[rabbitmq-discuss] Problem extending code from tutorial #6

Doug Gorley doug at gorley.ca
Wed Aug 24 14:32:17 BST 2011


Made the change as per your update and it works great.  Thanks Marek!
-- 
Doug Gorley | doug at gorley.ca

On Wed, August 24, 2011 3:52 am, Marek Majkowski wrote:
> On Wed, Aug 24, 2011 at 09:32, Marek Majkowski <majek04 at gmail.com> wrote:
>> Thanks for the report. It does look like a problem caused
>> by a bug in Pika or my misunderstanding how start/stop_consuming
>> work.
>
> Yup. I did misuse "stop_consuming". Apparently, it calls
> basic.cancel, which was completely not inteded:
> https://github.com/pika/pika/blob/v0.9.5/pika/adapters/blocking_connection.py#L287
>
> The fix is here:
> https://github.com/rabbitmq/rabbitmq-tutorials/commit/c1b178d9deec664cdf12770c24319c7d12d67efd
>
> Thanks again for the report!
>
> Cheers,
>   Marek
>
>> On Wed, Aug 24, 2011 at 02:49, Doug Gorley <doug at gorley.ca> wrote:
>>> I'm hoping someone can help he with my RabbitMQ problem; I've got some
>>> code based on the tutorial #6 code, and it's not doing what I'm
>>> expecting.
>>> I tried to create a shell where I can send strings to the server and
>>> receive the MD5 digest, but I only ever seem to get the first reply.
>>>
>>> Here's the source:
>>>
>>> ##########################################################################
>>> # server.py
>>>
>>> import pika
>>> import hashlib
>>>
>>> connection = pika.BlockingConnection(
>>>    pika.ConnectionParameters(host='localhost'))
>>>
>>> channel = connection.channel()
>>> channel.queue_declare(queue='my_request')
>>>
>>> def on_request(ch, method, props, body):
>>>
>>>    response = hashlib.md5(body).hexdigest()
>>>
>>>    print("Received '%r', sending '%r'" % (body, response))
>>>
>>>    ch.basic_publish(exchange='',
>>>                     routing_key=props.reply_to,
>>>                    
>>> properties=pika.BasicProperties(correlation_id = \
>>>                                                
>>>     props.correlation_id),
>>>                     body=response)
>>>
>>>    ch.basic_ack(delivery_tag = method.delivery_tag)
>>>
>>> channel.basic_qos(prefetch_count=1)
>>> channel.basic_consume(on_request, queue='my_request')
>>>
>>> print " [x] Awaiting requests"
>>> channel.start_consuming()
>>> ##########################################################################
>>>
>>> ##########################################################################
>>> # client.py
>>>
>>> import pika
>>> import uuid
>>>
>>> class RabbitClient(object):
>>>
>>>    def __init__(self):
>>>        self.connection = pika.BlockingConnection(
>>>            pika.ConnectionParameters(host='localhost'))
>>>
>>>        self.channel = self.connection.channel()
>>>
>>>        result = self.channel.queue_declare(exclusive=True)
>>>        self.callback_queue = result.method.queue
>>>
>>>        self.channel.basic_consume(self.on_response, no_ack=True,
>>>                                  
>>> queue=self.callback_queue)
>>>
>>>    def on_response(self, ch, method, props, body):
>>>        print(" [.] Received correlation ID %r" %
>>> (props.correlation_id,))
>>>        if self.corr_id == props.correlation_id:
>>>            self.response = body
>>>            self.channel.stop_consuming()
>>>        else:
>>>            print(" [~] Correlation IDs do not match")
>>>
>>>    def call(self, n):
>>>        self.corr_id = str(uuid.uuid4())
>>>        self.channel.basic_publish(exchange='',
>>>                                  
>>> routing_key='my_request',
>>>                                  
>>> properties=pika.BasicProperties(
>>>                                        
>>> reply_to=self.callback_queue,
>>>                                        
>>> correlation_id=self.corr_id,
>>>                                         ),
>>>                                   body=n)
>>>        self.channel.start_consuming()
>>>        return self.response
>>>
>>> auth = RabbitClient()
>>>
>>> while True:
>>>    send = raw_input('> ')
>>>    if send == 'quit': break
>>>    print(" [x] sending '%s'" % (send))
>>>    response = auth.call(send)
>>>    print(" [^] sent with correlation ID %s" % (auth.corr_id,))
>>>    print(" [.] Got %r" % (response,))
>>> ##########################################################################
>>>
>>> Here's the output from the server:
>>>
>>> ##########################################################################
>>>  [x] Awaiting requests
>>> Received ''Hello World'', sending ''b10a8db164e0754105b7a99be72e3fe5''
>>> Received ''Hello Rabbit'', sending ''5bec01f45b43f6202e84242fcb71b04f''
>>> ##########################################################################
>>>
>>> And here's the output from the server:
>>> ##########################################################################
>>>> Hello World
>>>  [x] sending 'Hello World'
>>>  [.] Received correlation ID '1805f131-1fbc-40a3-86fb-2a113b5f9b9a'
>>>  [^] sent with correlation ID 1805f131-1fbc-40a3-86fb-2a113b5f9b9a
>>>  [.] Got 'b10a8db164e0754105b7a99be72e3fe5'
>>>> Hello Rabbit
>>>  [x] sending 'Hello Rabbit'
>>>  [^] sent with correlation ID fdb089ff-44ea-4b81-885b-be7e0178d5a1
>>>  [.] Got 'b10a8db164e0754105b7a99be72e3fe5'
>>>> quit
>>> ##########################################################################
>>>
>>> So, my question is, what am I doing wrong that I didn't get the '5bec'
>>> response to the second message?
>>>
>>> Thanks for your help,
>>> --
>>> Doug Gorley | doug at gorley.ca
>>>
>>>
>>>
>>> _______________________________________________
>>> rabbitmq-discuss mailing list
>>> rabbitmq-discuss at lists.rabbitmq.com
>>> https://lists.rabbitmq.com/cgi-bin/mailman/listinfo/rabbitmq-discuss
>>>
>>
>




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