import com.google.common.base.Preconditions;
import com.google.protobuf.ByteString;
import java.io.IOException;
+import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
private Optional<SnapshotHolder> snapshot;
- public AbstractLeader(RaftActorContext context) {
- super(context, RaftState.Leader);
-
- setLeaderPayloadVersion(context.getPayloadVersion());
+ protected AbstractLeader(RaftActorContext context, RaftState state) {
+ super(context, state);
for(PeerInfo peerInfo: context.getPeers()) {
FollowerLogInformation followerLogInformation = new FollowerLogInformationImpl(peerInfo, -1, context);
followerToLog.put(peerInfo.getId(), followerLogInformation);
}
- leaderId = context.getId();
-
LOG.debug("{}: Election: Leader has following peers: {}", logName(), getFollowerIds());
updateMinReplicaCount();
public void removeFollower(String followerId) {
followerToLog.remove(followerId);
+ mapFollowerToSnapshot.remove(followerId);
}
public void updateMinReplicaCount() {
followerLogInformation.markFollowerActive();
followerLogInformation.setPayloadVersion(appendEntriesReply.getPayloadVersion());
+ followerLogInformation.setRaftVersion(appendEntriesReply.getRaftVersion());
boolean updated = false;
if (appendEntriesReply.isSuccess()) {
int replicatedCount = 1;
for (FollowerLogInformation info : followerToLog.values()) {
- if ((info.getMatchIndex() >= N) && (context.getPeerInfo(followerId).isVoting())) {
+ final PeerInfo peerInfo = context.getPeerInfo(info.getId());
+ if(info.getMatchIndex() >= N && (peerInfo != null && peerInfo.isVoting())) {
replicatedCount++;
}
}
if (replicatedCount >= minReplicationCount) {
ReplicatedLogEntry replicatedLogEntry = context.getReplicatedLog().get(N);
- if (replicatedLogEntry != null && replicatedLogEntry.getTerm() == currentTerm()) {
- context.setCommitIndex(N);
- } else {
+ if (replicatedLogEntry == null) {
break;
}
+
+ // Don't update the commit index if the log entry is from a previous term, as per §5.4.1:
+ // "Raft never commits log entries from previous terms by counting replicas".
+ // However we keep looping so we can make progress when new entries in the current term
+ // reach consensus, as per §5.4.1: "once an entry from the current term is committed by
+ // counting replicas, then all prior entries are committed indirectly".
+ if (replicatedLogEntry.getTerm() == currentTerm()) {
+ context.setCommitIndex(N);
+ }
} else {
break;
}
beforeSendHeartbeat();
sendHeartBeat();
scheduleHeartBeat(context.getConfigParams().getHeartBeatInterval());
- return this;
-
} else if(message instanceof SendInstallSnapshot) {
// received from RaftActor
setSnapshot(((SendInstallSnapshot) message).getSnapshot());
sendInstallSnapshot();
-
} else if (message instanceof Replicate) {
replicate((Replicate) message);
-
- } else if (message instanceof InstallSnapshotReply){
+ } else if (message instanceof InstallSnapshotReply) {
handleInstallSnapshotReply((InstallSnapshotReply) message);
-
+ } else {
+ return super.handleMessage(sender, message);
}
-
- return super.handleMessage(sender, message);
+ return this;
}
private void handleInstallSnapshotReply(InstallSnapshotReply reply) {
}
}
- private void sendAppendEntries(long timeSinceLastActivityInterval, boolean isHeartbeat) {
+ protected void sendAppendEntries(long timeSinceLastActivityInterval, boolean isHeartbeat) {
// Send an AppendEntries to all followers
for (Entry<String, FollowerLogInformation> e : followerToLog.entrySet()) {
final String followerId = e.getKey();
appendEntries);
}
- followerActor.tell(appendEntries.toSerializable(), actor());
+ followerActor.tell(appendEntries, actor());
}
/**
private void sendSnapshotChunk(ActorSelection followerActor, String followerId) {
try {
if (snapshot.isPresent()) {
- ByteString nextSnapshotChunk = getNextSnapshotChunk(followerId, snapshot.get().getSnapshotBytes());
+ byte[] nextSnapshotChunk = getNextSnapshotChunk(followerId, snapshot.get().getSnapshotBytes());
// Note: the previous call to getNextSnapshotChunk has the side-effect of adding
// followerId to the followerToSnapshot map.
