purgeInMemoryLog();
}
+ //Send the next log entry immediately, if possible, no need to wait for heartbeat to trigger that event
+ sendUpdatesToFollower(followerId, followerLogInformation, false);
return this;
}
followerLogInformation.markFollowerActive();
if (followerToSnapshot.getChunkIndex() == reply.getChunkIndex()) {
+ boolean wasLastChunk = false;
if (reply.isSuccess()) {
if(followerToSnapshot.isLastChunk(reply.getChunkIndex())) {
//this was the last chunk reply
// we can remove snapshot from the memory
setSnapshot(Optional.<ByteString>absent());
}
+ wasLastChunk = true;
} else {
followerToSnapshot.markSendStatus(true);
followerToSnapshot.markSendStatus(false);
}
+
+ if (!wasLastChunk && followerToSnapshot.canSendNextChunk()) {
+ ActorSelection followerActor = context.getPeerActorSelection(followerId);
+ if(followerActor != null) {
+ sendSnapshotChunk(followerActor, followerId);
+ }
+ }
+
} else {
LOG.error("{}: Chunk index {} in InstallSnapshotReply from follower {} does not match expected index {}",
context.getId(), reply.getChunkIndex(), followerId,
private void sendAppendEntries() {
// Send an AppendEntries to all followers
-
+ long heartbeatInterval = context.getConfigParams().getHeartBeatInterval().toMillis();
for (Entry<String, FollowerLogInformation> e : followerToLog.entrySet()) {
final String followerId = e.getKey();
- ActorSelection followerActor = context.getPeerActorSelection(followerId);
+ final FollowerLogInformation followerLogInformation = e.getValue();
+ // This checks helps not to send a repeat message to the follower
+ if(followerLogInformation.timeSinceLastActivity() >= heartbeatInterval) {
+ sendUpdatesToFollower(followerId, followerLogInformation, true);
+ }
+ }
+ }
- if (followerActor != null) {
- FollowerLogInformation followerLogInformation = followerToLog.get(followerId);
- long followerNextIndex = followerLogInformation.getNextIndex();
- boolean isFollowerActive = followerLogInformation.isFollowerActive();
+ /**
+ *
+ * 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.
+ * @return true if any update is sent, false otherwise
+ */
- FollowerToSnapshot followerToSnapshot = mapFollowerToSnapshot.get(followerId);
- if (followerToSnapshot != null) {
- // if install snapshot is in process , then sent next chunk if possible
- if (isFollowerActive && followerToSnapshot.canSendNextChunk()) {
- sendSnapshotChunk(followerActor, followerId);
- } else {
- // we send a heartbeat even if we have not received a reply for the last chunk
- sendAppendEntriesToFollower(followerActor, followerNextIndex,
- Collections.<ReplicatedLogEntry>emptyList(), followerId);
- }
+ private void sendUpdatesToFollower(String followerId, FollowerLogInformation followerLogInformation,
+ boolean sendHeartbeat) {
+
+ ActorSelection followerActor = context.getPeerActorSelection(followerId);
+ if (followerActor != null) {
+ long followerNextIndex = followerLogInformation.getNextIndex();
+ boolean isFollowerActive = followerLogInformation.isFollowerActive();
+
+ if (mapFollowerToSnapshot.get(followerId) != null) {
+ // if install snapshot is in process , then sent next chunk if possible
+ if (isFollowerActive && mapFollowerToSnapshot.get(followerId).canSendNextChunk()) {
+ sendSnapshotChunk(followerActor, followerId);
+ } else if(sendHeartbeat) {
+ // we send a heartbeat even if we have not received a reply for the last chunk
+ sendAppendEntriesToFollower(followerActor, followerLogInformation.getNextIndex(),
+ Collections.<ReplicatedLogEntry>emptyList(), followerId);
+ }
+ } else {
+ long leaderLastIndex = context.getReplicatedLog().lastIndex();
+ long leaderSnapShotIndex = context.getReplicatedLog().getSnapshotIndex();
+ if (isFollowerActive &&
+ context.getReplicatedLog().isPresent(followerNextIndex)) {
+ // FIXME : Sending one entry at a time
+ final List<ReplicatedLogEntry> entries = context.getReplicatedLog().getFrom(followerNextIndex, 1);
