import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
-import com.google.common.base.Throwables;
import com.google.common.io.ByteSource;
import java.io.IOException;
+import java.io.ObjectOutputStream;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Queue;
+import java.util.concurrent.TimeUnit;
import javax.annotation.Nullable;
+import org.opendaylight.controller.cluster.io.SharedFileBackedOutputStream;
+import org.opendaylight.controller.cluster.messaging.MessageSlicer;
+import org.opendaylight.controller.cluster.messaging.SliceOptions;
import org.opendaylight.controller.cluster.raft.ClientRequestTracker;
import org.opendaylight.controller.cluster.raft.ClientRequestTrackerImpl;
import org.opendaylight.controller.cluster.raft.FollowerLogInformation;
-import org.opendaylight.controller.cluster.raft.FollowerLogInformationImpl;
import org.opendaylight.controller.cluster.raft.PeerInfo;
import org.opendaylight.controller.cluster.raft.RaftActorContext;
import org.opendaylight.controller.cluster.raft.RaftState;
import org.opendaylight.controller.cluster.raft.messages.InstallSnapshot;
import org.opendaylight.controller.cluster.raft.messages.InstallSnapshotReply;
import org.opendaylight.controller.cluster.raft.messages.RaftRPC;
+import org.opendaylight.controller.cluster.raft.messages.RequestVote;
import org.opendaylight.controller.cluster.raft.messages.RequestVoteReply;
import org.opendaylight.controller.cluster.raft.messages.UnInitializedFollowerSnapshotReply;
import org.opendaylight.controller.cluster.raft.persisted.ServerConfigurationPayload;
import scala.concurrent.duration.FiniteDuration;
/**
- * The behavior of a RaftActor when it is in the Leader state
+ * The behavior of a RaftActor when it is in the Leader state.
*
* <p>
* Leaders:
*/
private final Queue<ClientRequestTracker> trackers = new LinkedList<>();
+ /**
+ * Map of serialized AppendEntries output streams keyed by log index. This is used in conjunction with the
+ * appendEntriesMessageSlicer for slicing single ReplicatedLogEntry payloads that exceed the message size threshold.
+ * This Map allows the SharedFileBackedOutputStreams to be reused for multiple followers.
+ */
+ private final Map<Long, SharedFileBackedOutputStream> sharedSerializedAppendEntriesStreams = new HashMap<>();
+ private final MessageSlicer appendEntriesMessageSlicer;
+
private Cancellable heartbeatSchedule = null;
private Optional<SnapshotHolder> snapshotHolder = Optional.absent();
private int minReplicationCount;
- protected AbstractLeader(RaftActorContext context, RaftState state,
- @Nullable AbstractLeader initializeFromLeader) {
+ protected AbstractLeader(final RaftActorContext context, final RaftState state,
+ @Nullable final AbstractLeader initializeFromLeader) {
super(context, state);
+ appendEntriesMessageSlicer = MessageSlicer.builder().logContext(logName())
+ .messageSliceSize(context.getConfigParams().getSnapshotChunkSize())
+ .expireStateAfterInactivity(context.getConfigParams().getElectionTimeOutInterval().toMillis() * 3,
+ TimeUnit.MILLISECONDS).build();
+
if (initializeFromLeader != null) {
followerToLog.putAll(initializeFromLeader.followerToLog);
snapshotHolder = initializeFromLeader.snapshotHolder;
trackers.addAll(initializeFromLeader.trackers);
} else {
