Examples with FollowerStates org.neo4j.causalclustering.core.consensus.roles.follower.FollowerStates used on opensource projects

Example 1 with FollowerStates

use of org.neo4j.causalclustering.core.consensus.roles.follower.FollowerStates in project neo4j by neo4j.

the class LeaderTest method leaderShouldNotRespondToSuccessResponseThatIndicatesUpToDateFollower.

@Test
public void leaderShouldNotRespondToSuccessResponseThatIndicatesUpToDateFollower() throws Exception {
    // given
    /*
         * A leader who
         * - has an append index of 100
         * - knows about instance 2
         * - assumes that instance 2 is at an index less than 100 -say 84
         */
    Leader leader = new Leader();
    MemberId instance2 = member(2);
    FollowerState instance2State = createArtificialFollowerState(84);
    ReadableRaftState state = mock(ReadableRaftState.class);
    FollowerStates<MemberId> followerState = new FollowerStates<>();
    followerState = new FollowerStates<>(followerState, instance2, instance2State);
    ReadableRaftLog logMock = mock(ReadableRaftLog.class);
    when(logMock.appendIndex()).thenReturn(100L);
    when(state.commitIndex()).thenReturn(-1L);
    when(state.entryLog()).thenReturn(logMock);
    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 up to date
    RaftMessages.AppendEntries.Response response = appendEntriesResponse().success().matchIndex(100).term(4).from(instance2).build();
    Outcome outcome = leader.handle(response, state, mock(Log.class));
    // then
    // The leader should not be trying to send any messages to that instance
    assertTrue(outcome.getOutgoingMessages().isEmpty());
    // And the follower state should be updated
    FollowerStates<MemberId> updatedFollowerStates = outcome.getFollowerStates();
    assertEquals(100, updatedFollowerStates.get(instance2).getMatchIndex());
}

Example 2 with FollowerStates

use of org.neo4j.causalclustering.core.consensus.roles.follower.FollowerStates in project neo4j by neo4j.

the class LeaderTest method leaderShouldRespondToSuccessResponseThatIndicatesLaggingFollowerWithJustWhatItsMissing.

@Test
public void leaderShouldRespondToSuccessResponseThatIndicatesLaggingFollowerWithJustWhatItsMissing() throws Exception {
    // given
    /*
         * A leader who
         * - has an append index of 100
         * - knows about instance 2
         * - assumes that instance 2 is at an index less than 100 -say 50
         */
    Leader leader = new Leader();
    MemberId instance2 = member(2);
    FollowerState instance2State = createArtificialFollowerState(50);
    ReadableRaftState state = mock(ReadableRaftState.class);
    FollowerStates<MemberId> followerState = new FollowerStates<>();
    followerState = new FollowerStates<>(followerState, instance2, instance2State);
    ReadableRaftLog logMock = mock(ReadableRaftLog.class);
    when(logMock.appendIndex()).thenReturn(100L);
    // with commit requests in this test
    when(state.commitIndex()).thenReturn(-1L);
    when(state.entryLog()).thenReturn(logMock);
    when(state.followerStates()).thenReturn(followerState);
    // both leader and follower are in the same term
    when(state.term()).thenReturn(231L);
    // 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().success().matchIndex(89).term(231).from(instance2).build();
    Outcome outcome = leader.handle(response, state, mock(Log.class));
    // then
    int matchCount = 0;
    for (ShipCommand shipCommand : outcome.getShipCommands()) {
        if (shipCommand instanceof ShipCommand.Match) {
            matchCount++;
        }
    }
    assertThat(matchCount, greaterThan(0));
}

Example 3 with FollowerStates

use of org.neo4j.causalclustering.core.consensus.roles.follower.FollowerStates 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 FollowerStates

use of org.neo4j.causalclustering.core.consensus.roles.follower.FollowerStates in project neo4j by neo4j.

the class LeaderTest method leaderShouldNotRespondToSuccessResponseFromFollowerThatWillSoonUpToDateViaInFlightMessages.

@Test
public void leaderShouldNotRespondToSuccessResponseFromFollowerThatWillSoonUpToDateViaInFlightMessages() throws Exception {
    // given
    /*
         * A leader who
         * - has an append index of 100
         * - knows about instance 2
         * - assumes that instance 2 is at an index less than 100 -say 84 but it has already been sent up to 100
         */
    Leader leader = new Leader();
    MemberId instance2 = member(2);
    FollowerState instance2State = createArtificialFollowerState(84);
    ReadableRaftState state = mock(ReadableRaftState.class);
    FollowerStates<MemberId> followerState = new FollowerStates<>();
    followerState = new FollowerStates<>(followerState, instance2, instance2State);
    ReadableRaftLog logMock = mock(ReadableRaftLog.class);
    when(logMock.appendIndex()).thenReturn(100L);
    when(state.commitIndex()).thenReturn(-1L);
    when(state.entryLog()).thenReturn(logMock);
    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 up to date
    RaftMessages.AppendEntries.Response response = appendEntriesResponse().success().matchIndex(90).term(4).from(instance2).build();
    Outcome outcome = leader.handle(response, state, mock(Log.class));
    // then
    // The leader should not be trying to send any messages to that instance
    assertTrue(outcome.getOutgoingMessages().isEmpty());
    // And the follower state should be updated
    FollowerStates<MemberId> leadersViewOfFollowerStates = outcome.getFollowerStates();
    assertEquals(90, leadersViewOfFollowerStates.get(instance2).getMatchIndex());
}

Example 5 with FollowerStates

use of org.neo4j.causalclustering.core.consensus.roles.follower.FollowerStates in project neo4j by neo4j.

the class RaftStateTest method shouldRemoveFollowerStateAfterBecomingLeader.

@Test
public void shouldRemoveFollowerStateAfterBecomingLeader() throws Exception {
    // given
    RaftState raftState = new RaftState(member(0), new InMemoryStateStorage<>(new TermState()), new FakeMembership(), new InMemoryRaftLog(), new InMemoryStateStorage<>(new VoteState()), new InFlightMap<>(), NullLogProvider.getInstance());
    raftState.update(new Outcome(CANDIDATE, 1, null, -1, null, emptySet(), -1, initialFollowerStates(), true, emptyLogCommands(), emptyOutgoingMessages(), emptySet(), -1, emptySet()));
    // when
    raftState.update(new Outcome(CANDIDATE, 1, null, -1, null, emptySet(), -1, new FollowerStates<>(), true, emptyLogCommands(), emptyOutgoingMessages(), emptySet(), -1, emptySet()));
    // then
    assertEquals(0, raftState.followerStates().size());
}