
+
+    @Override
+    public Set<Link> getClusterLinks(Topology topology, TopologyCluster cluster) {
+        return defaultTopology(topology).getClusterLinks(cluster);
+    }
+
+    @Override
+    public Set<Path> getPaths(Topology topology, DeviceId src, DeviceId dst) {
+        return defaultTopology(topology).getPaths(src, dst);
+    }
+
+    @Override
+    public Set<Path> getPaths(Topology topology, DeviceId src, DeviceId dst,
+            LinkWeight weight) {
+        return defaultTopology(topology).getPaths(src, dst, weight);
+    }
+
+    @Override
+    public boolean isInfrastructure(Topology topology, ConnectPoint connectPoint) {
+        return defaultTopology(topology).isInfrastructure(connectPoint);
+    }
+
+    @Override
+    public boolean isBroadcastPoint(Topology topology, ConnectPoint connectPoint) {
+        return defaultTopology(topology).isBroadcastPoint(connectPoint);
+    }
+
+    @Override
+    public TopologyEvent updateTopology(ProviderId providerId,
+            GraphDescription graphDescription,
+            List<Event> reasons) {
+        // First off, make sure that what we're given is indeed newer than
+        // what we already have.
+        if (current != null && graphDescription.timestamp() < current.time()) {
+            return null;
+        }
+
+        // Have the default topology construct self from the description data.
+        DefaultTopology newTopology =
+                new DefaultTopology(providerId, graphDescription);
+
+        // Promote the new topology to current and return a ready-to-send event.
+        synchronized (this) {
+            current = newTopology;
+            return new TopologyEvent(TopologyEvent.Type.TOPOLOGY_CHANGED, current);
+        }
+    }
+
+    // Validates the specified topology and returns it as a default
+    private DefaultTopology defaultTopology(Topology topology) {
+        if (topology instanceof DefaultTopology) {
+            return (DefaultTopology) topology;
+        }
+        throw new IllegalArgumentException("Topology class " + topology.getClass() +
+                " not supported");
+    }
+
+}
diff --git a/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/PathKey.java b/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/PathKey.java
new file mode 100644
index 0000000..60736b9
--- /dev/null
+++ b/core/store/hz/src/main/java/org/onlab/onos/store/topology/impl/PathKey.java
@@ -0,0 +1,40 @@
+package org.onlab.onos.store.topology.impl;
+
+import org.onlab.onos.net.DeviceId;
+
+import java.util.Objects;
+
+/**
+ * Key for filing pre-computed paths between source and destination devices.
+ */
+class PathKey {
+    private final DeviceId src;
+    private final DeviceId dst;
+
+    /**
+     * Creates a path key from the given source/dest pair.
+     * @param src source device
+     * @param dst destination device
+     */
+    PathKey(DeviceId src, DeviceId dst) {
+        this.src = src;
+        this.dst = dst;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(src, dst);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof PathKey) {
+            final PathKey other = (PathKey) obj;
+            return Objects.equals(this.src, other.src) && Objects.equals(this.dst, other.dst);
+        }
+        return false;
+    }
+}
diff --git a/core/store/hz/src/test/java/org/onlab/onos/store/device/impl/DistributedDeviceStoreTest.java b/core/store/hz/src/test/java/org/onlab/onos/store/device/impl/DistributedDeviceStoreTest.java
new file mode 100644
index 0000000..d7494be
--- /dev/null
+++ b/core/store/hz/src/test/java/org/onlab/onos/store/device/impl/DistributedDeviceStoreTest.java
@@ -0,0 +1,386 @@
+/**
+ *
+ */
+package org.onlab.onos.store.device.impl;
+
+import static org.junit.Assert.*;
+import static org.onlab.onos.net.Device.Type.SWITCH;
+import static org.onlab.onos.net.DeviceId.deviceId;
