public async Task <AddressAndTag> RegisterAsync(ActivationAddress address, bool singleActivation)
{
if (!singleActivation)
{
throw new OrleansException("global single instance protocol is incompatible with using multiple activations");
}
var myClusterId = Silo.CurrentSilo.ClusterId;
if (myClusterId == null)
{
// no multicluster network. Go to owned state directly.
return(directoryPartition.AddSingleActivation(address.Grain, address.Activation, address.Silo, GrainDirectoryEntryStatus.Owned));
}
// examine the multicluster configuration
var config = Silo.CurrentSilo.LocalMultiClusterOracle.GetMultiClusterConfiguration();
if (config == null || !config.Clusters.Contains(myClusterId))
{
// we are not joined to the cluster yet/anymore. Go to doubtful state directly.
gsiActivationMaintainer.TrackDoubtfulGrain(address.Grain);
return(directoryPartition.AddSingleActivation(address.Grain, address.Activation, address.Silo, GrainDirectoryEntryStatus.Doubtful));
}
var remoteClusters = config.Clusters.Where(id => id != myClusterId).ToList();
// Try to go into REQUESTED_OWNERSHIP state
var myActivation = directoryPartition.AddSingleActivation(address.Grain, address.Activation, address.Silo, GrainDirectoryEntryStatus.RequestedOwnership);
if (!myActivation.Address.Equals(address))
{
//This implies that the registration already existed in some state? return the existing activation.
return(myActivation);
}
// Do request rounds until successful or we run out of retries
int retries = numRetries;
while (retries-- > 0)
{
if (logger.IsVerbose)
{
logger.Verbose("GSIP:Req {0} Round={1} Act={2}", address.Grain.ToString(), numRetries - retries, myActivation.Address.ToString());
}
var outcome = await SendRequestRound(address, remoteClusters);
if (logger.IsVerbose)
{
logger.Verbose("GSIP:End {0} Round={1} Outcome={2}", address.Grain.ToString(), numRetries - retries, outcome);
}
switch (outcome.State)
{
case OutcomeState.RemoteOwner:
case OutcomeState.RemoteOwnerLikely:
{
directoryPartition.CacheOrUpdateRemoteClusterRegistration(address.Grain, address.Activation, outcome.RemoteOwnerAddress.Address);
return(outcome.RemoteOwnerAddress);
}
case OutcomeState.Succeed:
{
if (directoryPartition.UpdateClusterRegistrationStatus(address.Grain, address.Activation, GrainDirectoryEntryStatus.Owned, GrainDirectoryEntryStatus.RequestedOwnership))
{
return(myActivation);
}
else
{
break; // concurrently moved to RACE_LOSER
}
}
case OutcomeState.Inconclusive:
{
break;
}
}
// we were not successful, reread state to determine what is going on
int version;
var mcstatus = directoryPartition.TryGetActivation(address.Grain, out address, out version);
if (mcstatus == GrainDirectoryEntryStatus.RequestedOwnership)
{
// we failed because of inconclusive answers. Stay in this state for retry.
}
else if (mcstatus == GrainDirectoryEntryStatus.RaceLoser)
{
// we failed because an external request moved us to RACE_LOSER. Go back to REQUESTED_OWNERSHIP for retry
var success = directoryPartition.UpdateClusterRegistrationStatus(address.Grain, address.Activation, GrainDirectoryEntryStatus.RequestedOwnership, GrainDirectoryEntryStatus.RaceLoser);
if (!success)
{
ProtocolError(address, "unable to transition from RACE_LOSER to REQUESTED_OWNERSHIP");
}
// do not wait before retrying because there is a dominant remote request active so we can probably complete quickly
}
else
{
ProtocolError(address, "unhandled protocol state");
}
}
// we are done with the quick retries. Now we go into doubtful state, which means slower retries.
var ok = directoryPartition.UpdateClusterRegistrationStatus(address.Grain, address.Activation, GrainDirectoryEntryStatus.Doubtful, GrainDirectoryEntryStatus.RequestedOwnership);
if (!ok)
{
ProtocolError(address, "unable to transition into doubtful");
}
this.gsiActivationMaintainer.TrackDoubtfulGrain(address.Grain);
return(myActivation);
}
