/// <summary>
/// Persistents the subscription event appeared.
/// </summary>
/// <param name="subscription">The subscription.</param>
/// <param name="resolvedEvent">The resolved event.</param>
/// <param name="subscriptionGroupId">The subscription group identifier.</param>
/// <returns></returns>
private async Task PersistentSubscriptionEventAppeared(EventStorePersistentSubscriptionBase subscription, ResolvedEvent resolvedEvent, Guid subscriptionGroupId)
{
try
{
// Check the event data has been received
if (this.EventAppeared != null)
{
// Serialise the event data
//String serialisedData = this.Serialiser.Serialise(resolvedEvent);
// Get the event data from the resolved Event
var serialisedData = Encoding.UTF8.GetString(resolvedEvent.Event.Data);
SubscriptionDataTransferObject subscriptionInformation = new SubscriptionDataTransferObject()
{
SerialisedData = serialisedData,
EventId = (Guid)((RecordedEvent)resolvedEvent.Event).EventId,
SubscriptionGroupId = subscriptionGroupId.ToString(),
};
var handledSuccessfully = await this.EventAppeared(subscriptionInformation);
if (!handledSuccessfully)
{
throw new Exception(
$"Failed to Process Event {resolvedEvent.Event.EventId} on persistent subscription group {subscriptionGroupId}");
}
}
else
{
Logger.LogInformation("Unable to process event as EventAppeared Event handler is null");
}
// Acknowledge the event
subscription.Acknowledge(resolvedEvent);
}
catch (TimeoutException tex)
{
subscription.Fail(resolvedEvent, PersistentSubscriptionNakEventAction.Park, tex.Message);
}
catch (InvalidOperationException ioex)
{
subscription.Fail(resolvedEvent, PersistentSubscriptionNakEventAction.Skip, ioex.Message);
}
catch (Exception ex)
{
subscription.Fail(resolvedEvent, PersistentSubscriptionNakEventAction.Retry, ex.Message);
}
}
async Task ExecutePipeline(EventStorePersistentSubscriptionBase s, ResolvedEvent evnt, MessageContext pushContext, CancellationTokenSource tokenSource)
{
var errorHandleResult = ErrorHandleResult.RetryRequired;
var failures = 0;
while (errorHandleResult != ErrorHandleResult.Handled)
{
try
{
await pipeline(pushContext);
errorHandleResult = ErrorHandleResult.Handled;
}
catch (Exception ex)
{
failures++;
errorHandleResult = await onError(ToErrorContext(evnt, ex, pushContext.TransportTransaction, failures));
}
}
if (tokenSource.IsCancellationRequested)
{
s.Fail(evnt, PersistentSubscriptionNakEventAction.Retry, "User requested");
}
else
{
s.Acknowledge(evnt);
}
}
private async Task EventAppeared(EventStorePersistentSubscriptionBase sub, ResolvedEvent e, CancellationToken token,
Func <string, long, IFullEvent, Task> callback)
{
// Don't care about metadata streams
if (e.Event == null || e.Event.EventStreamId[0] == '$')
{
sub.Acknowledge(e.OriginalEvent.EventId);
return;
}
if (token.IsCancellationRequested)
{
Logger.WarnEvent("Cancelation", "Token cancel requested");
ThreadPool.QueueUserWorkItem((_) => sub.Stop(TimeSpan.FromSeconds(10)));
token.ThrowIfCancellationRequested();
}
var eventId = $"{e.Event.EventId}:{e.Event.EventStreamId}:{e.Event.EventNumber}";
_outstandingEvents[eventId] = new Tuple <EventStorePersistentSubscriptionBase, Guid>(sub, e.OriginalEvent.EventId);
try
{
await EventAppeared(e, token, callback).ConfigureAwait(false);
}
catch (Exception ex)
{
Logger.ErrorEvent("AppearedException", ex, "Stream: [{Stream:l}] Position: {StreamPosition} {ExceptionType} - {ExceptionMessage}", e.Event.EventStreamId, e.Event.EventNumber, ex.GetType().Name, ex.Message);
sub.Fail(e, PersistentSubscriptionNakEventAction.Park, ex.GetType().Name);
// don't throw, stops subscription and causes reconnect
//throw;
}
}
private Task EventAppeared(EventStorePersistentSubscriptionBase eventStorePersistentSubscriptionBase,
ResolvedEvent resolvedEvent)
{
try
{
if (resolvedEvent.OriginalEvent.EventType.StartsWith("$$"))
{
return(Task.CompletedTask);
}
var data = DeserializeObject <CloudEventRequest>(resolvedEvent.OriginalEvent.Data);
if (data == null)
{
return(Task.CompletedTask);
}
foreach (var handler in _handlers)
{
handler(data, CancellationToken.None);
}
}
catch (Exception ex)
{
// any specific log must be catch before this point
Log.Error($"Error while processing: '{ex.GetBaseException().Message}' StackTrace: {ex.StackTrace}");