+import static org.onlab.onos.net.device.DeviceEvent.Type.*;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.device.DefaultDeviceDescription;
+import org.onlab.onos.net.device.DefaultPortDescription;
+import org.onlab.onos.net.device.DeviceDescription;
+import org.onlab.onos.net.device.DeviceEvent;
+import org.onlab.onos.net.device.DeviceStoreDelegate;
+import org.onlab.onos.net.device.PortDescription;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.common.StoreService;
+import org.onlab.onos.store.impl.StoreManager;
+import org.onlab.onos.store.impl.TestStoreManager;
+
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Sets;
+import com.hazelcast.config.Config;
+import com.hazelcast.core.Hazelcast;
+
+public class DistributedDeviceStoreTest {
+
+    private static final ProviderId PID = new ProviderId("of", "foo");
+    private static final DeviceId DID1 = deviceId("of:foo");
+    private static final DeviceId DID2 = deviceId("of:bar");
+    private static final String MFR = "whitebox";
+    private static final String HW = "1.1.x";
+    private static final String SW1 = "3.8.1";
+    private static final String SW2 = "3.9.5";
+    private static final String SN = "43311-12345";
+
+    private static final PortNumber P1 = PortNumber.portNumber(1);
+    private static final PortNumber P2 = PortNumber.portNumber(2);
+    private static final PortNumber P3 = PortNumber.portNumber(3);
+
+    private DistributedDeviceStore deviceStore;
+
+    private StoreManager storeManager;
+
+
+    @BeforeClass
+    public static void setUpBeforeClass() throws Exception {
+    }
+
+    @AfterClass
+    public static void tearDownAfterClass() throws Exception {
+    }
+
+
+    @Before
+    public void setUp() throws Exception {
+        // TODO should find a way to clean Hazelcast instance without shutdown.
+        Config config = TestStoreManager.getTestConfig();
+
+        storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
+        storeManager.activate();
+
+        deviceStore = new TestDistributedDeviceStore(storeManager);
+        deviceStore.activate();
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        deviceStore.deactivate();
+
+        storeManager.deactivate();
+    }
+
+    private void putDevice(DeviceId deviceId, String swVersion) {
+        DeviceDescription description =
+                new DefaultDeviceDescription(deviceId.uri(), SWITCH, MFR,
+                        HW, swVersion, SN);
+        deviceStore.createOrUpdateDevice(PID, deviceId, description);
+    }
+
+    private static void assertDevice(DeviceId id, String swVersion, Device device) {
+        assertNotNull(device);
+        assertEquals(id, device.id());
+        assertEquals(MFR, device.manufacturer());
+        assertEquals(HW, device.hwVersion());
+        assertEquals(swVersion, device.swVersion());
+        assertEquals(SN, device.serialNumber());
+    }
+
+    @Test
+    public final void testGetDeviceCount() {
+        assertEquals("initialy empty", 0, deviceStore.getDeviceCount());
+
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW2);
+        putDevice(DID1, SW1);
+
+        assertEquals("expect 2 uniq devices", 2, deviceStore.getDeviceCount());
+    }
+
+    @Test
+    public final void testGetDevices() {
+        assertEquals("initialy empty", 0, Iterables.size(deviceStore.getDevices()));
+
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW2);
+        putDevice(DID1, SW1);
+
+        assertEquals("expect 2 uniq devices",
+                2, Iterables.size(deviceStore.getDevices()));
+
+        Map<DeviceId, Device> devices = new HashMap<>();
+        for (Device device : deviceStore.getDevices()) {
+            devices.put(device.id(), device);
+        }
+
+        assertDevice(DID1, SW1, devices.get(DID1));
+        assertDevice(DID2, SW2, devices.get(DID2));
+
+        // add case for new node?
