public LeaderElection(IList<Peer> peers, object lockObject, NetMQContext context, ILogger logger)
{
this.peers = peers;
this.lockObject = lockObject;
this.context = context;
this.logger = logger;
localPeer = this.peers.First(c => c.IsLocal);
}
public void ElectNewMaster(Peer thisPeer, IList<Peer> allPeers)
{
if (!thisPeer.IsLocal)
{
throw new Exception("ElectNewMaster: thisPeer is not local. Must initiate election message from my list of higher peers.");
}
// If there are no higher peers, I am the winner
if (!thisPeer.HigherPeers.Any())
{
IsLeaderProcess = true;
return;
}
// If any higher thisPeer responds to my election message with Ok
// I stop bothering them since they outrank me
if (thisPeer.HigherPeers.OrderByDescending(i => i).Any(id => SendElection(allPeers[id])))
{
IsLeaderProcess = false;
return;
}
IsLeaderProcess = true;
}
private bool SendElection(Peer peer)
{
if (peer.IsLocal)
{
throw new Exception("SendElection: peer is local. Cannot send election message to my self.");
}
string reply;
logger.Log($"Sending election message to {peer.ElectionSocket}");
bool didAnswer;
using (var client = context.CreateRequestSocket())
{
client.Connect(peer.ElectionSocket);
// Send election message to higher peer
client.TrySendFrame(TimeSpan.FromMilliseconds(1000), Message.Election);
// Wait for reply OK/NOK or timeout
didAnswer = client.TryReceiveFrameString(TimeSpan.FromMilliseconds(1000), out reply);
client.Close();
}
if (didAnswer)
{
return reply == Message.Ok;
}
return false;
}