/// <summary>
/// The main loop of a partition pump. It receives events from the Azure Event Hubs service
/// and delegates their processing to the event processor processing handlers.
/// </summary>
///
/// <param name="cancellationToken">A <see cref="CancellationToken"/> instance to signal the request to cancel the operation.</param>
///
/// <returns>A task to be resolved on when the operation has completed.</returns>
///
private async Task RunAsync(CancellationToken cancellationToken)
{
List <EventData> receivedEvents;
Exception unrecoverableException = null;
// We'll break from the loop upon encountering a non-retriable exception. The event processor periodically
// checks its pumps' status, so it should be aware of when one of them stops working.
while (!cancellationToken.IsCancellationRequested && unrecoverableException == null)
{
try
{
receivedEvents = (await InnerConsumer.ReceiveAsync(MaximumMessageCount, Options.MaximumReceiveWaitTime, cancellationToken).ConfigureAwait(false)).ToList();
using DiagnosticScope diagnosticScope = EventDataInstrumentation.ClientDiagnostics.CreateScope(DiagnosticProperty.EventProcessorProcessingActivityName);
diagnosticScope.AddAttribute("kind", "server");
if (diagnosticScope.IsEnabled)
{
foreach (var eventData in receivedEvents)
{
if (EventDataInstrumentation.TryExtractDiagnosticId(eventData, out string diagnosticId))
{
diagnosticScope.AddLink(diagnosticId);
}
}
}
// Small workaround to make sure we call ProcessEvent with EventData = null when no events have been received.
// The code is expected to get simpler when we start using the async enumerator internally to receive events.
if (receivedEvents.Count == 0)
{
receivedEvents.Add(null);
}
diagnosticScope.Start();
foreach (var eventData in receivedEvents)
{
try
{
var processorEvent = new EventProcessorEvent(Context, eventData, OwnerEventProcessor.UpdateCheckpointAsync);
await OwnerEventProcessor.ProcessEventAsync(processorEvent).ConfigureAwait(false);
}
catch (Exception eventProcessingException)
{
diagnosticScope.Failed(eventProcessingException);
unrecoverableException = eventProcessingException;
CloseReason = CloseReason.Exception;
break;
}
}
}
catch (Exception eventHubException)
{
// Stop running only if it's not a retriable exception.
if (RetryPolicy.CalculateRetryDelay(eventHubException, 1) == null)
{
unrecoverableException = eventHubException;
CloseReason = CloseReason.Exception;
break;
}
}
}
if (unrecoverableException != null)
{
// In case an exception is thrown by ProcessExceptionAsync, don't catch it and
// let the calling method (StopAsync) handle it.
var errorContext = new ProcessorErrorContext(Context.PartitionId, unrecoverableException);
await OwnerEventProcessor.ProcessExceptionAsync(errorContext).ConfigureAwait(false);
}
}
/// <summary>
/// The main loop of a partition pump. It receives events from the Azure Event Hubs service
/// and delegates their processing to the inner partition processor.
/// </summary>
///
/// <param name="cancellationToken">A <see cref="CancellationToken"/> instance to signal the request to cancel the operation.</param>
///
/// <returns>A task to be resolved on when the operation has completed.</returns>
///
private async Task RunAsync(CancellationToken cancellationToken)
{
IEnumerable <EventData> receivedEvents;
Exception unrecoverableException = null;
// We'll break from the loop upon encountering a non-retriable exception. The event processor periodically
// checks its pumps' status, so it should be aware of when one of them stops working.
while (!cancellationToken.IsCancellationRequested)
{
try
{
receivedEvents = await InnerConsumer.ReceiveAsync(MaximumMessageCount, Options.MaximumReceiveWaitTime, cancellationToken).ConfigureAwait(false);
using DiagnosticScope diagnosticScope = EventDataInstrumentation.ClientDiagnostics.CreateScope(DiagnosticProperty.EventProcessorProcessingActivityName);
diagnosticScope.AddAttribute("kind", "server");
if (diagnosticScope.IsEnabled)
{
foreach (var eventData in receivedEvents)
{
if (EventDataInstrumentation.TryExtractDiagnosticId(eventData, out string diagnosticId))
{
diagnosticScope.AddLink(diagnosticId);
}
}
}
diagnosticScope.Start();
try
{
await OwnerEventProcessor.ProcessEventsAsync(Context, receivedEvents).ConfigureAwait(false);
}
catch (Exception partitionProcessorException)
{
diagnosticScope.Failed(partitionProcessorException);
unrecoverableException = partitionProcessorException;
CloseReason = PartitionProcessorCloseReason.PartitionProcessorException;
break;
}
}
catch (Exception eventHubException)
{
// Stop running only if it's not a retriable exception.
if (RetryPolicy.CalculateRetryDelay(eventHubException, 1) == null)
{
unrecoverableException = eventHubException;
CloseReason = PartitionProcessorCloseReason.EventHubException;
break;
}
}
}
if (unrecoverableException != null)
{
// In case an exception is encountered while partition processor is processing the error, don't
// catch it and let the calling method (StopAsync) handle it.
await OwnerEventProcessor.ProcessExceptionAsync(Context, unrecoverableException).ConfigureAwait(false);
}
}