Lost messages if SimpleQueue/Connection not explicitly closed?

[rrauenza]

I was having an issue with periodic lost messages -- I figured out how to "fix" it, but I don't understand why it fixes it. So it leaves me uneasy...

It turns out in certain cases, I wasn't calling self.q.close() nor self.connection.release(). Does it make sense that a self.q.put() might never get actually sent if these aren't explicitly called? So that I might understand Kombu+Rabbit better -- why?

(The q and connections objects below otherwise would have been left to the python GC... they are not persistent, they're actually part of a context manager, and the containing function returns promptly.)

Using RabbitMQ, the q setup code was:

    self.no_ack = no_ack
    self.ttl = ttl  # This is set for 7 days.
    self.connection = kombu.Connection(AMQP_URL)
    self.q = SimpleQueue(
        channel=self.connection,
        name=self.qname,
        no_ack=no_ack,
        queue_args={"x-expires": int(self.ttl * 1000)},
        serializer="msgpack",
    )
    self.q.consumer.qos(prefetch_count=1)  # I've set this to 0 now.
    self.q.consumer.accept = prepare_accept_content(["msgpack", "json"])