Examples with RaftLog org.neo4j.causalclustering.core.consensus.log.RaftLog used on opensource projects

Example 1 with RaftLog

use of org.neo4j.causalclustering.core.consensus.log.RaftLog in project neo4j by neo4j.

the class SegmentedRaftLogRotationTruncationPruneTest method shouldPruneAwaySingleEntriesIfRotationHappenedEveryEntry.

@Test
public void shouldPruneAwaySingleEntriesIfRotationHappenedEveryEntry() throws Exception {
    /**
         * If you have a raft log which rotates after every append, therefore having a single entry in every segment,
         * we assert that every sequential prune attempt will result in the prevIndex incrementing by one.
         */
    // given
    RaftLog log = createRaftLog();
    long term = 0;
    for (int i = 0; i < 10; i++) {
        log.append(new RaftLogEntry(term, valueOf(i)));
    }
    assertEquals(-1, log.prevIndex());
    for (int i = 0; i < 9; i++) {
        log.prune(i);
        assertEquals(i, log.prevIndex());
    }
    log.prune(9);
    assertEquals(8, log.prevIndex());
}

Example 2 with RaftLog

use of org.neo4j.causalclustering.core.consensus.log.RaftLog in project neo4j by neo4j.

the class SegmentedRaftLogRotationTruncationPruneTest method shouldPruneAwaySingleEntriesAfterTruncationIfRotationHappenedEveryEntry.

@Test
public void shouldPruneAwaySingleEntriesAfterTruncationIfRotationHappenedEveryEntry() throws Exception {
    /**
         * Given a log with many single-entry segments, a series of truncations at decending values followed by
         * pruning at more previous segments will maintain the correct prevIndex for the log.
         *
         * Initial Scenario:    [0][1][2][3][4][5][6][7][8][9]              prevIndex = 0
         * Truncate segment 9 : [0][1][2][3][4][5][6][7][8]   (9)           prevIndex = 0
         * Truncate segment 8 : [0][1][2][3][4][5][6][7]      (8)(9)        prevIndex = 0
         * Truncate segment 7 : [0][1][2][3][4][5][6]         (7)(8)(9)     prevIndex = 0
         * Prune segment 0    :    [1][2][3][4][5][6]         (7)(8)(9)     prevIndex = 1
         * Prune segment 1    :       [2][3][4][5][6]         (7)(8)(9)     prevIndex = 2
         * Prune segment 2    :          [3][4][5][6]         (7)(8)(9)     prevIndex = 3
         * Prune segment 3    :             [4][5][6]         (7)(8)(9)     prevIndex = 4
         * Prune segment 4    :                [5][6]         (7)(8)(9)     prevIndex = 5
         * Prune segment 5    :                [5][6]         (7)(8)(9)     prevIndex = 5
         * Prune segment 6    :                [5][6]         (7)(8)(9)     prevIndex = 5
         * Etc...
         *
         * The prevIndex should not become corrupt and become greater than 5 in this example.
         */
    // given
    RaftLog log = createRaftLog();
    long term = 0;
    for (int i = 0; i < 10; i++) {
        log.append(new RaftLogEntry(term, valueOf(i)));
    }
    log.truncate(9);
    log.truncate(8);
    log.truncate(7);
    assertEquals(-1, log.prevIndex());
    for (int i = 0; i <= 5; i++) {
        log.prune(i);
        assertEquals(i, log.prevIndex());
    }
    for (int i = 5; i < 10; i++) {
        log.prune(i);
        assertEquals(5, log.prevIndex());
    }
}

Example 3 with RaftLog

use of org.neo4j.causalclustering.core.consensus.log.RaftLog in project neo4j by neo4j.

the class LeaderTest method leaderShouldSpawnMismatchCommandOnFailure.

