opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/ReplicationAndSnapshotsIntegrationTest.java

   1 /*
   2  * Copyright (c) 2015 Brocade Communications Systems, Inc. and others.  All rights reserved.
   3  *
   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
   7  */
   8 package org.opendaylight.controller.cluster.raft;
   9
  10 import static org.junit.Assert.assertEquals;
  11
  12 import akka.persistence.SaveSnapshotSuccess;
  13 import com.google.common.collect.ImmutableMap;
  14 import java.util.List;
  15 import org.junit.Test;
  16 import org.opendaylight.controller.cluster.raft.MockRaftActorContext.MockPayload;
  17 import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
  18 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshotReply;
  19 import org.opendaylight.controller.cluster.raft.messages.AppendEntries;
  20 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  21 import org.opendaylight.controller.cluster.raft.persisted.ApplyJournalEntries;
  22 import org.opendaylight.controller.cluster.raft.persisted.UpdateElectionTerm;
  23 import org.opendaylight.controller.cluster.raft.utils.InMemoryJournal;
  24 import org.opendaylight.controller.cluster.raft.utils.InMemorySnapshotStore;
  25 import org.opendaylight.controller.cluster.raft.utils.MessageCollectorActor;
  26
  27 /**
  28  * Tests replication and snapshots end-to-end using real RaftActors and behavior communication.
  29  *
  30  * @author Thomas Pantelis
  31  */
  32 public class ReplicationAndSnapshotsIntegrationTest extends AbstractRaftActorIntegrationTest {
  33
  34     private List<ReplicatedLogImplEntry> origLeaderJournal;
  35
  36     private MockPayload recoveredPayload0;
  37     private MockPayload recoveredPayload1;
  38     private MockPayload recoveredPayload2;
  39     private MockPayload payload3;
  40     private MockPayload payload4;
  41     private MockPayload payload5;
  42     private MockPayload payload6;
  43     private MockPayload payload7;
  44
  45     @Test
  46     public void runTest() throws Exception {
  47         testLog.info("testReplicationAndSnapshots starting");
  48
  49         // Setup the persistent journal for the leader. We'll start up with 3 journal log entries (one less
  50         // than the snapshotBatchCount).
  51         long seqId = 1;
  52         InMemoryJournal.addEntry(leaderId, seqId++, new UpdateElectionTerm(initialTerm, leaderId));
  53         recoveredPayload0 = new MockPayload("zero");
  54         InMemoryJournal.addEntry(leaderId, seqId++, new ReplicatedLogImplEntry(0, initialTerm, recoveredPayload0));
  55         recoveredPayload1 = new MockPayload("one");
  56         InMemoryJournal.addEntry(leaderId, seqId++, new ReplicatedLogImplEntry(1, initialTerm, recoveredPayload1));
  57         recoveredPayload2 = new MockPayload("two");
  58         InMemoryJournal.addEntry(leaderId, seqId++, new ReplicatedLogImplEntry(2, initialTerm, recoveredPayload2));
  59         InMemoryJournal.addEntry(leaderId, seqId++, new ApplyJournalEntries(2));
  60
  61         origLeaderJournal = InMemoryJournal.get(leaderId, ReplicatedLogImplEntry.class);
  62
  63         // Create the leader and 2 follower actors and verify initial syncing of the followers after leader
  64         // persistence recovery.
