First round of ClusterMetadata improvements:
    Introduced a PartitionId type for identifying partitions
    Introduced a admin service for making metadata updates
    Update cluster.json format to specify all partitions (including p0) and changed partitionId to be an int.

Change-Id: Ia0617f1ed0ce886680dcee4f5396a4bbdfa225da
diff --git a/core/store/dist/src/main/java/org/onosproject/store/cluster/impl/DefaultPartition.java b/core/store/dist/src/main/java/org/onosproject/store/cluster/impl/DefaultPartition.java
new file mode 100644
index 0000000..82a3ba7
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onosproject/store/cluster/impl/DefaultPartition.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2015-2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.store.cluster.impl;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Objects;
+
+import org.onosproject.cluster.NodeId;
+import org.onosproject.cluster.Partition;
+import org.onosproject.cluster.PartitionId;
+
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Sets;
+
+/**
+ * Default {@link Partition} implementation.
+ */
+public class DefaultPartition implements Partition {
+
+    private final PartitionId id;
+    private final Collection<NodeId> members;
+
+    private DefaultPartition() {
+        id = null;
+        members = null;
+    }
+
+    public DefaultPartition(PartitionId id, Collection<NodeId> members) {
+        this.id = checkNotNull(id);
+        this.members = ImmutableSet.copyOf(members);
+    }
+
+    @Override
+    public PartitionId getId() {
+        return this.id;
+    }
+
+    @Override
+    public Collection<NodeId> getMembers() {
+        return this.members;
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("id", id)
+                .add("members", members)
+                .toString();
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, members);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (!(other instanceof DefaultPartition)) {
+            return false;
+        }
+        DefaultPartition that = (DefaultPartition) other;
+        return this.getId().equals(that.getId()) &&
+                Sets.symmetricDifference(Sets.newHashSet(this.members), Sets.newHashSet(that.members)).isEmpty();
+    }
+}
\ No newline at end of file
diff --git a/core/store/dist/src/main/java/org/onosproject/store/cluster/impl/StaticClusterMetadataStore.java b/core/store/dist/src/main/java/org/onosproject/store/cluster/impl/StaticClusterMetadataStore.java
index 3cd992b..da4ec99 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/cluster/impl/StaticClusterMetadataStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/cluster/impl/StaticClusterMetadataStore.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright 2015-2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package org.onosproject.store.cluster.impl;
 
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -28,6 +43,7 @@
 import org.onosproject.cluster.DefaultControllerNode;
 import org.onosproject.cluster.NodeId;
 import org.onosproject.cluster.Partition;
+import org.onosproject.cluster.PartitionId;
 import org.onosproject.store.AbstractStore;
 import org.onosproject.store.service.Versioned;
 import org.slf4j.Logger;
@@ -44,6 +60,7 @@
 import com.fasterxml.jackson.databind.module.SimpleModule;
 import com.google.common.base.Throwables;
 import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
 import com.google.common.io.Files;
 
 /**
@@ -76,6 +93,7 @@
         module.addDeserializer(NodeId.class, new NodeIdDeserializer());
         module.addSerializer(ControllerNode.class, new ControllerNodeSerializer());
         module.addDeserializer(ControllerNode.class, new ControllerNodeDeserializer());
+        module.addDeserializer(Partition.class, new PartitionDeserializer());
         mapper.registerModule(module);
         File metadataFile = new File(CLUSTER_METADATA_FILE);
         if (metadataFile.exists()) {
@@ -89,10 +107,21 @@
             String localIp = getSiteLocalAddress();
             ControllerNode localNode =
                     new DefaultControllerNode(new NodeId(localIp), IpAddress.valueOf(localIp), DEFAULT_ONOS_PORT);
+            Partition defaultPartition = new Partition() {
+                @Override
+                public PartitionId getId() {
+                    return PartitionId.from(1);
+                }
+
+                @Override
+                public Collection<NodeId> getMembers() {
+                    return Sets.newHashSet(localNode.id());
+                }
+            };
             metadata.set(ClusterMetadata.builder()
                     .withName("default")
                     .withControllerNodes(Arrays.asList(localNode))
-                    .withPartitions(Lists.newArrayList(new Partition("p1", Lists.newArrayList(localNode.id()))))
+                    .withPartitions(Lists.newArrayList(defaultPartition))
                     .build());
             version = System.currentTimeMillis();
         }
@@ -138,25 +167,33 @@
     }
 
     @Override
-    public void setActiveReplica(String partitionId, NodeId nodeId) {
+    public void addActivePartitionMember(PartitionId partitionId, NodeId nodeId) {
         throw new UnsupportedOperationException();
     }
 
