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 log.debug("Removed member [{}], Active member list [{}]", member.address(), clusterMembers);
177 * Add member to the local copy of member list if it doesnt already
180 void receiveMemberUp(Member member) {
182 if (selfAddress.equals(member.address()))
183 return; //ignore up notification for self
185 if (!clusterMembers.contains(member.address()))
186 clusterMembers.add(member.address());
188 log.debug("Added member [{}], Active member list [{}]", member.address(), clusterMembers);
192 * Sends Gossip status to other members in the cluster. <br/>
193 * 1. If there are no member, ignore the tick. </br>
194 * 2. If there's only 1 member, send gossip status (bucket versions) to it. <br/>
195 * 3. If there are more than one member, randomly pick one and send gossip status (bucket versions) to it.
197 void receiveGossipTick(){
198 if (clusterMembers.size() == 0) return; //no members to send gossip status to
200 Address remoteMemberToGossipTo;
202 if (clusterMembers.size() == 1)
203 remoteMemberToGossipTo = clusterMembers.get(0);
205 Integer randomIndex = ThreadLocalRandom.current().nextInt(0, clusterMembers.size());
206 remoteMemberToGossipTo = clusterMembers.get(randomIndex);
209 log.debug("Gossiping to [{}]", remoteMemberToGossipTo);
210 getLocalStatusAndSendTo(remoteMemberToGossipTo);
214 * Process gossip status received from a remote gossiper. Remote versions are compared with
215 * the local copy. <p>
219 * <li>If local copy is newer, the newer buckets are sent in GossipEnvelope to remote</li>
220 * <li>If local is older, GossipStatus is sent to remote so that it can reply with GossipEnvelope</li>
221 * <li>If both are same, noop</li>
224 * @param status bucket versions from a remote member
226 void receiveGossipStatus(GossipStatus status){
227 //Don't accept messages from non-members
228 if (!clusterMembers.contains(status.from()))
231 final ActorRef sender = getSender();
232 Future<Object> futureReply =
233 Patterns.ask(getContext().parent(), new GetBucketVersions(), config.getAskDuration());
235 futureReply.map(getMapperToProcessRemoteStatus(sender, status), getContext().dispatcher());
240 * Sends the received buckets in the envelope to the parent Bucket store.
242 * @param envelope contains buckets from a remote gossiper
244 void receiveGossip(GossipEnvelope envelope){
245 //TODO: Add more validations
246 if (!selfAddress.equals(envelope.to())) {
247 log.debug("Ignoring message intended for someone else. From [{}] to [{}]", envelope.from(), envelope.to());
251 updateRemoteBuckets(envelope.getBuckets());
256 * Helper to send received buckets to bucket store
260 void updateRemoteBuckets(Map<Address, Bucket> buckets) {
262 UpdateRemoteBuckets updateRemoteBuckets = new UpdateRemoteBuckets(buckets);
263 getContext().parent().tell(updateRemoteBuckets, getSelf());
267 * Gets the buckets from bucket store for the given node addresses and sends them to remote gossiper
269 * @param remote remote node to send Buckets to
270 * @param addresses node addresses whose buckets needs to be sent
272 void sendGossipTo(final ActorRef remote, final Set<Address> addresses){
274 Future<Object> futureReply =
275 Patterns.ask(getContext().parent(), new GetBucketsByMembers(addresses), config.getAskDuration());
276 futureReply.map(getMapperToSendGossip(remote), getContext().dispatcher());
280 * Gets bucket versions from bucket store and sends to the supplied address
282 * @param remoteActorSystemAddress remote gossiper to send to
284 void getLocalStatusAndSendTo(Address remoteActorSystemAddress){
286 //Get local status from bucket store and send to remote
287 Future<Object> futureReply =
288 Patterns.ask(getContext().parent(), new GetBucketVersions(), config.getAskDuration());
290 //Find gossiper on remote system
291 ActorSelection remoteRef = getContext().system().actorSelection(
292 remoteActorSystemAddress.toString() + getSelf().path().toStringWithoutAddress());
294 log.debug("Sending bucket versions to [{}]", remoteRef);
296 futureReply.map(getMapperToSendLocalStatus(remoteRef), getContext().dispatcher());
301 * Helper to send bucket versions received from local store
302 * @param remote remote gossiper to send versions to
303 * @param localVersions bucket versions received from local store
305 void sendGossipStatusTo(ActorRef remote, Map<Address, Long> localVersions){
307 GossipStatus status = new GossipStatus(selfAddress, localVersions);
308 remote.tell(status, getSelf());
311 void sendGossipStatusTo(ActorSelection remote, Map<Address, Long> localVersions){
313 GossipStatus status = new GossipStatus(selfAddress, localVersions);
314 remote.tell(status, getSelf());
318 /// Private factories to create mappers
321 private Mapper<Object, Void> getMapperToSendLocalStatus(final ActorSelection remote){
323 return new Mapper<Object, Void>() {
325 public Void apply(Object replyMessage) {
326 if (replyMessage instanceof GetBucketVersionsReply) {
327 GetBucketVersionsReply reply = (GetBucketVersionsReply) replyMessage;
328 Map<Address, Long> localVersions = reply.getVersions();
330 sendGossipStatusTo(remote, localVersions);
339 * Process bucket versions received from
340 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.BucketStore}.
