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.messages.AppendEntries;
18 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
19 import org.opendaylight.controller.cluster.raft.messages.RequestVote;
20 import org.opendaylight.controller.cluster.raft.messages.RequestVoteReply;
23 * A leader election scenario test that causes partitioned leaders by dropping messages between 2 members.
25 * @author Thomas Pantelis
27 public class PartitionedLeadersElectionScenarioTest extends AbstractLeaderElectionScenarioTest {
30 * This test sets up a scenario with partitioned leaders member 2 and 3 where partitioned leader 3
31 * sends a heartbeat first when connectivity is re-established.
34 public void runTest1() throws Exception {
35 testLog.info("PartitionedLeadersElectionScenarioTest 1 starting");
37 setupInitialMemberBehaviors();
39 sendInitialElectionTimeoutToFollowerMember2();
41 sendInitialElectionTimeoutToFollowerMember3();
43 sendElectionTimeoutToNowCandidateMember2();
45 resolvePartitionedLeadersWithLeaderMember3SendingHeartbeatFirst();
47 testLog.info("PartitionedLeadersElectionScenarioTest 1 ending");
51 * This test sets up a scenario with partitioned leaders member 2 and 3 where partitioned leader 2
52 * sends a heartbeat first when connectivity is re-established.
55 public void runTest2() throws Exception {
56 testLog.info("PartitionedLeadersElectionScenarioTest 2 starting");
58 setupInitialMemberBehaviors();
60 sendInitialElectionTimeoutToFollowerMember2();
62 sendInitialElectionTimeoutToFollowerMember3();
64 sendElectionTimeoutToNowCandidateMember2();
66 resolvePartitionedLeadersWithLeaderMember2SendingHeartbeatFirst();
68 testLog.info("PartitionedLeadersElectionScenarioTest 2 ending");
71 private void resolvePartitionedLeadersWithLeaderMember2SendingHeartbeatFirst() {
72 testLog.info("resolvePartitionedLeadersWithLeaderMember2SendingHeartbeatFirst starting");
74 // Re-establish connectivity between member 2 and 3, ie stop dropping messages between
75 // the 2. Send heartbeats (AppendEntries) from partitioned leader member 2. Follower member 1 should
76 // return a successful AppendEntriesReply b/c its term matches member 2's. member 3 should switch to
77 // Follower as its term is less than member 2's.
80 member1Actor.expectMessageClass(AppendEntries.class, 1);
83 member2Actor.expectMessageClass(AppendEntriesReply.class, 1);
86 member3Actor.expectMessageClass(AppendEntries.class, 1);
88 sendHeartbeat(member2ActorRef);
90 member1Actor.waitForExpectedMessages(AppendEntries.class);
91 member3Actor.waitForExpectedMessages(AppendEntries.class);
93 member2Actor.waitForExpectedMessages(AppendEntriesReply.class);
95 verifyBehaviorState("member 1", member1Actor, RaftState.Follower);
96 verifyBehaviorState("member 2", member2Actor, RaftState.Leader);
97 verifyBehaviorState("member 3", member3Actor, RaftState.Follower);
99 assertEquals("member 1 election term", 3, member1Context.getTermInformation().getCurrentTerm());
100 assertEquals("member 2 election term", 3, member2Context.getTermInformation().getCurrentTerm());
101 assertEquals("member 3 election term", 3, member3Context.getTermInformation().getCurrentTerm());
103 testLog.info("resolvePartitionedLeadersWithLeaderMember2SendingHeartbeatFirst ending");
106 private void resolvePartitionedLeadersWithLeaderMember3SendingHeartbeatFirst() throws Exception {
107 testLog.info("resolvePartitionedLeadersWithLeaderMember3SendingHeartbeatFirst starting");
109 // Re-establish connectivity between member 2 and 3, ie stop dropping messages between
110 // the 2. Send heartbeats (AppendEntries) from now leader member 3. Both member 1 and 2 should send
111 // back an unsuccessful AppendEntriesReply b/c their term (3) is greater than member 3's term (2).
112 // This should cause member 3 to switch to Follower.
