private void TryReceiveMessage()
{
// NOTE this method _should not_ throw an exception!
ServiceBrokerMessage message = null;
SqlTransaction transaction = null;
try
{
transaction = BeginTransaction();
logger.Debug("RECEIVE FROM {0}", ServiceBrokerQueue);
message = ServiceBrokerWrapper.WaitAndReceive(transaction, ServiceBrokerQueue, waitTimeout);
}
catch (Exception e)
{
logger.Error(e, "Exception caught trying to receive from queue {0}. Rolling back and backing off before reconnecting.", ServiceBrokerQueue);
TryRollbackTransaction(transaction);
TryDisposeTransactionAndConnection(transaction);
workerThreadPool.Release(1);
Thread.Sleep(1000); // back-off because we will return and loop immediately
return;
}
// No message? That's okay
if (message == null)
{
try
{
transaction.Commit();
}
finally
{
TryDisposeTransactionAndConnection(transaction);
workerThreadPool.Release(1);
}
return;
}
// start a
Task.Run(() =>
{
// TryHandleHessage _should not_ throw an exception. It will also commit and cleanup the transactions
try
{
TryHandleMessage(transaction, message);
}
finally
{
workerThreadPool.Release(1); // release this semaphore back to the pool regardless of what happened
}
});
}
private static ServiceBrokerMessage ReceiveInternal(IDbTransaction transaction, string queueName, Guid?conversationHandle, bool wait, int?waitTimeout)
{
EnsureSqlTransaction(transaction);
var cmd = transaction.Connection.CreateCommand() as SqlCommand;
var query = new StringBuilder();
if (wait)
{
query.Append("WAITFOR(");
}
query.Append("RECEIVE TOP(1) ");
query.Append("conversation_handle");
query.Append(", service_name, service_contract_name, message_type_name");
query.Append(", message_body");
query.Append(" FROM ");
query.Append(queueName);
if (conversationHandle.HasValue && conversationHandle.Value != Guid.Empty)
{
query.Append(" WHERE conversation_handle = @ch");
var param = cmd.Parameters.Add("@ch", SqlDbType.UniqueIdentifier);
param.Value = conversationHandle.Value;
}
if (wait)
{
query.Append("), ");
if (waitTimeout.HasValue && waitTimeout.Value > 0)
{
query.Append(" TIMEOUT @to");
var param = cmd.Parameters.Add("@to", SqlDbType.Int);
param.Value = waitTimeout.Value;
cmd.CommandTimeout = 0;
}
}
cmd.CommandText = query.ToString();
cmd.Transaction = transaction as SqlTransaction;
using (var dataReader = cmd.ExecuteReader())
{
if (dataReader.Read())
{
return(ServiceBrokerMessage.Load(dataReader));
}
}
return(null);
}
private void TryHandleMessageInner(SqlTransaction transaction, ServiceBrokerMessage message)
{
// Only handle transport messages
if (message.MessageTypeName != ServiceBrokerMessageType &&
!message.IsDialogTimerMessage())
{
logger.Debug("Ignoring message of type {0} from queue {1}", message.MessageTypeName, ServiceBrokerQueue);
return; // ignore
}
IncomingTransportMessage transportMessage = null;
try
{
if (message.IsDialogTimerMessage())
{
transportMessage = TryLoadDialogTimerTimeoutMessage(transaction, message);
}
else
{
transportMessage = TryDeserializeTransportMessage(message);
}
if (!transportMessage.Headers.ContainsKey(StandardHeaders.OriginatingAddress))
{
transportMessage.Headers[StandardHeaders.OriginatingAddress] = ServiceBrokerWrapper.TryGetConversationFarService(transaction, message.ConversationHandle);
}
Exception lastException = null;
if (faultManager.MaxRetriesExceeded(transportMessage, out lastException))
{
logger.Debug("MaxRetriesExceeded: Moving message {0} from queue {1} to poison message table.", message.ConversationHandle.ToString(), ServiceBrokerQueue);
MoveToPoisonMessage(transaction, message, transportMessage, lastException, "MaxRetriesExceeded", MaxRetries);
return; // return without error to commit transaction
}
logger.Debug("Notifying observers of new TransportMessage for message {0} from queue {1}.", message.ConversationHandle, ServiceBrokerQueue);
if (this.MessageAvailable != null)
{
this.MessageAvailable(this, new MessageAvailable(transportMessage));
}
}
catch (CannotDeserializeMessageException e)
{
// If we can't deserialize the transport message or inner message, there is no reason to retry.
