X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-akka-raft%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fcluster%2Fraft%2Fbehaviors%2FLeader.java;h=21f823d08960b71111750120b3e451be7b7d4137;hb=refs%2Fchanges%2F25%2F82725%2F1;hp=924c30f657b927528a81ac9997564418c8ec2fe5;hpb=3d4e718d0fe598b33e50b8d3bbcca3ff3bbb8b3a;p=controller.git
diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Leader.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Leader.java
index 924c30f657..21f823d089 100644
--- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Leader.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Leader.java
@@ -7,25 +7,27 @@
*/
package org.opendaylight.controller.cluster.raft.behaviors;
+import static java.util.Objects.requireNonNull;
+
import akka.actor.ActorRef;
import akka.actor.ActorSelection;
import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Preconditions;
+import com.google.common.base.Optional;
import com.google.common.base.Stopwatch;
import java.util.concurrent.TimeUnit;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
import org.opendaylight.controller.cluster.raft.FollowerLogInformation;
import org.opendaylight.controller.cluster.raft.RaftActorContext;
import org.opendaylight.controller.cluster.raft.RaftActorLeadershipTransferCohort;
import org.opendaylight.controller.cluster.raft.RaftState;
-import org.opendaylight.controller.cluster.raft.base.messages.ElectionTimeout;
-import org.opendaylight.controller.cluster.raft.base.messages.IsolatedLeaderCheck;
+import org.opendaylight.controller.cluster.raft.base.messages.TimeoutNow;
import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
/**
- * The behavior of a RaftActor when it is in the Leader state
- *
+ * The behavior of a RaftActor when it is in the Leader state.
+ *
+ *
* Leaders:
*
* - Upon election: send initial empty AppendEntries RPCs
@@ -35,51 +37,62 @@ import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
* respond after entry applied to state machine (§5.3)
*
- If last log index ⥠nextIndex for a follower: send
* AppendEntries RPC with log entries starting at nextIndex
- *
* - If successful: update nextIndex and matchIndex for
* follower (§5.3)
*
- If AppendEntries fails because of log inconsistency:
* decrement nextIndex and retry (§5.3)
- *
- * - If there exists an N such that N > commitIndex, a majority
+ *
- If there exists an N such that N > commitIndex, a majority
* of matchIndex[i] ⥠N, and log[N].term == currentTerm:
* set commitIndex = N (§5.3, §5.4).
+ *
*/
public class Leader extends AbstractLeader {
- private static final IsolatedLeaderCheck ISOLATED_LEADER_CHECK = new IsolatedLeaderCheck();
- private final Stopwatch isolatedLeaderCheck;
+ /**
+ * Internal message sent to periodically check if this leader has become isolated and should transition
+ * to {@link IsolatedLeader}.
+ */
+ @VisibleForTesting
+ static final Object ISOLATED_LEADER_CHECK = new Object();
+
+ private final Stopwatch isolatedLeaderCheck = Stopwatch.createStarted();
private @Nullable LeadershipTransferContext leadershipTransferContext;
+ Leader(RaftActorContext context, @Nullable AbstractLeader initializeFromLeader) {
+ super(context, RaftState.Leader, initializeFromLeader);
+ }
+
public Leader(RaftActorContext context) {
- super(context);
- isolatedLeaderCheck = Stopwatch.createStarted();
+ this(context, null);
}
- @Override public RaftActorBehavior handleMessage(ActorRef sender, Object originalMessage) {
- Preconditions.checkNotNull(sender, "sender should not be null");
+ @Override
+ public RaftActorBehavior handleMessage(ActorRef sender, Object originalMessage) {
+ requireNonNull(sender, "sender should not be null");
- if (originalMessage instanceof IsolatedLeaderCheck) {
+ if (ISOLATED_LEADER_CHECK.equals(originalMessage)) {
if (isLeaderIsolated()) {
- LOG.warn("{}: At least {} followers need to be active, Switching {} from Leader to IsolatedLeader",
- context.getId(), getMinIsolatedLeaderPeerCount(), leaderId);
-
- return internalSwitchBehavior(RaftState.IsolatedLeader);
+ log.warn("{}: At least {} followers need to be active, Switching {} from Leader to IsolatedLeader",
+ context.getId(), getMinIsolatedLeaderPeerCount(), getLeaderId());
+ return internalSwitchBehavior(new IsolatedLeader(context, this));
+ } else {
+ return this;
}
+ } else {
+ return super.handleMessage(sender, originalMessage);
}
-
- return super.handleMessage(sender, originalMessage);
}
@Override
- protected void beforeSendHeartbeat(){
- if(isolatedLeaderCheck.elapsed(TimeUnit.MILLISECONDS) > context.getConfigParams().getIsolatedCheckIntervalInMillis()){
+ protected void beforeSendHeartbeat() {
+ if (isolatedLeaderCheck.elapsed(TimeUnit.MILLISECONDS)
+ > context.getConfigParams().getIsolatedCheckIntervalInMillis()) {
context.getActor().tell(ISOLATED_LEADER_CHECK, context.getActor());
isolatedLeaderCheck.reset().start();
}
- if(leadershipTransferContext != null && leadershipTransferContext.isExpired(
+ if (leadershipTransferContext != null && leadershipTransferContext.isExpired(
context.getConfigParams().getElectionTimeOutInterval().toMillis())) {
- LOG.debug("{}: Leadership transfer expired", logName());
+ log.debug("{}: Leadership transfer expired", logName());
leadershipTransferContext = null;
}
}
@@ -97,20 +110,20 @@ public class Leader extends AbstractLeader {
* Start a timer (Stopwatch).
