private IMessage CreateLeaseAckReadMessage(LeaseReadMessage payload)
{
Lease lastKnownLease = null;
Interlocked.Exchange(ref lastKnownLease, lease);
Ballot lastKnownWriteBallot = null;
Interlocked.Exchange(ref lastKnownWriteBallot, writeBallot);
return(Message.Create(new LeaseAckReadMessage
{
Ballot = payload.Ballot,
KnownWriteBallot = new Consensus.Messages.Ballot
{
Identity = lastKnownWriteBallot.Identity,
Timestamp = lastKnownWriteBallot.Timestamp.Ticks,
MessageNumber = lastKnownWriteBallot.MessageNumber
},
Lease = (lastKnownLease != null)
? new Consensus.Messages.Lease
{
Identity = lastKnownLease.OwnerIdentity,
ExpiresAt = lastKnownLease.ExpiresAt.Ticks,
OwnerPayload = lastKnownLease.OwnerPayload
}
: null,
SenderUri = synodConfigProvider.LocalNode.Uri.ToSocketAddress()
}));
}
public LeaseTxResult Write(Ballot ballot, Lease lease)
{
var ackFilter = new LeaderElectionMessageFilter(ballot, m => m.GetPayload <LeaseAckWriteMessage>(), synodConfigProvider);
var nackFilter = new LeaderElectionMessageFilter(ballot, m => m.GetPayload <LeaseNackWriteMessage>(), synodConfigProvider);
var awaitableAckFilter = new AwaitableMessageStreamFilter(ackFilter.Match, m => m.GetPayload <LeaseAckWriteMessage>(), GetQuorum());
var awaitableNackFilter = new AwaitableMessageStreamFilter(nackFilter.Match, m => m.GetPayload <LeaseNackWriteMessage>(), GetQuorum());
using (ackWriteStream.Subscribe(awaitableAckFilter))
{
using (nackWriteStream.Subscribe(awaitableNackFilter))
{
intercomMessageHub.Send(CreateWriteMessage(ballot, lease));
var index = WaitHandle.WaitAny(new[] { awaitableAckFilter.Filtered, awaitableNackFilter.Filtered },
leaseConfig.NodeResponseTimeout);
if (ReadNotAcknowledged(index))
{
return(new LeaseTxResult {
TxOutcome = TxOutcome.Abort
});
}
return(new LeaseTxResult
{
TxOutcome = TxOutcome.Commit,
// NOTE: needed???
Lease = lease
});
}
}
}
private IMessage CreateWriteMessage(Ballot ballot, Lease lease)
=> Message.Create(new LeaseWriteMessage
{
Ballot = new Consensus.Messages.Ballot
{
Identity = ballot.Identity,
Timestamp = ballot.Timestamp.Ticks,
MessageNumber = ballot.MessageNumber
},
Lease = new Consensus.Messages.Lease
{
Identity = lease.OwnerIdentity,
ExpiresAt = lease.ExpiresAt.Ticks,
OwnerPayload = lease.OwnerPayload
}
});
private void LogLeaseProlonged(Lease lastReadLease)
{
if (lastReadLease != null)
{
if (IsLeaseOwner(lastReadLease))
{
logger.Debug($"[{DateTime.UtcNow.ToString(format)}] " +
"PROLONG === process " +
$"{localNode.Uri.AbsoluteUri} " +
"wants to prolong it's lease " +
$"{lastReadLease.ExpiresAt.ToString(format)}");
}
else
{
logger.Debug($"[{DateTime.UtcNow.ToString(format)}] " +
"RENEW === process " +
$"{localNode.Uri.AbsoluteUri} " +
"wants to renew lease " +
$"{lastReadLease.ExpiresAt.ToString(format)}");
}
}
}
private bool LeaseIsNotSafelyExpired(Lease lease, DateTime now)
=> lease != null &&
lease.ExpiresAt <now &&
lease.ExpiresAt + config.ClockDrift> now;
private static bool LeaseNullOrExpired(Lease lease, DateTime now) => lease == null || lease.ExpiresAt < now;
private bool IsLeaseOwner(Lease lease) => lease != null && Unsafe.ArraysEqual(lease.OwnerIdentity, localNode.SocketIdentity);
private bool ProcessBecameLeader(Lease nextLease, Lease previousLease)
=> ((previousLease == null || !Unsafe.ArraysEqual(previousLease.OwnerIdentity, localNode.SocketIdentity)) &&
nextLease != null && Unsafe.ArraysEqual(nextLease.OwnerIdentity, localNode.SocketIdentity));
private bool ProcessLostLeadership(Lease nextLease, Lease previousLease)
=> (previousLease != null && Unsafe.ArraysEqual(previousLease.OwnerIdentity, localNode.SocketIdentity) &&
nextLease != null && !Unsafe.ArraysEqual(nextLease.OwnerIdentity, localNode.SocketIdentity));
public LastWrittenLease(Ballot writeBallot, Lease lease)
{
this.writeBallot = writeBallot;
Lease = lease;
}