+    }
+
+    @Test
+    public final void testGetDevice() {
+
+        putDevice(DID1, SW1);
+
+        assertDevice(DID1, SW1, deviceStore.getDevice(DID1));
+        assertNull("DID2 shouldn't be there", deviceStore.getDevice(DID2));
+    }
+
+    @Test
+    public final void testCreateOrUpdateDevice() {
+        DeviceDescription description =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW1, SN);
+        DeviceEvent event = deviceStore.createOrUpdateDevice(PID, DID1, description);
+        assertEquals(DEVICE_ADDED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+
+        DeviceDescription description2 =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW2, SN);
+        DeviceEvent event2 = deviceStore.createOrUpdateDevice(PID, DID1, description2);
+        assertEquals(DEVICE_UPDATED, event2.type());
+        assertDevice(DID1, SW2, event2.subject());
+
+        assertNull("No change expected", deviceStore.createOrUpdateDevice(PID, DID1, description2));
+    }
+
+    @Test
+    public final void testMarkOffline() {
+
+        putDevice(DID1, SW1);
+        assertTrue(deviceStore.isAvailable(DID1));
+
+        DeviceEvent event = deviceStore.markOffline(DID1);
+        assertEquals(DEVICE_AVAILABILITY_CHANGED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+        assertFalse(deviceStore.isAvailable(DID1));
+
+        DeviceEvent event2 = deviceStore.markOffline(DID1);
+        assertNull("No change, no event", event2);
+}
+
+    @Test
+    public final void testUpdatePorts() {
+        putDevice(DID1, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true),
+                new DefaultPortDescription(P2, true)
+                );
+
+        List<DeviceEvent> events = deviceStore.updatePorts(DID1, pds);
+
+        Set<PortNumber> expectedPorts = Sets.newHashSet(P1, P2);
+        for (DeviceEvent event : events) {
+            assertEquals(PORT_ADDED, event.type());
+            assertDevice(DID1, SW1, event.subject());
+            assertTrue("PortNumber is one of expected",
+                    expectedPorts.remove(event.port().number()));
+            assertTrue("Port is enabled", event.port().isEnabled());
+        }
+        assertTrue("Event for all expectedport appeared", expectedPorts.isEmpty());
+
+
+        List<PortDescription> pds2 = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, false),
+                new DefaultPortDescription(P2, true),
+                new DefaultPortDescription(P3, true)
+                );
+
+        events = deviceStore.updatePorts(DID1, pds2);
+        assertFalse("event should be triggered", events.isEmpty());
+        for (DeviceEvent event : events) {
+            PortNumber num = event.port().number();
+            if (P1.equals(num)) {
+                assertEquals(PORT_UPDATED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                assertFalse("Port is disabled", event.port().isEnabled());
+            } else if (P2.equals(num)) {
+                fail("P2 event not expected.");
+            } else if (P3.equals(num)) {
+                assertEquals(PORT_ADDED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                assertTrue("Port is enabled", event.port().isEnabled());
+            } else {
+                fail("Unknown port number encountered: " + num);
+            }
+        }
+
+        List<PortDescription> pds3 = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, false),
+                new DefaultPortDescription(P2, true)
+                );
+        events = deviceStore.updatePorts(DID1, pds3);
+        assertFalse("event should be triggered", events.isEmpty());
+        for (DeviceEvent event : events) {
+            PortNumber num = event.port().number();
+            if (P1.equals(num)) {
+                fail("P1 event not expected.");
+            } else if (P2.equals(num)) {
+                fail("P2 event not expected.");
+            } else if (P3.equals(num)) {
+                assertEquals(PORT_REMOVED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                assertTrue("Port was enabled", event.port().isEnabled());
+            } else {
+                fail("Unknown port number encountered: " + num);
+            }
+        }
+
+    }
+
+    @Test
+    public final void testUpdatePortStatus() {
+        putDevice(DID1, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true)
+                );
+        deviceStore.updatePorts(DID1, pds);
+
+        DeviceEvent event = deviceStore.updatePortStatus(DID1,
+                new DefaultPortDescription(P1, false));
+        assertEquals(PORT_UPDATED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+        assertEquals(P1, event.port().number());
+        assertFalse("Port is disabled", event.port().isEnabled());
+    }
+
+    @Test