for (PeerInfo peerInfo: context.getPeers()) {
- FollowerLogInformation followerLogInformation = new FollowerLogInformationImpl(peerInfo, -1, context);
+ FollowerLogInformation followerLogInformation = new FollowerLogInformation(peerInfo, context);
followerToLog.put(peerInfo.getId(), followerLogInformation);
}
}
scheduleHeartBeat(context.getConfigParams().getHeartBeatInterval());
}
- protected AbstractLeader(RaftActorContext context, RaftState state) {
+ protected AbstractLeader(final RaftActorContext context, final RaftState state) {
this(context, state, null);
}
return followerToLog.keySet();
}
- public void addFollower(String followerId) {
- FollowerLogInformation followerLogInformation = new FollowerLogInformationImpl(
- context.getPeerInfo(followerId), -1, context);
+ public void addFollower(final String followerId) {
+ FollowerLogInformation followerLogInformation = new FollowerLogInformation(context.getPeerInfo(followerId),
+ context);
followerToLog.put(followerId, followerLogInformation);
if (heartbeatSchedule == null) {
}
}
- public void removeFollower(String followerId) {
+ public void removeFollower(final String followerId) {
followerToLog.remove(followerId);
}
}
@VisibleForTesting
- void setSnapshot(@Nullable SnapshotHolder snapshotHolder) {
+ void setSnapshotHolder(@Nullable final SnapshotHolder snapshotHolder) {
this.snapshotHolder = Optional.fromNullable(snapshotHolder);
}
}
@Override
- protected RaftActorBehavior handleAppendEntries(ActorRef sender,
- AppendEntries appendEntries) {
+ protected RaftActorBehavior handleAppendEntries(final ActorRef sender,
+ final AppendEntries appendEntries) {
log.debug("{}: handleAppendEntries: {}", logName(), appendEntries);
}
@Override
- protected RaftActorBehavior handleAppendEntriesReply(ActorRef sender, AppendEntriesReply appendEntriesReply) {
+ protected RaftActorBehavior handleAppendEntriesReply(final ActorRef sender,
+ final AppendEntriesReply appendEntriesReply) {
log.trace("{}: handleAppendEntriesReply: {}", logName(), appendEntriesReply);
// Update the FollowerLogInformation
return this;
}
- if (followerLogInformation.timeSinceLastActivity()
- > context.getConfigParams().getElectionTimeOutInterval().toMillis()) {
+ final long lastActivityNanos = followerLogInformation.nanosSinceLastActivity();
+ if (lastActivityNanos > context.getConfigParams().getElectionTimeOutInterval().toNanos()) {
log.warn("{} : handleAppendEntriesReply delayed beyond election timeout, "
+ "appendEntriesReply : {}, timeSinceLastActivity : {}, lastApplied : {}, commitIndex : {}",
- logName(), appendEntriesReply, followerLogInformation.timeSinceLastActivity(),
+ logName(), appendEntriesReply, TimeUnit.NANOSECONDS.toMillis(lastActivityNanos),
context.getLastApplied(), context.getCommitIndex());
}
log.info("{}: follower {} appears to be behind the leader from the last snapshot - "
+ "updated: matchIndex: {}, nextIndex: {}", logName(), followerId,
- appendEntriesReply.getLogLastTerm(), followerLogInformation.getMatchIndex(),
- followerLogInformation.getNextIndex());
+ followerLogInformation.getMatchIndex(), followerLogInformation.getNextIndex());
} else {
// The follower's log conflicts with leader's log so decrement follower's next index by 1
// in an attempt to find where the logs match.
