public async Task <ChordHealthStatus> CheckHealth(
IChordEndpoint target, int timeoutInSecs = 10,
ChordHealthStatus failStatus = ChordHealthStatus.Questionable)
{
// send a health check request
var cancelCallback = new CancellationTokenSource();
var timeoutTask = Task.Delay(timeoutInSecs * 1000);
var healthCheckTask = Task.Run(() => sendRequest(
new ChordRequestMessage()
{
Type = ChordRequestType.HealthCheck,
RequesterId = local.NodeId,
},
target
), cancelCallback.Token);
// return the reported health state or the fail status (timeout)
bool timeout = await Task.WhenAny(timeoutTask, healthCheckTask) == timeoutTask;
if (timeout)
{
cancelCallback.Cancel();
}
return(timeout ? failStatus : healthCheckTask.Result.Responder.State);
}
private void updateHealth(List <IChordEndpoint> fingers, int timeoutSecs,
ChordHealthStatus failStatus = ChordHealthStatus.Questionable)
{
// run health checks for each finger in parallel
var healthCheckTasks = fingerTable.Values
.Select(x => Task.Run(() => new {
NodeId = x.NodeId,
Health = CheckHealth(x, timeoutSecs, failStatus).Result
})).ToArray();
Task.WaitAll(healthCheckTasks);
// collect health check results
var healthStates = healthCheckTasks.Select(x => x.Result)
.ToDictionary(x => x.NodeId, x => x.Health);
// update finger states
fingers.ForEach(finger => finger.State = healthStates[finger.NodeId]);
}