+    public final void testGetPorts() {
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true),
+                new DefaultPortDescription(P2, true)
+                );
+        deviceStore.updatePorts(DID1, pds);
+
+        Set<PortNumber> expectedPorts = Sets.newHashSet(P1, P2);
+        List<Port> ports = deviceStore.getPorts(DID1);
+        for (Port port : ports) {
+            assertTrue("Port is enabled", port.isEnabled());
+            assertTrue("PortNumber is one of expected",
+                    expectedPorts.remove(port.number()));
+        }
+        assertTrue("Event for all expectedport appeared", expectedPorts.isEmpty());
+
+
+        assertTrue("DID2 has no ports", deviceStore.getPorts(DID2).isEmpty());
+    }
+
+    @Test
+    public final void testGetPort() {
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true),
+                new DefaultPortDescription(P2, false)
+                );
+        deviceStore.updatePorts(DID1, pds);
+
+        Port port1 = deviceStore.getPort(DID1, P1);
+        assertEquals(P1, port1.number());
+        assertTrue("Port is enabled", port1.isEnabled());
+
+        Port port2 = deviceStore.getPort(DID1, P2);
+        assertEquals(P2, port2.number());
+        assertFalse("Port is disabled", port2.isEnabled());
+
+        Port port3 = deviceStore.getPort(DID1, P3);
+        assertNull("P3 not expected", port3);
+    }
+
+    @Test
+    public final void testRemoveDevice() {
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW1);
+
+        assertEquals(2, deviceStore.getDeviceCount());
+
+        DeviceEvent event = deviceStore.removeDevice(DID1);
+        assertEquals(DEVICE_REMOVED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+
+        assertEquals(1, deviceStore.getDeviceCount());
+    }
+
+    // TODO add test for Port events when we have them
+    @Test
+    public final void testEvents() throws InterruptedException {
+        final CountDownLatch addLatch = new CountDownLatch(1);
+        DeviceStoreDelegate checkAdd = new DeviceStoreDelegate() {
+            @Override
+            public void notify(DeviceEvent event) {
+                assertEquals(DEVICE_ADDED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                addLatch.countDown();
+            }
+        };
+        final CountDownLatch updateLatch = new CountDownLatch(1);
+        DeviceStoreDelegate checkUpdate = new DeviceStoreDelegate() {
+            @Override
+            public void notify(DeviceEvent event) {
+                assertEquals(DEVICE_UPDATED, event.type());
+                assertDevice(DID1, SW2, event.subject());
+                updateLatch.countDown();
+            }
+        };
+        final CountDownLatch removeLatch = new CountDownLatch(1);
+        DeviceStoreDelegate checkRemove = new DeviceStoreDelegate() {
+            @Override
+            public void notify(DeviceEvent event) {
+                assertEquals(DEVICE_REMOVED, event.type());
+                assertDevice(DID1, SW2, event.subject());
+                removeLatch.countDown();
+            }
+        };
+
+        DeviceDescription description =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW1, SN);
+        deviceStore.setDelegate(checkAdd);
+        deviceStore.createOrUpdateDevice(PID, DID1, description);
+        assertTrue("Add event fired", addLatch.await(1, TimeUnit.SECONDS));
+
+
+        DeviceDescription description2 =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW2, SN);
+        deviceStore.unsetDelegate(checkAdd);
+        deviceStore.setDelegate(checkUpdate);
+        deviceStore.createOrUpdateDevice(PID, DID1, description2);
+        assertTrue("Update event fired", updateLatch.await(1, TimeUnit.SECONDS));
+
+        deviceStore.unsetDelegate(checkUpdate);
+        deviceStore.setDelegate(checkRemove);
+        deviceStore.removeDevice(DID1);
+        assertTrue("Remove event fired", removeLatch.await(1, TimeUnit.SECONDS));
+    }
+
+    private class TestDistributedDeviceStore extends DistributedDeviceStore {
+        public TestDistributedDeviceStore(StoreService storeService) {
+            this.storeService = storeService;
+        }
+    }
+}
diff --git a/core/store/hz/src/test/java/org/onlab/onos/store/impl/TestStoreManager.java b/core/store/hz/src/test/java/org/onlab/onos/store/impl/TestStoreManager.java
new file mode 100644
index 0000000..c9d8821
--- /dev/null
+++ b/core/store/hz/src/test/java/org/onlab/onos/store/impl/TestStoreManager.java
@@ -0,0 +1,54 @@
+package org.onlab.onos.store.impl;
+
+import java.io.FileNotFoundException;
+import java.util.UUID;
+
+import com.hazelcast.config.Config;
+import com.hazelcast.config.FileSystemXmlConfig;
+import com.hazelcast.core.HazelcastInstance;
+
+/**
+ * Dummy StoreManager to use specified Hazelcast instance.
