Hello,<div><br></div><div>I am working an a Python program that receives XML-RPC calls from Java clients, and then create AMQP queues for each client.</div><div>To create channel, exchanges and queues, we use pika and SelectConnection.</div>
<div><br></div><div>So I first create and start a SelectConnection, then I create a channel. On the reception of the on_open_callback of the channel, I try to declare a queue.</div><div>The problem is that about 10% of time, a weird error occurs on the declaration of the queue :</div>
<div><br></div><div><div>File "/usr/lib/python2.6/multiprocessing/process.py", line 232, in _bootstrap</div><div> self.run()</div><div> File "/usr/lib/python2.6/multiprocessing/process.py", line 88, in run</div>
<div> self._target(*self._args, **self._kwargs)</div><div> File "/home/adgeg/Sources/svn/TOTEM/Sandbox/TSP-MARGE-Communication/RabbitMQ/RabbitMQTOTEMLibrary/Python/net/totem/gamelogic/creategamelogicserver.py", line 42, in createGameLogicServer</div>
<div> state.connection.ioloop.start()</div><div> File "/home/adgeg/local/bin/pika-0.9.5/pika/adapters/select_connection.py", line 124, in start</div><div> self.poller.start()</div><div> File "/home/adgeg/local/bin/pika-0.9.5/pika/adapters/select_connection.py", line 374, in start</div>
<div> self.poll()</div><div> File "/home/adgeg/local/bin/pika-0.9.5/pika/adapters/select_connection.py", line 388, in poll</div><div> self._handler(events[0][0], events[0][1])</div><div> File "/home/adgeg/local/bin/pika-0.9.5/pika/adapters/base_connection.py", line 134, in _handle_events</div>
<div> self._handle_read()</div><div> File "/home/adgeg/local/bin/pika-0.9.5/pika/adapters/base_connection.py", line 162, in _handle_read</div><div> self._on_data_available(data)</div><div> File "/home/adgeg/local/bin/pika-0.9.5/pika/connection.py", line 599, in _on_data_available</div>
<div> self._channels[frame.channel_number].transport.deliver(frame)</div><div> File "/home/adgeg/local/bin/pika-0.9.5/pika/channel.py", line 64, in deliver</div><div> self.frame_dispatcher.process(frame)</div>
<div> File "/home/adgeg/local/bin/pika-0.9.5/pika/frame.py", line 202, in process</div><div> self._handler(frame)</div><div> File "/home/adgeg/local/bin/pika-0.9.5/pika/frame.py", line 220, in _handle_method_frame</div>
<div> raise NotImplementedError(frame.method.__class__)</div><div>NotImplementedError: <class 'pika.spec.DeclareOk'></div></div><div><br></div><div>We have already sent you a mail 6 months ago, and someone tell us to change the pika source code to have a better understanding of this error, and here is the result :</div>
<div><div> File "/home/adgeg/local/bin/pika-0.9.5/pika/frame.py", line 220, in _handle_method_frame</div><div> raise NotImplementedError(frame.method.__class__)</div></div><div>NotImplementedError: <Method(['frame_type=1', 'channel_number=1', "method=<Queue.DeclareOk(['queue=michel', 'message_count=0', 'consumer_count=0'])>"])></div>
<div><br></div><div>I have looked to our source code, and I found that we were using the same channel in two different threads.</div><div>So I create a new channel (with its own SelectConnection) for the second thread... but the error is still raised.</div>
<div>Curiously, I have found a way to highly reduce appearance frequency of the error: I accidentally add a call to a system command on the Python source code on the on_open_callback, just before declaring the queue (rabbitmqctl list_user_permissions, to check that I have the required permissions to declare a queue).</div>
<div><br></div><div>And now, it seems that we arrived to an appearance frequency of 3 times on 2000 tries.</div><div>So I suppose that without this additional little time period, the on_open_callback is triggered, but the channel seems not able to declare a queue.</div>
<div>Do you know some related issues of this kind on SelectConnections?</div><div><br></div><div>Thanks a lot,</div><div><br></div><div>Gabriel Adgeg</div><div><br></div><div>PS : I am using RabbitMQ 2.7.0, Erlang R13B03, Python 2.6.5, pika 0.9.5, on Ubuntu 10.04.3 LTS. The error also occurs with Erlang R14B04, Python 2.7.2, on Windows XP and Windows 7. And it was already there when we were using RabbitMQ 2.5.1. </div>