Timeout On Publisher Call

Hi Dan. I'm not sure if I get what you want (it's a bit late here and I'm a bit sleepy), but if you use:

yield queue.get(timeout=10)

a Timeout exception should be raised. If you prefer the traditional idiom, you can use:

queue.get(timeout=10).addCallbacks(myCallback, myErrback)

Could you check if it works the way you want?

Okay if I look at the createThriftClient and parseServerMessage of the contrib.thrift package, the problem is that the queue.get(timeout=10).addCallback(parseServer....) times out and fires some errback which gets lost because nothing catches it I guess.

Moreover, that deferred is different than the deferred I am waiting for. That is the "pluck off the queue" deferred and I am waiting for the "matched response for service request" deferred. So I was just curious if you have anything on your radar to address the latter case. I could try and submit a patch but there is still a lot about txamqp I don't fully understand.

Hopefully I am being decently clear, my previous post was a little scatterbrain.

And would something like this work for you?

@defer.inlineCallbacks
def myFunc(client):
    d = client.doSomethingRemote()
    d.setTimeout(10) # 10 seconds
    try:
        yield d
    except TimeoutError:
        print "Expected a response after 10 seconds"

More info about setTimeout: http://twistedmatrix.com/documents/current/api/twisted.internet.defer.Deferred.html#setTimeout

Yeah that works, is there any way to perform a cleanup on the "waiting" deferred list, or does that happen in the background? I am not sure if that is an issue or not, just trying to track down some memory leaks with our production app. Thanks again!

That's an interesting question. If a request expires, its deferred should be removed from the outstanding requests dictionary. However, if a response is received even after the timeout exception is raised, the request deferred will raise an AlreadyCalledError exception. I'll try to fix this behavior.

Thanks for the response, that would be excellent. I was looking through the code and it looks you started to address that in client.py with the alreadyCalled flag.

Oh btw, I have gotten that error randomly on disconnect from the AMQP server. I could post this as a seperate bug if you want.

2009-02-18 11:30:33-0800 [AMQPublisher,client] Unhandled error in Deferred:
2009-02-18 11:30:33-0800 [AMQPublisher,client] Unhandled Error
        Traceback (most recent call last):
          File "/usr/lib/python2.5/site-packages/twisted/internet/defer.py", line 269, in errback
            self._startRunCallbacks(fail)
          File "/usr/lib/python2.5/site-packages/twisted/internet/defer.py", line 312, in _startRunCallbacks
            self._runCallbacks()
          File "/usr/lib/python2.5/site-packages/twisted/internet/defer.py", line 328, in _runCallbacks
            self.result = callback(self.result, *args, **kw)
          File "/usr/lib/python2.5/site-packages/twisted/internet/defer.py", line 757, in gotResult
            _inlineCallbacks(r, g, deferred)
        --- <exception caught here> ---
          File "/usr/lib/python2.5/site-packages/twisted/internet/defer.py", line 735, in _inlineCallbacks
            result = result.throwExceptionIntoGenerator(g)
          File "/usr/lib/python2.5/site-packages/twisted/python/failure.py", line 331, in throwExceptionIntoGenerator
            return g.throw(self.type, self.value, self.tb)
          File "/usr/lib64/python2.5/site-packages/txamqp/protocol.py", line 274, in worker
            self.close(e)
          File "/usr/lib64/python2.5/site-packages/txamqp/protocol.py", line 261, in close
            self.delegate.close(reason)
          File "/usr/lib64/python2.5/site-packages/txamqp/client.py", line 46, in close
            self.client.started.reset()
          File "/usr/lib64/python2.5/site-packages/txamqp/client.py", line 21, in reset
            deferred.callback(True)
          File "/usr/lib/python2.5/site-packages/twisted/internet/defer.py", line 243, in callback
            self._startRunCallbacks(result)
          File "/usr/lib/python2.5/site-packages/twisted/internet/defer.py", line 298, in _startRunCallbacks
            raise AlreadyCalledError
        twisted.internet.defer.AlreadyCalledError: