public async Task Dispatch(TransportOperations outgoingMessages, TransportTransaction transaction, ContextBag context)
{
try
{
foreach (var unicastMessage in outgoingMessages.UnicastTransportOperations)
{
var sqsTransportMessage = new SqsTransportMessage(unicastMessage.Message, unicastMessage.DeliveryConstraints);
var serializedMessage = JsonConvert.SerializeObject(sqsTransportMessage);
if (serializedMessage.Length > 256 * 1024)
{
if (string.IsNullOrEmpty(ConnectionConfiguration.S3BucketForLargeMessages))
{
throw new InvalidOperationException("Cannot send large message because no S3 bucket was configured. Add an S3 bucket name to your configuration.");
}
var key = ConnectionConfiguration.S3KeyPrefix + "/" + unicastMessage.Message.MessageId;
await S3Client.PutObjectAsync(new Amazon.S3.Model.PutObjectRequest
{
BucketName = ConnectionConfiguration.S3BucketForLargeMessages,
InputStream = new MemoryStream(unicastMessage.Message.Body),
Key = key
}).ConfigureAwait(false);
sqsTransportMessage.S3BodyKey = key;
sqsTransportMessage.Body = String.Empty;
serializedMessage = JsonConvert.SerializeObject(sqsTransportMessage);
}
try
{
await SendMessage(serializedMessage,
unicastMessage.Destination,
unicastMessage.DeliveryConstraints).ConfigureAwait(false);
}
catch (QueueDoesNotExistException)
{
await QueueCreator.CreateQueueIfNecessary(unicastMessage.Destination).ConfigureAwait(false);
await SendMessage(serializedMessage,
unicastMessage.Destination,
unicastMessage.DeliveryConstraints).ConfigureAwait(false);
}
}
}
catch (Exception e)
{
Logger.Error("Exception from Send.", e);
throw;
}
}
public void Send(TransportMessage message, SendOptions sendOptions)
{
try
{
var sqsTransportMessage = new SqsTransportMessage(message, sendOptions);
var serializedMessage = JsonConvert.SerializeObject(sqsTransportMessage);
if (serializedMessage.Length > 256 * 1024)
{
if (string.IsNullOrEmpty(ConnectionConfiguration.S3BucketForLargeMessages))
{
throw new InvalidOperationException("Cannot send large message because no S3 bucket was configured. Add an S3 bucket name to your configuration.");
}
var key = ConnectionConfiguration.S3KeyPrefix + "/" + message.Id;
S3Client.PutObject(new Amazon.S3.Model.PutObjectRequest
{
BucketName = ConnectionConfiguration.S3BucketForLargeMessages,
InputStream = new MemoryStream(message.Body),
Key = key
});
sqsTransportMessage.S3BodyKey = key;
sqsTransportMessage.Body = String.Empty;
serializedMessage = JsonConvert.SerializeObject(sqsTransportMessage);
}
try
{
SendMessage(serializedMessage, sendOptions);
}
catch (QueueDoesNotExistException)
{
QueueCreator.CreateQueueIfNecessary(sendOptions.Destination, "");
SendMessage(serializedMessage, sendOptions);
}
}
catch (Exception e)
{
Logger.Error("Exception from Send.", e);
throw;
}
}
async Task DeleteMessage(IAmazonSQS sqs,
IAmazonS3 s3,
Message message,
SqsTransportMessage sqsTransportMessage,
IncomingMessage incomingMessage)
{
await sqs.DeleteMessageAsync(_queueUrl, message.ReceiptHandle, _cancellationTokenSource.Token).ConfigureAwait(false);
if (sqsTransportMessage != null)
{
if (!String.IsNullOrEmpty(sqsTransportMessage.S3BodyKey))
{
try
{
await s3.DeleteObjectAsync(
new DeleteObjectRequest
{
BucketName = ConnectionConfiguration.S3BucketForLargeMessages,
Key = ConnectionConfiguration.S3KeyPrefix + incomingMessage.MessageId
},
_cancellationTokenSource.Token).ConfigureAwait(false);
}
catch (Exception ex)
{
// If deleting the message body from S3 fails, we don't
// want the exception to make its way through to the _endProcessMessage below,
// as the message has been successfully processed and deleted from the SQS queue
// and effectively doesn't exist anymore.
