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.
49 * It keeps a local scheduler that periodically sends Gossip ticks to
50 * itself to send bucket store's bucket versions to a randomly selected remote
54 * When bucket versions are received from a remote gossiper, it is compared
55 * with bucket store's bucket versions. Which ever buckets are newer
56 * locally, are sent to remote gossiper. If any bucket is older in bucket store,
57 * a gossip status is sent to remote gossiper so that it can send the newer buckets.
60 * When a bucket is received from a remote gossiper, its sent to the bucket store
63 public class Gossiper extends AbstractUntypedActorWithMetering {
65 private final Logger log = LoggerFactory.getLogger(getClass());
67 private Cluster cluster;
70 * ActorSystem's address for the current cluster node.
72 private Address selfAddress;
75 * All known cluster members.
77 private List<Address> clusterMembers = new ArrayList<>();
79 private Cancellable gossipTask;
81 private Boolean autoStartGossipTicks = true;
83 private final RemoteRpcProviderConfig config;
85 public Gossiper(RemoteRpcProviderConfig config) {
86 this.config = Preconditions.checkNotNull(config);
90 * Constructor for testing.
92 * @param autoStartGossipTicks used for turning off gossip ticks during testing.
93 * Gossip tick can be manually sent.
96 public Gossiper(Boolean autoStartGossipTicks, RemoteRpcProviderConfig config) {
98 this.autoStartGossipTicks = autoStartGossipTicks;
102 public void preStart() {
103 ActorRefProvider provider = getContext().provider();
104 selfAddress = provider.getDefaultAddress();
106 if ( provider instanceof ClusterActorRefProvider ) {
107 cluster = Cluster.get(getContext().system());
108 cluster.subscribe(getSelf(),
109 ClusterEvent.initialStateAsEvents(),
110 ClusterEvent.MemberEvent.class,
111 ClusterEvent.UnreachableMember.class);
114 if (autoStartGossipTicks) {
115 gossipTask = getContext().system().scheduler().schedule(
116 new FiniteDuration(1, TimeUnit.SECONDS), //initial delay
117 config.getGossipTickInterval(), //interval
119 new Messages.GossiperMessages.GossipTick(), //message
120 getContext().dispatcher(), //execution context
127 public void postStop() {
128 if (cluster != null) {
129 cluster.unsubscribe(getSelf());
131 if (gossipTask != null) {
136 @SuppressWarnings({ "rawtypes", "unchecked" })
138 protected void handleReceive(Object message) throws Exception {
139 //Usually sent by self via gossip task defined above. But its not enforced.
140 //These ticks can be sent by another actor as well which is esp. useful while testing
141 if (message instanceof GossipTick) {
143 } else if (message instanceof GossipStatus) {
144 // Message from remote gossiper with its bucket versions
145 receiveGossipStatus((GossipStatus) message);
146 } else if (message instanceof GossipEnvelope) {
147 // Message from remote gossiper with buckets. This is usually in response to GossipStatus
148 // message. The contained buckets are newer as determined by the remote gossiper by
149 // comparing the GossipStatus message with its local versions.
150 receiveGossip((GossipEnvelope) message);
151 } else if (message instanceof ClusterEvent.MemberUp) {
152 receiveMemberUp(((ClusterEvent.MemberUp) message).member());
154 } else if (message instanceof ClusterEvent.MemberRemoved) {
155 receiveMemberRemoveOrUnreachable(((ClusterEvent.MemberRemoved) message).member());
157 } else if ( message instanceof ClusterEvent.UnreachableMember) {
158 receiveMemberRemoveOrUnreachable(((ClusterEvent.UnreachableMember) message).member());
166 * Remove member from local copy of member list. If member down is self, then stop the actor
168 * @param member who went down
170 void receiveMemberRemoveOrUnreachable(Member member) {
171 //if its self, then stop itself
172 if (selfAddress.equals(member.address())) {
173 getContext().stop(getSelf());
177 clusterMembers.remove(member.address());
178 log.debug("Removed member [{}], Active member list [{}]", member.address(), clusterMembers);
182 * Add member to the local copy of member list if it doesn't already.
