public async Task ProcessWithHeartbeat()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample04_ProcessWithHeartbeat
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
/*@@*/
/*@@*/ storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
/*@@*/ blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
/*@@*/
/*@@*/ eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
/*@@*/ eventHubName = eventHubScope.EventHubName;
/*@@*/ consumerGroup = eventHubScope.ConsumerGroups.First();
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var processorOptions = new EventProcessorClientOptions
{
MaximumWaitTime = TimeSpan.FromMilliseconds(250)
};
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
eventHubsConnectionString,
eventHubName,
processorOptions);
async Task processEventHandler(ProcessEventArgs args)
{
try
{
if (args.HasEvent)
{
await Application.ProcessEventAndCheckpointAsync(
args.Data,
args.Partition,
args.CancellationToken);
}
await Application.SendHeartbeatAsync(args.CancellationToken);
}
catch (Exception ex)
{
Application.HandleProcessingException(args, ex);
}
}
try
{
using var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
// The error handler is not relevant for this sample; for
// illustration, it is delegating the implementation to the
// host application.
processor.ProcessEventAsync += processEventHandler;
processor.ProcessErrorAsync += Application.ProcessorErrorHandler;
try
{
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take slightly longer than the length of
// time defined as part of the MaximumWaitTime configured
// for the processor; in this example, 250 milliseconds.
await processor.StopProcessingAsync();
}
}
catch
{
// If this block is invoked, then something external to the
// processor was the source of the exception.
}
finally
{
// It is encouraged that you unregister your handlers when you have
// finished using the Event Processor to ensure proper cleanup.
processor.ProcessEventAsync -= processEventHandler;
processor.ProcessErrorAsync -= Application.ProcessorErrorHandler;
}
#endregion
}
public async Task EventHandlerStopOnException()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample03_EventHandlerStopOnException
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
/*@@*/
/*@@*/ storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
/*@@*/ blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
/*@@*/
/*@@*/ eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
/*@@*/ eventHubName = eventHubScope.EventHubName;
/*@@*/ consumerGroup = eventHubScope.ConsumerGroups.First();
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
eventHubsConnectionString,
eventHubName);
// This token is used to control processing,
// if signaled, then processing will be stopped.
using var cancellationSource = new CancellationTokenSource();
/*@@*/ cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
Task processEventHandler(ProcessEventArgs args)
{
try
{
if (args.CancellationToken.IsCancellationRequested)
{
return(Task.CompletedTask);
}
// Process the event.
}
catch
{
// Handle the exception. If fatal,
// signal for cancellation.
cancellationSource.Cancel();
}
return(Task.CompletedTask);
}
Task processErrorHandler(ProcessErrorEventArgs args)
{
// Process the error, as appropriate for the
// application.
return(Task.CompletedTask);
}
try
{
processor.ProcessEventAsync += processEventHandler;
processor.ProcessErrorAsync += processErrorHandler;
try
{
// Once processing has started, the delay will
// block to allow processing until cancellation
// is requested.
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
finally
{
processor.ProcessEventAsync -= processEventHandler;
processor.ProcessErrorAsync -= processErrorHandler;
}
#endregion
}
public async Task BasicEventProcessing()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample04_BasicEventProcessing
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
/*@@*/
/*@@*/ storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
/*@@*/ blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
/*@@*/
/*@@*/ eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
/*@@*/ eventHubName = eventHubScope.EventHubName;
/*@@*/ consumerGroup = eventHubScope.ConsumerGroups.First();
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
eventHubsConnectionString,
eventHubName);
Task processEventHandler(ProcessEventArgs args)
{
try
{
if (args.CancellationToken.IsCancellationRequested)
{
return(Task.CompletedTask);
}
string partition = args.Partition.PartitionId;
byte[] eventBody = args.Data.EventBody.ToArray();
Debug.WriteLine($"Event from partition { partition } with length { eventBody.Length }.");
}
catch
{
// It is very important that you always guard against
// exceptions in your handler code; the processor does
// not have enough understanding of your code to
// determine the correct action to take. Any
// exceptions from your handlers go uncaught by
// the processor and will NOT be redirected to
// the error handler.