// It doesn't really matter, as S3 is configured to delete message body data
// automatically after a certain period of time.
Logger.Warn("Couldn't delete message body from S3. Message body data will be aged out by the S3 lifecycle policy when the TTL expires.", ex);
}
}
}
else
{
Logger.Warn("Couldn't delete message body from S3 because the SqsTransportMessage was null. Message body data will be aged out by the S3 lifecycle policy when the TTL expires.");
}
}
private void DeleteMessage(IAmazonSQS sqs,
IAmazonS3 s3,
Message message,
SqsTransportMessage sqsTransportMessage,
TransportMessage transportMessage)
{
sqs.DeleteMessage(_queueUrl, message.ReceiptHandle);
if (!String.IsNullOrEmpty(sqsTransportMessage.S3BodyKey))
{
// Delete the S3 body asynchronously.
// We don't really care too much if this call succeeds or fails - if it fails,
// the S3 bucket lifecycle configuration will eventually delete the message anyway.
// So, we can get better performance by not waiting around for this call to finish.
var s3DeleteTask = s3.DeleteObjectAsync(
new DeleteObjectRequest
{
BucketName = ConnectionConfiguration.S3BucketForLargeMessages,
Key = ConnectionConfiguration.S3KeyPrefix + transportMessage.Id
});
s3DeleteTask.ContinueWith(t =>
{
if (t.Exception != null)
{
// If deleting the message body from S3 fails, we don't
// want the exception to make its way through to the _endProcessMessage below,
// as the message has been successfully processed and deleted from the SQS queue
// and effectively doesn't exist anymore.
// It doesn't really matter, as S3 is configured to delete message body data
// automatically after a certain period of time.
Logger.Warn("Couldn't delete message body from S3. Message body data will be aged out at a later time.", t.Exception);
}
});
}
}
async Task ConsumeMessages()
{
while (!_cancellationTokenSource.IsCancellationRequested)
{
try
{
var receiveResult = await SqsClient.ReceiveMessageAsync(new ReceiveMessageRequest
{
MaxNumberOfMessages = 10,
QueueUrl = _queueUrl,
WaitTimeSeconds = 20,
AttributeNames = new List <String> {
"SentTimestamp"
}
},
_cancellationTokenSource.Token).ConfigureAwait(false);
var tasks = receiveResult.Messages.Select(async message =>
{
IncomingMessage incomingMessage = null;
SqsTransportMessage sqsTransportMessage = null;
TransportTransaction transportTransaction = new TransportTransaction();
ContextBag contextBag = new ContextBag();
var messageProcessedOk = false;
var messageExpired = false;
var isPoisonMessage = false;
var errorHandled = false;
try
{
sqsTransportMessage = JsonConvert.DeserializeObject <SqsTransportMessage>(message.Body);
incomingMessage = await sqsTransportMessage.ToIncomingMessage(S3Client,
ConnectionConfiguration,
_cancellationTokenSource.Token).ConfigureAwait(false);
}
catch (Exception ex)
{
// Can't deserialize. This is a poison message
Logger.Warn($"Deleting poison message with SQS Message Id {message.MessageId} due to exception {ex}");
isPoisonMessage = true;
}
if (incomingMessage == null || sqsTransportMessage == null)
{
Logger.Warn($"Deleting poison message with SQS Message Id {message.MessageId}");
isPoisonMessage = true;
}
if (isPoisonMessage)
{
await DeleteMessage(SqsClient,
S3Client,
message,
sqsTransportMessage,
incomingMessage).ConfigureAwait(false);
}
else
{
// Check that the message hasn't expired
string rawTtbr;
if (incomingMessage.Headers.TryGetValue(SqsTransportHeaders.TimeToBeReceived, out rawTtbr))
{
incomingMessage.Headers.Remove(SqsTransportHeaders.TimeToBeReceived);
var timeToBeReceived = TimeSpan.Parse(rawTtbr);
if (timeToBeReceived != TimeSpan.MaxValue)
{
var sentDateTime = message.GetSentDateTime();
var utcNow = DateTime.UtcNow;
if (sentDateTime + timeToBeReceived <= utcNow)
{
// Message has expired.