184 * @param member the member to add
186 void receiveMemberUp(Member member) {
188 if (selfAddress.equals(member.address())) {
189 return; //ignore up notification for self
192 if (!clusterMembers.contains(member.address())) {
193 clusterMembers.add(member.address());
196 log.debug("Added member [{}], Active member list [{}]", member.address(), clusterMembers);
200 * Sends Gossip status to other members in the cluster.
202 * 1. If there are no member, ignore the tick. <br>
203 * 2. If there's only 1 member, send gossip status (bucket versions) to it. <br>
204 * 3. If there are more than one member, randomly pick one and send gossip status (bucket versions) to it.
206 void receiveGossipTick() {
207 if (clusterMembers.size() == 0) {
208 return; //no members to send gossip status to
211 Address remoteMemberToGossipTo;
213 if (clusterMembers.size() == 1) {
214 remoteMemberToGossipTo = clusterMembers.get(0);
216 Integer randomIndex = ThreadLocalRandom.current().nextInt(0, clusterMembers.size());
217 remoteMemberToGossipTo = clusterMembers.get(randomIndex);
220 log.trace("Gossiping to [{}]", remoteMemberToGossipTo);
221 getLocalStatusAndSendTo(remoteMemberToGossipTo);
225 * Process gossip status received from a remote gossiper. Remote versions are compared with
230 * <li>If local copy is newer, the newer buckets are sent in GossipEnvelope to remote</li>
231 * <li>If local is older, GossipStatus is sent to remote so that it can reply with GossipEnvelope</li>
232 * <li>If both are same, noop</li>
235 * @param status bucket versions from a remote member
237 void receiveGossipStatus(GossipStatus status) {
238 //Don't accept messages from non-members
239 if (!clusterMembers.contains(status.from())) {
243 final ActorRef sender = getSender();
244 Future<Object> futureReply =
245 Patterns.ask(getContext().parent(), new GetBucketVersions(), config.getAskDuration());
247 futureReply.map(getMapperToProcessRemoteStatus(sender, status), getContext().dispatcher());
252 * Sends the received buckets in the envelope to the parent Bucket store.
254 * @param envelope contains buckets from a remote gossiper
256 <T extends Copier<T>> void receiveGossip(GossipEnvelope<T> envelope) {
257 //TODO: Add more validations
258 if (!selfAddress.equals(envelope.to())) {
259 if (log.isTraceEnabled()) {
260 log.trace("Ignoring message intended for someone else. From [{}] to [{}]", envelope.from(),
266 updateRemoteBuckets(envelope.getBuckets());
271 * Helper to send received buckets to bucket store.
273 * @param buckets map of Buckets to update
275 <T extends Copier<T>> void updateRemoteBuckets(Map<Address, Bucket<T>> buckets) {
276 UpdateRemoteBuckets<T> updateRemoteBuckets = new UpdateRemoteBuckets<>(buckets);
277 getContext().parent().tell(updateRemoteBuckets, getSelf());
281 * Gets the buckets from bucket store for the given node addresses and sends them to remote gossiper.
283 * @param remote remote node to send Buckets to
284 * @param addresses node addresses whose buckets needs to be sent
286 void sendGossipTo(final ActorRef remote, final Set<Address> addresses) {
288 Future<Object> futureReply =
289 Patterns.ask(getContext().parent(), new GetBucketsByMembers(addresses), config.getAskDuration());
290 futureReply.map(getMapperToSendGossip(remote), getContext().dispatcher());
294 * Gets bucket versions from bucket store and sends to the supplied address.
296 * @param remoteActorSystemAddress remote gossiper to send to
298 void getLocalStatusAndSendTo(Address remoteActorSystemAddress) {
300 //Get local status from bucket store and send to remote
301 Future<Object> futureReply =
302 Patterns.ask(getContext().parent(), new GetBucketVersions(), config.getAskDuration());
304 //Find gossiper on remote system
305 ActorSelection remoteRef = getContext().system().actorSelection(
306 remoteActorSystemAddress.toString() + getSelf().path().toStringWithoutAddress());
308 log.trace("Sending bucket versions to [{}]", remoteRef);
310 futureReply.map(getMapperToSendLocalStatus(remoteRef), getContext().dispatcher());
315 * Helper to send bucket versions received from local store.