- } else {
- long leaderLastIndex = context.getReplicatedLog().lastIndex();
- long leaderSnapShotIndex = context.getReplicatedLog().getSnapshotIndex();
- final List<ReplicatedLogEntry> entries;
-
- LOG.debug("{}: Checking sendAppendEntries for {}, leaderLastIndex: {}, leaderSnapShotIndex: {}",
- context.getId(), leaderLastIndex, leaderSnapShotIndex);
-
- if (isFollowerActive && context.getReplicatedLog().isPresent(followerNextIndex)) {
- LOG.debug("{}: sendAppendEntries: {} is present for {}", context.getId(),
- followerNextIndex, followerId);
-
- // FIXME : Sending one entry at a time
- entries = context.getReplicatedLog().getFrom(followerNextIndex, 1);
-
- } else if (isFollowerActive && followerNextIndex >= 0 &&
- leaderLastIndex >= followerNextIndex ) {
- // if the followers next index is not present in the leaders log, and
- // if the follower is just not starting and if leader's index is more than followers index
- // then snapshot should be sent
-
- if(LOG.isDebugEnabled()) {
- LOG.debug(String.format("%s: InitiateInstallSnapshot to follower: %s," +
- "follower-nextIndex: %s, leader-snapshot-index: %s, " +
- "leader-last-index: %s", context.getId(), followerId,
- followerNextIndex, leaderSnapShotIndex, leaderLastIndex));
- }
- actor().tell(new InitiateInstallSnapshot(), actor());
-
- // we would want to sent AE as the capture snapshot might take time
- entries = Collections.<ReplicatedLogEntry>emptyList();
-
- } else {
- //we send an AppendEntries, even if the follower is inactive
- // in-order to update the followers timestamp, in case it becomes active again
- entries = Collections.<ReplicatedLogEntry>emptyList();
+ sendAppendEntriesToFollower(followerActor, followerNextIndex, entries, followerId);
+
+ } else if (isFollowerActive && followerNextIndex >= 0 &&
+ leaderLastIndex >= followerNextIndex) {
+ // if the followers next index is not present in the leaders log, and
+ // if the follower is just not starting and if leader's index is more than followers index
+ // then snapshot should be sent
+
+ if (LOG.isDebugEnabled()) {
+ LOG.debug("InitiateInstallSnapshot to follower:{}," +
+ "follower-nextIndex:{}, leader-snapshot-index:{}, " +
+ "leader-last-index:{}", followerId,
+ followerNextIndex, leaderSnapShotIndex, leaderLastIndex
+ );
}
+ actor().tell(new InitiateInstallSnapshot(), actor());
- sendAppendEntriesToFollower(followerActor, followerNextIndex, entries, followerId);
+ // Send heartbeat to follower whenever install snapshot is initiated.
+ sendAppendEntriesToFollower(followerActor, followerLogInformation.getNextIndex(),
+ Collections.<ReplicatedLogEntry>emptyList(), followerId);
+
+ } else if(sendHeartbeat) {
+ //we send an AppendEntries, even if the follower is inactive
+ // in-order to update the followers timestamp, in case it becomes active again
+ sendAppendEntriesToFollower(followerActor, followerLogInformation.getNextIndex(),
+ Collections.<ReplicatedLogEntry>emptyList(), followerId);
}
+
}
}
}
// no need to capture snapshot
sendSnapshotChunk(followerActor, e.getKey());
- } else {
+ } else if (!context.isSnapshotCaptureInitiated()) {
initiateCaptureSnapshot();
//we just need 1 follower who would need snapshot to be installed.
// when we have the snapshot captured, we would again check (in SendInstallSnapshot)
actor().tell(new CaptureSnapshot(lastIndex(), lastTerm(),
lastAppliedIndex, lastAppliedTerm, isInstallSnapshotInitiated),
actor());
+ context.setSnapshotCaptureInitiated(true);
}
context.getReplicatedLog().getSnapshotIndex(),
context.getReplicatedLog().getSnapshotTerm(),
nextSnapshotChunk,
- followerToSnapshot.incrementChunkIndex(),
- followerToSnapshot.getTotalChunks(),
+ followerToSnapshot.incrementChunkIndex(),
+ followerToSnapshot.getTotalChunks(),
Optional.of(followerToSnapshot.getLastChunkHashCode())
).toSerializable(),
actor()
Code Review / controller.git / blobdiff