eventStorePersistentSubscriptionBase.Fail(resolvedEvent, PersistentSubscriptionNakEventAction.Park,
ex.GetBaseException().Message);
}
return(Task.CompletedTask);
}
public void Nack(ResolvedEvent[] events)
{
while (!Live)
{
Thread.Sleep(10);
}
_subscription.Fail(events, PersistentSubscriptionNakEventAction.Retry, "Failed to process");
}
private static async Task PushEventToProcessManager(AppFunc chain, IManageProcess processManager, DeSerializationResult evnt, IDictionary <string, object> environment, EventStorePersistentSubscriptionBase subscription)
{
if (!running)
{
return;
}
if (!evnt.Successful)
{
subscription.Fail(evnt.OriginalEvent, PersistentSubscriptionNakEventAction.Unknown, evnt.Error.Message);
return;
}
try
{
var requestEnvironment = new Dictionary <string, object>();
foreach (var item in environment)
{
requestEnvironment[item.Key] = item.Value;
}
var request = requestEnvironment.GetEventStoreRequest();
request.ProcessManager = processManager;
request.Event = evnt;
var correlationId = evnt.Metadata.Get(DefaultRepository.CorrelationIdKey, Guid.NewGuid().ToString());
using (requestEnvironment.OpenCorrelationContext(correlationId))
using (requestEnvironment.OpenCausationContext(evnt.EventId.ToString()))
{
await chain(requestEnvironment).ConfigureAwait(false);
}
subscription.Acknowledge(evnt.OriginalEvent);
}
catch (Exception ex)
{
environment.Log(ex, "Couldn't push event to processmanager: {0}", LogLevel.Error, processManager.ProcessName);
subscription.Fail(evnt.OriginalEvent, PersistentSubscriptionNakEventAction.Unknown, ex.Message);
}
}
private Task HandleEvent(EventStorePersistentSubscriptionBase sub, ResolvedEvent resolvedEvent, int?retryCount)
{
if (retryCount > 4)
{
_retryCount = retryCount;
sub.Acknowledge(resolvedEvent);
_resetEvent.Set();
}
else
{
sub.Fail(resolvedEvent, PersistentSubscriptionNakEventAction.Retry, "Not yet tried enough times");
}
return(Task.CompletedTask);
}
private void DoSomething(EventStorePersistentSubscriptionBase _, ResolvedEvent x)
{
var data = Encoding.ASCII.GetString(x.Event.Data);
try
{
Console.WriteLine(data);
var pictureInfo = JsonConvert.DeserializeObject <PictureInfo>(data);
AddToDB(pictureInfo);
_.Acknowledge(x);
}catch (Exception ex)
{
Console.Write(ex);
_.Fail(x, PersistentSubscriptionNakEventAction.Park, ex.Message);
}
}
void OnEvent(EventStorePersistentSubscriptionBase s, ResolvedEvent evnt)
{
concurrencyLimiter.Wait(cancellationToken);
var tokenSource = new CancellationTokenSource();
var pushContext = ToMessageContext(evnt, tokenSource);
if (pushContext == null) //system message
{
return;
}
var receiveTask = Task.Run(() =>
{
try
{
ExecutePipeline(s, evnt, pushContext, tokenSource).GetAwaiter().GetResult();
receiveCircuitBreaker.Success();
}
catch (Exception ex)
{
s.Fail(evnt, PersistentSubscriptionNakEventAction.Retry, "Unhandled exception");
receiveCircuitBreaker.Failure(ex).GetAwaiter().GetResult();
}
finally
{
concurrencyLimiter.Release();
}
}, tokenSource.Token).ContinueWith(t => tokenSource.Dispose());
runningReceiveTasks.TryAdd(receiveTask, receiveTask);
// We insert the original task into the runningReceiveTasks because we want to await the completion
// of the running receives. ExecuteSynchronously is a request to execute the continuation as part of
// the transition of the antecedents completion phase. This means in most of the cases the continuation
// will be executed during this transition and the antecedent task goes into the completion state only
// after the continuation is executed. This is not always the case. When the TPL thread handling the
// antecedent task is aborted the continuation will be scheduled. But in this case we don't need to await
// the continuation to complete because only really care about the receive operations. The final operation
// when shutting down is a clear of the running tasks anyway.
receiveTask.ContinueWith(t =>
{
Task toBeRemoved;
runningReceiveTasks.TryRemove(t, out toBeRemoved);
}, TaskContinuationOptions.ExecuteSynchronously);
}
public override Task NotAcknowledge(string?reason = null)
{
_eventStorePersistentSubscriptionBase?.Fail(ResolvedEvent, PersistentSubscriptionNakEventAction.Retry, reason);
return(Task.CompletedTask);
}