- followerLogInformation.decrNextIndex();
- updated = true;
+ if (followerLogInformation.decrNextIndex()) {
+ updated = true;
- log.info("{}: follower {} last log term {} conflicts with the leader's {} - dec next index to {}",
- logName(), followerId, appendEntriesReply.getLogLastTerm(), followersLastLogTermInLeadersLog,
- followerLogInformation.getNextIndex());
+ log.info("{}: follower {} last log term {} conflicts with the leader's {} - dec next index to {}",
+ logName(), followerId, appendEntriesReply.getLogLastTerm(),
+ followersLastLogTermInLeadersLog, followerLogInformation.getNextIndex());
+ }
}
}
}
}
- private boolean updateFollowerLogInformation(FollowerLogInformation followerLogInformation,
- AppendEntriesReply appendEntriesReply) {
+ private boolean updateFollowerLogInformation(final FollowerLogInformation followerLogInformation,
+ final AppendEntriesReply appendEntriesReply) {
boolean updated = followerLogInformation.setMatchIndex(appendEntriesReply.getLogLastIndex());
updated = followerLogInformation.setNextIndex(appendEntriesReply.getLogLastIndex() + 1) || updated;
}
@Override
- protected ClientRequestTracker removeClientRequestTracker(long logIndex) {
+ protected ClientRequestTracker removeClientRequestTracker(final long logIndex) {
final Iterator<ClientRequestTracker> it = trackers.iterator();
while (it.hasNext()) {
final ClientRequestTracker t = it.next();
}
@Override
- protected RaftActorBehavior handleRequestVoteReply(ActorRef sender,
- RequestVoteReply requestVoteReply) {
+ protected RaftActorBehavior handleRequestVoteReply(final ActorRef sender,
+ final RequestVoteReply requestVoteReply) {
return this;
}
protected void beforeSendHeartbeat(){}
@Override
- public RaftActorBehavior handleMessage(ActorRef sender, Object message) {
+ public RaftActorBehavior handleMessage(final ActorRef sender, final Object message) {
Preconditions.checkNotNull(sender, "sender should not be null");
+ if (appendEntriesMessageSlicer.handleMessage(message)) {
+ return this;
+ }
+
if (message instanceof RaftRPC) {
RaftRPC rpc = (RaftRPC) message;
// If RPC request or response contains term T > currentTerm:
context.getTermInformation().updateAndPersist(rpc.getTerm(), null);
+ // This is a special case. Normally when stepping down as leader we don't process and reply to the
+ // RaftRPC as per raft. But if we're in the process of transferring leadership and we get a
+ // RequestVote, process the RequestVote before switching to Follower. This enables the requesting
+ // candidate node to be elected the leader faster and avoids us possibly timing out in the Follower
+ // state and starting a new election and grabbing leadership back before the other candidate node can
+ // start a new election due to lack of responses. This case would only occur if there isn't a majority
+ // of other nodes available that can elect the requesting candidate. Since we're transferring
+ // leadership, we should make every effort to get the requesting node elected.
+ if (message instanceof RequestVote && context.getRaftActorLeadershipTransferCohort() != null) {
+ log.debug("{}: Leadership transfer in progress - processing RequestVote", logName());
+ super.handleMessage(sender, message);
+ }
+
return internalSwitchBehavior(RaftState.Follower);
}
}
scheduleHeartBeat(context.getConfigParams().getHeartBeatInterval());
} else if (message instanceof SendInstallSnapshot) {
SendInstallSnapshot sendInstallSnapshot = (SendInstallSnapshot) message;
- setSnapshot(new SnapshotHolder(sendInstallSnapshot.getSnapshot(), sendInstallSnapshot.getSnapshotBytes()));
+ setSnapshotHolder(new SnapshotHolder(sendInstallSnapshot.getSnapshot(),
+ sendInstallSnapshot.getSnapshotBytes()));
sendInstallSnapshot();
} else if (message instanceof Replicate) {
replicate((Replicate) message);
return this;
}
- private void handleInstallSnapshotReply(InstallSnapshotReply reply) {
+ private void handleInstallSnapshotReply(final InstallSnapshotReply reply) {
log.debug("{}: handleInstallSnapshotReply: {}", logName(), reply);
String followerId = reply.getFollowerId();
if (!anyFollowersInstallingSnapshot()) {
// once there are no pending followers receiving snapshots
// we can remove snapshot from the memory
- setSnapshot(null);
+ setSnapshotHolder(null);
}
wasLastChunk = true;
installSnapshotState.markSendStatus(false);
}
- if (wasLastChunk && !context.getSnapshotManager().isCapturing()) {
- // Since the follower is now caught up try to purge the log.
- purgeInMemoryLog();
- } else if (!wasLastChunk && installSnapshotState.canSendNextChunk()) {
+ if (wasLastChunk) {
+ if (!context.getSnapshotManager().isCapturing()) {
+ // Since the follower is now caught up try to purge the log.
