* It keeps a local scheduler that periodically sends Gossip ticks to
* itself to send bucket store's bucket versions to a randomly selected remote
* gossiper.
- *
+ *
+ *
* When bucket versions are received from a remote gossiper, it is compared
* with bucket store's bucket versions. Which ever buckets are newer
* locally, are sent to remote gossiper. If any bucket is older in bucket store,
* a gossip status is sent to remote gossiper so that it can send the newer buckets.
- *
+ *
+ *
* When a bucket is received from a remote gossiper, its sent to the bucket store
* for update.
- *
*/
public class Gossiper extends AbstractUntypedActorWithMetering {
+ private final boolean autoStartGossipTicks;
+ private final RemoteRpcProviderConfig config;
- private final Logger log = LoggerFactory.getLogger(getClass());
+ /**
+ * All known cluster members.
+ */
+ private final List
clusterMembers = new ArrayList<>();
- private Cluster cluster;
+ /**
+ * Cached ActorSelections for remote peers.
+ */
+ private final Map peers = new HashMap<>();
/**
* ActorSystem's address for the current cluster node.
*/
private Address selfAddress;
- /**
- * All known cluster members.
- */
- private List clusterMembers = new ArrayList<>();
+ private Cluster cluster;
private Cancellable gossipTask;
- private Boolean autoStartGossipTicks = true;
+ Gossiper(final RemoteRpcProviderConfig config, final Boolean autoStartGossipTicks) {
+ this.config = Preconditions.checkNotNull(config);
+ this.autoStartGossipTicks = autoStartGossipTicks.booleanValue();
+ }
- private final RemoteRpcProviderConfig config;
+ Gossiper(final RemoteRpcProviderConfig config) {
+ this(config, Boolean.TRUE);
+ }
- public Gossiper(RemoteRpcProviderConfig config) {
- this.config = Preconditions.checkNotNull(config);
+ public static Props props(final RemoteRpcProviderConfig config) {
+ return Props.create(Gossiper.class, config);
}
- /**
- * Constructor for testing.
- *
- * @param autoStartGossipTicks used for turning off gossip ticks during testing.
- * Gossip tick can be manually sent.
- */
- @VisibleForTesting
- public Gossiper(Boolean autoStartGossipTicks, RemoteRpcProviderConfig config) {
- this(config);
- this.autoStartGossipTicks = autoStartGossipTicks;
+ static Props testProps(final RemoteRpcProviderConfig config) {
+ return Props.create(Gossiper.class, config, Boolean.FALSE);
}
@Override
@@ -101,11 +107,12 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
ActorRefProvider provider = getContext().provider();
selfAddress = provider.getDefaultAddress();
- if ( provider instanceof ClusterActorRefProvider ) {
+ if (provider instanceof ClusterActorRefProvider ) {
cluster = Cluster.get(getContext().system());
cluster.subscribe(getSelf(),
ClusterEvent.initialStateAsEvents(),
ClusterEvent.MemberEvent.class,
+ ClusterEvent.ReachableMember.class,
ClusterEvent.UnreachableMember.class);
}
@@ -113,10 +120,10 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
gossipTask = getContext().system().scheduler().schedule(
new FiniteDuration(1, TimeUnit.SECONDS), //initial delay
config.getGossipTickInterval(), //interval
- getSelf(), //target
- new Messages.GossiperMessages.GossipTick(), //message
- getContext().dispatcher(), //execution context
- getSelf() //sender
+ getSelf(), //target
+ new Messages.GossiperMessages.GossipTick(), //message
+ getContext().dispatcher(), //execution context
+ getSelf() //sender
);
}
}
@@ -133,7 +140,7 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
@SuppressWarnings({ "rawtypes", "unchecked" })
@Override
- protected void handleReceive(Object message) throws Exception {
+ protected void handleReceive(final Object message) throws Exception {
//Usually sent by self via gossip task defined above. But its not enforced.
//These ticks can be sent by another actor as well which is esp. useful while testing
if (message instanceof GossipTick) {
@@ -147,12 +154,15 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
// comparing the GossipStatus message with its local versions.
