X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-akka-raft%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fcluster%2Fraft%2Fbehaviors%2FFollower.java;h=7e6654d5d6b9849b106a36bf56c76928798d912d;hp=0f251a3012e7afe492b867ced86859316fde6d88;hb=f276ae33b951d173b51c467bb7bb1a5f5cf9a1e6;hpb=95589305be51630beab2f6b80c098ebf72bca4b9 diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Follower.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Follower.java index 0f251a3012..7e6654d5d6 100644 --- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Follower.java +++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Follower.java @@ -9,20 +9,23 @@ package org.opendaylight.controller.cluster.raft.behaviors; import akka.actor.ActorRef; +import akka.japi.Procedure; import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.Preconditions; 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.base.messages.FollowerInitialSyncUpStatus; import org.opendaylight.controller.cluster.raft.messages.AppendEntries; import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply; 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; /** @@ -36,19 +39,59 @@ import org.opendaylight.controller.cluster.raft.messages.RequestVoteReply; * */ public class Follower extends AbstractRaftActorBehavior { + private static final int SYNC_THRESHOLD = 10; + private final SyncStatusTracker initialSyncStatusTracker; + private final Procedure appendAndPersistCallback = new Procedure() { + @Override + public void apply(ReplicatedLogEntry logEntry) { + context.getReplicatedLog().captureSnapshotIfReady(logEntry); + } + }; private SnapshotTracker snapshotTracker = null; - - private final InitialSyncStatusTracker initialSyncStatusTracker; + private String leaderId; + private short leaderPayloadVersion; public Follower(RaftActorContext context) { + this(context, null, (short)-1); + } + + public Follower(RaftActorContext context, String initialLeaderId, short initialLeaderPayloadVersion) { super(context, RaftState.Follower); + this.leaderId = initialLeaderId; + this.leaderPayloadVersion = initialLeaderPayloadVersion; + + initialSyncStatusTracker = new SyncStatusTracker(context.getActor(), getId(), SYNC_THRESHOLD); + + if(canStartElection()) { + if (context.getPeerIds().isEmpty() && getLeaderId() == null) { + actor().tell(ElectionTimeout.INSTANCE, actor()); + } else { + scheduleElection(electionDuration()); + } + } + } - scheduleElection(electionDuration()); + @Override + public final String getLeaderId() { + return leaderId; + } + + @VisibleForTesting + protected final void setLeaderId(final String leaderId) { + this.leaderId = Preconditions.checkNotNull(leaderId); + } + + @Override + public short getLeaderPayloadVersion() { + return leaderPayloadVersion; + } - initialSyncStatusTracker = new InitialSyncStatusTracker(context.getActor()); + @VisibleForTesting + protected final void setLeaderPayloadVersion(short leaderPayloadVersion) { + this.leaderPayloadVersion = leaderPayloadVersion; } private boolean isLogEntryPresent(long index){ @@ -82,8 +125,8 @@ public class Follower extends AbstractRaftActorBehavior { initialSyncStatusTracker.update(leaderId, currentLeaderCommit, context.getCommitIndex()); } - @Override protected RaftActorBehavior handleAppendEntries(ActorRef sender, - AppendEntries appendEntries) { + @Override + protected RaftActorBehavior handleAppendEntries(ActorRef sender, AppendEntries appendEntries) { int numLogEntries = appendEntries.getEntries() != null ? appendEntries.getEntries().size() : 0; if(LOG.isTraceEnabled()) { @@ -96,53 +139,28 @@ public class Follower extends AbstractRaftActorBehavior { // 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 (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 we got here then we do appear to be talking to the leader - leaderId = appendEntries.getLeaderId(); + if(LOG.isDebugEnabled()) { + LOG.debug("{}: snapshot install is in progress, replying immediately with {}", logName(), reply); + } + sender.tell(reply, actor()); - // 