2 * Copyright (c) 2015 Brocade Communications 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 static org.junit.Assert.assertEquals;
11 import akka.actor.ActorRef;
12 import com.google.common.collect.ImmutableMap;
13 import org.junit.Test;
14 import org.opendaylight.controller.cluster.raft.DefaultConfigParamsImpl;
15 import org.opendaylight.controller.cluster.raft.RaftState;
16 import org.opendaylight.controller.cluster.raft.base.messages.ElectionTimeout;
17 import org.opendaylight.controller.cluster.raft.base.messages.TimeoutNow;
18 import org.opendaylight.controller.cluster.raft.messages.AppendEntries;
19 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
20 import org.opendaylight.controller.cluster.raft.messages.RequestVote;
21 import org.opendaylight.controller.cluster.raft.messages.RequestVoteReply;
24 * A leader election scenario test that causes partitioned leaders by dropping messages between 2 members.
26 * @author Thomas Pantelis
28 public class PartitionedLeadersElectionScenarioTest extends AbstractLeaderElectionScenarioTest {
31 * This test sets up a scenario with partitioned leaders member 2 and 3 where partitioned leader 3
32 * sends a heartbeat first when connectivity is re-established.
35 public void runTest1() throws Exception {
36 testLog.info("PartitionedLeadersElectionScenarioTest 1 starting");
38 setupInitialMemberBehaviors();
40 sendInitialElectionTimeoutToFollowerMember2();
42 sendInitialElectionTimeoutToFollowerMember3();
44 sendElectionTimeoutToNowCandidateMember2();
46 resolvePartitionedLeadersWithLeaderMember3SendingHeartbeatFirst();
48 testLog.info("PartitionedLeadersElectionScenarioTest 1 ending");
52 * This test sets up a scenario with partitioned leaders member 2 and 3 where partitioned leader 2
53 * sends a heartbeat first when connectivity is re-established.
56 public void runTest2() throws Exception {
57 testLog.info("PartitionedLeadersElectionScenarioTest 2 starting");
59 setupInitialMemberBehaviors();
61 sendInitialElectionTimeoutToFollowerMember2();
63 sendInitialElectionTimeoutToFollowerMember3();
65 sendElectionTimeoutToNowCandidateMember2();
67 resolvePartitionedLeadersWithLeaderMember2SendingHeartbeatFirst();
69 testLog.info("PartitionedLeadersElectionScenarioTest 2 ending");
72 private void resolvePartitionedLeadersWithLeaderMember2SendingHeartbeatFirst() {
73 testLog.info("resolvePartitionedLeadersWithLeaderMember2SendingHeartbeatFirst starting");
75 // Re-establish connectivity between member 2 and 3, ie stop dropping messages between
76 // the 2. Send heartbeats (AppendEntries) from partitioned leader member 2. Follower member 1 should
77 // return a successful AppendEntriesReply b/c its term matches member 2's. member 3 should switch to
78 // Follower as its term is less than member 2's.
81 member1Actor.expectMessageClass(AppendEntries.class, 1);
84 member2Actor.expectMessageClass(AppendEntriesReply.class, 1);
87 member3Actor.expectMessageClass(AppendEntries.class, 1);
89 sendHeartbeat(member2ActorRef);
91 member1Actor.waitForExpectedMessages(AppendEntries.class);
92 member3Actor.waitForExpectedMessages(AppendEntries.class);
94 member2Actor.waitForExpectedMessages(AppendEntriesReply.class);
96 verifyBehaviorState("member 1", member1Actor, RaftState.Follower);
97 verifyBehaviorState("member 2", member2Actor, RaftState.Leader);
98 verifyBehaviorState("member 3", member3Actor, RaftState.Follower);
100 assertEquals("member 1 election term", 3, member1Context.getTermInformation().getCurrentTerm());
101 assertEquals("member 2 election term", 3, member2Context.getTermInformation().getCurrentTerm());
102 assertEquals("member 3 election term", 3, member3Context.getTermInformation().getCurrentTerm());
104 testLog.info("resolvePartitionedLeadersWithLeaderMember2SendingHeartbeatFirst ending");
107 private void resolvePartitionedLeadersWithLeaderMember3SendingHeartbeatFirst() throws Exception {
108 testLog.info("resolvePartitionedLeadersWithLeaderMember3SendingHeartbeatFirst starting");
110 // Re-establish connectivity between member 2 and 3, ie stop dropping messages between
111 // the 2. Send heartbeats (AppendEntries) from now leader member 3. Both member 1 and 2 should send
112 // back an unsuccessful AppendEntriesReply b/c their term (3) is greater than member 3's term (2).
113 // This should cause member 3 to switch to Follower.