114 member1Actor.clear();
115 member1Actor.expectMessageClass(AppendEntries.class, 1);
117 member2Actor.clear();
118 member2Actor.expectMessageClass(AppendEntries.class, 1);
120 member3Actor.clear();
121 member3Actor.expectMessageClass(AppendEntriesReply.class, 1);
123 sendHeartbeat(member3ActorRef);
125 member3Actor.waitForExpectedMessages(AppendEntriesReply.class);
127 AppendEntriesReply appendEntriesReply = member3Actor.getCapturedMessage(AppendEntriesReply.class);
128 assertEquals("isSuccess", false, appendEntriesReply.isSuccess());
129 assertEquals("getTerm", 3, appendEntriesReply.getTerm());
131 verifyBehaviorState("member 1", member1Actor, RaftState.Follower);
132 verifyBehaviorState("member 2", member2Actor, RaftState.Leader);
133 verifyBehaviorState("member 3", member3Actor, RaftState.Follower);
135 assertEquals("member 1 election term", 3, member1Context.getTermInformation().getCurrentTerm());
136 assertEquals("member 2 election term", 3, member2Context.getTermInformation().getCurrentTerm());
137 assertEquals("member 3 election term", 3, member3Context.getTermInformation().getCurrentTerm());
139 testLog.info("resolvePartitionedLeadersWithLeaderMember3SendingHeartbeatFirst ending");
142 private void sendElectionTimeoutToNowCandidateMember2() throws Exception {
143 testLog.info("sendElectionTimeoutToNowCandidateMember2 starting");
145 // member 2, now a candidate, is partitioned from the Leader (now member 3) and hasn't received any
146 // messages. It would get another ElectionTimeout so simulate that. member 1 should send back a reply
147 // granting the vote. Messages (RequestVote and AppendEntries) from member 2 to member 3
148 // are dropped to simulate loss of network connectivity. Note member 2 will increment its
149 // election term to 3.
151 member1Actor.clear();
152 member1Actor.expectMessageClass(AppendEntries.class, 1);
154 member2Actor.clear();
155 member2Actor.expectMessageClass(RequestVoteReply.class, 1);
156 member2Actor.expectMessageClass(AppendEntriesReply.class, 1);
158 member3Actor.clear();
159 member3Actor.dropMessagesToBehavior(AppendEntries.class);
160 member3Actor.dropMessagesToBehavior(RequestVote.class);
162 member2ActorRef.tell(new ElectionTimeout(), ActorRef.noSender());
164 member2Actor.waitForExpectedMessages(RequestVoteReply.class);
166 RequestVoteReply requestVoteReply = member2Actor.getCapturedMessage(RequestVoteReply.class);
167 assertEquals("getTerm", member2Context.getTermInformation().getCurrentTerm(), requestVoteReply.getTerm());
168 assertEquals("isVoteGranted", true, requestVoteReply.isVoteGranted());
170 member3Actor.waitForExpectedMessages(RequestVote.class);
172 member1Actor.waitForExpectedMessages(AppendEntries.class);
173 member3Actor.waitForExpectedMessages(AppendEntries.class);
174 member2Actor.waitForExpectedMessages(AppendEntriesReply.class);
176 // We end up with 2 partitioned leaders both leading member 1. The term for member 1 and 3
177 // is 3 and member 3's term is 2.
179 verifyBehaviorState("member 1", member1Actor, RaftState.Follower);
180 verifyBehaviorState("member 2", member2Actor, RaftState.Leader);
181 verifyBehaviorState("member 3", member3Actor, RaftState.Leader);
183 assertEquals("member 1 election term", 3, member1Context.getTermInformation().getCurrentTerm());
184 assertEquals("member 2 election term", 3, member2Context.getTermInformation().getCurrentTerm());
185 assertEquals("member 3 election term", 2, member3Context.getTermInformation().getCurrentTerm());
187 testLog.info("sendElectionTimeoutToNowCandidateMember2 ending");
190 private void sendInitialElectionTimeoutToFollowerMember3() throws Exception {
191 testLog.info("sendInitialElectionTimeoutToFollowerMember3 starting");
193 // Send ElectionTimeout to member 3 to simulate no heartbeat from a Leader (originally member 1).
194 // member 3 should switch to Candidate and send out RequestVote messages. member 1, now a follower,
195 // should reply and grant the vote but member 2 will drop the message to simulate loss of network
196 // connectivity between members 2 and 3. member 3 should switch to leader.
198 member1Actor.clear();
199 member1Actor.expectMessageClass(RequestVote.class, 1);
200 member1Actor.expectMessageClass(AppendEntries.class, 1);
202 member2Actor.clear();
203 member2Actor.dropMessagesToBehavior(RequestVote.class);
204 member2Actor.dropMessagesToBehavior(AppendEntries.class);
206 member3Actor.clear();
207 member3Actor.expectMessageClass(RequestVoteReply.class, 1);
208 member3Actor.expectMessageClass(AppendEntriesReply.class, 1);
210 member3ActorRef.tell(new ElectionTimeout(), ActorRef.noSender());
212 member1Actor.waitForExpectedMessages(RequestVote.class);
213 member2Actor.waitForExpectedMessages(RequestVote.class);
214 member3Actor.waitForExpectedMessages(RequestVoteReply.class);
216 RequestVoteReply requestVoteReply = member3Actor.getCapturedMessage(RequestVoteReply.class);
217 assertEquals("getTerm", member3Context.getTermInformation().getCurrentTerm(), requestVoteReply.getTerm());
218 assertEquals("isVoteGranted", true, requestVoteReply.isVoteGranted());
220 // when member 3 switches to Leader it will immediately send out heartbeat AppendEntries to
221 // the followers. Wait for AppendEntries to member 1 and its AppendEntriesReply. The
222 // AppendEntries message to member 2 is dropped.
