public void Start(Func <Task> task, TimeSpan delay)
{
if (task == null)
{
throw new ArgumentNullException(nameof(task));
}
#pragma warning disable 4014
// Fire-and-forget
Task.Factory.StartNew(async() => {
await _delayer.Delay(delay).ConfigureAwait(false);
await task().ConfigureAwait(false);
});
#pragma warning restore 4014
}
private bool CreateChannel(CancellationToken cancellationToken)
{
_grpcWrapper.Shutdown();
var attemptId = 0;
LogMessage(LogLevel.Finest, $"Creating gRPC channel to endpoint {EndpointHost}:{EndpointPort}. (attempt {attemptId})");
while (!cancellationToken.IsCancellationRequested && IsServiceEnabled)
{
try
{
var createdChannel = false;
using (_agentTimerService.StartNew(_timerEventNameForChannel))
{
createdChannel = _grpcWrapper.CreateChannel(EndpointHost, EndpointPort, EndpointSsl, MetadataHeaders, TimeoutConnectMs, cancellationToken);
}
if (createdChannel)
{
LogMessage(LogLevel.Finest, $"gRPC channel to endpoint {EndpointHost}:{EndpointPort} connected.");
return(true);
}
if (cancellationToken.IsCancellationRequested)
{
break;
}
LogMessage(LogLevel.Debug, $"Timeout creating gRPC channel at endpoint {EndpointHost}:{EndpointPort}. (attempt {attemptId}, timeout {TimeoutConnectMs}ms)");
}
catch (Exception ex)
{
LogMessage(LogLevel.Debug, $"Error creating gRPC channel to endpoint {EndpointHost}:{EndpointPort}. (attempt {attemptId})", ex);
RecordResponseError();
var grpcWrapperEx = ex as GrpcWrapperException;
if (grpcWrapperEx != null && !string.IsNullOrWhiteSpace(grpcWrapperEx.Status))
{
RecordGrpcError(grpcWrapperEx.Status);
if (grpcWrapperEx.Status == UnimplementedStatus)
{
LogMessage(LogLevel.Error, $"The gRPC endpoint defined at {EndpointHost}:{EndpointPort} is not available and no reconnection attempts will be made.");
Shutdown(false);
return(false);
}
if (grpcWrapperEx.Status == OkStatus)
{
//Getting the OK status back indicates that the channel was created successfully, but the test stream
//needed to be rebalanced to another handler. Since the test stream is only used to ensure that the
//channel is valid we can just return true here.
LogMessage(LogLevel.Finest, $"gRPC channel to endpoint {EndpointHost}:{EndpointPort} connected.");
return(true);
}
}
}
var delayIdx = Math.Min(attemptId, _backoffDelaySequenceConnectMs.Length - 1);
var delayPeriodMs = _backoffDelaySequenceConnectMs[delayIdx];
LogMessage(LogLevel.Finest, $"Backoff for {delayPeriodMs}ms before attempting to reconnect.");
_delayer.Delay(delayPeriodMs, cancellationToken);
attemptId++;
}
return(false);
}