  65
  66         DefaultConfigParamsImpl followerConfigParams = newFollowerConfigParams();
  67         followerConfigParams.setSnapshotBatchCount(snapshotBatchCount);
  68         follower1Actor = newTestRaftActor(follower1Id, ImmutableMap.of(leaderId, testActorPath(leaderId),
  69                 follower2Id, testActorPath(follower2Id)), followerConfigParams);
  70
  71         follower2Actor = newTestRaftActor(follower2Id, ImmutableMap.of(leaderId, testActorPath(leaderId),
  72                 follower1Id, testActorPath(follower1Id)), followerConfigParams);
  73
  74         peerAddresses = ImmutableMap.<String, String>builder()
  75                 .put(follower1Id, follower1Actor.path().toString())
  76                 .put(follower2Id, follower2Actor.path().toString()).build();
  77
  78         leaderConfigParams = newLeaderConfigParams();
  79         leaderActor = newTestRaftActor(leaderId, peerAddresses, leaderConfigParams);
  80
  81         follower1CollectorActor = follower1Actor.underlyingActor().collectorActor();
  82         follower2CollectorActor = follower2Actor.underlyingActor().collectorActor();
  83         leaderCollectorActor = leaderActor.underlyingActor().collectorActor();
  84
  85         leaderContext = leaderActor.underlyingActor().getRaftActorContext();
  86
  87         verifyLeaderRecoveryAndInitialization();
  88
  89         testFirstSnapshot();
  90
  91         testSubsequentReplications();
  92
  93         testSecondSnapshot();
  94
  95         testLeaderReinstatement();
  96
  97         testLog.info("testReplicationAndSnapshots ending");
  98     }
  99
 100     /**
 101      * Verify the expected leader is elected as the leader and verify initial syncing of the followers
 102      * from the leader's persistence recovery.
 103      */
 104     void verifyLeaderRecoveryAndInitialization() {
 105         testLog.info("verifyLeaderRecoveryAndInitialization starting");
 106
 107         waitUntilLeader(leaderActor);
 108
 109         currentTerm = leaderContext.getTermInformation().getCurrentTerm();
 110         assertEquals("Current term > " + initialTerm, true, currentTerm > initialTerm);
 111
 112         leader = leaderActor.underlyingActor().getCurrentBehavior();
 113
 114         // The followers should receive AppendEntries for each leader log entry that was recovered from
 115         // persistence and apply each one.
 116         List<ApplyState> applyStates = MessageCollectorActor.expectMatching(
 117                 follower1CollectorActor, ApplyState.class, 3);
 118         verifyApplyState(applyStates.get(0), null, null, initialTerm, 0, recoveredPayload0);
 119         verifyApplyState(applyStates.get(1), null, null, initialTerm, 1, recoveredPayload1);
 120         verifyApplyState(applyStates.get(2), null, null, initialTerm, 2, recoveredPayload2);
 121
 122         // Verify follower 1 applies a log entry for at least the last entry index.
 123         verifyApplyJournalEntries(follower1CollectorActor, 2);
 124
 125         applyStates = MessageCollectorActor.expectMatching(follower2CollectorActor, ApplyState.class, 3);
 126         verifyApplyState(applyStates.get(0), null, null, initialTerm, 0, recoveredPayload0);
 127         verifyApplyState(applyStates.get(1), null, null, initialTerm, 1, recoveredPayload1);
 128         verifyApplyState(applyStates.get(2), null, null, initialTerm, 2, recoveredPayload2);
 129
 130         // Verify follower 1]2 applies a log entry for at least the last entry index.
 131         verifyApplyJournalEntries(follower2CollectorActor, 2);
 132
 133         MessageCollectorActor.clearMessages(leaderCollectorActor);
 134         MessageCollectorActor.clearMessages(follower1CollectorActor);
 135         MessageCollectorActor.clearMessages(follower2CollectorActor);
 136
 137         // The leader should have performed fake snapshots due to the follower's AppendEntriesReplies and
 138         // trimmed the in-memory log so that only the last entry remains.
 139         assertEquals("Leader snapshot term", initialTerm, leaderContext.getReplicatedLog().getSnapshotTerm());
 140         assertEquals("Leader snapshot index", 1, leaderContext.getReplicatedLog().getSnapshotIndex());
 141         assertEquals("Leader journal log size", 1, leaderContext.getReplicatedLog().size());
 142         assertEquals("Leader journal last index", 2, leaderContext.getReplicatedLog().lastIndex());
 143         assertEquals("Leader commit index", 2, leaderContext.getCommitIndex());
 144         assertEquals("Leader last applied", 2, leaderContext.getLastApplied());
 145         assertEquals("Leader replicatedToAllIndex", 1, leader.getReplicatedToAllIndex());
 146
 147         // Verify the follower's persisted journal log.