followerToSnapshot.incrementChunkIndex(),
followerToSnapshot.getTotalChunks(),
Optional.of(followerToSnapshot.getLastChunkHashCode())
- ).toSerializable(),
+ ).toSerializable(followerToLog.get(followerId).getRaftVersion()),
actor()
);
* Acccepts snaphot as ByteString, enters into map for future chunks
* creates and return a ByteString chunk
*/
- private ByteString getNextSnapshotChunk(String followerId, ByteString snapshotBytes) throws IOException {
+ private byte[] getNextSnapshotChunk(String followerId, ByteString snapshotBytes) throws IOException {
FollowerToSnapshot followerToSnapshot = mapFollowerToSnapshot.get(followerId);
if (followerToSnapshot == null) {
followerToSnapshot = new FollowerToSnapshot(snapshotBytes);
mapFollowerToSnapshot.put(followerId, followerToSnapshot);
}
- ByteString nextChunk = followerToSnapshot.getNextChunk();
+ byte[] nextChunk = followerToSnapshot.getNextChunk();
- LOG.debug("{}: next snapshot chunk size for follower {}: {}", logName(), followerId, nextChunk.size());
+ LOG.debug("{}: next snapshot chunk size for follower {}: {}", logName(), followerId, nextChunk.length);
return nextChunk;
}
// need to be sent if there are other messages being sent to the remote
// actor.
heartbeatSchedule = context.getActorSystem().scheduler().scheduleOnce(
- interval, context.getActor(), new SendHeartBeat(),
+ interval, context.getActor(), SendHeartBeat.INSTANCE,
context.getActorSystem().dispatcher(), context.getActor());
}
@Override
- public void close() throws Exception {
+ public void close() {
stopHeartBeat();
}
@Override
- public String getLeaderId() {
+ public final String getLeaderId() {
return context.getId();
}
+ @Override
+ public final short getLeaderPayloadVersion() {
+ return context.getPayloadVersion();
+ }
+
protected boolean isLeaderIsolated() {
int minPresent = getMinIsolatedLeaderPeerCount();
for (FollowerLogInformation followerLogInformation : followerToLog.values()) {
}
}
- public ByteString getNextChunk() {
+ public byte[] getNextChunk() {
int snapshotLength = getSnapshotBytes().size();
int start = incrementOffset();
int size = context.getConfigParams().getSnapshotChunkSize();
if (context.getConfigParams().getSnapshotChunkSize() > snapshotLength) {
size = snapshotLength;
- } else {
- if ((start + context.getConfigParams().getSnapshotChunkSize()) > snapshotLength) {
- size = snapshotLength - start;
- }
+ } else if ((start + context.getConfigParams().getSnapshotChunkSize()) > snapshotLength) {
+ size = snapshotLength - start;
}
+ byte[] nextChunk = new byte[size];
+ getSnapshotBytes().copyTo(nextChunk, start, 0, size);
+ nextChunkHashCode = Arrays.hashCode(nextChunk);
- LOG.debug("{}: Next chunk: length={}, offset={},size={}", logName(),
- snapshotLength, start, size);
-
- ByteString substring = getSnapshotBytes().substring(start, start + size);
- nextChunkHashCode = substring.hashCode();
- return substring;
+ LOG.debug("{}: Next chunk: total length={}, offset={}, size={}, hashCode={}", logName(),
+ snapshotLength, start, size, nextChunkHashCode);
+ return nextChunk;
}
/**