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
8 package org.opendaylight.controller.remote.rpc.registry.gossip;
10 import akka.actor.ActorRef;
11 import akka.actor.ActorRefProvider;
12 import akka.actor.ActorSelection;
13 import akka.actor.Address;
14 import akka.actor.Cancellable;
15 import akka.cluster.Cluster;
16 import akka.cluster.ClusterActorRefProvider;
17 import akka.cluster.ClusterEvent;
18 import akka.cluster.Member;
19 import akka.dispatch.Mapper;
20 import akka.event.Logging;
21 import akka.event.LoggingAdapter;
22 import akka.pattern.Patterns;
23 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedActorWithMetering;
24 import org.opendaylight.controller.remote.rpc.RemoteRpcProviderConfig;
25 import scala.concurrent.Future;
26 import scala.concurrent.duration.FiniteDuration;
28 import java.util.ArrayList;
29 import java.util.HashSet;
30 import java.util.List;
33 import java.util.concurrent.ThreadLocalRandom;
34 import java.util.concurrent.TimeUnit;
36 import static org.opendaylight.controller.remote.rpc.registry.gossip.Messages.BucketStoreMessages.GetBucketVersions;
37 import static org.opendaylight.controller.remote.rpc.registry.gossip.Messages.BucketStoreMessages.GetBucketVersionsReply;
38 import static org.opendaylight.controller.remote.rpc.registry.gossip.Messages.BucketStoreMessages.GetBucketsByMembers;
39 import static org.opendaylight.controller.remote.rpc.registry.gossip.Messages.BucketStoreMessages.GetBucketsByMembersReply;
40 import static org.opendaylight.controller.remote.rpc.registry.gossip.Messages.BucketStoreMessages.UpdateRemoteBuckets;
41 import static org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipEnvelope;
42 import static org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipStatus;
43 import static org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipTick;
46 * Gossiper that syncs bucket store across nodes in the cluster.
48 * It keeps a local scheduler that periodically sends Gossip ticks to
49 * itself to send bucket store's bucket versions to a randomly selected remote
52 * When bucket versions are received from a remote gossiper, it is compared
53 * with bucket store's bucket versions. Which ever buckets are newer
54 * locally, are sent to remote gossiper. If any bucket is older in bucket store,
55 * a gossip status is sent to remote gossiper so that it can send the newer buckets.
57 * When a bucket is received from a remote gossiper, its sent to the bucket store
62 public class Gossiper extends AbstractUntypedActorWithMetering {
64 final LoggingAdapter log = Logging.getLogger(getContext().system(), this);
66 private Cluster cluster;
69 * ActorSystem's address for the current cluster node.
71 private Address selfAddress;
74 * All known cluster members
76 private List<Address> clusterMembers = new ArrayList<>();
78 private Cancellable gossipTask;
80 private Boolean autoStartGossipTicks = true;
82 private RemoteRpcProviderConfig config;
85 config = new RemoteRpcProviderConfig(getContext().system().settings().config());
90 * @param autoStartGossipTicks used for turning off gossip ticks during testing.
91 * Gossip tick can be manually sent.
93 public Gossiper(Boolean autoStartGossipTicks){
94 this.autoStartGossipTicks = autoStartGossipTicks;
98 public void preStart(){
99 ActorRefProvider provider = getContext().provider();
100 selfAddress = provider.getDefaultAddress();
102 if ( provider instanceof ClusterActorRefProvider ) {
103 cluster = Cluster.get(getContext().system());
104 cluster.subscribe(getSelf(),
105 ClusterEvent.initialStateAsEvents(),
106 ClusterEvent.MemberEvent.class,
107 ClusterEvent.UnreachableMember.class);
110 if (autoStartGossipTicks) {
111 gossipTask = getContext().system().scheduler().schedule(
112 new FiniteDuration(1, TimeUnit.SECONDS), //initial delay
113 config.getGossipTickInterval(), //interval
115 new Messages.GossiperMessages.GossipTick(), //message
116 getContext().dispatcher(), //execution context
123 public void postStop(){
125 cluster.unsubscribe(getSelf());
126 if (gossipTask != null)
131 protected void handleReceive(Object message) throws Exception {
132 //Usually sent by self via gossip task defined above. But its not enforced.