 148         verifyPersistedJournal(follower1Id, origLeaderJournal);
 149         verifyPersistedJournal(follower2Id, origLeaderJournal);
 150
 151         MessageCollectorActor.clearMessages(leaderCollectorActor);
 152         MessageCollectorActor.clearMessages(follower1CollectorActor);
 153         MessageCollectorActor.clearMessages(follower2CollectorActor);
 154
 155         testLog.info("verifyLeaderRecoveryAndInitialization ending");
 156     }
 157
 158     /**
 159      * Send a payload to the TestRaftActor to persist and replicate. Since snapshotBatchCount is set to
 160      * 4 and we already have 3 entries in the journal log, this should initiate a snapshot. In this
 161      * scenario, the follower consensus and application of state is delayed until after the snapshot
 162      * completes.
 163      */
 164     private void testFirstSnapshot() throws Exception {
 165         testLog.info("testFirstSnapshot starting");
 166
 167         expSnapshotState.add(recoveredPayload0);
 168         expSnapshotState.add(recoveredPayload1);
 169         expSnapshotState.add(recoveredPayload2);
 170
 171         // Delay the consensus by temporarily dropping the AppendEntries to both followers.
 172         follower1Actor.underlyingActor().startDropMessages(AppendEntries.class);
 173         follower2Actor.underlyingActor().startDropMessages(AppendEntries.class);
 174
 175         // Send the payload.
 176         payload3 = sendPayloadData(leaderActor, "three");
 177
 178         // Wait for snapshot complete.
 179         MessageCollectorActor.expectFirstMatching(leaderCollectorActor, SaveSnapshotSuccess.class);
 180
 181         // The snapshot index should not be advanced nor the log trimmed because replicatedToAllIndex
 182         // is behind due the followers not being replicated yet via AppendEntries.
 183         assertEquals("Leader snapshot term", initialTerm, leaderContext.getReplicatedLog().getSnapshotTerm());
 184         assertEquals("Leader snapshot index", 1, leaderContext.getReplicatedLog().getSnapshotIndex());
 185         assertEquals("Leader journal log size", 2, leaderContext.getReplicatedLog().size());
 186         assertEquals("Leader journal last index", 3, leaderContext.getReplicatedLog().lastIndex());
 187
 188         // Verify the persisted snapshot in the leader. This should reflect the advanced snapshot index as
 189         // the last applied log entry (2) even though the leader hasn't yet advanced its cached snapshot index.
 190         List<Snapshot> persistedSnapshots = InMemorySnapshotStore.getSnapshots(leaderId, Snapshot.class);
 191         assertEquals("Persisted snapshots size", 1, persistedSnapshots.size());
 192         verifySnapshot("Persisted", persistedSnapshots.get(0), initialTerm, 2, currentTerm, 3);
 193         List<ReplicatedLogEntry> unAppliedEntry = persistedSnapshots.get(0).getUnAppliedEntries();
 194         assertEquals("Persisted Snapshot getUnAppliedEntries size", 1, unAppliedEntry.size());
 195         verifyReplicatedLogEntry(unAppliedEntry.get(0), currentTerm, 3, payload3);
 196
 197         // The leader's persisted journal log should be cleared since we snapshotted.
 198         List<ReplicatedLogImplEntry> persistedLeaderJournal =
 199                 InMemoryJournal.get(leaderId, ReplicatedLogImplEntry.class);
 200         assertEquals("Persisted journal log size", 0, persistedLeaderJournal.size());
 201
 202         // Allow AppendEntries to both followers to proceed. This should catch up the followers and cause a
 203         // "fake" snapshot in the leader to advance the snapshot index to 2. Also the state should be applied
 204         // in all members (via ApplyState).