2. Reply false if log doesn’t contain an entry at prevLogIndex - // whose term matches prevLogTerm (§5.3) + return this; + } - long prevLogTerm = getLogEntryTerm(appendEntries.getPrevLogIndex()); - boolean prevEntryPresent = isLogEntryPresent(appendEntries.getPrevLogIndex()); + // If we got here then we do appear to be talking to the leader + leaderId = appendEntries.getLeaderId(); + leaderPayloadVersion = appendEntries.getPayloadVersion(); updateInitialSyncStatus(appendEntries.getLeaderCommit(), appendEntries.getLeaderId()); - - boolean outOfSync = true; - // First check if the logs are in sync or not long lastIndex = lastIndex(); - 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 { - outOfSync = false; - } - - if (outOfSync) { + if (isOutOfSync(appendEntries)) { // We found that the log was out of sync so just send a negative // reply and return @@ -150,7 +168,7 @@ public class Follower extends AbstractRaftActorBehavior { logName(), lastIndex, lastTerm()); sender.tell(new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex, - lastTerm()), actor()); + lastTerm(), context.getPayloadVersion()), actor()); return this; } @@ -165,7 +183,7 @@ public class Follower extends AbstractRaftActorBehavior { 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()); @@ -179,12 +197,19 @@ public class Follower extends AbstractRaftActorBehavior { continue; } - LOG.debug("{}: Removing entries from log starting at {}", logName(), + 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; + } } } @@ -198,7 +223,11 @@ public class Follower extends AbstractRaftActorBehavior { LOG.debug("{}: Append entry to log {}", logName(), entry.getData()); - context.getReplicatedLog().appendAndPersist(entry); + context.getReplicatedLog().appendAndPersist(entry, appendAndPersistCallback); + + if(entry.getData() instanceof ServerConfigurationPayload) { + context.updatePeerIds((ServerConfigurationPayload)entry.getData()); + } } LOG.debug("{}: Log size is now {}", logName(), context.getReplicatedLog().size()); @@ -232,7 +261,7 @@ public class Follower extends AbstractRaftActorBehavior { } AppendEntriesReply reply = new AppendEntriesReply(context.getId(), currentTerm(), true, - lastIndex, lastTerm()); + lastIndex, lastTerm(), context.getPayloadVersion()); if(LOG.isTraceEnabled()) { LOG.trace("{}: handleAppendEntries returning : {}", logName(), reply); @@ -242,59 +271,127 @@ public class Follower extends AbstractRaftActorBehavior { sender.tell(reply, actor()); - if (!context.isSnapshotCaptureInitiated()) { + if (!context.getSnapshotManager().isCapturing()) { super.performSnapshotWithoutCapture(appendEntries.getReplicatedToAllIndex()); } return this; } - @Override protected RaftActorBehavior handleAppendEntriesReply(ActorRef sender, + 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()) + && !context.getReplicatedLog().isInSnapshot(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) + && !context.getReplicatedLog().isInSnapshot(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; } - @Override protected RaftActorBehavior handleRequestVoteReply(ActorRef sender, + @Override + protected RaftActorBehavior handleRequestVoteReply(ActorRef sender, RequestVoteReply requestVoteReply) { return this; } - @Override public RaftActorBehavior handleMessage(ActorRef sender, Object originalMessage) { + @Override + public RaftActorBehavior handleMessage(ActorRef sender, Object originalMessage) { + if (originalMessage instanceof ElectionTimeout) { + if (canStartElection()) { + LOG.debug("{}: Received ElectionTimeout - switching to Candidate", logName()); + return internalSwitchBehavior(RaftState.Candidate); + } else { + return this; + } + } - Object message = fromSerializableMessage(originalMessage); + final Object message = fromSerializableMessage(originalMessage); + if (!