import akka.actor.ActorRef;
import com.google.common.annotations.VisibleForTesting;
-import com.google.protobuf.ByteString;
import java.util.ArrayList;
import org.opendaylight.controller.cluster.raft.RaftActorContext;
import org.opendaylight.controller.cluster.raft.RaftState;
import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
+import org.opendaylight.controller.cluster.raft.ServerConfigurationPayload;
import org.opendaylight.controller.cluster.raft.Snapshot;
import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
import org.opendaylight.controller.cluster.raft.base.messages.ElectionTimeout;
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;
/**
private SnapshotTracker snapshotTracker = null;
+ private final SyncStatusTracker initialSyncStatusTracker;
+
+ private static final int SYNC_THRESHOLD = 10;
+
public Follower(RaftActorContext context) {
- super(context);
+ this(context, null);
+ }
+
+ public Follower(RaftActorContext context, String initialLeaderId) {
+ super(context, RaftState.Follower);
+ leaderId = initialLeaderId;
+
+ initialSyncStatusTracker = new SyncStatusTracker(context.getActor(), getId(), SYNC_THRESHOLD);
+
+ if(context.getRaftPolicy().automaticElectionsEnabled()) {
+ if (context.getPeerIds().isEmpty() && getLeaderId() == null) {
+ actor().tell(ELECTION_TIMEOUT, actor());
+ } else {
+ scheduleElection(electionDuration());
+ }
+ }
- scheduleElection(electionDuration());
}
private boolean isLogEntryPresent(long index){
return -1;
}
+ private void updateInitialSyncStatus(long currentLeaderCommit, String leaderId){
+ initialSyncStatusTracker.update(leaderId, currentLeaderCommit, context.getCommitIndex());
+ }
+
@Override protected RaftActorBehavior handleAppendEntries(ActorRef sender,
AppendEntries appendEntries) {
- if(appendEntries.getEntries() != null && appendEntries.getEntries().size() > 0) {
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: handleAppendEntries: {}", context.getId(), appendEntries);
- }
+ int numLogEntries = appendEntries.getEntries() != null ? appendEntries.getEntries().size() : 0;
+ if(LOG.isTraceEnabled()) {
+ LOG.trace("{}: handleAppendEntries: {}", logName(), appendEntries);
+ } else if(LOG.isDebugEnabled() && numLogEntries > 0) {
+ LOG.debug("{}: handleAppendEntries: {}", logName(), appendEntries);
}
// TODO : Refactor this method into a bunch of smaller methods
// to make it easier to read. Before refactoring ensure tests
// cover the code properly
- // 1. Reply false if term < currentTerm (§5.1)
- // This is handled in the appendEntries method of the base class
-
- // If we got here then we do appear to be talking to the leader
- leaderId = appendEntries.getLeaderId();
-
- // 2. Reply false if log doesn’t contain an entry at prevLogIndex
- // whose term matches prevLogTerm (§5.3)
-
- long prevLogTerm = getLogEntryTerm(appendEntries.getPrevLogIndex());
- boolean prevEntryPresent = isLogEntryPresent(appendEntries.getPrevLogIndex());
-
-
- boolean outOfSync = true;
-
- // First check if the logs are in sync or not
- if (lastIndex() == -1
- && appendEntries.getPrevLogIndex() != -1) {
-
- // The follower's log is out of sync because the leader does have
- // an entry at prevLogIndex and this follower has no entries in
- // it's log.
+ if (snapshotTracker != null || context.getSnapshotManager().isApplying()) {
+ // if snapshot install is in progress, follower should just acknowledge append entries with a reply.