+ */
+public class TestStoreManager extends StoreManager {
+
+    /**
+     * Gets the Hazelcast Config for testing.
+     *
+     * @return
+     */
+    public static Config getTestConfig() {
+        Config config;
+        try {
+            config = new FileSystemXmlConfig(HAZELCAST_XML_FILE);
+        } catch (FileNotFoundException e) {
+            // falling back to default
+            config = new Config();
+        }
+        // avoid accidentally joining other cluster
+        config.getGroupConfig().setName(UUID.randomUUID().toString());
+        // quickly form single node cluster
+        config.getNetworkConfig().getJoin()
+            .getTcpIpConfig()
+            .setEnabled(true).setConnectionTimeoutSeconds(0);
+        config.getNetworkConfig().getJoin()
+            .getMulticastConfig()
+            .setEnabled(false);
+        return config;
+    }
+
+    /**
+     * Constructor.
+     *
+     * @param instance Hazelast instance to return on #getHazelcastInstance()
+     */
+    public TestStoreManager(HazelcastInstance instance) {
+        this.instance = instance;
+    }
+
+    // Hazelcast setup removed from original code.
+    @Override
+    public void activate() {
+        setupKryoPool();
+    }
+}
diff --git a/core/store/hz/src/test/java/org/onlab/onos/store/link/impl/DistributedLinkStoreTest.java b/core/store/hz/src/test/java/org/onlab/onos/store/link/impl/DistributedLinkStoreTest.java
new file mode 100644
index 0000000..41853f6
--- /dev/null
+++ b/core/store/hz/src/test/java/org/onlab/onos/store/link/impl/DistributedLinkStoreTest.java
@@ -0,0 +1,361 @@
+package org.onlab.onos.store.link.impl;
+
+import static org.junit.Assert.*;
+import static org.onlab.onos.net.DeviceId.deviceId;
+import static org.onlab.onos.net.Link.Type.*;
+import static org.onlab.onos.net.link.LinkEvent.Type.*;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.LinkKey;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.Link.Type;
+import org.onlab.onos.net.link.DefaultLinkDescription;
+import org.onlab.onos.net.link.LinkEvent;
+import org.onlab.onos.net.link.LinkStoreDelegate;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.common.StoreService;
+import org.onlab.onos.store.impl.StoreManager;
+import org.onlab.onos.store.impl.TestStoreManager;
+
+import com.google.common.collect.Iterables;
+import com.hazelcast.config.Config;
+import com.hazelcast.core.Hazelcast;
+
+public class DistributedLinkStoreTest {
+
+    private static final ProviderId PID = new ProviderId("of", "foo");
+    private static final DeviceId DID1 = deviceId("of:foo");
+    private static final DeviceId DID2 = deviceId("of:bar");
+//    private static final String MFR = "whitebox";
+//    private static final String HW = "1.1.x";
+//    private static final String SW1 = "3.8.1";
+//    private static final String SW2 = "3.9.5";
+//    private static final String SN = "43311-12345";
+
+    private static final PortNumber P1 = PortNumber.portNumber(1);
+    private static final PortNumber P2 = PortNumber.portNumber(2);
+    private static final PortNumber P3 = PortNumber.portNumber(3);
+
+    private StoreManager storeManager;
+
+    private DistributedLinkStore linkStore;
+
+    @BeforeClass
+    public static void setUpBeforeClass() throws Exception {
+    }
+
+    @AfterClass
+    public static void tearDownAfterClass() throws Exception {
+    }
+
+    @Before
+    public void setUp() throws Exception {
+        // TODO should find a way to clean Hazelcast instance without shutdown.
