internal bool EnsureExistGreaterTermAndChangeRole(ulong term)
{
lock (_ensureTermLockObj)
{
if (term > _stateController.PersistentState.CurrentTerm)
{
DebugConsole.WriteLine($"Existed a term greater than current term.");
_stateController.UpdateTerm(term);
ChangeRole(RoleType.Follower);
return(true);
}
return(false);
}
}
private void RequestVote()
{
_stateController.UpdateTerm(_stateController.PersistentState.CurrentTerm + 1);
DebugConsole.WriteLine($"Starting election ... term :{_stateController.PersistentState.CurrentTerm}" + Environment.NewLine);
//Vote for current object
int votes = 1;
bool transferedLeader = false;
List <Task> taskList = new List <Task>();
int majorityCount = _node.Peers.Count;
foreach (Peer peer in _node.Peers)
{
Task task = Task.Run(() =>
{
try
{
VoteResponse response = RequestVoteCore(peer.RemoteClient);
if (_node.EnsureExistGreaterTermAndChangeRole(response.Term))
{
return;
}
if (response.VoteGranted)
{
lock (_transferedLeaderLockObj)
{
votes += 1;
if (!transferedLeader && votes > majorityCount / 2 + 1)
{
transferedLeader = true;
_node.ChangeRole(RoleType.Leader);
}
}
}
}
catch (Exception ex)
{
DebugConsole.WriteLine($"{ex.Message}");
}
});
taskList.Add(task);
}
Task.WaitAll(taskList.ToArray());
}
public AppendEntriesResponse AppendEntries(AppendEntriesRequest request)
{
if (string.IsNullOrEmpty(LeaderId))
{
LeaderId = request.LeaderId;
}
if (request.Term == _stateController.PersistentState.CurrentTerm)
{
lock (this)
{
_isFromLegalLeaderRequest = true;
}
}
AppendEntriesResponse response = new AppendEntriesResponse();
if (_stateController.PersistentState.Logs.Any())
{
LogEntry logEntry = _stateController.PersistentState.Logs.SingleOrDefault(w => w.Index == request.PrevLogIndex && w.Term == request.PrevLogTerm);
if (logEntry == null)
{
response.IsSuccess = false;
response.Term = _stateController.PersistentState.CurrentTerm;
return(response);
}
LogEntry diffTermLogEntry = _stateController.PersistentState.Logs.SingleOrDefault(w => request.Entries.Exists(e => e.Index == w.Index && w.Term != e.Term));
if (diffTermLogEntry != null)
{
_stateController.PersistentState.Logs.RemoveRange((int)diffTermLogEntry.Index, _stateController.PersistentState.Logs.Count - (int)diffTermLogEntry.Index);
}
_stateController.PersistentState.Logs.AddRange(request.Entries);
}
if (request.LeaderCommit > _stateController.VolatileState.CommitIndex)
{
_stateController.UpdateTerm(request.Term);
_stateController.UpdateCommitIndex(Math.Min(request.LeaderCommit, request.PrevLogIndex));
}
response.IsSuccess = true;
response.Term = _stateController.PersistentState.CurrentTerm;
return(response);
}
