PRECONDITION_FAILED - unknown delivery tag

[bslima]

I'm trying to write a threaded rpc communication with puka and rabbitmq. But i'm keeping getting:

puka.spec_exceptions.PreconditionFailed: {'class_id': 60, 'method_id': 80, 'reply_code': 406, 'reply_text': 'PRECONDITION_FAILED - unknown delivery tag X'}, where X can be any msg number.

The error is always on the RPCServer, following my code:

            #!/usr/bin/env python
            from threading import Thread
            import puka
            import uuid
            import logging

            class RPCServer(object):
                def __init__(self):
                    self.client = None
                    self.consume = None
                    try:
                        self.client = puka.Client("amqp://localhost/")
                        promise = self.client.connect(callback=self.on_connected)
                        self.client.wait(promise,timeout=2)#Waits 2s
                    except  Exception as e:
                        print "Error connecting to server - ",e

                def close(self):
                    self.client.wait(self.client.close())

                def on_connected(self,promise,result):
                    try:
                        self.client.wait(self.client.queue_declare(queue='rpc_queue_test'))
                        self.consume = self.client.basic_consume(queue='rpc_queue_test',
                                                                 callback=self.on_request)
                    except Exception as e:
                        print "Error declaring queue - ",e

                def on_request(self,promise,request):
                    th=Thread(target=self.test, args = [request])
                    th.start()

                def test(self,request):
                    pr = self.client.basic_publish(exchange='',routing_key=request['headers']['reply_to'],
                                              headers={'correlation_id':request['headers']['correlation_id']},
                                              body=str(2))
                    self.client.wait(pr)
                    self.client.basic_ack(request)

                def run(self):
                    while True:
                        request = self.client.wait(self.consume)
                        print "Request received (%s)"%(request)

            print " [x] Awaiting RPC requests"
            rpc_server = RPCServer()

            th1 = Thread(target=rpc_server.run())
            th1.start()

Is there anyway to get this server done in a thread for every request ??

Thanks in advance.

[majek]

You've seen that, right? https://github.com/rabbitmq/rabbitmq-tutorials/blob/master/python-puka/rpc_client.py https://github.com/rabbitmq/rabbitmq-tutorials/blob/master/python-puka/rpc_server.py

http://www.rabbitmq.com/tutorials/tutorial-six-python.html

[majek]

That makes no sense:

                        promise = self.client.connect(callback=self.on_connected)
                        self.client.wait(promise,timeout=2)#Waits 2s

so you want a callback or you want to wait on a promise?

Also, you're using a single puka connection from multiple threads. That just won't work.

[bslima]

The problem is not on the wait and the callback, that works fine. So what is the difference between puka and pika ? For what i read puka allows me to share connection between threads.

[majek]

The problem is not on the wait and the callback, that works fine.

Yes, I know. It just doesn't make any sense. You may as well do "self.client.wait(promise); self.on_connected()" and it will be so much more readable.

So what is the difference between puka and pika ?

They are two separate projects.

For what i read puka allows me to share connection between threads.

Interesting, where did you read that?