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.pattern.Patterns;
21 import com.google.common.annotations.VisibleForTesting;
22 import com.google.common.base.Preconditions;
23 import java.util.ArrayList;
24 import java.util.HashSet;
25 import java.util.List;
28 import java.util.concurrent.ThreadLocalRandom;
29 import java.util.concurrent.TimeUnit;
30 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedActorWithMetering;
31 import org.opendaylight.controller.remote.rpc.RemoteRpcProviderConfig;
32 import org.opendaylight.controller.remote.rpc.registry.gossip.Messages.BucketStoreMessages.GetBucketVersions;
33 import org.opendaylight.controller.remote.rpc.registry.gossip.Messages.BucketStoreMessages.GetBucketVersionsReply;
34 import org.opendaylight.controller.remote.rpc.registry.gossip.Messages.BucketStoreMessages.GetBucketsByMembers;
35 import org.opendaylight.controller.remote.rpc.registry.gossip.Messages.BucketStoreMessages.GetBucketsByMembersReply;
36 import org.opendaylight.controller.remote.rpc.registry.gossip.Messages.BucketStoreMessages.UpdateRemoteBuckets;
37 import org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipEnvelope;
38 import org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipStatus;
39 import org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipTick;
40 import org.slf4j.Logger;
41 import org.slf4j.LoggerFactory;
42 import scala.concurrent.Future;
43 import scala.concurrent.duration.FiniteDuration;
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
61 public class Gossiper extends AbstractUntypedActorWithMetering {
63 private final Logger log = LoggerFactory.getLogger(getClass());
65 private Cluster cluster;
68 * ActorSystem's address for the current cluster node.
70 private Address selfAddress;
73 * All known cluster members.
75 private List<Address> clusterMembers = new ArrayList<>();
77 private Cancellable gossipTask;
79 private Boolean autoStartGossipTicks = true;
81 private final RemoteRpcProviderConfig config;
83 public Gossiper(RemoteRpcProviderConfig config) {
84 this.config = Preconditions.checkNotNull(config);
88 * Constructor for testing.
90 * @param autoStartGossipTicks used for turning off gossip ticks during testing.
91 * Gossip tick can be manually sent.
94 public Gossiper(Boolean autoStartGossipTicks, RemoteRpcProviderConfig config) {
96 this.autoStartGossipTicks = autoStartGossipTicks;
100 public void preStart() {
101 ActorRefProvider provider = getContext().provider();
102 selfAddress = provider.getDefaultAddress();
104 if ( provider instanceof ClusterActorRefProvider ) {
105 cluster = Cluster.get(getContext().system());
106 cluster.subscribe(getSelf(),
107 ClusterEvent.initialStateAsEvents(),
108 ClusterEvent.MemberEvent.class,
109 ClusterEvent.UnreachableMember.class);
112 if (autoStartGossipTicks) {
113 gossipTask = getContext().system().scheduler().schedule(
114 new FiniteDuration(1, TimeUnit.SECONDS), //initial delay
115 config.getGossipTickInterval(), //interval
117 new Messages.GossiperMessages.GossipTick(), //message
118 getContext().dispatcher(), //execution context
125 public void postStop() {
126 if (cluster != null) {
127 cluster.unsubscribe(getSelf());
129 if (gossipTask != null) {
134 @SuppressWarnings({ "rawtypes", "unchecked" })
136 protected void handleReceive(Object message) throws Exception {
137 //Usually sent by self via gossip task defined above. But its not enforced.
138 //These ticks can be sent by another actor as well which is esp. useful while testing
139 if (message instanceof GossipTick) {
141 } else if (message instanceof GossipStatus) {
142 // Message from remote gossiper with its bucket versions
143 receiveGossipStatus((GossipStatus) message);
144 } else if (message instanceof GossipEnvelope) {
145 // Message from remote gossiper with buckets. This is usually in response to GossipStatus
146 // message. The contained buckets are newer as determined by the remote gossiper by
147 // comparing the GossipStatus message with its local versions.
148 receiveGossip((GossipEnvelope) message);
149 } else if (message instanceof ClusterEvent.MemberUp) {
150 receiveMemberUp(((ClusterEvent.MemberUp) message).member());
152 } else if (message instanceof ClusterEvent.MemberRemoved) {
153 receiveMemberRemoveOrUnreachable(((ClusterEvent.MemberRemoved) message).member());
155 } else if ( message instanceof ClusterEvent.UnreachableMember) {
156 receiveMemberRemoveOrUnreachable(((ClusterEvent.UnreachableMember) message).member());
164 * Remove member from local copy of member list. If member down is self, then stop the actor
166 * @param member who went down
168 void receiveMemberRemoveOrUnreachable(Member member) {
169 //if its self, then stop itself
170 if (selfAddress.equals(member.address())) {
171 getContext().stop(getSelf());
175 clusterMembers.remove(member.address());
176 log.debug("Removed member [{}], Active member list [{}]", member.address(), clusterMembers);
180 * Add member to the local copy of member list if it doesn't already.
