// TODO: This method is inefficient.. we should not have to update this state by a complete
// TODO: iteration each time. Instead it should be updated as a direct response to each
// TODO: append response.
public static long QuorumAppendIndex <MEMBER>(ISet <MEMBER> votingMembers, FollowerStates <MEMBER> states)
{
/*
* Build up a map of tx id -> number of instances that have appended,
* sorted by tx id.
*
* This allows us to then iterate backwards over the values in the map,
* adding up a total count of how many have appended, until we reach a majority.
* Once we do, the tx id at the current entry in the map will be the highest one
* with a majority appended.
*/
SortedDictionary <long, int> appendedCounts = new SortedDictionary <long, int>();
foreach (MEMBER member in votingMembers)
{
long txId = states.Get(member).MatchIndex;
appendedCounts.merge(txId, 1, (a, b) => a + b);
}
// Iterate over it until we find a majority
int total = 0;
foreach (KeyValuePair <long, int> entry in appendedCounts.descendingMap().entrySet())
{
total += entry.Value;
if (MajorityIncludingSelfQuorum.IsQuorum(votingMembers.Count, total))
{
return(entry.Key);
}
}
// No majority for any appended entry
return(-1);
}
//JAVA TO C# CONVERTER TODO TASK: Most Java annotations will not have direct .NET equivalent attributes:
//ORIGINAL LINE: @Test public void leaderShouldIgnoreSuccessResponseThatIndicatesLaggingWhileLocalStateIndicatesFollowerIsCaughtUp() throws Exception
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
public virtual void LeaderShouldIgnoreSuccessResponseThatIndicatesLaggingWhileLocalStateIndicatesFollowerIsCaughtUp()
{
// 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);
int j = 100;
FollowerState instance2State = CreateArtificialFollowerState(j);
ReadableRaftState state = mock(typeof(ReadableRaftState));
FollowerStates <MemberId> followerState = new FollowerStates <MemberId>();
followerState = new FollowerStates <MemberId>(followerState, instance2, instance2State);
ReadableRaftLog logMock = mock(typeof(ReadableRaftLog));
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);
when(state.Term()).thenReturn(4L); // both leader and follower are in the same term
// when that leader is asked to handle a response from that follower that says that the follower is still
// missing things
Org.Neo4j.causalclustering.core.consensus.RaftMessages_AppendEntries_Response response = appendEntriesResponse().success().matchIndex(80).term(4).from(instance2).build();
Outcome outcome = leader.Handle(response, state, mock(typeof(Log)));
// then the leader should not send anything, since this is a delayed, out of order response to a previous append
// request
assertTrue(outcome.OutgoingMessages.Count == 0);
// The follower state should not be touched
FollowerStates <MemberId> updatedFollowerStates = outcome.FollowerStates;
assertEquals(100, updatedFollowerStates.Get(instance2).MatchIndex);
}
//JAVA TO C# CONVERTER TODO TASK: Most Java annotations will not have direct .NET equivalent attributes:
//ORIGINAL LINE: @Test public void leaderShouldNotRespondToSuccessResponseThatIndicatesUpToDateFollower() throws Exception
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
public virtual void LeaderShouldNotRespondToSuccessResponseThatIndicatesUpToDateFollower()
{
// 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(typeof(ReadableRaftState));
FollowerStates <MemberId> followerState = new FollowerStates <MemberId>();
followerState = new FollowerStates <MemberId>(followerState, instance2, instance2State);
ReadableRaftLog logMock = mock(typeof(ReadableRaftLog));
when(logMock.AppendIndex()).thenReturn(100L);
when(state.CommitIndex()).thenReturn(-1L);
when(state.EntryLog()).thenReturn(logMock);
when(state.FollowerStates()).thenReturn(followerState);
when(state.Term()).thenReturn(4L); // both leader and follower are in the same term
// when
// that leader is asked to handle a response from that follower that says that the follower is up to date
Org.Neo4j.causalclustering.core.consensus.RaftMessages_AppendEntries_Response response = appendEntriesResponse().success().matchIndex(100).term(4).from(instance2).build();
Outcome outcome = leader.Handle(response, state, mock(typeof(Log)));
// then
// The leader should not be trying to send any messages to that instance
assertTrue(outcome.OutgoingMessages.Count == 0);
// And the follower state should be updated
FollowerStates <MemberId> updatedFollowerStates = outcome.FollowerStates;
assertEquals(100, updatedFollowerStates.Get(instance2).MatchIndex);
}
public override RaftMembershipStateMachineEventHandler OnFollowerStateChange(FollowerStates <MemberId> followerStates)
{
CatchupGoalTracker.updateProgress(followerStates.Get(outerInstance.catchingUpMember));
if (CatchupGoalTracker.Finished)
{
if (CatchupGoalTracker.GoalAchieved)
{
ISet <MemberId> updatedVotingMembers = new HashSet <MemberId>(outerInstance.membershipManager.VotingMembers());
updatedVotingMembers.Add(outerInstance.catchingUpMember);
outerInstance.membershipManager.DoConsensus(updatedVotingMembers);
MovingToConsensus = true;
return(new ConsensusInProgress(_outerInstance));
}
else
{
return(new Idle(_outerInstance));
}
}
return(this);
}