Provoke RabbitMQ Queue Crash With Deadlettering (Issue #216)

provoke_rabbitmq_queue_crash_with_deadlettering.py

#!/usr/bin/env python
#  -*- coding: utf-8 -*-
from __future__ import absolute_import, print_function
import logging
import puka


logger = logging.getLogger("provoke_rabbitmq_queue_crash_with_deadlettering")
logger.setLevel(logging.DEBUG)
logger.addHandler(logging.StreamHandler())


AMQP_URL = "amqp://user:pass@localhost/%2f"
QUEUE = "test.issue_216_crashing_queue"
EXCHANGE = 'amq.topic'
ROUTING_KEY = 'test.issue_216'
DLX = 'amq.topic'
TRIES = 5


def get_death_count(message):
    return sum(death.get('count', 1)
               for death in message['headers'].get('x-death', []))


def filter_headers(headers):
    blacklisted_headers = ('x-puka-delivery-tag',)
    return {
        k: v for k, v in headers.iteritems()
        if k not in blacklisted_headers
    }


def setup_queue_with_dlx(client, queue, exchange=EXCHANGE, routing_key=ROUTING_KEY, dlx=DLX):
    client.wait(client.queue_declare(queue, durable=True))
    client.wait(client.queue_bind(queue, exchange, routing_key))
    client.wait(client.queue_bind(queue, dlx, queue))


def send_to_timeout(client, message):
    timeout_queue = "toq-gen{}-{}".format(get_death_count(message), QUEUE)
    new_message_ttl = 0
    queue_ttl_extra = 1000

    logger.info("declaring timeout queue %s", timeout_queue)
    client.wait(client.queue_declare(
        timeout_queue,
        arguments={
            'x-expires': new_message_ttl + queue_ttl_extra,
            'x-message-ttl': new_message_ttl,
            'x-dead-letter-exchange': DLX,
            'x-dead-letter-routing-key': QUEUE,
        },
    ))

    logger.info("publishing to %s: %s", timeout_queue, message)
    client.wait(client.basic_publish(
        exchange='',
        routing_key=timeout_queue,
        body=message['body'],
        headers=filter_headers(message['headers']),
    ))


def main():
    logger.info("connecting ...")
    client = puka.Client(AMQP_URL)
    client.wait(client.connect())

    logger.info("setting up ...")
    setup_queue_with_dlx(client, QUEUE, routing_key=ROUTING_KEY)

    logger.info("publishing ...")
    client.wait(client.basic_publish(EXCHANGE, ROUTING_KEY, body="foo"))

    for i in xrange(TRIES):
        message = client.wait(client.basic_get(QUEUE, no_ack=True))
        logger.info("fetched message: %s", message)
        if 'body' in message:
            send_to_timeout(client, message)

    client.wait(client.close())


if __name__ == "__main__":
    main()

Update the AMQP_URL to point to your RabbitMQ instance.
Install dependencies with:

pip install puka

FYI: you can follow the discussion in rabbitmq/rabbitmq-server#216