}
return(Task.CompletedTask);
}
Task processErrorHandler(ProcessErrorEventArgs args)
{
try
{
Debug.WriteLine("Error in the EventProcessorClient");
Debug.WriteLine($"\tOperation: { args.Operation }");
Debug.WriteLine($"\tException: { args.Exception }");
Debug.WriteLine("");
}
catch (Exception ex)
{
// It is very important that you always guard against
// exceptions in your handler code; the processor does
// not have enough understanding of your code to
// determine the correct action to take. Any
// exceptions from your handlers go uncaught by
// the processor and will NOT be handled in any
// way.
Application.HandleErrorException(args, ex);
}
return(Task.CompletedTask);
}
try
{
using var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
processor.ProcessEventAsync += processEventHandler;
processor.ProcessErrorAsync += processErrorHandler;
try
{
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
catch
{
// The processor will automatically attempt to recover from any
// failures, either transient or fatal, and continue processing.
// Errors in the processor's operation will be surfaced through
// its error handler.
//
// If this block is invoked, then something external to the
// processor was the source of the exception.
}
finally
{
// It is encouraged that you unregister your handlers when you have
// finished using the Event Processor to ensure proper cleanup. This
// is especially important when using lambda expressions or handlers
// in any form that may contain closure scopes or hold other references.
processor.ProcessEventAsync -= processEventHandler;
processor.ProcessErrorAsync -= processErrorHandler;
}
#endregion
}
public async Task ProcessByBatch()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample04_ProcessByBatch
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
/*@@*/
/*@@*/ storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
/*@@*/ blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
/*@@*/
/*@@*/ eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
/*@@*/ eventHubName = eventHubScope.EventHubName;
/*@@*/ consumerGroup = eventHubScope.ConsumerGroups.First();
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
eventHubsConnectionString,
eventHubName);
const int EventsInBatch = 50;
var partitionEventBatches = new ConcurrentDictionary <string, List <EventData> >();
var checkpointNeeded = false;
async Task processEventHandler(ProcessEventArgs args)
{
try
{
string partition = args.Partition.PartitionId;
List <EventData> partitionBatch =
partitionEventBatches.GetOrAdd(
partition,
new List <EventData>());
partitionBatch.Add(args.Data);
if (partitionBatch.Count >= EventsInBatch)
{
await Application.ProcessEventBatchAsync(
partitionBatch,
args.Partition,
args.CancellationToken);
checkpointNeeded = true;
partitionBatch.Clear();
}
if (checkpointNeeded)
{
await args.UpdateCheckpointAsync();
checkpointNeeded = false;
}
}
catch (Exception ex)
{
Application.HandleProcessingException(args, ex);
}
}
try
{
using var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
// The error handler is not relevant for this sample; for
// illustration, it is delegating the implementation to the
// host application.
processor.ProcessEventAsync += processEventHandler;
processor.ProcessErrorAsync += Application.ProcessorErrorHandler;
try
{
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
catch
{
// If this block is invoked, then something external to the
// processor was the source of the exception.
}
finally
{
// It is encouraged that you unregister your handlers when you have
// finished using the Event Processor to ensure proper cleanup.
processor.ProcessEventAsync -= processEventHandler;
processor.ProcessErrorAsync -= Application.ProcessorErrorHandler;
}
#endregion
}
public async Task CheckpointByEventCount()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample04_CheckpointByEventCount
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
/*@@*/
/*@@*/ storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
/*@@*/ blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
/*@@*/
/*@@*/ eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
/*@@*/ eventHubName = eventHubScope.EventHubName;
/*@@*/ consumerGroup = eventHubScope.ConsumerGroups.First();
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
eventHubsConnectionString,
eventHubName);
const int EventsBeforeCheckpoint = 25;
var partitionEventCount = new ConcurrentDictionary <string, int>();
async Task processEventHandler(ProcessEventArgs args)
{
try
{
await Application.ProcessEventAsync(
args.Data,
args.Partition,
args.CancellationToken);
// If the number of events that have been processed
// since the last checkpoint was created exceeds the
// checkpointing threshold, a new checkpoint will be
// created and the count reset.
string partition = args.Partition.PartitionId;
int eventsSinceLastCheckpoint = partitionEventCount.AddOrUpdate(
key: partition,
addValue: 1,
updateValueFactory: (_, currentCount) => currentCount + 1);
if (eventsSinceLastCheckpoint >= EventsBeforeCheckpoint)
{
await args.UpdateCheckpointAsync();
partitionEventCount[partition] = 0;
}
}
catch (Exception ex)
{
Application.HandleProcessingException(args, ex);
}
}
try
{
using var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
// The error handler is not relevant for this sample; for
// illustration, it is delegating the implementation to the
// host application.
processor.ProcessEventAsync += processEventHandler;
processor.ProcessErrorAsync += Application.ProcessorErrorHandler;
try
{
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
catch
{
// If this block is invoked, then something external to the
// processor was the source of the exception.