     @Override
-    public void unsetActiveReplica(String partitionId, NodeId nodeId) {
+    public void removeActivePartitionMember(PartitionId partitionId, NodeId nodeId) {
         throw new UnsupportedOperationException();
     }
 
     @Override
-    public Collection<NodeId> getActiveReplicas(String partitionId) {
+    public Collection<NodeId> getActivePartitionMembers(PartitionId partitionId) {
         return metadata.get().getPartitions()
                        .stream()
-                       .filter(r -> r.getName().equals(partitionId))
+                       .filter(r -> r.getId().equals(partitionId))
                        .findFirst()
                        .map(r -> r.getMembers())
                        .orElse(null);
     }
 
+    private static class PartitionDeserializer extends JsonDeserializer<Partition> {
+        @Override
+        public Partition deserialize(JsonParser jp, DeserializationContext ctxt)
+                throws IOException, JsonProcessingException {
+            return jp.readValueAs(DefaultPartition.class);
+        }
+    }
+
     private static class ControllerNodeSerializer extends JsonSerializer<ControllerNode> {
         @Override
         public void serialize(ControllerNode node, JsonGenerator jgen, SerializerProvider provider)
diff --git a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseManager.java b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseManager.java
index 90d81ee..8436526 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseManager.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseManager.java
@@ -53,6 +53,7 @@
 import org.onosproject.cluster.ClusterService;
 import org.onosproject.cluster.ControllerNode;
 import org.onosproject.cluster.NodeId;
+import org.onosproject.cluster.PartitionId;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.core.IdGenerator;
 import org.onosproject.persistence.PersistenceService;
@@ -82,6 +83,7 @@
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 
 import static org.slf4j.LoggerFactory.getLogger;
@@ -151,12 +153,11 @@
     public void activate() {
         localNodeId = clusterService.getLocalNode().id();
 
-        Map<String, Set<NodeId>> partitionMap = Maps.newHashMap();
+        Map<PartitionId, Set<NodeId>> partitionMap = Maps.newHashMap();
         clusterMetadataService.getClusterMetadata().getPartitions().forEach(p -> {
-            partitionMap.put(p.getName(), Sets.newHashSet(p.getMembers()));
+            partitionMap.put(p.getId(), Sets.newHashSet(p.getMembers()));
         });
 
-
         String[] activeNodeUris = partitionMap.values()
                     .stream()
                     .reduce((s1, s2) -> Sets.union(s1, s2))
@@ -183,28 +184,19 @@
 
         coordinator = new DefaultClusterCoordinator(copycatConfig.resolve());
 
-        DatabaseConfig inMemoryDatabaseConfig =
-                newDatabaseConfig(BASE_PARTITION_NAME, newInMemoryLog(), activeNodeUris);
-        inMemoryDatabase = coordinator
-                .getResource(inMemoryDatabaseConfig.getName(), inMemoryDatabaseConfig.resolve(clusterConfig)
-                .withSerializer(copycatConfig.getDefaultSerializer())
-                .withDefaultExecutor(copycatConfig.getDefaultExecutor()));
+        Function<PartitionId, Log> logFunction = id -> id.asInt() == 0 ? newInMemoryLog() : newPersistentLog();
 
-        List<Database> partitions = partitionMap.entrySet()
-            .stream()
-            .map(entry -> {
-                String[] replicas = entry.getValue().stream().map(this::nodeIdToUri).toArray(String[]::new);
-                return newDatabaseConfig(entry.getKey(), newPersistentLog(), replicas);
-                })
-            .map(config -> {
-                Database db = coordinator.getResource(config.getName(), config.resolve(clusterConfig)
-                        .withSerializer(copycatConfig.getDefaultSerializer())
-                        .withDefaultExecutor(copycatConfig.getDefaultExecutor()));
-                return db;
-            })
-            .collect(Collectors.toList());
+        Map<PartitionId, Database> databases = Maps.transformEntries(partitionMap, (k, v) -> {
+                    String[] replicas = v.stream().map(this::nodeIdToUri).toArray(String[]::new);
+                    DatabaseConfig config = newDatabaseConfig(String.format("p%s", k), logFunction.apply(k), replicas);
+                    return coordinator.getResource(config.getName(), config.resolve(clusterConfig)
+                            .withSerializer(copycatConfig.getDefaultSerializer())
+                            .withDefaultExecutor(copycatConfig.getDefaultExecutor()));
+        });
 
-        partitionedDatabase = new PartitionedDatabase("onos-store", partitions);
+        inMemoryDatabase = databases.remove(PartitionId.from(0));
+
+        partitionedDatabase = new PartitionedDatabase("onos-store", databases.values());
 
         CompletableFuture<Void> status = coordinator.open()
             .thenCompose(v -> CompletableFuture.allOf(inMemoryDatabase.open(), partitionedDatabase.open())