2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
9 package org.opendaylight.controller.cluster.datastore;
11 import akka.actor.ActorPath;
12 import akka.actor.ActorRef;
13 import akka.actor.Address;
14 import akka.actor.Props;
15 import akka.actor.UntypedActor;
16 import akka.event.Logging;
17 import akka.event.LoggingAdapter;
18 import akka.japi.Creator;
19 import org.opendaylight.controller.cluster.datastore.messages.FindPrimary;
20 import org.opendaylight.controller.cluster.datastore.messages.PrimaryFound;
21 import org.opendaylight.controller.cluster.datastore.messages.PrimaryNotFound;
22 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
24 import java.util.HashMap;
25 import java.util.List;
29 * The ShardManager has the following jobs,
31 * <li> Create all the local shard replicas that belong on this cluster member
32 * <li> Find the primary replica for any given shard
33 * <li> Engage in shard replica elections which decide which replica should be the primary
36 * <h3>>Creation of Shard replicas</h3
38 * When the ShardManager is constructed it reads the cluster configuration to find out which shard replicas
39 * belong on this member. It finds out the name of the current cluster member from the Akka Clustering Service.
42 * <h3> Replica Elections </h3>
45 * The Shard Manager uses multiple cues to initiate election.
46 * <li> When a member of the cluster dies
47 * <li> When a local shard replica dies
48 * <li> When a local shard replica comes alive
51 public class ShardManager extends UntypedActor {
53 // Stores a mapping between a shard name and the address of the current primary
54 private final Map<String, Address> shardNameToPrimaryAddress = new HashMap<>();
56 // Stores a mapping between a member name and the address of the member
57 private final Map<String, Address> memberNameToAddress = new HashMap<>();
59 // Stores a mapping between the shard name and all the members on which a replica of that shard are available
60 private final Map<String, List<String>> shardNameToMembers = new HashMap<>();
62 private final LoggingAdapter log = Logging.getLogger(getContext().system(), this);
64 private final ActorPath defaultShardPath;
68 * @param type defines the kind of data that goes into shards created by this shard manager. Examples of type would be
69 * configuration or operational
71 private ShardManager(String type){
72 ActorRef actor = getContext().actorOf(Shard.props(Shard.DEFAULT_NAME + "-" + type));
73 defaultShardPath = actor.path();
76 public static Props props(final String type){
77 return Props.create(new Creator<ShardManager>(){
80 public ShardManager create() throws Exception {
81 return new ShardManager(type);
87 public void onReceive(Object message) throws Exception {
88 if (message instanceof FindPrimary) {
89 FindPrimary msg = ((FindPrimary) message);
90 String shardName = msg.getShardName();
91 if(Shard.DEFAULT_NAME.equals(shardName)){
92 getSender().tell(new PrimaryFound(defaultShardPath.toString()), getSelf());
94 getSender().tell(new PrimaryNotFound(shardName), getSelf());
96 } else if(message instanceof UpdateSchemaContext){
97 // FIXME : Notify all local shards of a context change
98 getContext().system().actorSelection(defaultShardPath).forward(message, getContext());