has anyone implemented a more complex IBodyProducer than class POSTRequestProducer(): implements(IBodyProducer) def __init__(self, body): self.body = body self.length = len(self.body) def startProducing(self, consumer): consumer.write(self.body) return succeed(None) def pauseProducing(self): pass def stopProducing(self): pass I have an upload intensive application, that during periods of poor connectivity ends up with a lots on zombie http TCP connections. I'm thinking maybe that the "pause" is being called and that my request deferred is in a paused state.