 205         follower1Actor.underlyingActor().stopDropMessages(AppendEntries.class);
 206         follower2Actor.underlyingActor().stopDropMessages(AppendEntries.class);
 207
 208         ApplyState applyState = MessageCollectorActor.expectFirstMatching(leaderCollectorActor, ApplyState.class);
 209         verifyApplyState(applyState, leaderCollectorActor, payload3.toString(), currentTerm, 3, payload3);
 210
 211         verifyApplyJournalEntries(leaderCollectorActor, 3);
 212
 213         assertEquals("Leader commit index", 3, leaderContext.getCommitIndex());
 214
 215         applyState = MessageCollectorActor.expectFirstMatching(follower1CollectorActor, ApplyState.class);
 216         verifyApplyState(applyState, null, null, currentTerm, 3, payload3);
 217
 218         verifyApplyJournalEntries(follower1CollectorActor, 3);
 219
 220         applyState = MessageCollectorActor.expectFirstMatching(follower2CollectorActor, ApplyState.class);
 221         verifyApplyState(applyState, null, null, currentTerm, 3, payload3);
 222
 223         verifyApplyJournalEntries(follower2CollectorActor, 3);
 224
 225         assertEquals("Leader snapshot term", initialTerm, leaderContext.getReplicatedLog().getSnapshotTerm());
 226         assertEquals("Leader snapshot index", 2, leaderContext.getReplicatedLog().getSnapshotIndex());
 227         assertEquals("Leader journal log size", 1, leaderContext.getReplicatedLog().size());
 228         assertEquals("Leader commit index", 3, leaderContext.getCommitIndex());
 229         assertEquals("Leader last applied", 3, leaderContext.getLastApplied());
 230         assertEquals("Leader replicatedToAllIndex", 2, leader.getReplicatedToAllIndex());
 231
 232         // The followers should also snapshot so verify.
 233
 234         MessageCollectorActor.expectFirstMatching(follower1CollectorActor, SaveSnapshotSuccess.class);
 235         persistedSnapshots = InMemorySnapshotStore.getSnapshots(follower1Id, Snapshot.class);
 236         assertEquals("Persisted snapshots size", 1, persistedSnapshots.size());
 237         // The last applied index in the snapshot may or may not be the last log entry depending on
 238         // timing so to avoid intermittent test failures, we'll just verify the snapshot's last term/index.
 239         assertEquals("Follower1 Snapshot getLastTerm", currentTerm, persistedSnapshots.get(0).getLastTerm());
 240         assertEquals("Follower1 Snapshot getLastIndex", 3, persistedSnapshots.get(0).getLastIndex());
 241
 242         MessageCollectorActor.expectFirstMatching(follower2CollectorActor, SaveSnapshotSuccess.class);
 243
 244         MessageCollectorActor.clearMessages(leaderCollectorActor);
 245         MessageCollectorActor.clearMessages(follower1CollectorActor);
 246         MessageCollectorActor.clearMessages(follower2CollectorActor);
 247
 248         testLog.info("testFirstSnapshot ending");
 249     }
 250
 251     /**
 252      * Send 3 more payload instances and verify they get applied by all members.
 253      */
 254     private void testSubsequentReplications() {
 255         testLog.info("testSubsequentReplications starting");
 256
 257         payload4 = sendPayloadData(leaderActor, "four");
 258         payload5 = sendPayloadData(leaderActor, "five");
 259         payload6 = sendPayloadData(leaderActor, "six");
 260
 261         // Verify the leader applies the states.
 262         List<ApplyState> applyStates = MessageCollectorActor.expectMatching(leaderCollectorActor, ApplyState.class, 3);
 263         verifyApplyState(applyStates.get(0), leaderCollectorActor, payload4.toString(), currentTerm, 4, payload4);
 264         verifyApplyState(applyStates.get(1), leaderCollectorActor, payload5.toString(), currentTerm, 5, payload5);
 265         verifyApplyState(applyStates.get(2), leaderCollectorActor, payload6.toString(), currentTerm, 6, payload6);
 266
 267         // Verify the leader applies a log entry for at least the last entry index.