Logger.Warn($"Discarding expired message with Id {incomingMessage.MessageId}");
messageExpired = true;
}
}
}
if (!messageExpired)
{
int immediateProcessingAttempts = 0;
while (!errorHandled && !messageProcessedOk)
{
try
{
await _maxConcurrencySempahore
.WaitAsync(_cancellationTokenSource.Token)
.ConfigureAwait(false);
using (var messageContextCancellationTokenSource =
new CancellationTokenSource())
{
var messageContext = new MessageContext(
incomingMessage.MessageId,
incomingMessage.Headers,
incomingMessage.Body,
transportTransaction,
messageContextCancellationTokenSource,
contextBag);
await _onMessage(messageContext)
.ConfigureAwait(false);
messageProcessedOk = !messageContextCancellationTokenSource.IsCancellationRequested;
}
}
catch (Exception ex)
when(!(ex is OperationCanceledException && _cancellationTokenSource.IsCancellationRequested))
{
immediateProcessingAttempts++;
var errorHandlerResult = ErrorHandleResult.RetryRequired;
try
{
errorHandlerResult = await _onError(new ErrorContext(ex,
incomingMessage.Headers,
incomingMessage.MessageId,
incomingMessage.Body,
transportTransaction,
immediateProcessingAttempts)).ConfigureAwait(false);
}
catch (Exception onErrorEx)
{
Logger.Error("Exception thrown from error handler", onErrorEx);
}
errorHandled = errorHandlerResult == ErrorHandleResult.Handled;
}
finally
{
_maxConcurrencySempahore.Release();
}
}
}
// Always delete the message from the queue.
// If processing failed, the _onError handler will have moved the message
// to a retry queue.
await DeleteMessage(SqsClient, S3Client, message, sqsTransportMessage, incomingMessage).ConfigureAwait(false);
}
});
await Task.WhenAll(tasks).ConfigureAwait(false);
}
catch (Exception ex)
when(!(ex is OperationCanceledException && _cancellationTokenSource.IsCancellationRequested))
{
Logger.Error("Exception thrown when consuming messages", ex);
}
}// while
}
void ConsumeMessages()
{
_tracksRunningThreads.Wait(TimeSpan.FromSeconds(1));
try
{
while (!_cancellationTokenSource.IsCancellationRequested)
{
Exception exception = null;
var receiveTask = SqsClient.ReceiveMessageAsync(new ReceiveMessageRequest
{
MaxNumberOfMessages = ConnectionConfiguration.MaxReceiveMessageBatchSize,
QueueUrl = _queueUrl,
WaitTimeSeconds = 20,
AttributeNames = new List <String> {
"SentTimestamp"
}
},
_cancellationTokenSource.Token);
receiveTask.Wait(_cancellationTokenSource.Token);
foreach (var message in receiveTask.Result.Messages)
{
TransportMessage transportMessage = null;
SqsTransportMessage sqsTransportMessage = null;
var messageProcessedOk = false;
var messageExpired = false;
try
{
sqsTransportMessage = JsonConvert.DeserializeObject <SqsTransportMessage>(message.Body);
transportMessage = sqsTransportMessage.ToTransportMessage(S3Client, ConnectionConfiguration);
// Check that the message hasn't expired
if (transportMessage.TimeToBeReceived != TimeSpan.MaxValue)
{
var sentDateTime = message.GetSentDateTime();
if (sentDateTime + transportMessage.TimeToBeReceived <= DateTime.UtcNow)
{
// Message has expired.
Logger.Warn(String.Format("Discarding expired message with Id {0}", transportMessage.Id));
messageExpired = true;
}
}
if (!messageExpired)
{
messageProcessedOk = _tryProcessMessage(transportMessage);
}
}
catch (Exception ex)
{
exception = ex;
}
finally
{
var deleteMessage = !_isTransactional || (_isTransactional && messageProcessedOk);
if (deleteMessage)
{
DeleteMessage(SqsClient, S3Client, message, sqsTransportMessage, transportMessage);
}
else
{
SqsClient.ChangeMessageVisibility(_queueUrl, message.ReceiptHandle, 0);
}
_endProcessMessage(transportMessage, exception);
}
}
}
}
finally
{
_tracksRunningThreads.Release();
}
}