// TODO: rethink this test, it does too much
@Test
public void leaderShouldSpawnMismatchCommandOnFailure() throws Exception {
    // given
    /*
         * A leader who
         * - has an append index of 100
         * - knows about instance 2
         * - assumes that instance 2 is fully caught up
         */
    Leader leader = new Leader();
    MemberId instance2 = member(2);
    FollowerState instance2State = createArtificialFollowerState(100);
    ReadableRaftState state = mock(ReadableRaftState.class);
    FollowerStates<MemberId> followerState = new FollowerStates<>();
    followerState = new FollowerStates<>(followerState, instance2, instance2State);
    RaftLog log = new InMemoryRaftLog();
    for (int i = 0; i <= 100; i++) {
        log.append(new RaftLogEntry(0, valueOf(i)));
    }
    when(state.commitIndex()).thenReturn(-1L);
    when(state.entryLog()).thenReturn(log);
    when(state.followerStates()).thenReturn(followerState);
    // both leader and follower are in the same term
    when(state.term()).thenReturn(4L);
    // when
    // that leader is asked to handle a response from that follower that says that the follower is still missing
    // things
    RaftMessages.AppendEntries.Response response = appendEntriesResponse().failure().appendIndex(0).matchIndex(-1).term(4).from(instance2).build();
    Outcome outcome = leader.handle(response, state, mock(Log.class));
    // then
    int mismatchCount = 0;
    for (ShipCommand shipCommand : outcome.getShipCommands()) {
        if (shipCommand instanceof ShipCommand.Mismatch) {
            mismatchCount++;
        }
    }
    assertThat(mismatchCount, greaterThan(0));
}

Example 4 with RaftLog

use of org.neo4j.causalclustering.core.consensus.log.RaftLog in project neo4j by neo4j.

the class FollowerTest method followerReceivingHeartbeatIndicatingClusterIsAheadShouldElicitAppendResponse.

@Test
public void followerReceivingHeartbeatIndicatingClusterIsAheadShouldElicitAppendResponse() throws Exception {
    // given
    int term = 1;
    int followerAppendIndex = 9;
    RaftLog entryLog = new InMemoryRaftLog();
    entryLog.append(new RaftLogEntry(0, new RaftTestGroup(0)));
    RaftState state = raftState().myself(myself).term(term).build();
    Follower follower = new Follower();
    appendSomeEntriesToLog(state, follower, followerAppendIndex - 1, term, 1);
    AppendEntries.Request heartbeat = appendEntriesRequest().from(member1).leaderTerm(term).prevLogIndex(// leader has appended 2 ahead from this follower
    followerAppendIndex + 2).prevLogTerm(// in the same term
    term).build();
    Outcome outcome = follower.handle(heartbeat, state, log());
    assertEquals(1, outcome.getOutgoingMessages().size());
    RaftMessage outgoing = outcome.getOutgoingMessages().iterator().next().message();
    assertEquals(RaftMessages.Type.APPEND_ENTRIES_RESPONSE, outgoing.type());
    RaftMessages.AppendEntries.Response response = (AppendEntries.Response) outgoing;
    assertFalse(response.success());
}

Example 5 with RaftLog

use of org.neo4j.causalclustering.core.consensus.log.RaftLog in project neo4j by neo4j.

the class FollowerTest method shouldTruncateIfTermDoesNotMatch.

@Test
public void shouldTruncateIfTermDoesNotMatch() throws Exception {
    // given
    RaftLog entryLog = new InMemoryRaftLog();
    entryLog.append(new RaftLogEntry(0, new RaftTestGroup(0)));
    int term = 1;
    RaftState state = raftState().myself(myself).entryLog(entryLog).term(term).build();
    Follower follower = new Follower();
    state.update(follower.handle(new AppendEntries.Request(member1, 1, 0, 0, new RaftLogEntry[] { new RaftLogEntry(2, ContentGenerator.content()) }, 0), state, log()));
    RaftLogEntry[] entries = { new RaftLogEntry(1, new ReplicatedString("commit this!")) };
    Outcome outcome = follower.handle(new AppendEntries.Request(member1, 1, 0, 0, entries, 0), state, log());
    state.update(outcome);
    // then
    assertEquals(1, state.entryLog().appendIndex());
    assertEquals(1, state.entryLog().readEntryTerm(1));
}