 268         verifyApplyJournalEntries(leaderCollectorActor, 6);
 269
 270         // The leader should have performed fake snapshots due to the follower's AppendEntriesReplies and
 271         // trimmed the in-memory log so that only the last entry remains.
 272         assertEquals("Leader snapshot term", currentTerm, leaderContext.getReplicatedLog().getSnapshotTerm());
 273         assertEquals("Leader snapshot index", 5, leaderContext.getReplicatedLog().getSnapshotIndex());
 274         assertEquals("Leader journal log size", 1, leaderContext.getReplicatedLog().size());
 275         assertEquals("Leader journal last index", 6, leaderContext.getReplicatedLog().lastIndex());
 276         assertEquals("Leader commit index", 6, leaderContext.getCommitIndex());
 277         assertEquals("Leader last applied", 6, leaderContext.getLastApplied());
 278         assertEquals("Leader replicatedToAllIndex", 5, leader.getReplicatedToAllIndex());
 279
 280         // Verify follower 1 applies the states.
 281         applyStates = MessageCollectorActor.expectMatching(follower1CollectorActor, ApplyState.class, 3);
 282         verifyApplyState(applyStates.get(0), null, null, currentTerm, 4, payload4);
 283         verifyApplyState(applyStates.get(1), null, null, currentTerm, 5, payload5);
 284         verifyApplyState(applyStates.get(2), null, null, currentTerm, 6, payload6);
 285
 286         // Verify follower 1 applies a log entry for at least the last entry index.
 287         verifyApplyJournalEntries(follower1CollectorActor, 6);
 288
 289         // Verify follower 2 applies the states.
 290         applyStates = MessageCollectorActor.expectMatching(follower2CollectorActor, ApplyState.class, 3);
 291         verifyApplyState(applyStates.get(0), null, null, currentTerm, 4, payload4);
 292         verifyApplyState(applyStates.get(1), null, null, currentTerm, 5, payload5);
 293         verifyApplyState(applyStates.get(2), null, null, currentTerm, 6, payload6);
 294
 295         // Verify follower 2 applies a log entry for at least the last entry index.
 296         verifyApplyJournalEntries(follower2CollectorActor, 6);
 297
 298         MessageCollectorActor.clearMessages(leaderCollectorActor);
 299
 300         testLog.info("testSubsequentReplications ending");
 301     }
 302
 303     /**
 304      * Send one more payload to trigger another snapshot. In this scenario, we delay the snapshot until
 305      * consensus occurs and the leader applies the state.
 306      */
 307     private void testSecondSnapshot() throws Exception {
 308         testLog.info("testSecondSnapshot starting");
 309
 310         expSnapshotState.add(payload3);
 311         expSnapshotState.add(payload4);
 312         expSnapshotState.add(payload5);
 313         expSnapshotState.add(payload6);
 314
 315         // Delay the CaptureSnapshot message to the leader actor.
 316         leaderActor.underlyingActor().startDropMessages(CaptureSnapshotReply.class);
 317
 318         // Send the payload.
 319         payload7 = sendPayloadData(leaderActor, "seven");
 320
 321         // Capture the CaptureSnapshotReply message so we can send it later.
 322         final CaptureSnapshotReply captureSnapshotReply = MessageCollectorActor.expectFirstMatching(
 323                 leaderCollectorActor, CaptureSnapshotReply.class);
 324
 325         // Wait for the state to be applied in the leader.
 326         ApplyState applyState = MessageCollectorActor.expectFirstMatching(leaderCollectorActor, ApplyState.class);
 327         verifyApplyState(applyState, leaderCollectorActor, payload7.toString(), currentTerm, 7, payload7);
 328
 329         // At this point the leader has applied the new state but the cached snapshot index should not be
 330         // advanced by a "fake" snapshot because we're in the middle of a snapshot. We'll wait for at least
 331         // one more heartbeat AppendEntriesReply to ensure this does not occur.