182 * @param member the member to add
184 void receiveMemberUp(Member member) {
186 if (selfAddress.equals(member.address())) {
187 return; //ignore up notification for self
190 if (!clusterMembers.contains(member.address())) {
191 clusterMembers.add(member.address());
194 log.debug("Added member [{}], Active member list [{}]", member.address(), clusterMembers);
198 * Sends Gossip status to other members in the cluster.
200 * 1. If there are no member, ignore the tick. <br>
201 * 2. If there's only 1 member, send gossip status (bucket versions) to it. <br>
202 * 3. If there are more than one member, randomly pick one and send gossip status (bucket versions) to it.
204 void receiveGossipTick() {
205 if (clusterMembers.size() == 0) {
206 return; //no members to send gossip status to
209 Address remoteMemberToGossipTo;
211 if (clusterMembers.size() == 1) {
212 remoteMemberToGossipTo = clusterMembers.get(0);
214 Integer randomIndex = ThreadLocalRandom.current().nextInt(0, clusterMembers.size());
215 remoteMemberToGossipTo = clusterMembers.get(randomIndex);
218 log.trace("Gossiping to [{}]", remoteMemberToGossipTo);
219 getLocalStatusAndSendTo(remoteMemberToGossipTo);
223 * Process gossip status received from a remote gossiper. Remote versions are compared with
228 * <li>If local copy is newer, the newer buckets are sent in GossipEnvelope to remote</li>
229 * <li>If local is older, GossipStatus is sent to remote so that it can reply with GossipEnvelope</li>
230 * <li>If both are same, noop</li>
233 * @param status bucket versions from a remote member
235 void receiveGossipStatus(GossipStatus status) {
236 //Don't accept messages from non-members
237 if (!clusterMembers.contains(status.from())) {
241 final ActorRef sender = getSender();
242 Future<Object> futureReply =
243 Patterns.ask(getContext().parent(), new GetBucketVersions(), config.getAskDuration());
245 futureReply.map(getMapperToProcessRemoteStatus(sender, status), getContext().dispatcher());
250 * Sends the received buckets in the envelope to the parent Bucket store.
252 * @param envelope contains buckets from a remote gossiper
254 <T extends Copier<T>> void receiveGossip(GossipEnvelope<T> envelope) {
255 //TODO: Add more validations
256 if (!selfAddress.equals(envelope.to())) {
257 if (log.isTraceEnabled()) {
258 log.trace("Ignoring message intended for someone else. From [{}] to [{}]", envelope.from(),
264 updateRemoteBuckets(envelope.getBuckets());
269 * Helper to send received buckets to bucket store.
271 * @param buckets map of Buckets to update
273 <T extends Copier<T>> void updateRemoteBuckets(Map<Address, Bucket<T>> buckets) {
274 UpdateRemoteBuckets<T> updateRemoteBuckets = new UpdateRemoteBuckets<>(buckets);
275 getContext().parent().tell(updateRemoteBuckets, getSelf());
279 * Gets the buckets from bucket store for the given node addresses and sends them to remote gossiper.
281 * @param remote remote node to send Buckets to
282 * @param addresses node addresses whose buckets needs to be sent
284 void sendGossipTo(final ActorRef remote, final Set<Address> addresses) {
286 Future<Object> futureReply =
287 Patterns.ask(getContext().parent(), new GetBucketsByMembers(addresses), config.getAskDuration());
288 futureReply.map(getMapperToSendGossip(remote), getContext().dispatcher());
292 * Gets bucket versions from bucket store and sends to the supplied address.
294 * @param remoteActorSystemAddress remote gossiper to send to
296 void getLocalStatusAndSendTo(Address remoteActorSystemAddress) {
298 //Get local status from bucket store and send to remote
299 Future<Object> futureReply =
300 Patterns.ask(getContext().parent(), new GetBucketVersions(), config.getAskDuration());
302 //Find gossiper on remote system
303 ActorSelection remoteRef = getContext().system().actorSelection(
304 remoteActorSystemAddress.toString() + getSelf().path().toStringWithoutAddress());
306 log.trace("Sending bucket versions to [{}]", remoteRef);
308 futureReply.map(getMapperToSendLocalStatus(remoteRef), getContext().dispatcher());
313 * Helper to send bucket versions received from local store.