224 member1Actor.waitForExpectedMessages(AppendEntries.class);
225 member2Actor.waitForExpectedMessages(AppendEntries.class);
226 member3Actor.waitForExpectedMessages(AppendEntriesReply.class);
228 verifyBehaviorState("member 1", member1Actor, RaftState.Follower);
229 verifyBehaviorState("member 2", member2Actor, RaftState.Candidate);
230 verifyBehaviorState("member 3", member3Actor, RaftState.Leader);
232 assertEquals("member 1 election term", 2, member1Context.getTermInformation().getCurrentTerm());
233 assertEquals("member 2 election term", 2, member2Context.getTermInformation().getCurrentTerm());
234 assertEquals("member 3 election term", 2, member3Context.getTermInformation().getCurrentTerm());
236 testLog.info("sendInitialElectionTimeoutToFollowerMember3 ending");
239 private void sendInitialElectionTimeoutToFollowerMember2() {
240 testLog.info("sendInitialElectionTimeoutToFollowerMember2 starting");
242 // Send ElectionTimeout to member 2 to simulate no heartbeat from the Leader (member 1).
243 // member 2 should switch to Candidate, start new term 2 and send out RequestVote messages.
244 // member 1 will switch to Follower b/c its term is less than the member 2's RequestVote term, also it
245 // won't send back a reply. member 3 will drop the message (ie won't forward it to its behavior) to
246 // simulate loss of network connectivity between members 2 and 3.
248 member1Actor.expectMessageClass(RequestVote.class, 1);
250 member2Actor.expectBehaviorStateChange();
252 member3Actor.dropMessagesToBehavior(RequestVote.class);
254 member2ActorRef.tell(new ElectionTimeout(), ActorRef.noSender());
256 member1Actor.waitForExpectedMessages(RequestVote.class);
257 member3Actor.waitForExpectedMessages(RequestVote.class);
259 // Original leader member 1 should switch to Follower as the RequestVote term is greater than its
260 // term. It won't send back a RequestVoteReply in this case.
262 verifyBehaviorState("member 1", member1Actor, RaftState.Follower);
264 // member 2 should switch to Candidate since it didn't get a RequestVoteReply from the other 2 members.
266 member2Actor.waitForBehaviorStateChange();
267 verifyBehaviorState("member 2", member2Actor, RaftState.Candidate);
269 assertEquals("member 1 election term", 2, member1Context.getTermInformation().getCurrentTerm());
270 assertEquals("member 2 election term", 2, member2Context.getTermInformation().getCurrentTerm());
271 assertEquals("member 3 election term", 1, member3Context.getTermInformation().getCurrentTerm());
273 testLog.info("sendInitialElectionTimeoutToFollowerMember2 ending");
276 private void setupInitialMemberBehaviors() throws Exception {
277 testLog.info("setupInitialMemberBehaviors starting");
279 // Create member 2's behavior initially as Follower
281 member2Context = newRaftActorContext("member2", member2ActorRef,
282 ImmutableMap.<String,String>builder().
283 put("member1", member1ActorRef.path().toString()).
284 put("member3", member3ActorRef.path().toString()).build());
286 DefaultConfigParamsImpl member2ConfigParams = newConfigParams();
287 member2Context.setConfigParams(member2ConfigParams);
289 member2Actor.behavior = new Follower(member2Context);
291 // Create member 3's behavior initially as Follower
293 member3Context = newRaftActorContext("member3", member3ActorRef,
294 ImmutableMap.<String,String>builder().
295 put("member1", member1ActorRef.path().toString()).
296 put("member2", member2ActorRef.path().toString()).build());
298 DefaultConfigParamsImpl member3ConfigParams = newConfigParams();
299 member3Context.setConfigParams(member3ConfigParams);
301 member3Actor.behavior = new Follower(member3Context);
303 // Create member 1's behavior initially as Leader
305 member1Context = newRaftActorContext("member1", member1ActorRef,
306 ImmutableMap.<String,String>builder().
307 put("member2", member2ActorRef.path().toString()).
308 put("member3", member3ActorRef.path().toString()).build());
310 DefaultConfigParamsImpl member1ConfigParams = newConfigParams();
311 member1Context.setConfigParams(member1ConfigParams);
313 initializeLeaderBehavior(member1Actor, member1Context, 2);
315 member2Actor.clear();
316 member3Actor.clear();
318 testLog.info("setupInitialMemberBehaviors ending");