115 member1Actor.clear();
116 member1Actor.expectMessageClass(AppendEntries.class, 1);
118 member2Actor.clear();
119 member2Actor.expectMessageClass(AppendEntries.class, 1);
121 member3Actor.clear();
122 member3Actor.expectMessageClass(AppendEntriesReply.class, 1);
124 sendHeartbeat(member3ActorRef);
126 member3Actor.waitForExpectedMessages(AppendEntriesReply.class);
128 AppendEntriesReply appendEntriesReply = member3Actor.getCapturedMessage(AppendEntriesReply.class);
129 assertEquals("isSuccess", false, appendEntriesReply.isSuccess());
130 assertEquals("getTerm", 3, appendEntriesReply.getTerm());
132 verifyBehaviorState("member 1", member1Actor, RaftState.Follower);
133 verifyBehaviorState("member 2", member2Actor, RaftState.Leader);
134 verifyBehaviorState("member 3", member3Actor, RaftState.Follower);
136 assertEquals("member 1 election term", 3, member1Context.getTermInformation().getCurrentTerm());
137 assertEquals("member 2 election term", 3, member2Context.getTermInformation().getCurrentTerm());
138 assertEquals("member 3 election term", 3, member3Context.getTermInformation().getCurrentTerm());
140 testLog.info("resolvePartitionedLeadersWithLeaderMember3SendingHeartbeatFirst ending");
143 private void sendElectionTimeoutToNowCandidateMember2() throws Exception {
144 testLog.info("sendElectionTimeoutToNowCandidateMember2 starting");
146 // member 2, now a candidate, is partitioned from the Leader (now member 3) and hasn't received any
147 // messages. It would get another ElectionTimeout so simulate that. member 1 should send back a reply
148 // granting the vote. Messages (RequestVote and AppendEntries) from member 2 to member 3
149 // are dropped to simulate loss of network connectivity. Note member 2 will increment its
150 // election term to 3.
152 member1Actor.clear();
153 member1Actor.expectMessageClass(AppendEntries.class, 1);
155 member2Actor.clear();
156 member2Actor.expectMessageClass(RequestVoteReply.class, 1);
157 member2Actor.expectMessageClass(AppendEntriesReply.class, 1);
159 member3Actor.clear();
160 member3Actor.dropMessagesToBehavior(AppendEntries.class);
161 member3Actor.dropMessagesToBehavior(RequestVote.class);
163 member2ActorRef.tell(ElectionTimeout.INSTANCE, ActorRef.noSender());
165 member2Actor.waitForExpectedMessages(RequestVoteReply.class);
167 RequestVoteReply requestVoteReply = member2Actor.getCapturedMessage(RequestVoteReply.class);
168 assertEquals("getTerm", member2Context.getTermInformation().getCurrentTerm(), requestVoteReply.getTerm());
169 assertEquals("isVoteGranted", true, requestVoteReply.isVoteGranted());
171 member3Actor.waitForExpectedMessages(RequestVote.class);
173 member1Actor.waitForExpectedMessages(AppendEntries.class);
174 member3Actor.waitForExpectedMessages(AppendEntries.class);
175 member2Actor.waitForExpectedMessages(AppendEntriesReply.class);
177 // We end up with 2 partitioned leaders both leading member 1. The term for member 1 and 3
178 // is 3 and member 3's term is 2.
180 verifyBehaviorState("member 1", member1Actor, RaftState.Follower);
181 verifyBehaviorState("member 2", member2Actor, RaftState.Leader);
182 verifyBehaviorState("member 3", member3Actor, RaftState.Leader);
184 assertEquals("member 1 election term", 3, member1Context.getTermInformation().getCurrentTerm());
185 assertEquals("member 2 election term", 3, member2Context.getTermInformation().getCurrentTerm());
186 assertEquals("member 3 election term", 2, member3Context.getTermInformation().getCurrentTerm());
188 testLog.info("sendElectionTimeoutToNowCandidateMember2 ending");
191 private void sendInitialElectionTimeoutToFollowerMember3() throws Exception {
192 testLog.info("sendInitialElectionTimeoutToFollowerMember3 starting");
194 // Send ElectionTimeout to member 3 to simulate no heartbeat from a Leader (originally member 1).
195 // member 3 should switch to Candidate and send out RequestVote messages. member 1, now a follower,
196 // should reply and grant the vote but member 2 will drop the message to simulate loss of network
197 // connectivity between members 2 and 3. member 3 should switch to leader.
199 member1Actor.clear();
200 member1Actor.expectMessageClass(RequestVote.class, 1);
201 member1Actor.expectMessageClass(AppendEntries.class, 1);
203 member2Actor.clear();
204 member2Actor.dropMessagesToBehavior(RequestVote.class);
205 member2Actor.dropMessagesToBehavior(AppendEntries.class);
207 member3Actor.clear();
208 member3Actor.expectMessageClass(RequestVoteReply.class, 1);
209 member3Actor.expectMessageClass(AppendEntriesReply.class, 1);
211 member3ActorRef.tell(TimeoutNow.INSTANCE, ActorRef.noSender());
213 member1Actor.waitForExpectedMessages(RequestVote.class);
214 member2Actor.waitForExpectedMessages(RequestVote.class);
215 member3Actor.waitForExpectedMessages(RequestVoteReply.class);
217 RequestVoteReply requestVoteReply = member3Actor.getCapturedMessage(RequestVoteReply.class);
218 assertEquals("getTerm", member3Context.getTermInformation().getCurrentTerm(), requestVoteReply.getTerm());
219 assertEquals("isVoteGranted", true, requestVoteReply.isVoteGranted());
221 // when member 3 switches to Leader it will immediately send out heartbeat AppendEntries to
222 // the followers. Wait for AppendEntries to member 1 and its AppendEntriesReply. The
223 // AppendEntries message to member 2 is dropped.