+        Config config = TestStoreManager.getTestConfig();
+
+        storeManager = new TestStoreManager(Hazelcast.newHazelcastInstance(config));
+        storeManager.activate();
+
+        linkStore = new TestDistributedLinkStore(storeManager);
+        linkStore.activate();
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        linkStore.deactivate();
+        storeManager.deactivate();
+    }
+
+    private void putLink(DeviceId srcId, PortNumber srcNum,
+                         DeviceId dstId, PortNumber dstNum, Type type) {
+        ConnectPoint src = new ConnectPoint(srcId, srcNum);
+        ConnectPoint dst = new ConnectPoint(dstId, dstNum);
+        linkStore.createOrUpdateLink(PID, new DefaultLinkDescription(src, dst, type));
+    }
+
+    private void putLink(LinkKey key, Type type) {
+        putLink(key.src().deviceId(), key.src().port(),
+                key.dst().deviceId(), key.dst().port(),
+                type);
+    }
+
+    private static void assertLink(DeviceId srcId, PortNumber srcNum,
+                            DeviceId dstId, PortNumber dstNum, Type type,
+                            Link link) {
+        assertEquals(srcId, link.src().deviceId());
+        assertEquals(srcNum, link.src().port());
+        assertEquals(dstId, link.dst().deviceId());
+        assertEquals(dstNum, link.dst().port());
+        assertEquals(type, link.type());
+    }
+
+    private static void assertLink(LinkKey key, Type type, Link link) {
+        assertLink(key.src().deviceId(), key.src().port(),
+                   key.dst().deviceId(), key.dst().port(),
+                   type, link);
+    }
+
+    @Test
+    public final void testGetLinkCount() {
+        assertEquals("initialy empty", 0, linkStore.getLinkCount());
+
+        putLink(DID1, P1, DID2, P2, DIRECT);
+        putLink(DID2, P2, DID1, P1, DIRECT);
+        putLink(DID1, P1, DID2, P2, DIRECT);
+
+        assertEquals("expecting 2 unique link", 2, linkStore.getLinkCount());
+    }
+
+    @Test
+    public final void testGetLinks() {
+        assertEquals("initialy empty", 0,
+                Iterables.size(linkStore.getLinks()));
+
+        LinkKey linkId1 = new LinkKey(new ConnectPoint(DID1, P1), new ConnectPoint(DID2, P2));
+        LinkKey linkId2 = new LinkKey(new ConnectPoint(DID2, P2), new ConnectPoint(DID1, P1));
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+        putLink(linkId1, DIRECT);
+
+        assertEquals("expecting 2 unique link", 2,
+                Iterables.size(linkStore.getLinks()));
+
+        Map<LinkKey, Link> links = new HashMap<>();
+        for (Link link : linkStore.getLinks()) {
+            links.put(new LinkKey(link.src(), link.dst()), link);
+        }
+
+        assertLink(linkId1, DIRECT, links.get(linkId1));
+        assertLink(linkId2, DIRECT, links.get(linkId2));
+    }
+
+    @Test
+    public final void testGetDeviceEgressLinks() {
+        LinkKey linkId1 = new LinkKey(new ConnectPoint(DID1, P1), new ConnectPoint(DID2, P2));
+        LinkKey linkId2 = new LinkKey(new ConnectPoint(DID2, P2), new ConnectPoint(DID1, P1));
+        LinkKey linkId3 = new LinkKey(new ConnectPoint(DID1, P2), new ConnectPoint(DID2, P3));
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+        putLink(linkId3, DIRECT);
+
+        // DID1,P1 => DID2,P2
+        // DID2,P2 => DID1,P1
+        // DID1,P2 => DID2,P3
+
+        Set<Link> links1 = linkStore.getDeviceEgressLinks(DID1);
+        assertEquals(2, links1.size());
+        // check
+
+        Set<Link> links2 = linkStore.getDeviceEgressLinks(DID2);