341 * Then this method compares remote bucket versions with local bucket versions.
343 * <li>The buckets that are newer locally, send
344 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipEnvelope}
346 * <li>The buckets that are older locally, send
347 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipStatus}
348 * to remote so that remote sends GossipEnvelop.
351 * @param sender the remote member
352 * @param status bucket versions from a remote member
353 * @return a {@link akka.dispatch.Mapper} that gets evaluated in future
356 private Mapper<Object, Void> getMapperToProcessRemoteStatus(final ActorRef sender, final GossipStatus status){
358 final Map<Address, Long> remoteVersions = status.getVersions();
360 return new Mapper<Object, Void>() {
362 public Void apply(Object replyMessage) {
363 if (replyMessage instanceof GetBucketVersionsReply) {
364 GetBucketVersionsReply reply = (GetBucketVersionsReply) replyMessage;
365 Map<Address, Long> localVersions = reply.getVersions();
367 //diff between remote list and local
368 Set<Address> localIsOlder = new HashSet<>();
369 localIsOlder.addAll(remoteVersions.keySet());
370 localIsOlder.removeAll(localVersions.keySet());
372 //diff between local list and remote
373 Set<Address> localIsNewer = new HashSet<>();
374 localIsNewer.addAll(localVersions.keySet());
375 localIsNewer.removeAll(remoteVersions.keySet());
378 for (Address address : remoteVersions.keySet()){
380 if (localVersions.get(address) == null || remoteVersions.get(address) == null)
381 continue; //this condition is taken care of by above diffs
382 if (localVersions.get(address) < remoteVersions.get(address))
383 localIsOlder.add(address);
384 else if (localVersions.get(address) > remoteVersions.get(address))
385 localIsNewer.add(address);
388 if (!localIsOlder.isEmpty())
389 sendGossipStatusTo(sender, localVersions );
391 if (!localIsNewer.isEmpty())
392 sendGossipTo(sender, localIsNewer);//send newer buckets to remote
401 * Processes the message from {@link org.opendaylight.controller.remote.rpc.registry.gossip.BucketStore}
402 * that contains {@link org.opendaylight.controller.remote.rpc.registry.gossip.Bucket}.
403 * These buckets are sent to a remote member encapsulated in
404 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipEnvelope}
406 * @param sender the remote member that sent
407 * {@link org.opendaylight.controller.remote.rpc.registry.gossip.Messages.GossiperMessages.GossipStatus}
408 * in reply to which bucket is being sent back
409 * @return a {@link akka.dispatch.Mapper} that gets evaluated in future
412 private Mapper<Object, Void> getMapperToSendGossip(final ActorRef sender) {
414 return new Mapper<Object, Void>() {
416 public Void apply(Object msg) {
417 if (msg instanceof GetBucketsByMembersReply) {
418 Map<Address, Bucket> buckets = ((GetBucketsByMembersReply) msg).getBuckets();
419 log.debug("Buckets to send from {}: {}", selfAddress, buckets);
420 GossipEnvelope envelope = new GossipEnvelope(selfAddress, sender.path().address(), buckets);
421 sender.tell(envelope, getSelf());
431 List<Address> getClusterMembers() {
432 return clusterMembers;
435 void setClusterMembers(List<Address> clusterMembers) {
436 this.clusterMembers = clusterMembers;
439 Address getSelfAddress() {
443 void setSelfAddress(Address selfAddress) {
444 this.selfAddress = selfAddress;