225 member1Actor.waitForExpectedMessages(AppendEntries.class);
226 member2Actor.waitForExpectedMessages(AppendEntries.class);
227 member3Actor.waitForExpectedMessages(AppendEntriesReply.class);
229 verifyBehaviorState("member 1", member1Actor, RaftState.Follower);
230 verifyBehaviorState("member 2", member2Actor, RaftState.Candidate);
231 verifyBehaviorState("member 3", member3Actor, RaftState.Leader);
233 assertEquals("member 1 election term", 2, member1Context.getTermInformation().getCurrentTerm());
234 assertEquals("member 2 election term", 2, member2Context.getTermInformation().getCurrentTerm());
235 assertEquals("member 3 election term", 2, member3Context.getTermInformation().getCurrentTerm());
237 testLog.info("sendInitialElectionTimeoutToFollowerMember3 ending");
240 private void sendInitialElectionTimeoutToFollowerMember2() {
241 testLog.info("sendInitialElectionTimeoutToFollowerMember2 starting");
243 // Send ElectionTimeout to member 2 to simulate no heartbeat from the Leader (member 1).
244 // member 2 should switch to Candidate, start new term 2 and send out RequestVote messages.
245 // member 1 will switch to Follower b/c its term is less than the member 2's RequestVote term, also it
246 // won't send back a reply. member 3 will drop the message (ie won't forward it to its behavior) to
247 // simulate loss of network connectivity between members 2 and 3.
249 member1Actor.expectMessageClass(RequestVote.class, 1);
251 member2Actor.expectBehaviorStateChange();
253 member3Actor.dropMessagesToBehavior(RequestVote.class);
255 member2ActorRef.tell(TimeoutNow.INSTANCE, ActorRef.noSender());
257 member1Actor.waitForExpectedMessages(RequestVote.class);
258 member3Actor.waitForExpectedMessages(RequestVote.class);
260 // Original leader member 1 should switch to Follower as the RequestVote term is greater than its
261 // term. It won't send back a RequestVoteReply in this case.
263 verifyBehaviorState("member 1", member1Actor, RaftState.Follower);
265 // member 2 should switch to Candidate since it didn't get a RequestVoteReply from the other 2 members.
267 member2Actor.waitForBehaviorStateChange();
268 verifyBehaviorState("member 2", member2Actor, RaftState.Candidate);
270 assertEquals("member 1 election term", 2, member1Context.getTermInformation().getCurrentTerm());
271 assertEquals("member 2 election term", 2, member2Context.getTermInformation().getCurrentTerm());
272 assertEquals("member 3 election term", 1, member3Context.getTermInformation().getCurrentTerm());
274 testLog.info("sendInitialElectionTimeoutToFollowerMember2 ending");
277 private void setupInitialMemberBehaviors() throws Exception {
278 testLog.info("setupInitialMemberBehaviors starting");
280 // Create member 2's behavior initially as Follower
282 member2Context = newRaftActorContext("member2", member2ActorRef,
283 ImmutableMap.<String,String>builder().
284 put("member1", member1ActorRef.path().toString()).
285 put("member3", member3ActorRef.path().toString()).build());
287 DefaultConfigParamsImpl member2ConfigParams = newConfigParams();
288 member2Context.setConfigParams(member2ConfigParams);
290 member2Actor.behavior = new Follower(member2Context);
291 member2Context.setCurrentBehavior(member2Actor.behavior);
293 // Create member 3's behavior initially as Follower
295 member3Context = newRaftActorContext("member3", member3ActorRef,
296 ImmutableMap.<String,String>builder().
297 put("member1", member1ActorRef.path().toString()).
298 put("member2", member2ActorRef.path().toString()).build());
300 DefaultConfigParamsImpl member3ConfigParams = newConfigParams();
301 member3Context.setConfigParams(member3ConfigParams);
303 member3Actor.behavior = new Follower(member3Context);
304 member3Context.setCurrentBehavior(member3Actor.behavior);
306 // Create member 1's behavior initially as Leader
308 member1Context = newRaftActorContext("member1", member1ActorRef,
309 ImmutableMap.<String,String>builder().
310 put("member2", member2ActorRef.path().toString()).
311 put("member3", member3ActorRef.path().toString()).build());
313 DefaultConfigParamsImpl member1ConfigParams = newConfigParams();
314 member1Context.setConfigParams(member1ConfigParams);
316 initializeLeaderBehavior(member1Actor, member1Context, 2);
318 member2Actor.clear();
319 member3Actor.clear();
321 testLog.info("setupInitialMemberBehaviors ending");