+        assertEquals(1, links2.size());
+        assertLink(linkId2, DIRECT, links2.iterator().next());
+    }
+
+    @Test
+    public final void testGetDeviceIngressLinks() {
+        LinkKey linkId1 = new LinkKey(new ConnectPoint(DID1, P1), new ConnectPoint(DID2, P2));
+        LinkKey linkId2 = new LinkKey(new ConnectPoint(DID2, P2), new ConnectPoint(DID1, P1));
+        LinkKey linkId3 = new LinkKey(new ConnectPoint(DID1, P2), new ConnectPoint(DID2, P3));
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+        putLink(linkId3, DIRECT);
+
+        // DID1,P1 => DID2,P2
+        // DID2,P2 => DID1,P1
+        // DID1,P2 => DID2,P3
+
+        Set<Link> links1 = linkStore.getDeviceIngressLinks(DID2);
+        assertEquals(2, links1.size());
+        // check
+
+        Set<Link> links2 = linkStore.getDeviceIngressLinks(DID1);
+        assertEquals(1, links2.size());
+        assertLink(linkId2, DIRECT, links2.iterator().next());
+    }
+
+    @Test
+    public final void testGetLink() {
+        ConnectPoint src = new ConnectPoint(DID1, P1);
+        ConnectPoint dst = new ConnectPoint(DID2, P2);
+        LinkKey linkId1 = new LinkKey(src, dst);
+
+        putLink(linkId1, DIRECT);
+
+        Link link = linkStore.getLink(src, dst);
+        assertLink(linkId1, DIRECT, link);
+
+        assertNull("There shouldn't be reverese link",
+                linkStore.getLink(dst, src));
+    }
+
+    @Test
+    public final void testGetEgressLinks() {
+        final ConnectPoint d1P1 = new ConnectPoint(DID1, P1);
+        final ConnectPoint d2P2 = new ConnectPoint(DID2, P2);
+        LinkKey linkId1 = new LinkKey(d1P1, d2P2);
+        LinkKey linkId2 = new LinkKey(d2P2, d1P1);
+        LinkKey linkId3 = new LinkKey(new ConnectPoint(DID1, P2), new ConnectPoint(DID2, P3));
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+        putLink(linkId3, DIRECT);
+
+        // DID1,P1 => DID2,P2
+        // DID2,P2 => DID1,P1
+        // DID1,P2 => DID2,P3
+
+        Set<Link> links1 = linkStore.getEgressLinks(d1P1);
+        assertEquals(1, links1.size());
+        assertLink(linkId1, DIRECT, links1.iterator().next());
+
+        Set<Link> links2 = linkStore.getEgressLinks(d2P2);
+        assertEquals(1, links2.size());
+        assertLink(linkId2, DIRECT, links2.iterator().next());
+    }
+
+    @Test
+    public final void testGetIngressLinks() {
+        final ConnectPoint d1P1 = new ConnectPoint(DID1, P1);
+        final ConnectPoint d2P2 = new ConnectPoint(DID2, P2);
+        LinkKey linkId1 = new LinkKey(d1P1, d2P2);
+        LinkKey linkId2 = new LinkKey(d2P2, d1P1);
+        LinkKey linkId3 = new LinkKey(new ConnectPoint(DID1, P2), new ConnectPoint(DID2, P3));
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+        putLink(linkId3, DIRECT);
+
+        // DID1,P1 => DID2,P2
+        // DID2,P2 => DID1,P1
+        // DID1,P2 => DID2,P3
+
+        Set<Link> links1 = linkStore.getIngressLinks(d2P2);
+        assertEquals(1, links1.size());
+        assertLink(linkId1, DIRECT, links1.iterator().next());
+
+        Set<Link> links2 = linkStore.getIngressLinks(d1P1);
+        assertEquals(1, links2.size());
+        assertLink(linkId2, DIRECT, links2.iterator().next());
+    }
+
+    @Test
+    public final void testCreateOrUpdateLink() {
+        ConnectPoint src = new ConnectPoint(DID1, P1);
+        ConnectPoint dst = new ConnectPoint(DID2, P2);
+
+        // add link
+        LinkEvent event = linkStore.createOrUpdateLink(PID,
+                    new DefaultLinkDescription(src, dst, INDIRECT));
+