// note: error is already logged so we don't need to log here
logger.Debug("DeserializeError: Moving message {0} from queue {1} to poison message table.", message.ConversationHandle.ToString(), ServiceBrokerQueue);
MoveToPoisonMessage(transaction, message, transportMessage, e, "DeserializeError", 0);
return; // return without error to commit transaction
}
}
private IncomingTransportMessage TryDeserializeTransportMessage(ServiceBrokerMessage message)
{
using (var stream = new MemoryStream(message.Body))
{
try
{
return(FastXmlTransportMessageSerializer.Deserialize(message.ConversationHandle.ToString(), stream));
}
catch (Exception e)
{
logger.Error(e, "Cannot deserialize transport message for message {0} from queue {1}.", message.ConversationHandle, ServiceBrokerQueue);
throw new CannotDeserializeMessageException(e);
}
}
}
public static ServiceBrokerMessage Load(SqlDataReader reader)
{
var message = new ServiceBrokerMessage();
message.ConversationHandle = reader.GetGuid(0);
message.ServiceName = reader.GetString(1);
message.ServiceContractName = reader.GetString(2);
message.MessageTypeName = reader.GetString(3);
if (!reader.IsDBNull(4))
{
message.Body = reader.GetSqlBytes(4).Buffer;
}
else
{
message.Body = new byte[0];
}
return message;
}
public static ServiceBrokerMessage Load(SqlDataReader reader)
{
var message = new ServiceBrokerMessage();
message.ConversationHandle = reader.GetGuid(0);
message.ServiceName = reader.GetString(1);
message.ServiceContractName = reader.GetString(2);
message.MessageTypeName = reader.GetString(3);
if (!reader.IsDBNull(4))
{
message.Body = reader.GetSqlBytes(4).Buffer;
}
else
{
message.Body = new byte[0];
}
return(message);
}
private void TryHandleMessage(SqlTransaction transaction, ServiceBrokerMessage message)
{
logger.Debug("Received message {0} from queue {1}", message.ConversationHandle, ServiceBrokerQueue);
// NOTE this method _should not_ throw an exception!
// It is responsible for committing or rolling back the SqlTransaction
// that was passed in.
// We can keep track of the openTransaction on the current thread in case we need it.
openTransaction = transaction;
try
{
// this may throw an exception if we need to rollback
TryHandleMessageInner(transaction, message);
// End the conversation and commit
ServiceBrokerWrapper.EndConversation(transaction, message.ConversationHandle);
transaction.Commit();
faultManager.ClearFailuresForMessage(message.ConversationHandle.ToString());
logger.Debug("Committed message {0} from queue {1}", message.ConversationHandle, ServiceBrokerQueue);
}
catch (Exception e)
{
TryRollbackTransaction(transaction);
faultManager.IncrementFailuresForMessage(message.ConversationHandle.ToString(), e);
logger.Error(e, "Exception caught handling message {0} from queue {1}. Rolling back transaction to retry.", message.ConversationHandle, ServiceBrokerQueue);
#if DEBUG
if (System.Diagnostics.Debugger.IsAttached)
{
System.Diagnostics.Debugger.Break();
}
#endif
}
finally
{
openTransaction = null;
TryDisposeTransactionAndConnection(transaction); // shoud not throw exception
}
}
private IncomingTransportMessage TryLoadDialogTimerTimeoutMessage(SqlTransaction transaction, ServiceBrokerMessage message)
{
var messageBuffer = PopTimeoutMessage(transaction, message.ConversationHandle);
if (messageBuffer == null || messageBuffer.Length == 0)
{
var errorMessage = string.Format("Cannot deserialize transport message. DialogTimer TimeoutMessage is missing for for message {0} from queue {1}.", message.ConversationHandle, ServiceBrokerQueue);
logger.Error(errorMessage);
throw new CannotDeserializeMessageException(errorMessage);
}
using (var stream = new MemoryStream(messageBuffer))
{
try
{
return FastXmlTransportMessageSerializer.Deserialize(message.ConversationHandle.ToString(), stream);
}
catch (Exception e)
{
logger.Error(e, "Cannot deserialize transport message for message {0} from queue {1}.", message.ConversationHandle, ServiceBrokerQueue);
throw new CannotDeserializeMessageException(e);
}
}
}
private void TryHandleMessageInner(SqlTransaction transaction, ServiceBrokerMessage message)
{
// Only handle transport messages
if (message.MessageTypeName != ServiceBrokerMessageType &&
!message.IsDialogTimerMessage())
{
logger.Debug("Ignoring message of type {0} from queue {1}", message.MessageTypeName, ServiceBrokerQueue);
return; // ignore
}
IncomingTransportMessage transportMessage = null;
try
{
if (message.IsDialogTimerMessage())
{
transportMessage = TryLoadDialogTimerTimeoutMessage(transaction, message);
}
else
{
transportMessage = TryDeserializeTransportMessage(message);
}
if (!transportMessage.Headers.ContainsKey(StandardHeaders.OriginatingAddress))
{
transportMessage.Headers[StandardHeaders.OriginatingAddress] = ServiceBrokerWrapper.TryGetConversationFarService(transaction, message.ConversationHandle);
}
Exception lastException = null;
if (faultManager.MaxRetriesExceeded(transportMessage, out lastException))
{
logger.Debug("MaxRetriesExceeded: Moving message {0} from queue {1} to poison message table.", message.ConversationHandle.ToString(), ServiceBrokerQueue);
MoveToPoisonMessage(transaction, message, transportMessage, lastException, "MaxRetriesExceeded", MaxRetries);
return; // return without error to commit transaction
}
logger.Debug("Notifying observers of new TransportMessage for message {0} from queue {1}.", message.ConversationHandle, ServiceBrokerQueue);
if (this.MessageAvailable != null)
{
this.MessageAvailable(this, new MessageAvailable(transportMessage));
}
}
catch (CannotDeserializeMessageException e)
{
// If we can't deserialize the transport message or inner message, there is no reason to retry.