315 * @param remote remote gossiper to send versions to
316 * @param localVersions bucket versions received from local store
318 void sendGossipStatusTo(ActorRef remote, Map<Address, Long> localVersions) {
320 GossipStatus status = new GossipStatus(selfAddress, localVersions);
321 remote.tell(status, getSelf());
324 void sendGossipStatusTo(ActorSelection remote, Map<Address, Long> localVersions) {
326 GossipStatus status = new GossipStatus(selfAddress, localVersions);
327 remote.tell(status, getSelf());
331 /// Private factories to create mappers
334 private Mapper<Object, Void> getMapperToSendLocalStatus(final ActorSelection remote) {
336 return new Mapper<Object, Void>() {
338 public Void apply(Object replyMessage) {
339 if (replyMessage instanceof GetBucketVersionsReply) {
340 GetBucketVersionsReply reply = (GetBucketVersionsReply) replyMessage;
341 Map<Address, Long> localVersions = reply.getVersions();
343 sendGossipStatusTo(remote, localVersions);
352 * Process bucket versions received from
353 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.BucketStore}.
354 * Then this method compares remote bucket versions with local bucket versions.
356 * <li>The buckets that are newer locally, send
357 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipEnvelope}
359 * <li>The buckets that are older locally, send
360 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipStatus}
361 * to remote so that remote sends GossipEnvelop.
364 * @param sender the remote member
365 * @param status bucket versions from a remote member
366 * @return a {@link akka.dispatch.Mapper} that gets evaluated in future
369 private Mapper<Object, Void> getMapperToProcessRemoteStatus(final ActorRef sender, final GossipStatus status) {
371 final Map<Address, Long> remoteVersions = status.getVersions();
373 return new Mapper<Object, Void>() {
375 public Void apply(Object replyMessage) {
376 if (replyMessage instanceof GetBucketVersionsReply) {
377 GetBucketVersionsReply reply = (GetBucketVersionsReply) replyMessage;
378 Map<Address, Long> localVersions = reply.getVersions();
380 //diff between remote list and local
381 Set<Address> localIsOlder = new HashSet<>();
382 localIsOlder.addAll(remoteVersions.keySet());
383 localIsOlder.removeAll(localVersions.keySet());
385 //diff between local list and remote
386 Set<Address> localIsNewer = new HashSet<>();
387 localIsNewer.addAll(localVersions.keySet());
388 localIsNewer.removeAll(remoteVersions.keySet());
391 for (Address address : remoteVersions.keySet()) {
393 if (localVersions.get(address) == null || remoteVersions.get(address) == null) {
394 continue; //this condition is taken care of by above diffs
396 if (localVersions.get(address) < remoteVersions.get(address)) {
397 localIsOlder.add(address);
398 } else if (localVersions.get(address) > remoteVersions.get(address)) {
399 localIsNewer.add(address);
403 if (!localIsOlder.isEmpty()) {
404 sendGossipStatusTo(sender, localVersions );
407 if (!localIsNewer.isEmpty()) {
408 sendGossipTo(sender, localIsNewer);//send newer buckets to remote
418 * Processes the message from {@link org.opendaylight.controller.remote.rpc.registry.gossip.BucketStore}
419 * that contains {@link org.opendaylight.controller.remote.rpc.registry.gossip.Bucket}.
420 * These buckets are sent to a remote member encapsulated in
421 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipEnvelope}
423 * @param sender the remote member that sent
424 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipStatus}
425 * in reply to which bucket is being sent back
426 * @return a {@link akka.dispatch.Mapper} that gets evaluated in future
429 private Mapper<Object, Void> getMapperToSendGossip(final ActorRef sender) {
431 return new Mapper<Object, Void>() {
432 @SuppressWarnings({ "rawtypes", "unchecked" })
434 public Void apply(Object msg) {
435 if (msg instanceof GetBucketsByMembersReply) {
436 Map<Address, Bucket<?>> buckets = ((GetBucketsByMembersReply) msg).getBuckets();
437 log.trace("Buckets to send from {}: {}", selfAddress, buckets);
438 GossipEnvelope envelope = new GossipEnvelope(selfAddress, sender.path().address(), buckets);
439 sender.tell(envelope, getSelf());
449 List<Address> getClusterMembers() {
450 return clusterMembers;
453 void setClusterMembers(List<Address> clusterMembers) {
454 this.clusterMembers = clusterMembers;
457 Address getSelfAddress() {
461 void setSelfAddress(Address selfAddress) {
462 this.selfAddress = selfAddress;