}
finally
{
// It is encouraged that you unregister your handlers when you have
// finished using the Event Processor to ensure proper cleanup
processor.ProcessEventAsync -= processEventHandler;
processor.ProcessErrorAsync -= Application.ProcessorErrorHandler;
}
#endregion
}
public async Task InitializePartition()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample04_InitializePartition
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
/*@@*/
/*@@*/ storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
/*@@*/ blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
/*@@*/
/*@@*/ eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
/*@@*/ eventHubName = eventHubScope.EventHubName;
/*@@*/ consumerGroup = eventHubScope.ConsumerGroups.First();
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
eventHubsConnectionString,
eventHubName);
Task initializeEventHandler(PartitionInitializingEventArgs args)
{
try
{
if (args.CancellationToken.IsCancellationRequested)
{
return(Task.CompletedTask);
}
// If no checkpoint was found, start processing
// events enqueued now or in the future.
EventPosition startPositionWhenNoCheckpoint =
EventPosition.FromEnqueuedTime(DateTimeOffset.UtcNow);
args.DefaultStartingPosition = startPositionWhenNoCheckpoint;
}
catch (Exception ex)
{
Application.HandleInitializeException(args, ex);
}
return(Task.CompletedTask);
}
try
{
using var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
// The event handlers for processing events and errors are
// not relevant for this sample; for illustration, they're
// delegating the implementation to the host application.
processor.PartitionInitializingAsync += initializeEventHandler;
processor.ProcessEventAsync += Application.ProcessorEventHandler;
processor.ProcessErrorAsync += Application.ProcessorErrorHandler;
try
{
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
catch
{
// If this block is invoked, then something external to the
// processor was the source of the exception.
}
finally
{
// It is encouraged that you unregister your handlers when you have
// finished using the Event Processor to ensure proper cleanup
processor.PartitionInitializingAsync -= initializeEventHandler;
processor.ProcessEventAsync -= Application.ProcessorEventHandler;
processor.ProcessErrorAsync -= Application.ProcessorErrorHandler;
}
#endregion
}
public async Task SharedAccessSignature()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample05_SharedAccessSignature
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
/*@@*/
/*@@*/ storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
/*@@*/ blobContainerName = storageScope.ContainerName;
var credential = new AzureSasCredential("<< SHARED ACCESS KEY STRING >>");
var fullyQualifiedNamespace = "<< NAMESPACE (likely similar to {your-namespace}.servicebus.windows.net) >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
/*@@*/
/*@@*/ fullyQualifiedNamespace = EventHubsTestEnvironment.Instance.FullyQualifiedNamespace;
/*@@*/ eventHubName = eventHubScope.EventHubName;
/*@@*/ consumerGroup = eventHubScope.ConsumerGroups.First();
/*@@*/
/*@@*/ var resource = $"amqps://{ EventHubsTestEnvironment.Instance.FullyQualifiedNamespace }/{ eventHubScope.EventHubName }".ToLowerInvariant();
/*@@*/ var signature = new SharedAccessSignature(resource, EventHubsTestEnvironment.Instance.SharedAccessKeyName, EventHubsTestEnvironment.Instance.SharedAccessKey);
/*@@*/ credential = new AzureSasCredential(signature.Value);
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
fullyQualifiedNamespace,
eventHubName,
credential);
try
{
using var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
// The event handlers are not relevant for this sample; for
// illustration, they're delegating the implementation to the
// host application.
processor.ProcessEventAsync += Application.ProcessorEventHandler;
processor.ProcessErrorAsync += Application.ProcessorErrorHandler;
try
{
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
catch
{
// If this block is invoked, then something external to the
// processor was the source of the exception.