 332         MessageCollectorActor.clearMessages(leaderCollectorActor);
 333         MessageCollectorActor.expectFirstMatching(leaderCollectorActor, AppendEntriesReply.class);
 334
 335         assertEquals("Leader snapshot term", currentTerm, leaderContext.getReplicatedLog().getSnapshotTerm());
 336         assertEquals("Leader snapshot index", 5, leaderContext.getReplicatedLog().getSnapshotIndex());
 337         assertEquals("Leader journal log size", 2, leaderContext.getReplicatedLog().size());
 338         assertEquals("Leader journal last index", 7, leaderContext.getReplicatedLog().lastIndex());
 339         assertEquals("Leader commit index", 7, leaderContext.getCommitIndex());
 340         assertEquals("Leader last applied", 7, leaderContext.getLastApplied());
 341         assertEquals("Leader replicatedToAllIndex", 5, leader.getReplicatedToAllIndex());
 342
 343         // Now deliver the CaptureSnapshotReply.
 344         leaderActor.underlyingActor().stopDropMessages(CaptureSnapshotReply.class);
 345         leaderActor.tell(captureSnapshotReply, leaderActor);
 346
 347         // Wait for snapshot complete.
 348         MessageCollectorActor.expectFirstMatching(leaderCollectorActor, SaveSnapshotSuccess.class);
 349
 350         // Wait for another heartbeat AppendEntriesReply. This should cause a "fake" snapshot to advance the
 351         // snapshot index and trimmed the log since we're no longer in a snapshot.
 352         MessageCollectorActor.clearMessages(leaderCollectorActor);
 353         MessageCollectorActor.expectFirstMatching(leaderCollectorActor, AppendEntriesReply.class);
 354         assertEquals("Leader snapshot term", currentTerm, leaderContext.getReplicatedLog().getSnapshotTerm());
 355         assertEquals("Leader snapshot index", 6, leaderContext.getReplicatedLog().getSnapshotIndex());
 356         assertEquals("Leader journal log size", 1, leaderContext.getReplicatedLog().size());
 357         assertEquals("Leader journal last index", 7, leaderContext.getReplicatedLog().lastIndex());
 358         assertEquals("Leader commit index", 7, leaderContext.getCommitIndex());
 359
 360         // Verify the persisted snapshot. This should reflect the snapshot index as the last applied
 361         // log entry (7) and shouldn't contain any unapplied entries as we capture persisted the snapshot data
 362         // when the snapshot is created (ie when the CaptureSnapshot is processed).
 363         List<Snapshot> persistedSnapshots = InMemorySnapshotStore.getSnapshots(leaderId, Snapshot.class);
 364         assertEquals("Persisted snapshots size", 1, persistedSnapshots.size());
 365         verifySnapshot("Persisted", persistedSnapshots.get(0), currentTerm, 6, currentTerm, 7);
 366         List<ReplicatedLogEntry> unAppliedEntry = persistedSnapshots.get(0).getUnAppliedEntries();
 367         assertEquals("Persisted Snapshot getUnAppliedEntries size", 1, unAppliedEntry.size());
 368         verifyReplicatedLogEntry(unAppliedEntry.get(0), currentTerm, 7, payload7);
 369
 370         // The leader's persisted journal log should be cleared since we did a snapshot.
 371         List<ReplicatedLogImplEntry> persistedLeaderJournal = InMemoryJournal.get(
 372                 leaderId, ReplicatedLogImplEntry.class);
 373         assertEquals("Persisted journal log size", 0, persistedLeaderJournal.size());
 374
 375         // Verify the followers apply all 4 new log entries.