+ AppendEntriesReply reply = new AppendEntriesReply(context.getId(), currentTerm(), true,
+ lastIndex(), lastTerm(), context.getPayloadVersion());
if(LOG.isDebugEnabled()) {
- LOG.debug("{}: The followers log is empty and the senders prevLogIndex is {}",
- context.getId(), appendEntries.getPrevLogIndex());
+ LOG.debug("{}: snapshot install is in progress, replying immediately with {}", logName(), reply);
}
+ sender.tell(reply, actor());
- } else if (lastIndex() > -1
- && appendEntries.getPrevLogIndex() != -1
- && !prevEntryPresent) {
-
- // The follower's log is out of sync because the Leader's
- // prevLogIndex entry was not found in it's log
-
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: The log is not empty but the prevLogIndex {} was not found in it",
- context.getId(), appendEntries.getPrevLogIndex());
- }
+ return this;
+ }
- } else if (lastIndex() > -1
- && prevEntryPresent
- && prevLogTerm != appendEntries.getPrevLogTerm()) {
+ // If we got here then we do appear to be talking to the leader
+ leaderId = appendEntries.getLeaderId();
- // The follower's log is out of sync because the Leader's
- // prevLogIndex entry does exist in the follower's log but it has
- // a different term in it
+ setLeaderPayloadVersion(appendEntries.getPayloadVersion());
- if (LOG.isDebugEnabled()) {
- LOG.debug(
- "{}: Cannot append entries because previous entry term {} is not equal to append entries prevLogTerm {}"
- , context.getId(), prevLogTerm
- , appendEntries.getPrevLogTerm());
- }
- } else {
- outOfSync = false;
- }
+ updateInitialSyncStatus(appendEntries.getLeaderCommit(), appendEntries.getLeaderId());
+ // First check if the logs are in sync or not
+ long lastIndex = lastIndex();
- if (outOfSync) {
+ if (isOutOfSync(appendEntries)) {
// We found that the log was out of sync so just send a negative
// reply and return
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Follower ({}) is out-of-sync, " +
- "so sending negative reply, lastIndex():{}, lastTerm():{}",
- context.getId(), context.getId(), lastIndex(), lastTerm()
- );
- }
- sender.tell(
- new AppendEntriesReply(context.getId(), currentTerm(), false,
- lastIndex(), lastTerm()), actor()
- );
+
+ LOG.debug("{}: Follower is out-of-sync, so sending negative reply, lastIndex: {}, lastTerm: {}",
+ logName(), lastIndex, lastTerm());
+
+ sender.tell(new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex,
+ lastTerm(), context.getPayloadVersion()), actor());
return this;
}
- if (appendEntries.getEntries() != null
- && appendEntries.getEntries().size() > 0) {
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Number of entries to be appended = {}", context.getId(),
+ if (appendEntries.getEntries() != null && appendEntries.getEntries().size() > 0) {
+
+ LOG.debug("{}: Number of entries to be appended = {}", logName(),
appendEntries.getEntries().size());
- }
// 3. If an existing entry conflicts with a new one (same index
// but different terms), delete the existing entry and all that
int addEntriesFrom = 0;
if (context.getReplicatedLog().size() > 0) {
- // Find the entry up until which the one that is not in the follower's log
+ // Find the entry up until the one that is not in the follower's log
for (int i = 0;i < appendEntries.getEntries().size(); i++, addEntriesFrom++) {
ReplicatedLogEntry matchEntry = appendEntries.getEntries().get(i);
ReplicatedLogEntry newEntry = context.getReplicatedLog().get(matchEntry.getIndex());
break;
}
- if (newEntry.getTerm() == matchEntry
- .getTerm()) {
+ if (newEntry.getTerm() == matchEntry.getTerm()) {
continue;
}
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Removing entries from log starting at {}", context.getId(),
+ if(!context.getRaftPolicy().applyModificationToStateBeforeConsensus()) {
+
+ LOG.debug("{}: Removing entries from log starting at {}", logName(),
matchEntry.getIndex());
- }
- // Entries do not match so remove all subsequent entries
- context.getReplicatedLog()
- .removeFromAndPersist(matchEntry.getIndex());
- break;
+ // Entries do not match so remove all subsequent entries
+ context.getReplicatedLog().removeFromAndPersist(matchEntry.getIndex());
+ break;
+ } else {