* Send an initial AppendEntries heartbeat to all followers.
* On AppendEntriesReply, check if the follower's new match Index matches the leader's last index
- * If it matches,
+ * If it matches,
*
* - Send an additional AppendEntries to ensure the follower has applied all its log entries to its state.
* - Send an ElectionTimeout to the follower to immediately start an election.
* - Notify {@link RaftActorLeadershipTransferCohort#transferComplete}.
- *
+ *
* Otherwise if the election time out period elapses, notify
- * {@link RaftActorLeadershipTransferCohort#abortTtransfer}.
+ * {@link RaftActorLeadershipTransferCohort#abortTransfer}.
*
*
- * @param leadershipTransferCohort
+ * @param leadershipTransferCohort the cohort participating in the leadership transfer
*/
- public void transferLeadership(@Nonnull RaftActorLeadershipTransferCohort leadershipTransferCohort) {
- LOG.debug("{}: Attempting to transfer leadership", logName());
+ public void transferLeadership(@NonNull RaftActorLeadershipTransferCohort leadershipTransferCohort) {
+ log.debug("{}: Attempting to transfer leadership", logName());
leadershipTransferContext = new LeadershipTransferContext(leadershipTransferCohort);
@@ -119,33 +132,40 @@ public class Leader extends AbstractLeader {
}
private void tryToCompleteLeadershipTransfer(String followerId) {
- if(leadershipTransferContext == null) {
+ if (leadershipTransferContext == null) {
+ return;
+ }
+
+ final Optional requestedFollowerIdOptional
+ = leadershipTransferContext.transferCohort.getRequestedFollowerId();
+ if (requestedFollowerIdOptional.isPresent() && !requestedFollowerIdOptional.get().equals(followerId)) {
+ // we want to transfer leadership to specific follower
return;
}
FollowerLogInformation followerInfo = getFollower(followerId);
- if(followerInfo == null) {
+ if (followerInfo == null) {
return;
}
long lastIndex = context.getReplicatedLog().lastIndex();
boolean isVoting = context.getPeerInfo(followerId).isVoting();
- LOG.debug("{}: tryToCompleteLeadershipTransfer: followerId: {}, matchIndex: {}, lastIndex: {}, isVoting: {}",
+ log.debug("{}: tryToCompleteLeadershipTransfer: followerId: {}, matchIndex: {}, lastIndex: {}, isVoting: {}",
logName(), followerId, followerInfo.getMatchIndex(), lastIndex, isVoting);
- if(isVoting && followerInfo.getMatchIndex() == lastIndex) {
- LOG.debug("{}: Follower's log matches - sending ElectionTimeout", logName());
+ if (isVoting && followerInfo.getMatchIndex() == lastIndex) {
+ log.debug("{}: Follower's log matches - sending ElectionTimeout", logName());
// We can't be sure if the follower has applied all its log entries to its state so send an
// additional AppendEntries with the latest commit index.
sendAppendEntries(0, false);
- // Now send an ElectionTimeout to the matching follower to immediately start an election.
+ // Now send a TimeoutNow message to the matching follower to immediately start an election.
ActorSelection followerActor = context.getPeerActorSelection(followerId);
- followerActor.tell(ElectionTimeout.INSTANCE, context.getActor());
+ followerActor.tell(TimeoutNow.INSTANCE, context.getActor());
- LOG.debug("{}: Leader transfer complete", logName());
+ log.debug("{}: Leader transfer complete", logName());
leadershipTransferContext.transferCohort.transferComplete();
leadershipTransferContext = null;
@@ -153,9 +173,11 @@ public class Leader extends AbstractLeader {
}
@Override
- public void close() throws Exception {
- if(leadershipTransferContext != null) {
- leadershipTransferContext.transferCohort.abortTransfer();
+ public void close() {
+ if (leadershipTransferContext != null) {
+ LeadershipTransferContext localLeadershipTransferContext = leadershipTransferContext;
+ leadershipTransferContext = null;
+ localLeadershipTransferContext.transferCohort.abortTransfer();
}
super.close();
@@ -180,7 +202,7 @@ public class Leader extends AbstractLeader {
}
boolean isExpired(long timeout) {
- if(timer.elapsed(TimeUnit.MILLISECONDS) >= timeout) {
+ if (timer.elapsed(TimeUnit.MILLISECONDS) >= timeout) {
transferCohort.abortTransfer();
return true;
}