317 * @param remote remote gossiper to send versions to
318 * @param localVersions bucket versions received from local store
320 void sendGossipStatusTo(ActorRef remote, Map<Address, Long> localVersions) {
322 GossipStatus status = new GossipStatus(selfAddress, localVersions);
323 remote.tell(status, getSelf());
326 void sendGossipStatusTo(ActorSelection remote, Map<Address, Long> localVersions) {
328 GossipStatus status = new GossipStatus(selfAddress, localVersions);
329 remote.tell(status, getSelf());
333 /// Private factories to create mappers
336 private Mapper<Object, Void> getMapperToSendLocalStatus(final ActorSelection remote) {
338 return new Mapper<Object, Void>() {
340 public Void apply(Object replyMessage) {
341 if (replyMessage instanceof GetBucketVersionsReply) {
342 GetBucketVersionsReply reply = (GetBucketVersionsReply) replyMessage;
343 Map<Address, Long> localVersions = reply.getVersions();
345 sendGossipStatusTo(remote, localVersions);
354 * Process bucket versions received from
355 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.BucketStore}.
356 * Then this method compares remote bucket versions with local bucket versions.
358 * <li>The buckets that are newer locally, send
359 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipEnvelope}
361 * <li>The buckets that are older locally, send
362 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipStatus}
363 * to remote so that remote sends GossipEnvelop.
366 * @param sender the remote member
367 * @param status bucket versions from a remote member
368 * @return a {@link akka.dispatch.Mapper} that gets evaluated in future
371 private Mapper<Object, Void> getMapperToProcessRemoteStatus(final ActorRef sender, final GossipStatus status) {
373 final Map<Address, Long> remoteVersions = status.getVersions();
375 return new Mapper<Object, Void>() {
377 public Void apply(Object replyMessage) {
378 if (replyMessage instanceof GetBucketVersionsReply) {
379 GetBucketVersionsReply reply = (GetBucketVersionsReply) replyMessage;
380 Map<Address, Long> localVersions = reply.getVersions();
382 //diff between remote list and local
383 Set<Address> localIsOlder = new HashSet<>();
384 localIsOlder.addAll(remoteVersions.keySet());
385 localIsOlder.removeAll(localVersions.keySet());
387 //diff between local list and remote
388 Set<Address> localIsNewer = new HashSet<>();
389 localIsNewer.addAll(localVersions.keySet());
390 localIsNewer.removeAll(remoteVersions.keySet());
393 for (Address address : remoteVersions.keySet()) {
395 if (localVersions.get(address) == null || remoteVersions.get(address) == null) {
396 continue; //this condition is taken care of by above diffs
398 if (localVersions.get(address) < remoteVersions.get(address)) {
399 localIsOlder.add(address);
400 } else if (localVersions.get(address) > remoteVersions.get(address)) {
401 localIsNewer.add(address);
405 if (!localIsOlder.isEmpty()) {
406 sendGossipStatusTo(sender, localVersions );
409 if (!localIsNewer.isEmpty()) {
410 sendGossipTo(sender, localIsNewer);//send newer buckets to remote
420 * Processes the message from {@link org.opendaylight.controller.remote.rpc.registry.gossip.BucketStore}
421 * that contains {@link org.opendaylight.controller.remote.rpc.registry.gossip.Bucket}.
422 * These buckets are sent to a remote member encapsulated in
423 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipEnvelope}
425 * @param sender the remote member that sent
426 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipStatus}
427 * in reply to which bucket is being sent back
428 * @return a {@link akka.dispatch.Mapper} that gets evaluated in future
431 private Mapper<Object, Void> getMapperToSendGossip(final ActorRef sender) {
433 return new Mapper<Object, Void>() {
434 @SuppressWarnings({ "rawtypes", "unchecked" })
436 public Void apply(Object msg) {
437 if (msg instanceof GetBucketsByMembersReply) {
438 Map<Address, Bucket<?>> buckets = ((GetBucketsByMembersReply) msg).getBuckets();
439 log.trace("Buckets to send from {}: {}", selfAddress, buckets);
440 GossipEnvelope envelope = new GossipEnvelope(selfAddress, sender.path().address(), buckets);
441 sender.tell(envelope, getSelf());
451 List<Address> getClusterMembers() {
452 return clusterMembers;
455 void setClusterMembers(List<Address> clusterMembers) {
456 this.clusterMembers = clusterMembers;
459 Address getSelfAddress() {
463 void setSelfAddress(Address selfAddress) {
464 this.selfAddress = selfAddress;