+ sender.tell(new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex,
+ lastTerm(), context.getPayloadVersion(), true), actor());
+ return this;
+ }
}
}
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: After cleanup entries to be added from = {}", context.getId(),
- (addEntriesFrom + lastIndex()));
- }
+ lastIndex = lastIndex();
+ LOG.debug("{}: After cleanup entries to be added from = {}", logName(),
+ (addEntriesFrom + lastIndex));
// 4. Append any new entries not already in the log
- for (int i = addEntriesFrom;
- i < appendEntries.getEntries().size(); i++) {
+ for (int i = addEntriesFrom; i < appendEntries.getEntries().size(); i++) {
+ ReplicatedLogEntry entry = appendEntries.getEntries().get(i);
+
+ LOG.debug("{}: Append entry to log {}", logName(), entry.getData());
+
+ context.getReplicatedLog().appendAndPersist(entry);
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Append entry to log {}", context.getId(),
- appendEntries.getEntries().get(i).getData());
+ if(entry.getData() instanceof ServerConfigurationPayload) {
+ context.updatePeerIds((ServerConfigurationPayload)entry.getData());
}
- context.getReplicatedLog().appendAndPersist(appendEntries.getEntries().get(i));
}
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Log size is now {}", context.getId(), context.getReplicatedLog().size());
- }
+ LOG.debug("{}: Log size is now {}", logName(), context.getReplicatedLog().size());
}
-
// 5. If leaderCommit > commitIndex, set commitIndex =
// min(leaderCommit, index of last new entry)
+ lastIndex = lastIndex();
long prevCommitIndex = context.getCommitIndex();
- context.setCommitIndex(Math.min(appendEntries.getLeaderCommit(),
- context.getReplicatedLog().lastIndex()));
+ context.setCommitIndex(Math.min(appendEntries.getLeaderCommit(), lastIndex));
if (prevCommitIndex != context.getCommitIndex()) {
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Commit index set to {}", context.getId(), context.getCommitIndex());
- }
+ LOG.debug("{}: Commit index set to {}", logName(), context.getCommitIndex());
}
// If commitIndex > lastApplied: increment lastApplied, apply
// log[lastApplied] to state machine (§5.3)
// check if there are any entries to be applied. last-applied can be equal to last-index
if (appendEntries.getLeaderCommit() > context.getLastApplied() &&
- context.getLastApplied() < lastIndex()) {
+ context.getLastApplied() < lastIndex) {
if(LOG.isDebugEnabled()) {
LOG.debug("{}: applyLogToStateMachine, " +
- "appendEntries.getLeaderCommit():{}," +
- "context.getLastApplied():{}, lastIndex():{}", context.getId(),
- appendEntries.getLeaderCommit(), context.getLastApplied(), lastIndex()
- );
+ "appendEntries.getLeaderCommit(): {}," +
+ "context.getLastApplied(): {}, lastIndex(): {}", logName(),
+ appendEntries.getLeaderCommit(), context.getLastApplied(), lastIndex);
}
applyLogToStateMachine(appendEntries.getLeaderCommit());
}
- sender.tell(new AppendEntriesReply(context.getId(), currentTerm(), true,
- lastIndex(), lastTerm()), actor());
+ AppendEntriesReply reply = new AppendEntriesReply(context.getId(), currentTerm(), true,
+ lastIndex, lastTerm(), context.getPayloadVersion());
+
+ if(LOG.isTraceEnabled()) {
+ LOG.trace("{}: handleAppendEntries returning : {}", logName(), reply);
+ } else if(LOG.isDebugEnabled() && numLogEntries > 0) {
+ LOG.debug("{}: handleAppendEntries returning : {}", logName(), reply);
+ }
+
+ sender.tell(reply, actor());
+
+ if (!context.getSnapshotManager().isCapturing()) {
+ super.performSnapshotWithoutCapture(appendEntries.getReplicatedToAllIndex());
+ }
return this;
}
+ private boolean isOutOfSync(AppendEntries appendEntries) {
+
+ long prevLogTerm = getLogEntryTerm(appendEntries.getPrevLogIndex());
+ boolean prevEntryPresent = isLogEntryPresent(appendEntries.getPrevLogIndex());
+ long lastIndex = lastIndex();
+ int numLogEntries = appendEntries.getEntries() != null ? appendEntries.getEntries().size() : 0;
+ boolean outOfSync = true;
+
+ if (lastIndex == -1 && appendEntries.getPrevLogIndex() != -1) {
+
+ // The follower's log is out of sync because the leader does have
+ // an entry at prevLogIndex and this follower has no entries in
+ // it's log.