+ purgeInMemoryLog();
+ }
+ } else {
ActorSelection followerActor = context.getPeerActorSelection(followerId);
if (followerActor != null) {
sendSnapshotChunk(followerActor, followerLogInformation);
return false;
}
- private void replicate(Replicate replicate) {
+ private void replicate(final Replicate replicate) {
long logIndex = replicate.getReplicatedLogEntry().getIndex();
log.debug("{}: Replicate message: identifier: {}, logIndex: {}, payload: {}, isSendImmediate: {}", logName(),
}
}
- protected void sendAppendEntries(long timeSinceLastActivityInterval, boolean isHeartbeat) {
+ protected void sendAppendEntries(final long timeSinceLastActivityIntervalNanos, final boolean isHeartbeat) {
// Send an AppendEntries to all followers
for (Entry<String, FollowerLogInformation> e : followerToLog.entrySet()) {
final String followerId = e.getKey();
final FollowerLogInformation followerLogInformation = e.getValue();
// This checks helps not to send a repeat message to the follower
if (!followerLogInformation.isFollowerActive()
- || followerLogInformation.timeSinceLastActivity() >= timeSinceLastActivityInterval) {
+ || followerLogInformation.nanosSinceLastActivity() >= timeSinceLastActivityIntervalNanos) {
sendUpdatesToFollower(followerId, followerLogInformation, true, isHeartbeat);
}
}
* This method checks if any update needs to be sent to the given follower. This includes append log entries,
* sending next snapshot chunk, and initiating a snapshot.
*/
- private void sendUpdatesToFollower(String followerId, FollowerLogInformation followerLogInformation,
- boolean sendHeartbeat, boolean isHeartbeat) {
+ private void sendUpdatesToFollower(final String followerId, final FollowerLogInformation followerLogInformation,
+ final boolean sendHeartbeat, final boolean isHeartbeat) {
ActorSelection followerActor = context.getPeerActorSelection(followerId);
if (followerActor != null) {
// we send a heartbeat even if we have not received a reply for the last chunk
sendAppendEntries = true;
}
+ } else if (followerLogInformation.isLogEntrySlicingInProgress()) {
+ sendAppendEntries = sendHeartbeat;
} else {
long leaderLastIndex = context.getReplicatedLog().lastIndex();
long leaderSnapShotIndex = context.getReplicatedLog().getSnapshotIndex();
followerNextIndex, followerId);
if (followerLogInformation.okToReplicate()) {
- // Try to send all the entries in the journal but not exceeding the max data size
- // for a single AppendEntries message.
- int maxEntries = (int) context.getReplicatedLog().size();
- entries = context.getReplicatedLog().getFrom(followerNextIndex, maxEntries,
- context.getConfigParams().getSnapshotChunkSize());
+ entries = getEntriesToSend(followerLogInformation, followerActor);
sendAppendEntries = true;
}
} else if (isFollowerActive && followerNextIndex >= 0
}
}
- private void sendAppendEntriesToFollower(ActorSelection followerActor, List<ReplicatedLogEntry> entries,
- FollowerLogInformation followerLogInformation) {
+ private List<ReplicatedLogEntry> getEntriesToSend(final FollowerLogInformation followerLogInfo,
+ final ActorSelection followerActor) {
+ // Try to get all the entries in the journal but not exceeding the max data size for a single AppendEntries
+ // message.
+ int maxEntries = (int) context.getReplicatedLog().size();
+ final int maxDataSize = context.getConfigParams().getSnapshotChunkSize();
+ final long followerNextIndex = followerLogInfo.getNextIndex();
+ List<ReplicatedLogEntry> entries = context.getReplicatedLog().getFrom(followerNextIndex,
+ maxEntries, maxDataSize);
+
+ // If the first entry's size exceeds the max data size threshold, it will be returned from the call above. If
+ // that is the case, then we need to slice it into smaller chunks.
+ if (!(entries.size() == 1 && entries.get(0).getData().size() > maxDataSize)) {
+ // Don't need to slice.