// note: error is already logged so we don't need to log here
logger.Debug("DeserializeError: Moving message {0} from queue {1} to poison message table.", message.ConversationHandle.ToString(), ServiceBrokerQueue);
MoveToPoisonMessage(transaction, message, transportMessage, e, "DeserializeError", 0);
return; // return without error to commit transaction
}
}
private void TryHandleMessage(SqlTransaction transaction, ServiceBrokerMessage message)
{
logger.Debug("Received message {0} from queue {1}", message.ConversationHandle, ServiceBrokerQueue);
// NOTE this method _should not_ throw an exception!
// It is responsible for committing or rolling back the SqlTransaction
// that was passed in.
// We can keep track of the openTransaction on the current thread in case we need it.
openTransaction = transaction;
try
{
// this may throw an exception if we need to rollback
TryHandleMessageInner(transaction, message);
// End the conversation and commit
ServiceBrokerWrapper.EndConversation(transaction, message.ConversationHandle);
transaction.Commit();
faultManager.ClearFailuresForMessage(message.ConversationHandle.ToString());
logger.Debug("Committed message {0} from queue {1}", message.ConversationHandle, ServiceBrokerQueue);
}
catch (Exception e)
{
TryRollbackTransaction(transaction);
faultManager.IncrementFailuresForMessage(message.ConversationHandle.ToString(), e);
logger.Error(e, "Exception caught handling message {0} from queue {1}. Rolling back transaction to retry.", message.ConversationHandle, ServiceBrokerQueue);
#if DEBUG
if (System.Diagnostics.Debugger.IsAttached)
{
System.Diagnostics.Debugger.Break();
}
#endif
}
finally
{
openTransaction = null;
TryDisposeTransactionAndConnection(transaction); // shoud not throw exception
}
}
private IncomingTransportMessage TryDeserializeTransportMessage(ServiceBrokerMessage message)
{
using (var stream = new MemoryStream(message.Body))
{
try
{
return FastXmlTransportMessageSerializer.Deserialize(message.ConversationHandle.ToString(), stream);
}
catch (Exception e)
{
logger.Error(e, "Cannot deserialize transport message for message {0} from queue {1}.", message.ConversationHandle, ServiceBrokerQueue);
throw new CannotDeserializeMessageException(e);
}
}
}
private void MoveToPoisonMessage(SqlTransaction transaction, ServiceBrokerMessage serviceBrokerMessage, IncomingTransportMessage transportMessage, Exception exception, string errorCode, int retries)
{
var origin_service_name = "";
if (transportMessage != null && transportMessage.Headers.ContainsKey(StandardHeaders.OriginatingAddress))
{
origin_service_name = transportMessage.Headers[StandardHeaders.OriginatingAddress];
}
else if (transportMessage != null && transportMessage.Headers.ContainsKey(StandardHeaders.ReplyToAddress))
{
origin_service_name = transportMessage.Headers[StandardHeaders.ReplyToAddress];
}
else
{
origin_service_name = ServiceBrokerWrapper.TryGetConversationFarService(transaction, serviceBrokerMessage.ConversationHandle);
}
try
{
// write to the message to the PosionMessage table
using (var command = transaction.Connection.CreateCommand())
{
command.CommandText = "spInsertPoisonMessage";
command.CommandType = CommandType.StoredProcedure;
command.Parameters.AddWithValue("@conversation_handle", serviceBrokerMessage.ConversationHandle);
command.Parameters.AddWithValue("@origin_service_name", origin_service_name);
command.Parameters.AddWithValue("@service_name", this.ServiceBrokerService);
command.Parameters.AddWithValue("@queue_name", this.ServiceBrokerQueue);
command.Parameters.AddWithValue("@message_body", serviceBrokerMessage.Body);
command.Parameters.AddWithValue("@retries", retries);
command.Parameters.AddWithValue("@errorCode", errorCode);
if (exception != null)
command.Parameters.AddWithValue("@errorMessage", FormatErrorMessage(exception));
else
command.Parameters.AddWithValue("@errorMessage", DBNull.Value);
command.Transaction = transaction;