}
finally
{
// It is encouraged that you unregister your handlers when you have
// finished using the Event Processor to ensure proper cleanup.
processor.ProcessEventAsync -= Application.ProcessorEventHandler;
processor.ProcessErrorAsync -= Application.ProcessorErrorHandler;
}
#endregion
}
public async Task ConnectionStringParse()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample05_ConnectionStringParse
#if SNIPPET
var credential = new DefaultAzureCredential();
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
#else
var credential = EventHubsTestEnvironment.Instance.Credential;
var eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
var eventHubName = eventHubScope.EventHubName;
var consumerGroup = eventHubScope.ConsumerGroups.First();
var storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
var blobContainerName = storageScope.ContainerName;
#endif
var storageEndpoint = new BlobServiceClient(storageConnectionString).Uri;
var blobUriBuilder = new BlobUriBuilder(storageEndpoint)
{
BlobContainerName = blobContainerName
};
var storageClient = new BlobContainerClient(
blobUriBuilder.ToUri(),
credential);
EventHubsConnectionStringProperties properties =
EventHubsConnectionStringProperties.Parse(eventHubsConnectionString);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
properties.FullyQualifiedNamespace,
properties.EventHubName ?? eventHubName,
credential);
try
{
using var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
// The event handlers are not relevant for this sample; for
// illustration, they're delegating the implementation to the
// host application.
processor.ProcessEventAsync += Application.ProcessorEventHandler;
processor.ProcessErrorAsync += Application.ProcessorErrorHandler;
try
{
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
catch
{
// If this block is invoked, then something external to the
// processor was the source of the exception.
}
finally
{
// It is encouraged that you unregister your handlers when you have
// finished using the Event Processor to ensure proper cleanup.
processor.ProcessEventAsync -= Application.ProcessorEventHandler;
processor.ProcessErrorAsync -= Application.ProcessorErrorHandler;
}
#endregion
}
public async Task ProcessByBatch()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample07_ProcessByBatch_Usage
#if SNIPPET
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
#else
var storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
var blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
var eventHubName = eventHubScope.EventHubName;
var consumerGroup = eventHubScope.ConsumerGroups.First();
#endif
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var checkpointStore = new BlobCheckpointStore(storageClient);
var maximumBatchSize = 100;
var processor = new SimpleBatchProcessor(
checkpointStore,
maximumBatchSize,
consumerGroup,
eventHubsConnectionString,
eventHubName);
using var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
// There are no event handlers to set for the processor. All logic
// normally associated with the processor event handlers is
// implemented directly via method override in the custom processor.
try
{
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// Stopping may take up to the length of time defined
// as the TryTimeout configured for the processor;
// By default, this is 60 seconds.
await processor.StopProcessingAsync();
}
#endregion
}
public async Task ProcessUntilCanceled()
{
await using var eventHubScope = await EventHubScope.CreateAsync(2);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_ReadMe_ProcessUntilCanceled
var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(45));
#if SNIPPET
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
#else
var storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
var blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
var eventHubName = eventHubScope.EventHubName;
var consumerGroup = eventHubScope.ConsumerGroups.First();
#endif
Task processEventHandler(ProcessEventArgs eventArgs) => Task.CompletedTask;
Task processErrorHandler(ProcessErrorEventArgs eventArgs) => Task.CompletedTask;
var storageClient = new BlobContainerClient(storageConnectionString, blobContainerName);
var processor = new EventProcessorClient(storageClient, consumerGroup, eventHubsConnectionString, eventHubName);
processor.ProcessEventAsync += processEventHandler;
processor.ProcessErrorAsync += processErrorHandler;
await processor.StartProcessingAsync();
try
{
// The processor performs its work in the background; block until cancellation
// to allow processing to take place.
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected when the delay is canceled.
}
try
{
await processor.StopProcessingAsync();
}
finally
{
// To prevent leaks, the handlers should be removed when processing is complete.
processor.ProcessEventAsync -= processEventHandler;
processor.ProcessErrorAsync -= processErrorHandler;
}
#endregion
}
public async Task ProcessEvents()
{
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample01_ProcessEvents
#if SNIPPET
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
#else
var storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
var blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
var eventHubName = _eventHubScope.EventHubName;
var consumerGroup = _eventHubScope.ConsumerGroups.First();
#endif
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
eventHubsConnectionString,
eventHubName);
var partitionEventCount = new ConcurrentDictionary <string, int>();
async Task processEventHandler(ProcessEventArgs args)
{
try
{
// If the cancellation token is signaled, then the
// processor has been asked to stop. It will invoke
// this handler with any events that were in flight;
// these will not be lost if not processed.