(message instanceof RaftRPC)) { + // The rest of the processing requires the message to be a RaftRPC + return null; + } - if (message instanceof RaftRPC) { - RaftRPC rpc = (RaftRPC) message; - // If RPC request or response contains term T > currentTerm: - // 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()); + final RaftRPC rpc = (RaftRPC) message; + // If RPC request or response contains term T > currentTerm: + // 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); - } + context.getTermInformation().updateAndPersist(rpc.getTerm(), null); } - if (message instanceof ElectionTimeout) { - LOG.debug("{}: Received ElectionTimeout - switching to Candidate", logName()); - return switchBehavior(new Candidate(context)); - - } else if (message instanceof InstallSnapshot) { - InstallSnapshot installSnapshot = (InstallSnapshot) message; + if (rpc instanceof InstallSnapshot) { + InstallSnapshot installSnapshot = (InstallSnapshot) rpc; handleInstallSnapshot(sender, installSnapshot); + scheduleElection(electionDuration()); + return this; } - scheduleElection(electionDuration()); + if (!(rpc instanceof RequestVote) || canGrantVote((RequestVote) rpc)) { + scheduleElection(electionDuration()); + } - return super.handleMessage(sender, message); + return super.handleMessage(sender, rpc); } - private void handleInstallSnapshot(ActorRef sender, InstallSnapshot installSnapshot) { + private void handleInstallSnapshot(final ActorRef sender, InstallSnapshot installSnapshot) { + + LOG.debug("{}: handleInstallSnapshot: {}", logName(), installSnapshot); - 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()); @@ -303,6 +400,9 @@ public class Follower extends AbstractRaftActorBehavior { 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(), @@ -310,21 +410,33 @@ public class Follower extends AbstractRaftActorBehavior { installSnapshot.getLastIncludedIndex(), installSnapshot.getLastIncludedTerm(), installSnapshot.getLastIncludedIndex(), - installSnapshot.getLastIncludedTerm()); - - actor().tell(new ApplySnapshot(snapshot), actor()); + installSnapshot.getLastIncludedTerm(), + context.getTermInformation().getCurrentTerm(), + context.getTermInformation().getVotedFor(), + context.getPeerServerInfo(true)); - snapshotTracker = null; + ApplySnapshot.Callback applySnapshotCallback = new ApplySnapshot.Callback() { + @Override + public void onSuccess() { + LOG.debug("{}: handleInstallSnapshot returning: {}", logName(), reply); - } + sender.tell(reply, actor()); + } - InstallSnapshotReply reply = new InstallSnapshotReply( - currentTerm(), context.getId(), installSnapshot.getChunkIndex(), true); + @Override + public void onFailure() { + sender.tell(new InstallSnapshotReply(currentTerm(), context.getId(), -1, false), actor()); + } + }; - LOG.debug("{}: handleInstallSnapshot returning: {}", logName(), reply); + actor().tell(new ApplySnapshot(snapshot, applySnapshotCallback), actor()); - sender.tell(reply, 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); @@ -343,7 +455,7 @@ public class Follower extends AbstractRaftActorBehavior { } @Override - public void close() throws Exception { + public void close() { stopElection(); } @@ -351,36 +463,4 @@ public class Follower extends AbstractRaftActorBehavior { SnapshotTracker getSnapshotTracker(){ return snapshotTracker; } - - private class InitialSyncStatusTracker { - - private static final long INVALID_LOG_INDEX = -2L; - private long initialLeaderCommit = INVALID_LOG_INDEX; - private boolean initialSyncUpDone = false; - private String syncedLeaderId = null; - private final ActorRef actor; - - public InitialSyncStatusTracker(ActorRef actor) { - this.actor = actor; - } - - public void update(String leaderId, long leaderCommit, long commitIndex){ - - if(!leaderId.equals(syncedLeaderId)){ - initialSyncUpDone = false; - initialLeaderCommit = INVALID_LOG_INDEX; - syncedLeaderId = leaderId; - } - - if(!initialSyncUpDone){ - if(initialLeaderCommit == INVALID_LOG_INDEX){ - actor.tell(new FollowerInitialSyncUpStatus(false, getId()), ActorRef.noSender()); - initialLeaderCommit = leaderCommit; - } else if(commitIndex >= initialLeaderCommit){ - actor.tell(new FollowerInitialSyncUpStatus(true, getId()), ActorRef.noSender()); - initialSyncUpDone = true; - } - } - } - } }