133 //These ticks can be sent by another actor as well which is esp. useful while testing
134 if (message instanceof GossipTick)
137 //Message from remote gossiper with its bucket versions
138 else if (message instanceof GossipStatus)
139 receiveGossipStatus((GossipStatus) message);
141 //Message from remote gossiper with buckets. This is usually in response to GossipStatus message
142 //The contained buckets are newer as determined by the remote gossiper by comparing the GossipStatus
143 //message with its local versions
144 else if (message instanceof GossipEnvelope)
145 receiveGossip((GossipEnvelope) message);
147 else if (message instanceof ClusterEvent.MemberUp) {
148 receiveMemberUp(((ClusterEvent.MemberUp) message).member());
150 } else if (message instanceof ClusterEvent.MemberRemoved) {
151 receiveMemberRemoveOrUnreachable(((ClusterEvent.MemberRemoved) message).member());
153 } else if ( message instanceof ClusterEvent.UnreachableMember){
154 receiveMemberRemoveOrUnreachable(((ClusterEvent.UnreachableMember) message).member());
161 * Remove member from local copy of member list. If member down is self, then stop the actor
163 * @param member who went down
165 void receiveMemberRemoveOrUnreachable(Member member) {
166 //if its self, then stop itself
167 if (selfAddress.equals(member.address())){
168 getContext().stop(getSelf());
172 clusterMembers.remove(member.address());
173 if(log.isDebugEnabled()) {
174 log.debug("Removed member [{}], Active member list [{}]", member.address(), clusterMembers);
179 * Add member to the local copy of member list if it doesnt already
182 void receiveMemberUp(Member member) {
184 if (selfAddress.equals(member.address()))
185 return; //ignore up notification for self
187 if (!clusterMembers.contains(member.address()))
188 clusterMembers.add(member.address());
189 if(log.isDebugEnabled()) {
190 log.debug("Added member [{}], Active member list [{}]", member.address(), clusterMembers);
195 * Sends Gossip status to other members in the cluster. <br/>
196 * 1. If there are no member, ignore the tick. </br>
197 * 2. If there's only 1 member, send gossip status (bucket versions) to it. <br/>
198 * 3. If there are more than one member, randomly pick one and send gossip status (bucket versions) to it.
200 void receiveGossipTick(){
201 if (clusterMembers.size() == 0) return; //no members to send gossip status to
203 Address remoteMemberToGossipTo;
205 if (clusterMembers.size() == 1)
206 remoteMemberToGossipTo = clusterMembers.get(0);
208 Integer randomIndex = ThreadLocalRandom.current().nextInt(0, clusterMembers.size());
209 remoteMemberToGossipTo = clusterMembers.get(randomIndex);
211 if(log.isDebugEnabled()) {
212 log.debug("Gossiping to [{}]", remoteMemberToGossipTo);
214 getLocalStatusAndSendTo(remoteMemberToGossipTo);
218 * Process gossip status received from a remote gossiper. Remote versions are compared with
219 * the local copy. <p>
223 * <li>If local copy is newer, the newer buckets are sent in GossipEnvelope to remote</li>
224 * <li>If local is older, GossipStatus is sent to remote so that it can reply with GossipEnvelope</li>
225 * <li>If both are same, noop</li>
228 * @param status bucket versions from a remote member
230 void receiveGossipStatus(GossipStatus status){
231 //Don't accept messages from non-members
232 if (!clusterMembers.contains(status.from()))
235 final ActorRef sender = getSender();
236 Future<Object> futureReply =
237 Patterns.ask(getContext().parent(), new GetBucketVersions(), config.getAskDuration());
239 futureReply.map(getMapperToProcessRemoteStatus(sender, status), getContext().dispatcher());
244 * Sends the received buckets in the envelope to the parent Bucket store.
246 * @param envelope contains buckets from a remote gossiper
248 void receiveGossip(GossipEnvelope envelope){
249 //TODO: Add more validations
250 if (!selfAddress.equals(envelope.to())) {
251 if(log.isDebugEnabled()) {
252 log.debug("Ignoring message intended for someone else. From [{}] to [{}]", envelope.from(), envelope.to());
257 updateRemoteBuckets(envelope.getBuckets());
262 * Helper to send received buckets to bucket store
266 void updateRemoteBuckets(Map<Address, Bucket> buckets) {
268 UpdateRemoteBuckets updateRemoteBuckets = new UpdateRemoteBuckets(buckets);
269 getContext().parent().tell(updateRemoteBuckets, getSelf());
273 * Gets the buckets from bucket store for the given node addresses and sends them to remote gossiper
275 * @param remote remote node to send Buckets to
276 * @param addresses node addresses whose buckets needs to be sent
278 void sendGossipTo(final ActorRef remote, final Set<Address> addresses){
280 Future<Object> futureReply =
281 Patterns.ask(getContext().parent(), new GetBucketsByMembers(addresses), config.getAskDuration());
282 futureReply.map(getMapperToSendGossip(remote), getContext().dispatcher());
286 * Gets bucket versions from bucket store and sends to the supplied address
288 * @param remoteActorSystemAddress remote gossiper to send to
290 void getLocalStatusAndSendTo(Address remoteActorSystemAddress){