+ return entries;
+ }
+
+ log.debug("{}: Log entry size {} exceeds max payload size {}", logName(), entries.get(0).getData().size(),
+ maxDataSize);
+
+ // If an AppendEntries has already been serialized for the log index then reuse the
+ // SharedFileBackedOutputStream.
+ final Long logIndex = entries.get(0).getIndex();
+ SharedFileBackedOutputStream fileBackedStream = sharedSerializedAppendEntriesStreams.get(logIndex);
+ if (fileBackedStream == null) {
+ fileBackedStream = context.getFileBackedOutputStreamFactory().newSharedInstance();
+
+ final AppendEntries appendEntries = new AppendEntries(currentTerm(), context.getId(),
+ getLogEntryIndex(followerNextIndex - 1), getLogEntryTerm(followerNextIndex - 1), entries,
+ context.getCommitIndex(), getReplicatedToAllIndex(), context.getPayloadVersion());
+
+ log.debug("{}: Serializing {} for slicing for follower {}", logName(), appendEntries,
+ followerLogInfo.getId());
+
+ try (ObjectOutputStream out = new ObjectOutputStream(fileBackedStream)) {
+ out.writeObject(appendEntries);
+ } catch (IOException e) {
+ log.error("{}: Error serializing {}", logName(), appendEntries, e);
+ fileBackedStream.cleanup();
+ return Collections.emptyList();
+ }
+
+ sharedSerializedAppendEntriesStreams.put(logIndex, fileBackedStream);
+
+ fileBackedStream.setOnCleanupCallback(index -> {
+ log.debug("{}: On SharedFileBackedOutputStream cleanup for index {}", logName(), index);
+ sharedSerializedAppendEntriesStreams.remove(index);
+ }, logIndex);
+ } else {
+ log.debug("{}: Reusing SharedFileBackedOutputStream for follower {}", logName(), followerLogInfo.getId());
+ fileBackedStream.incrementUsageCount();
+ }
+
+ log.debug("{}: Slicing stream for index {}, follower {}", logName(), logIndex, followerLogInfo.getId());
+
+ // Record that slicing is in progress for the follower.
+ followerLogInfo.setSlicedLogEntryIndex(logIndex);
+
+ final FollowerIdentifier identifier = new FollowerIdentifier(followerLogInfo.getId());
+ appendEntriesMessageSlicer.slice(SliceOptions.builder().identifier(identifier)
+ .fileBackedOutputStream(fileBackedStream).sendTo(followerActor).replyTo(actor())
+ .onFailureCallback(failure -> {
+ log.error("{}: Error slicing AppendEntries for follower {}", logName(),
+ followerLogInfo.getId(), failure);
+ followerLogInfo.setSlicedLogEntryIndex(FollowerLogInformation.NO_INDEX);
+ }).build());
+
+ return Collections.emptyList();
+ }
+
+ private void sendAppendEntriesToFollower(final ActorSelection followerActor, final List<ReplicatedLogEntry> entries,
+ final FollowerLogInformation followerLogInformation) {
// In certain cases outlined below we don't want to send the actual commit index to prevent the follower from
// possibly committing and applying conflicting entries (those with same index, different term) from a prior
// term that weren't replicated to a majority, which would be a violation of raft.
// empty AppendEntries as a heart beat to prevent election.
// - if we're in the process of installing a snapshot. In this case we don't send any new entries but still
// need to send AppendEntries to prevent election.
+ // - if we're in the process of slicing an AppendEntries with a large log entry payload. In this case we
+ // need to send an empty AppendEntries to prevent election.
boolean isInstallingSnaphot = followerLogInformation.getInstallSnapshotState() != null;
- long leaderCommitIndex = isInstallingSnaphot || !followerLogInformation.isFollowerActive() ? -1 :
- context.getCommitIndex();
+ long leaderCommitIndex = isInstallingSnaphot || followerLogInformation.isLogEntrySlicingInProgress()
+ || !followerLogInformation.isFollowerActive() ? -1 : context.getCommitIndex();
long followerNextIndex = followerLogInformation.getNextIndex();
AppendEntries appendEntries = new AppendEntries(currentTerm(), context.getId(),
* @param followerId the id of the follower.