+
+ LOG.debug("{}: The followers log is empty and the senders prevLogIndex is {}",
+ logName(), appendEntries.getPrevLogIndex());
+ } else if (lastIndex > -1 && appendEntries.getPrevLogIndex() != -1 && !prevEntryPresent) {
+
+ // The follower's log is out of sync because the Leader's
+ // prevLogIndex entry was not found in it's log
+
+ LOG.debug("{}: The log is not empty but the prevLogIndex {} was not found in it",
+ logName(), appendEntries.getPrevLogIndex());
+ } else if (lastIndex > -1 && prevEntryPresent && prevLogTerm != appendEntries.getPrevLogTerm()) {
+
+ // The follower's log is out of sync because the Leader's
+ // prevLogIndex entry does exist in the follower's log but it has
+ // a different term in it
+
+ LOG.debug(
+ "{}: Cannot append entries because previous entry term {} is not equal to append entries prevLogTerm {}",
+ logName(), prevLogTerm, appendEntries.getPrevLogTerm());
+ } else if(appendEntries.getPrevLogIndex() == -1 && appendEntries.getPrevLogTerm() == -1
+ && appendEntries.getReplicatedToAllIndex() != -1
+ && !isLogEntryPresent(appendEntries.getReplicatedToAllIndex())) {
+ // This append entry comes from a leader who has it's log aggressively trimmed and so does not have
+ // the previous entry in it's in-memory journal
+
+ LOG.debug(
+ "{}: Cannot append entries because the replicatedToAllIndex {} does not appear to be in the in-memory journal",
+ logName(), appendEntries.getReplicatedToAllIndex());
+ } else if(appendEntries.getPrevLogIndex() == -1 && appendEntries.getPrevLogTerm() == -1
+ && appendEntries.getReplicatedToAllIndex() != -1 && numLogEntries > 0 &&
+ !isLogEntryPresent(appendEntries.getEntries().get(0).getIndex() - 1)){
+ LOG.debug(
+ "{}: Cannot append entries because the calculated previousIndex {} was not found in the in-memory journal",
+ logName(), appendEntries.getEntries().get(0).getIndex() - 1);
+ } else {
+ outOfSync = false;
+ }
+ return outOfSync;
+ }
+
@Override protected RaftActorBehavior handleAppendEntriesReply(ActorRef sender,
AppendEntriesReply appendEntriesReply) {
return this;
return this;
}
- @Override public RaftState state() {
- return RaftState.Follower;
- }
-
@Override public RaftActorBehavior handleMessage(ActorRef sender, Object originalMessage) {
Object message = fromSerializableMessage(originalMessage);
// set currentTerm = T, convert to follower (§5.1)
// This applies to all RPC messages and responses
if (rpc.getTerm() > context.getTermInformation().getCurrentTerm()) {
+ LOG.debug("{}: Term {} in \"{}\" message is greater than follower's term {} - updating term",
+ logName(), rpc.getTerm(), rpc, context.getTermInformation().getCurrentTerm());
+
context.getTermInformation().updateAndPersist(rpc.getTerm(), null);
}
}
if (message instanceof ElectionTimeout) {
- return switchBehavior(new Candidate(context));
+ LOG.debug("{}: Received ElectionTimeout - switching to Candidate", logName());
+ return internalSwitchBehavior(RaftState.Candidate);
} else if (message instanceof InstallSnapshot) {
InstallSnapshot installSnapshot = (InstallSnapshot) message;
handleInstallSnapshot(sender, installSnapshot);
}
- scheduleElection(electionDuration());
+ if(message instanceof RaftRPC && (!(message instanceof RequestVote) || (canGrantVote((RequestVote) message)))){
+ scheduleElection(electionDuration());
+ }
return super.handleMessage(sender, message);
}