292 //Get local status from bucket store and send to remote
293 Future<Object> futureReply =
294 Patterns.ask(getContext().parent(), new GetBucketVersions(), config.getAskDuration());
296 //Find gossiper on remote system
297 ActorSelection remoteRef = getContext().system().actorSelection(
298 remoteActorSystemAddress.toString() + getSelf().path().toStringWithoutAddress());
300 if(log.isDebugEnabled()) {
301 log.debug("Sending bucket versions to [{}]", remoteRef);
304 futureReply.map(getMapperToSendLocalStatus(remoteRef), getContext().dispatcher());
309 * Helper to send bucket versions received from local store
310 * @param remote remote gossiper to send versions to
311 * @param localVersions bucket versions received from local store
313 void sendGossipStatusTo(ActorRef remote, Map<Address, Long> localVersions){
315 GossipStatus status = new GossipStatus(selfAddress, localVersions);
316 remote.tell(status, getSelf());
319 void sendGossipStatusTo(ActorSelection remote, Map<Address, Long> localVersions){
321 GossipStatus status = new GossipStatus(selfAddress, localVersions);
322 remote.tell(status, getSelf());
326 /// Private factories to create mappers
329 private Mapper<Object, Void> getMapperToSendLocalStatus(final ActorSelection remote){
331 return new Mapper<Object, Void>() {
333 public Void apply(Object replyMessage) {
334 if (replyMessage instanceof GetBucketVersionsReply) {
335 GetBucketVersionsReply reply = (GetBucketVersionsReply) replyMessage;
336 Map<Address, Long> localVersions = reply.getVersions();
338 sendGossipStatusTo(remote, localVersions);
347 * Process bucket versions received from
348 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.BucketStore}.
349 * Then this method compares remote bucket versions with local bucket versions.
351 * <li>The buckets that are newer locally, send
352 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipEnvelope}
354 * <li>The buckets that are older locally, send
355 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipStatus}
356 * to remote so that remote sends GossipEnvelop.
359 * @param sender the remote member
360 * @param status bucket versions from a remote member
361 * @return a {@link akka.dispatch.Mapper} that gets evaluated in future
364 private Mapper<Object, Void> getMapperToProcessRemoteStatus(final ActorRef sender, final GossipStatus status){
366 final Map<Address, Long> remoteVersions = status.getVersions();
368 return new Mapper<Object, Void>() {
370 public Void apply(Object replyMessage) {
371 if (replyMessage instanceof GetBucketVersionsReply) {
372 GetBucketVersionsReply reply = (GetBucketVersionsReply) replyMessage;
373 Map<Address, Long> localVersions = reply.getVersions();
375 //diff between remote list and local
376 Set<Address> localIsOlder = new HashSet<>();
377 localIsOlder.addAll(remoteVersions.keySet());
378 localIsOlder.removeAll(localVersions.keySet());
380 //diff between local list and remote
381 Set<Address> localIsNewer = new HashSet<>();
382 localIsNewer.addAll(localVersions.keySet());
383 localIsNewer.removeAll(remoteVersions.keySet());
386 for (Address address : remoteVersions.keySet()){
388 if (localVersions.get(address) == null || remoteVersions.get(address) == null)
389 continue; //this condition is taken care of by above diffs
390 if (localVersions.get(address) < remoteVersions.get(address))
391 localIsOlder.add(address);
392 else if (localVersions.get(address) > remoteVersions.get(address))
393 localIsNewer.add(address);
396 if (!localIsOlder.isEmpty())
397 sendGossipStatusTo(sender, localVersions );
399 if (!localIsNewer.isEmpty())
400 sendGossipTo(sender, localIsNewer);//send newer buckets to remote
409 * Processes the message from {@link org.opendaylight.controller.remote.rpc.registry.gossip.BucketStore}
410 * that contains {@link org.opendaylight.controller.remote.rpc.registry.gossip.Bucket}.
411 * These buckets are sent to a remote member encapsulated in
412 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipEnvelope}
414 * @param sender the remote member that sent
415 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipStatus}
416 * in reply to which bucket is being sent back
417 * @return a {@link akka.dispatch.Mapper} that gets evaluated in future
420 private Mapper<Object, Void> getMapperToSendGossip(final ActorRef sender) {
422 return new Mapper<Object, Void>() {
424 public Void apply(Object msg) {
425 if (msg instanceof GetBucketsByMembersReply) {
426 Map<Address, Bucket> buckets = ((GetBucketsByMembersReply) msg).getBuckets();
427 if(log.isDebugEnabled()) {
428 log.debug("Buckets to send from {}: {}", selfAddress, buckets);
430 GossipEnvelope envelope = new GossipEnvelope(selfAddress, sender.path().address(), buckets);
431 sender.tell(envelope, getSelf());
441 List<Address> getClusterMembers() {
442 return clusterMembers;
445 void setClusterMembers(List<Address> clusterMembers) {
446 this.clusterMembers = clusterMembers;
449 Address getSelfAddress() {
453 void setSelfAddress(Address selfAddress) {
454 this.selfAddress = selfAddress;