receiveGossip((GossipEnvelope) message);
} else if (message instanceof ClusterEvent.MemberUp) {
- receiveMemberUp(((ClusterEvent.MemberUp) message).member());
+ receiveMemberUpOrReachable(((ClusterEvent.MemberUp) message).member());
+
+ } else if (message instanceof ClusterEvent.ReachableMember) {
+ receiveMemberUpOrReachable(((ClusterEvent.ReachableMember) message).member());
} else if (message instanceof ClusterEvent.MemberRemoved) {
receiveMemberRemoveOrUnreachable(((ClusterEvent.MemberRemoved) message).member());
- } else if ( message instanceof ClusterEvent.UnreachableMember) {
+ } else if (message instanceof ClusterEvent.UnreachableMember) {
receiveMemberRemoveOrUnreachable(((ClusterEvent.UnreachableMember) message).member());
} else {
@@ -165,15 +175,29 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
*
* @param member who went down
*/
- void receiveMemberRemoveOrUnreachable(Member member) {
+ private void receiveMemberRemoveOrUnreachable(final Member member) {
//if its self, then stop itself
if (selfAddress.equals(member.address())) {
getContext().stop(getSelf());
return;
}
- clusterMembers.remove(member.address());
- log.debug("Removed member [{}], Active member list [{}]", member.address(), clusterMembers);
+ removePeer(member.address());
+ LOG.debug("Removed member [{}], Active member list [{}]", member.address(), clusterMembers);
+ }
+
+ private void addPeer(final Address address) {
+ if (!clusterMembers.contains(address)) {
+ clusterMembers.add(address);
+ }
+ peers.computeIfAbsent(address, input -> getContext().system()
+ .actorSelection(input.toString() + getSelf().path().toStringWithoutAddress()));
+ }
+
+ private void removePeer(final Address address) {
+ clusterMembers.remove(address);
+ peers.remove(address);
+ getContext().parent().tell(new RemoveRemoteBucket(address), ActorRef.noSender());
}
/**
@@ -181,17 +205,14 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
*
* @param member the member to add
*/
- void receiveMemberUp(Member member) {
-
+ private void receiveMemberUpOrReachable(final Member member) {
+ //ignore up notification for self
if (selfAddress.equals(member.address())) {
- return; //ignore up notification for self
- }
-
- if (!clusterMembers.contains(member.address())) {
- clusterMembers.add(member.address());
+ return;
}
- log.debug("Added member [{}], Active member list [{}]", member.address(), clusterMembers);
+ addPeer(member.address());
+ LOG.debug("Added member [{}], Active member list [{}]", member.address(), clusterMembers);
}
/**
@@ -201,22 +222,24 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
* 2. If there's only 1 member, send gossip status (bucket versions) to it.
* 3. If there are more than one member, randomly pick one and send gossip status (bucket versions) to it.
*/
+ @VisibleForTesting
void receiveGossipTick() {
- if (clusterMembers.size() == 0) {
- return; //no members to send gossip status to
- }
-
- Address remoteMemberToGossipTo;
-
- if (clusterMembers.size() == 1) {
- remoteMemberToGossipTo = clusterMembers.get(0);
- } else {
- Integer randomIndex = ThreadLocalRandom.current().nextInt(0, clusterMembers.size());
- remoteMemberToGossipTo = clusterMembers.get(randomIndex);
+ final Address address;
+ switch (clusterMembers.size()) {
+ case 0:
+ //no members to send gossip status to
+ return;
+ case 1:
+ address = clusterMembers.get(0);
+ break;
+ default:
+ final int randomIndex = ThreadLocalRandom.current().nextInt(0, clusterMembers.size());
+ address = clusterMembers.get(randomIndex);
+ break;
}
- log.trace("Gossiping to [{}]", remoteMemberToGossipTo);
- getLocalStatusAndSendTo(remoteMemberToGossipTo);
+ LOG.trace("Gossiping to [{}]", address);
+ getLocalStatusAndSendTo(Verify.verifyNotNull(peers.get(address)));
}
/**
@@ -232,9 +255,10 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
*
* @param status bucket versions from a remote member
*/
- void receiveGossipStatus(GossipStatus status) {
- //Don't accept messages from non-members
- if (!clusterMembers.contains(status.from())) {
+ @VisibleForTesting
+ void receiveGossipStatus(final GossipStatus status) {
+ // Don't accept messages from non-members
+ if (!peers.containsKey(status.from())) {
return;
}
@@ -243,7 +267,6 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
Patterns.ask(getContext().parent(), new GetBucketVersions(), config.getAskDuration());
futureReply.map(getMapperToProcessRemoteStatus(sender, status), getContext().dispatcher());
-
}
/**
@@ -251,18 +274,15 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
*
* @param envelope contains buckets from a remote gossiper
*/
- > void receiveGossip(GossipEnvelope envelope) {
+ @VisibleForTesting
+ > void receiveGossip(final GossipEnvelope envelope) {
//TODO: Add more validations
if (!selfAddress.equals(envelope.to())) {
- if (log.isTraceEnabled()) {
- log.trace("Ignoring message intended for someone else. From [{}] to [{}]", envelope.from(),
- envelope.to());
- }
+ LOG.trace("Ignoring message intended for someone else. From [{}] to [{}]", envelope.from(), envelope.to());
return;
}
updateRemoteBuckets(envelope.getBuckets());
-
}
/**
@@ -270,9 +290,9 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
*
* @param buckets map of Buckets to update
*/
- > void updateRemoteBuckets(Map> buckets) {
- UpdateRemoteBuckets updateRemoteBuckets = new UpdateRemoteBuckets<>(buckets);
- getContext().parent().tell(updateRemoteBuckets, getSelf());
+ @VisibleForTesting
+ > void updateRemoteBuckets(final Map> buckets) {
+ getContext().parent().tell(new UpdateRemoteBuckets<>(buckets), getSelf());
}
/**
@@ -293,38 +313,16 @@ public class Gossiper extends AbstractUntypedActorWithMetering {
*
* @param remoteActorSystemAddress remote gossiper to send to
*/
- void getLocalStatusAndSendTo(Address remoteActorSystemAddress) {
+ @VisibleForTesting
+ void getLocalStatusAndSendTo(final ActorSelection remoteGossiper) {
//Get local status from bucket store and send to remote
Future