//
// It is up to the handler to decide whether to take
// action to process the event or to cancel immediately.
if (args.CancellationToken.IsCancellationRequested)
{
return;
}
string partition = args.Partition.PartitionId;
byte[] eventBody = args.Data.EventBody.ToArray();
Debug.WriteLine($"Event from partition { partition } with length { eventBody.Length }.");
int eventsSinceLastCheckpoint = partitionEventCount.AddOrUpdate(
key: partition,
addValue: 1,
updateValueFactory: (_, currentCount) => currentCount + 1);
if (eventsSinceLastCheckpoint >= 50)
{
await args.UpdateCheckpointAsync();
partitionEventCount[partition] = 0;
}
}
catch
{
// It is very important that you always guard against
// exceptions in your handler code; the processor does
// not have enough understanding of your code to
// determine the correct action to take. Any
// exceptions from your handlers go uncaught by
// the processor and will NOT be redirected to
// the error handler.
}
}
Task processErrorHandler(ProcessErrorEventArgs args)
{
try
{
Debug.WriteLine("Error in the EventProcessorClient");
Debug.WriteLine($"\tOperation: { args.Operation }");
Debug.WriteLine($"\tException: { args.Exception }");
Debug.WriteLine("");
}
catch
{
// It is very important that you always guard against
// exceptions in your handler code; the processor does
// not have enough understanding of your code to
// determine the correct action to take. Any
// exceptions from your handlers go uncaught by
// the processor and will NOT be handled in any
// way.
}
return(Task.CompletedTask);
}
try
{
using var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
processor.ProcessEventAsync += processEventHandler;
processor.ProcessErrorAsync += processErrorHandler;
try
{
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
catch
{
// The processor will automatically attempt to recover from any
// failures, either transient or fatal, and continue processing.
// Errors in the processor's operation will be surfaced through
// its error handler.
//
// If this block is invoked, then something external to the
// processor was the source of the exception.
}
finally
{
// It is encouraged that you unregister your handlers when you have
// finished using the Event Processor to ensure proper cleanup. This
// is especially important when using lambda expressions or handlers
// in any form that may contain closure scopes or hold other references.
processor.ProcessEventAsync -= processEventHandler;
processor.ProcessErrorAsync -= processErrorHandler;
}
#endregion
}
public async Task ClaimOwnershipAsyncReturnsOnlyTheSuccessfullyClaimedOwnership()
{
await using (var storageScope = await StorageScope.CreateAsync())
{
var storageConnectionString = StorageTestEnvironment.StorageConnectionString;
var containerClient = new BlobContainerClient(storageConnectionString, storageScope.ContainerName);
var partitionManager = new BlobPartitionManager(containerClient);
var ownershipList = new List <PartitionOwnership>();
var ownershipCount = 5;
for (int i = 0; i < ownershipCount; i++)
{
ownershipList.Add(
new MockPartitionOwnership
(
"eventHubName",
"consumerGroup",
"ownerIdentifier",
$"partitionId_{ i }"
));
}
await partitionManager.ClaimOwnershipAsync(ownershipList);
// The ETags must have been set by the partition manager.
var eTags = ownershipList.Select(ownership => ownership.ETag).ToList();
ownershipList.Clear();
// Use a valid eTag when 'i' is odd. This way, we can expect 'ownershipCount / 2' successful
// claims (rounded down).
var expectedClaimedCount = ownershipCount / 2;
for (int i = 0; i < ownershipCount; i++)
{
ownershipList.Add(
new MockPartitionOwnership
(
"eventHubName",
"consumerGroup",
"ownerIdentifier",
$"partitionId_{ i }",
offset: i,
eTag: i % 2 == 1 ? eTags[i] : null
));
}
var claimedOwnershipList = await partitionManager.ClaimOwnershipAsync(ownershipList);
var expectedOwnership = ownershipList.Where(ownership => ownership.Offset % 2 == 1);
Assert.That(claimedOwnershipList, Is.Not.Null);
Assert.That(claimedOwnershipList.Count, Is.EqualTo(expectedClaimedCount));
var index = 0;
foreach (var ownership in claimedOwnershipList.OrderBy(ownership => ownership.PartitionId))
{
Assert.That(ownership.IsEquivalentTo(expectedOwnership.ElementAt(index)), Is.True, $"Ownership of partition '{ ownership.PartitionId }' should be equivalent.");
++index;
}
}
}
public async Task ErrorHandlerCancellationRecovery()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample03_ErrorHandlerCancellationRecovery
#if SNIPPET
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
#else
var storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
var blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
var eventHubName = eventHubScope.EventHubName;
var consumerGroup = eventHubScope.ConsumerGroups.First();
#endif
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
eventHubsConnectionString,
eventHubName);
// This token is used to control processing,
// if signaled, then processing will be stopped.