* @return true if capture was initiated, false otherwise.
*/
- public boolean initiateCaptureSnapshot(String followerId) {
+ public boolean initiateCaptureSnapshot(final String followerId) {
FollowerLogInformation followerLogInfo = followerToLog.get(followerId);
if (snapshotHolder.isPresent()) {
// If a snapshot is present in the memory, most likely another install is in progress no need to capture
return captureInitiated;
}
- private boolean canInstallSnapshot(long nextIndex) {
+ private boolean canInstallSnapshot(final long nextIndex) {
// If the follower's nextIndex is -1 then we might as well send it a snapshot
// Otherwise send it a snapshot only if the nextIndex is not present in the log but is present
// in the snapshot
* Sends a snapshot chunk to a given follower
* InstallSnapshot should qualify as a heartbeat too.
*/
- private void sendSnapshotChunk(ActorSelection followerActor, FollowerLogInformation followerLogInfo) {
+ private void sendSnapshotChunk(final ActorSelection followerActor, final FollowerLogInformation followerLogInfo) {
if (snapshotHolder.isPresent()) {
LeaderInstallSnapshotState installSnapshotState = followerLogInfo.getInstallSnapshotState();
if (installSnapshotState == null) {
// Ensure the snapshot bytes are set - this is a no-op.
installSnapshotState.setSnapshotBytes(snapshotHolder.get().getSnapshotBytes());
+ if (!installSnapshotState.canSendNextChunk()) {
+ return;
+ }
+
byte[] nextSnapshotChunk = installSnapshotState.getNextChunk();
log.debug("{}: next snapshot chunk size for follower {}: {}", logName(), followerLogInfo.getId(),
actor()
);
- log.debug("{}: InstallSnapshot sent to follower {}, Chunk: {}/{}", logName(), followerActor.path(),
- installSnapshotState.getChunkIndex(), installSnapshotState.getTotalChunks());
} catch (IOException e) {
- throw Throwables.propagate(e);
+ throw new RuntimeException(e);
}
+
+ log.debug("{}: InstallSnapshot sent to follower {}, Chunk: {}/{}", logName(), followerActor.path(),
+ installSnapshotState.getChunkIndex(), installSnapshotState.getTotalChunks());
}
}
private void sendHeartBeat() {
if (!followerToLog.isEmpty()) {
log.trace("{}: Sending heartbeat", logName());
- sendAppendEntries(context.getConfigParams().getHeartBeatInterval().toMillis(), true);
+ sendAppendEntries(context.getConfigParams().getHeartBeatInterval().toNanos(), true);
+
+ appendEntriesMessageSlicer.checkExpiredSlicedMessageState();
}
}
}
}
- private void scheduleHeartBeat(FiniteDuration interval) {
+ private void scheduleHeartBeat(final FiniteDuration interval) {
if (followerToLog.isEmpty()) {
// Optimization - do not bother scheduling a heartbeat as there are
// no followers
@Override
public void close() {
stopHeartBeat();
+ appendEntriesMessageSlicer.close();
}
@Override
}
@VisibleForTesting
- public FollowerLogInformation getFollower(String followerId) {
+ public FollowerLogInformation getFollower(final String followerId) {
return followerToLog.get(followerId);
}
private final long lastIncludedIndex;
private final ByteSource snapshotBytes;
- SnapshotHolder(Snapshot snapshot, ByteSource snapshotBytes) {
+ SnapshotHolder(final Snapshot snapshot, final ByteSource snapshotBytes) {
this.lastIncludedTerm = snapshot.getLastAppliedTerm();
this.lastIncludedIndex = snapshot.getLastAppliedIndex();
this.snapshotBytes = snapshotBytes;
Code Review / controller.git / blobdiff