 376         List<ApplyState> applyStates = MessageCollectorActor.expectMatching(follower1CollectorActor,
 377                 ApplyState.class, 4);
 378         verifyApplyState(applyStates.get(0), null, null, currentTerm, 4, payload4);
 379         verifyApplyState(applyStates.get(1), null, null, currentTerm, 5, payload5);
 380         verifyApplyState(applyStates.get(2), null, null, currentTerm, 6, payload6);
 381         verifyApplyState(applyStates.get(3), null, null, currentTerm, 7, payload7);
 382
 383         applyStates = MessageCollectorActor.expectMatching(follower2CollectorActor, ApplyState.class, 4);
 384         verifyApplyState(applyStates.get(0), null, null, currentTerm, 4, payload4);
 385         verifyApplyState(applyStates.get(1), null, null, currentTerm, 5, payload5);
 386         verifyApplyState(applyStates.get(2), null, null, currentTerm, 6, payload6);
 387         verifyApplyState(applyStates.get(3), null, null, currentTerm, 7, payload7);
 388
 389         // Verify the follower's snapshot index has also advanced. (after another AppendEntries heartbeat
 390         // to be safe).
 391
 392         MessageCollectorActor.clearMessages(follower1CollectorActor);
 393         MessageCollectorActor.expectFirstMatching(follower1CollectorActor, AppendEntries.class);
 394         follower1Context = follower1Actor.underlyingActor().getRaftActorContext();
 395         assertEquals("Follower 1 snapshot term", currentTerm, follower1Context.getReplicatedLog().getSnapshotTerm());
 396         assertEquals("Follower 1 snapshot index", 6, follower1Context.getReplicatedLog().getSnapshotIndex());
 397         assertEquals("Follower 1 journal log size", 1, follower1Context.getReplicatedLog().size());
 398         assertEquals("Follower 1 journal last index", 7, follower1Context.getReplicatedLog().lastIndex());
 399         assertEquals("Follower 1 commit index", 7, follower1Context.getCommitIndex());
 400
 401         MessageCollectorActor.clearMessages(follower2CollectorActor);
 402         MessageCollectorActor.expectFirstMatching(follower2CollectorActor, AppendEntries.class);
 403         follower2Context = follower2Actor.underlyingActor().getRaftActorContext();
 404         assertEquals("Follower 2 snapshot term", currentTerm, follower2Context.getReplicatedLog().getSnapshotTerm());
 405         assertEquals("Follower 2 snapshot index", 6, follower2Context.getReplicatedLog().getSnapshotIndex());
 406         assertEquals("Follower 2 journal log size", 1, follower2Context.getReplicatedLog().size());
 407         assertEquals("Follower 2 journal last index", 7, follower2Context.getReplicatedLog().lastIndex());
 408         assertEquals("Follower 2 commit index", 7, follower2Context.getCommitIndex());
 409
 410         expSnapshotState.add(payload7);
 411
 412         testLog.info("testSecondSnapshot ending");
 413     }
 414
 415     /**
 416      * Kill the leader actor, reinstate it and verify the recovered journal.
 417      */
 418     private void testLeaderReinstatement() {
 419         testLog.info("testLeaderReinstatement starting");
 420
 421         killActor(leaderActor);
 422
 423         leaderActor = newTestRaftActor(leaderId, peerAddresses, leaderConfigParams);
 424
 425         leaderActor.underlyingActor().waitForRecoveryComplete();
 426
 427         leaderContext = leaderActor.underlyingActor().getRaftActorContext();
 428
 429         assertEquals("Leader snapshot term", currentTerm, leaderContext.getReplicatedLog().getSnapshotTerm());
 430         assertEquals("Leader snapshot index", 6, leaderContext.getReplicatedLog().getSnapshotIndex());
 431         assertEquals("Leader journal log size", 1, leaderContext.getReplicatedLog().size());
 432         assertEquals("Leader journal last index", 7, leaderContext.getReplicatedLog().lastIndex());
 433         assertEquals("Leader commit index", 7, leaderContext.getCommitIndex());
 434         assertEquals("Leader last applied", 7, leaderContext.getLastApplied());
 435         verifyReplicatedLogEntry(leaderContext.getReplicatedLog().last(), currentTerm, 7, payload7);
 436
 437         testLog.info("testLeaderReinstatement ending");
 438     }
 439 }