using var cancellationSource = new CancellationTokenSource();
#if !SNIPPET
cancellationSource.CancelAfter(TimeSpan.FromSeconds(10));
#endif
Task processEventHandler(ProcessEventArgs args)
{
try
{
// TODO:
// Process the event according to application needs.
}
catch
{
// TODO:
// Take action to handle the exception.
//
// It is important that all exceptions are
// handled and none are permitted to bubble up.
}
return(Task.CompletedTask);
}
async Task processErrorHandler(ProcessErrorEventArgs args)
{
try
{
// Always log the exception.
Debug.WriteLine("Error in the EventProcessorClient");
Debug.WriteLine($"\tOperation: { args.Operation ?? "Unknown" }");
Debug.WriteLine($"\tPartition: { args.PartitionId ?? "None" }");
Debug.WriteLine($"\tException: { args.Exception }");
Debug.WriteLine("");
// If cancellation was requested, assume that
// it was in response to an application request
// and take no action.
if (args.CancellationToken.IsCancellationRequested)
{
return;
}
// Allow the application to handle the exception according to
// its business logic.
await HandleExceptionAsync(args.Exception, args.CancellationToken);
}
catch
{
// Handle the exception. If fatal, signal
// for cancellation.
}
}
try
{
processor.ProcessEventAsync += processEventHandler;
processor.ProcessErrorAsync += processErrorHandler;
try
{
// Once processing has started, the delay will
// block to allow processing until cancellation
// is requested.
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
finally
{
processor.ProcessEventAsync -= processEventHandler;
processor.ProcessErrorAsync -= processErrorHandler;
}
#endregion
}
public async Task ErrorHandlerCancellationRecovery()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample03_ErrorHandlerCancellationRecovery
var storageConnectionString = "<< CONNECTION STRING FOR THE STORAGE ACCOUNT >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
/*@@*/
/*@@*/ storageConnectionString = StorageTestEnvironment.Instance.StorageConnectionString;
/*@@*/ blobContainerName = storageScope.ContainerName;
var eventHubsConnectionString = "<< CONNECTION STRING FOR THE EVENT HUBS NAMESPACE >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
/*@@*/
/*@@*/ eventHubsConnectionString = EventHubsTestEnvironment.Instance.EventHubsConnectionString;
/*@@*/ eventHubName = eventHubScope.EventHubName;
/*@@*/ consumerGroup = eventHubScope.ConsumerGroups.First();
var storageClient = new BlobContainerClient(
storageConnectionString,
blobContainerName);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
eventHubsConnectionString,
eventHubName);
// This token is used to control processing,
// if signaled, then processing will be stopped.
using var cancellationSource = new CancellationTokenSource();
/*@@*/ cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
Task processEventHandler(ProcessEventArgs args)
{
try
{
// Process the event.
}
catch
{
// Handle the exception.
}
return(Task.CompletedTask);
}
async Task processErrorHandler(ProcessErrorEventArgs args)
{
try
{
// Always log the exception.
Debug.WriteLine("Error in the EventProcessorClient");
Debug.WriteLine($"\tOperation: { args.Operation ?? "Unknown" }");
Debug.WriteLine($"\tPartition: { args.PartitionId ?? "None" }");
Debug.WriteLine($"\tException: { args.Exception }");
Debug.WriteLine("");
// If cancellation was requested, assume that
// it was in response to an application request
// and take no action.
if (args.CancellationToken.IsCancellationRequested)
{
return;
}
// If out of memory, signal for cancellation.
if (args.Exception is OutOfMemoryException)
{
cancellationSource.Cancel();
return;
}
// If processing stopped and this handler determined
// the error to be non-fatal, restart processing.
if ((!processor.IsRunning) &&
(!cancellationSource.IsCancellationRequested))
{
// To be safe, request that processing stop before
// requesting the start; this will ensure that any
// processor state is fully reset.
await processor.StopProcessingAsync();
await processor.StartProcessingAsync(cancellationSource.Token);
}
}
catch
{
// Handle the exception. If fatal, signal
// for cancellation.