+        assertLink(DID1, P1, DID2, P2, INDIRECT, event.subject());
+        assertEquals(LINK_ADDED, event.type());
+
+        // update link type
+        LinkEvent event2 = linkStore.createOrUpdateLink(PID,
+                new DefaultLinkDescription(src, dst, DIRECT));
+
+        assertLink(DID1, P1, DID2, P2, DIRECT, event2.subject());
+        assertEquals(LINK_UPDATED, event2.type());
+
+        // no change
+        LinkEvent event3 = linkStore.createOrUpdateLink(PID,
+                new DefaultLinkDescription(src, dst, DIRECT));
+
+        assertNull("No change event expected", event3);
+    }
+
+    @Test
+    public final void testRemoveLink() {
+        final ConnectPoint d1P1 = new ConnectPoint(DID1, P1);
+        final ConnectPoint d2P2 = new ConnectPoint(DID2, P2);
+        LinkKey linkId1 = new LinkKey(d1P1, d2P2);
+        LinkKey linkId2 = new LinkKey(d2P2, d1P1);
+
+        putLink(linkId1, DIRECT);
+        putLink(linkId2, DIRECT);
+
+        // DID1,P1 => DID2,P2
+        // DID2,P2 => DID1,P1
+        // DID1,P2 => DID2,P3
+
+        LinkEvent event = linkStore.removeLink(d1P1, d2P2);
+        assertEquals(LINK_REMOVED, event.type());
+        LinkEvent event2 = linkStore.removeLink(d1P1, d2P2);
+        assertNull(event2);
+
+        assertLink(linkId2, DIRECT, linkStore.getLink(d2P2, d1P1));
+    }
+
+    @Test
+    public final void testEvents() throws InterruptedException {
+
+        final ConnectPoint d1P1 = new ConnectPoint(DID1, P1);
+        final ConnectPoint d2P2 = new ConnectPoint(DID2, P2);
+        final LinkKey linkId1 = new LinkKey(d1P1, d2P2);
+
+        final CountDownLatch addLatch = new CountDownLatch(1);
+        LinkStoreDelegate checkAdd = new LinkStoreDelegate() {
+            @Override
+            public void notify(LinkEvent event) {
+                assertEquals(LINK_ADDED, event.type());
+                assertLink(linkId1, INDIRECT, event.subject());
+                addLatch.countDown();
+            }
+        };
+        final CountDownLatch updateLatch = new CountDownLatch(1);
+        LinkStoreDelegate checkUpdate = new LinkStoreDelegate() {
+            @Override
+            public void notify(LinkEvent event) {
+                assertEquals(LINK_UPDATED, event.type());
+                assertLink(linkId1, DIRECT, event.subject());
+                updateLatch.countDown();
+            }
+        };
+        final CountDownLatch removeLatch = new CountDownLatch(1);
+        LinkStoreDelegate checkRemove = new LinkStoreDelegate() {
+            @Override
+            public void notify(LinkEvent event) {
+                assertEquals(LINK_REMOVED, event.type());
+                assertLink(linkId1, DIRECT, event.subject());
+                removeLatch.countDown();
+            }
+        };
+
+        linkStore.setDelegate(checkAdd);
+        putLink(linkId1, INDIRECT);
+        assertTrue("Add event fired", addLatch.await(1, TimeUnit.SECONDS));
+
+        linkStore.unsetDelegate(checkAdd);
+        linkStore.setDelegate(checkUpdate);
+        putLink(linkId1, DIRECT);
+        assertTrue("Update event fired", updateLatch.await(1, TimeUnit.SECONDS));
+
+        linkStore.unsetDelegate(checkUpdate);
+        linkStore.setDelegate(checkRemove);
+        linkStore.removeLink(d1P1, d2P2);
+        assertTrue("Remove event fired", removeLatch.await(1, TimeUnit.SECONDS));
+    }
+
+
+    class TestDistributedLinkStore extends DistributedLinkStore {
+        TestDistributedLinkStore(StoreService storeService) {
+            this.storeService = storeService;
+        }
+    }
+}