command.ExecuteNonQuery();
}
}
catch (Exception e)
{
logger.Fatal(e, "Failed to write PoisonMessage for message {0} from queue {1}", serviceBrokerMessage.ConversationHandle, ServiceBrokerQueue);
// suppress -- don't let this exception take down the process
}
if (PoisonMessageDetected != null)
{
PoisonMessageDetected(this, new PoisonMessageDetectedEventArgs()
{
MessageId = serviceBrokerMessage.ConversationHandle.ToString(),
OriginServiceName = origin_service_name,
ServiceName = this.ServiceBrokerService,
QueueName = this.ServiceBrokerQueue,
MessageBody = serviceBrokerMessage.Body,
Retries = retries,
ErrorCode = errorCode,
Exception = exception,
});
}
}
private void MoveToPoisonMessage(SqlTransaction transaction, ServiceBrokerMessage serviceBrokerMessage, IncomingTransportMessage transportMessage, Exception exception, string errorCode, int retries)
{
var origin_service_name = "";
if (transportMessage != null && transportMessage.Headers.ContainsKey(StandardHeaders.OriginatingAddress))
{
origin_service_name = transportMessage.Headers[StandardHeaders.OriginatingAddress];
}
else if (transportMessage != null && transportMessage.Headers.ContainsKey(StandardHeaders.ReplyToAddress))
{
origin_service_name = transportMessage.Headers[StandardHeaders.ReplyToAddress];
}
else
{
origin_service_name = ServiceBrokerWrapper.TryGetConversationFarService(transaction, serviceBrokerMessage.ConversationHandle);
}
try
{
// write to the message to the PosionMessage table
using (var command = transaction.Connection.CreateCommand())
{
command.CommandText = "spInsertPoisonMessage";
command.CommandType = CommandType.StoredProcedure;
command.Parameters.AddWithValue("@conversation_handle", serviceBrokerMessage.ConversationHandle);
command.Parameters.AddWithValue("@origin_service_name", origin_service_name);
command.Parameters.AddWithValue("@service_name", this.ServiceBrokerService);
command.Parameters.AddWithValue("@queue_name", this.ServiceBrokerQueue);
command.Parameters.AddWithValue("@message_body", serviceBrokerMessage.Body);
command.Parameters.AddWithValue("@retries", retries);
command.Parameters.AddWithValue("@errorCode", errorCode);
if (exception != null)
{
command.Parameters.AddWithValue("@errorMessage", FormatErrorMessage(exception));
}
else
{
command.Parameters.AddWithValue("@errorMessage", DBNull.Value);
}
command.Transaction = transaction;
command.ExecuteNonQuery();
}
}
catch (Exception e)
{
logger.Fatal(e, "Failed to write PoisonMessage for message {0} from queue {1}", serviceBrokerMessage.ConversationHandle, ServiceBrokerQueue);
// suppress -- don't let this exception take down the process
}
if (PoisonMessageDetected != null)
{
PoisonMessageDetected(this, new PoisonMessageDetectedEventArgs()
{
MessageId = serviceBrokerMessage.ConversationHandle.ToString(),
OriginServiceName = origin_service_name,
ServiceName = this.ServiceBrokerService,
QueueName = this.ServiceBrokerQueue,
MessageBody = serviceBrokerMessage.Body,
Retries = retries,
ErrorCode = errorCode,
Exception = exception,
});
}
}
private IncomingTransportMessage TryLoadDialogTimerTimeoutMessage(SqlTransaction transaction, ServiceBrokerMessage message)
{
var messageBuffer = PopTimeoutMessage(transaction, message.ConversationHandle);
if (messageBuffer == null || messageBuffer.Length == 0)
{
var errorMessage = string.Format("Cannot deserialize transport message. DialogTimer TimeoutMessage is missing for for message {0} from queue {1}.", message.ConversationHandle, ServiceBrokerQueue);
logger.Error(errorMessage);
throw new CannotDeserializeMessageException(errorMessage);
}
using (var stream = new MemoryStream(messageBuffer))
{
try
{
return(FastXmlTransportMessageSerializer.Deserialize(message.ConversationHandle.ToString(), stream));
}
catch (Exception e)
{
logger.Error(e, "Cannot deserialize transport message for message {0} from queue {1}.", message.ConversationHandle, ServiceBrokerQueue);
throw new CannotDeserializeMessageException(e);
}
}
}