}
}
try
{
processor.ProcessEventAsync += processEventHandler;
processor.ProcessErrorAsync += processErrorHandler;
try
{
// Once processing has started, the delay will
// block to allow processing until cancellation
// is requested.
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
finally
{
processor.ProcessEventAsync -= processEventHandler;
processor.ProcessErrorAsync -= processErrorHandler;
}
#endregion
}
public async Task DefaultAzureCredential()
{
await using var eventHubScope = await EventHubScope.CreateAsync(1);
await using var storageScope = await StorageScope.CreateAsync();
#region Snippet:EventHubs_Processor_Sample05_DefaultAzureCredential
TokenCredential credential = new DefaultAzureCredential();
var storageEndpoint = "<< STORAGE ENDPOINT (likely similar to {your-account}.blob.core.windows.net) >>";
var blobContainerName = "<< NAME OF THE BLOB CONTAINER >>";
/*@@*/
/*@@*/ storageEndpoint = new BlobServiceClient(StorageTestEnvironment.Instance.StorageConnectionString).Uri.ToString();
/*@@*/ blobContainerName = storageScope.ContainerName;
var fullyQualifiedNamespace = "<< NAMESPACE (likely similar to {your-namespace}.servicebus.windows.net) >>";
var eventHubName = "<< NAME OF THE EVENT HUB >>";
var consumerGroup = "<< NAME OF THE EVENT HUB CONSUMER GROUP >>";
/*@@*/
/*@@*/ fullyQualifiedNamespace = EventHubsTestEnvironment.Instance.FullyQualifiedNamespace;
/*@@*/ eventHubName = eventHubScope.EventHubName;
/*@@*/ consumerGroup = eventHubScope.ConsumerGroups.First();
/*@@*/ credential = EventHubsTestEnvironment.Instance.Credential;
var blobUriBuilder = new BlobUriBuilder(new Uri(storageEndpoint));
blobUriBuilder.BlobContainerName = blobContainerName;
var storageClient = new BlobContainerClient(
blobUriBuilder.ToUri(),
credential);
var processor = new EventProcessorClient(
storageClient,
consumerGroup,
fullyQualifiedNamespace,
eventHubName,
credential);
try
{
using var cancellationSource = new CancellationTokenSource();
cancellationSource.CancelAfter(TimeSpan.FromSeconds(30));
// The event handlers are not relevant for this sample; for
// illustration, they're delegating the implementation to the
// host application.
processor.ProcessEventAsync += Application.ProcessorEventHandler;
processor.ProcessErrorAsync += Application.ProcessorErrorHandler;
try
{
await processor.StartProcessingAsync(cancellationSource.Token);
await Task.Delay(Timeout.Infinite, cancellationSource.Token);
}
catch (TaskCanceledException)
{
// This is expected if the cancellation token is
// signaled.
}
finally
{
// This may take up to the length of time defined
// as part of the configured TryTimeout of the processor;
// by default, this is 60 seconds.
await processor.StopProcessingAsync();
}
}
catch
{
// If this block is invoked, then something external to the
// processor was the source of the exception.
}
finally
{
// It is encouraged that you unregister your handlers when you have
// finished using the Event Processor to ensure proper cleanup.
processor.ProcessEventAsync -= Application.ProcessorEventHandler;
processor.ProcessErrorAsync -= Application.ProcessorErrorHandler;
}
#endregion
}
public async Task FixtureSetUp()
{
_eventHubScope = await EventHubScope.CreateAsync(2);
_storageScope = await StorageScope.CreateAsync();
}
/// <summary> /// Requests creation of an Azure storage account to use for a specific test run, /// transforming the asynchronous request into a synchronous one that can be used with /// lazy instantiation. /// </summary> /// /// <returns>The active Azure storage account for this test run./returns> /// private static StorageScope.StorageProperties CreateStorageAccount() => Task .Run(async() => await StorageScope.CreateStorageAccountAsync().ConfigureAwait(false)) .ConfigureAwait(false) .GetAwaiter() .GetResult();
