On 08/11/2010 09:54 AM, Chris Howard wrote:
Hi,
I am having difficulty with sending a simple request/response between a
server written in C# and a client written in python. I have no such
problems when the client and server are both written in python. I am
using qpid 0.7 (built from the trunk approx. 3 weeks ago)
Here is the code for the C# server:
try
{
Connection connection = new Connection("localhost:5672");
connection.Open();
Session session = connection.CreateSession();
Receiver receiver = session.CreateReceiver("send ; {create: always,
delete: always}");
while (true)
{
Message request = receiver.Fetch(DurationConstants.FORVER);
Sender sender = session.CreateSender(request.ReplyTo);
Message response = new Message("pong");
sender.Send(response);
}
}
catch (System.Exception e)
{
Console.WriteLine(e.ToString());
}
And here is the code for the python client:
import qpid.messaging
connection = qpid.messaging.Connection('amqp://localhost:5672')
connection.open()
session = connection.session()
receiver = session.receiver('#reply ; {create: always, delete: always}')
sender = session.sender('send ; {create: always, delete: always}')
request = qpid.messaging.Message(content = 'ping', reply_to =
receiver.source)
sender.send(request)
response = receiver.fetch(10)
print response.content
connection.close()
I start the server, and then start the client. The server receives the
request from the client, but the call to CreateSender throws an
exception with the message:
"Exchange 9224f93b-8c4b-4675-bc04-61e721387140#reply does not exist"
This appears to me to be a bug in the python client in converting an
address to an AMQP 0-10 reply-to struct. It is sending the reply-to as
an exchange value:
{MessageProperties: reply-to={ReplyTo:
exchange=95004e55-23c9-4c41-acd0-bde7c09a6096#reply; };
application-headers={}; }
As it represents a queue, I believe the name should be sent as the
routing-key of the reply-to struct, with the exchange left empty to
refer to the default (nameless exchange). Certainly this is what the c++
client expects.
Rafi, do you agree?
Furthermore, there is another exception thrown during program exit:
Unhandled Exception: System.AccessViolationException: Attempted to read
or write
protected memory. This is often an indication that other memory is corrupt.
at qpid.messaging.Message.{dtor}(Message* )
at qpid.messaging.Message.__delDtor(Message* , UInt32 )
at Org.Apache.Qpid.Messaging.Message.Cleanup()
at Org.Apache.Qpid.Messaging.Message.!Message()
at Org.Apache.Qpid.Messaging.Message.Dispose(Boolean )
at Org.Apache.Qpid.Messaging.Message.Finalize()
This is a different issue and looks on first glance like a bug in the
.NET 'binding' for the c++ implementation of the messaging API.
Chuck, any thoughts on this?
Also, the output from the broker suggests that the queue /has /been
created:
2010-08-11 09:44:37 info Queue
"9224f93b-8c4b-4675-bc04-61e721387140#reply": Policy created:
type=reject; maxCount=0; maxSize=104857600
2010-08-11 09:44:37 error Execution exception: not-found: Exchange not
found: 9224f93b-8c4b-4675-bc04-61e721387140#reply
(..\..\qpid\cpp\src\qpid\broker\ExchangeRegistry.cpp:92)
Can anyone explain what I am doing wrong here? Or is this a bug?
It's a bug (perhaps two in fact!).
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