2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.controller.cluster.raft.behaviors;
10 import akka.actor.ActorRef;
11 import com.google.common.annotations.VisibleForTesting;
12 import com.google.common.base.Preconditions;
13 import com.google.common.base.Stopwatch;
14 import java.util.concurrent.TimeUnit;
15 import org.opendaylight.controller.cluster.raft.RaftActorContext;
16 import org.opendaylight.controller.cluster.raft.RaftState;
17 import org.opendaylight.controller.cluster.raft.base.messages.IsolatedLeaderCheck;
20 * The behavior of a RaftActor when it is in the Leader state
24 * <li> Upon election: send initial empty AppendEntries RPCs
25 * (heartbeat) to each server; repeat during idle periods to
26 * prevent election timeouts (§5.2)
27 * <li> If command received from client: append entry to local log,
28 * respond after entry applied to state machine (§5.3)
29 * <li> If last log index ≥ nextIndex for a follower: send
30 * AppendEntries RPC with log entries starting at nextIndex
32 * <li> If successful: update nextIndex and matchIndex for
34 * <li> If AppendEntries fails because of log inconsistency:
35 * decrement nextIndex and retry (§5.3)
37 * <li> If there exists an N such that N > commitIndex, a majority
38 * of matchIndex[i] ≥ N, and log[N].term == currentTerm:
39 * set commitIndex = N (§5.3, §5.4).
41 public class Leader extends AbstractLeader {
42 private static final IsolatedLeaderCheck ISOLATED_LEADER_CHECK = new IsolatedLeaderCheck();
43 private final Stopwatch isolatedLeaderCheck;
45 public Leader(RaftActorContext context) {
47 isolatedLeaderCheck = Stopwatch.createStarted();
50 @Override public RaftActorBehavior handleMessage(ActorRef sender, Object originalMessage) {
51 Preconditions.checkNotNull(sender, "sender should not be null");
53 if (originalMessage instanceof IsolatedLeaderCheck) {
54 if (isLeaderIsolated()) {
55 LOG.warn("{}: At least {} followers need to be active, Switching {} from Leader to IsolatedLeader",
56 context.getId(), getMinIsolatedLeaderPeerCount(), leaderId);
58 return internalSwitchBehavior(RaftState.IsolatedLeader);
62 return super.handleMessage(sender, originalMessage);
66 protected void beforeSendHeartbeat(){
67 if(isolatedLeaderCheck.elapsed(TimeUnit.MILLISECONDS) > context.getConfigParams().getIsolatedCheckIntervalInMillis()){
68 context.getActor().tell(ISOLATED_LEADER_CHECK, context.getActor());
69 isolatedLeaderCheck.reset().start();
75 public void close() throws Exception {
80 void markFollowerActive(String followerId) {
81 getFollower(followerId).markFollowerActive();
85 void markFollowerInActive(String followerId) {
86 getFollower(followerId).markFollowerInActive();