- private void handleInstallSnapshot(ActorRef sender, InstallSnapshot installSnapshot) {
+ private void handleInstallSnapshot(final ActorRef sender, InstallSnapshot installSnapshot) {
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: InstallSnapshot received by follower " +
- "datasize:{} , Chunk:{}/{}", context.getId(), installSnapshot.getData().size(),
- installSnapshot.getChunkIndex(), installSnapshot.getTotalChunks()
- );
- }
+ LOG.debug("{}: InstallSnapshot received from leader {}, datasize: {} , Chunk: {}/{}",
+ logName(), installSnapshot.getLeaderId(), installSnapshot.getData().size(),
+ installSnapshot.getChunkIndex(), installSnapshot.getTotalChunks());
+
+ leaderId = installSnapshot.getLeaderId();
if(snapshotTracker == null){
snapshotTracker = new SnapshotTracker(LOG, installSnapshot.getTotalChunks());
}
+ updateInitialSyncStatus(installSnapshot.getLastIncludedIndex(), installSnapshot.getLeaderId());
+
try {
+ final InstallSnapshotReply reply = new InstallSnapshotReply(
+ currentTerm(), context.getId(), installSnapshot.getChunkIndex(), true);
+
if(snapshotTracker.addChunk(installSnapshot.getChunkIndex(), installSnapshot.getData(),
installSnapshot.getLastChunkHashCode())){
Snapshot snapshot = Snapshot.create(snapshotTracker.getSnapshot(),
installSnapshot.getLastIncludedIndex(),
installSnapshot.getLastIncludedTerm(),
installSnapshot.getLastIncludedIndex(),
- installSnapshot.getLastIncludedTerm());
+ installSnapshot.getLastIncludedTerm(),
+ context.getTermInformation().getCurrentTerm(),
+ context.getTermInformation().getVotedFor(),
+ context.getPeerServerInfo());
- actor().tell(new ApplySnapshot(snapshot), actor());
+ ApplySnapshot.Callback applySnapshotCallback = new ApplySnapshot.Callback() {
+ @Override
+ public void onSuccess() {
+ LOG.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
- snapshotTracker = null;
+ sender.tell(reply, actor());
+ }
- }
+ @Override
+ public void onFailure() {
+ sender.tell(new InstallSnapshotReply(currentTerm(), context.getId(), -1, false), actor());
+ }
+ };
+
+ actor().tell(new ApplySnapshot(snapshot, applySnapshotCallback), actor());
- sender.tell(new InstallSnapshotReply(
- currentTerm(), context.getId(), installSnapshot.getChunkIndex(),
- true), actor());
+ snapshotTracker = null;
+ } else {
+ LOG.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
+ sender.tell(reply, actor());
+ }
} catch (SnapshotTracker.InvalidChunkException e) {
+ LOG.debug("{}: Exception in InstallSnapshot of follower", logName(), e);
sender.tell(new InstallSnapshotReply(currentTerm(), context.getId(),
-1, false), actor());
snapshotTracker = null;
} catch (Exception e){
- LOG.error(e, "{}: Exception in InstallSnapshot of follower", context.getId());
+ LOG.error("{}: Exception in InstallSnapshot of follower", logName(), e);
+
//send reply with success as false. The chunk will be sent again on failure
sender.tell(new InstallSnapshotReply(currentTerm(), context.getId(),
installSnapshot.getChunkIndex(), false), actor());
}
}
- @Override public void close() throws Exception {
+ @Override
+ public void close() throws Exception {
stopElection();
}
@VisibleForTesting
- ByteString getSnapshotChunksCollected(){
- return snapshotTracker != null ? snapshotTracker.getCollectedChunks() : ByteString.EMPTY;
+ SnapshotTracker getSnapshotTracker(){
+ return snapshotTracker;
}
-
-
}
Code Review / controller.git / blobdiff