How Can i recover RabbitMQ queue? - rabbitmq

Question

We are using RabbitMQ for celery tasks execution. We were having one queue operating over 230000 tasks which was crashed yesterday with below log,
<code>2019-02-11 22:30:32,770 WARNING 13003 [celery.worker.consumer] consumer.py:289 - consumer: Connection to broker lost. Trying to re-establish the connection...
Traceback (most recent call last):
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/celery/worker/consumer.py", line 278, in start
blueprint.start(self)
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/celery/bootsteps.py", line 123, in start
step.start(parent)
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/celery/worker/consumer.py", line 821, in start
c.loop(*c.loop_args())
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/celery/worker/loops.py", line 70, in asynloop
next(loop)
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/kombu/async/hub.py", line 340, in create_loop
cb(*cbargs)
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/kombu/transport/base.py", line 164, in on_readable
reader(loop)
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/kombu/transport/base.py", line 146, in _read
drain_events(timeout=0)
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/amqp/connection.py", line 324, in drain_events
return amqp_method(channel, args)
File "/edx/app/edxapp/venvs/edxapp/local/lib/python2.7/site-packages/amqp/channel.py", line 1647, in _basic_cancel_notify
raise ConsumerCancelled(consumer_tag, (60, 30))
ConsumerCancelled: Basic.cancel: (0) None8
2019-02-11 22:30:32,878 INFO 13003 [celery.worker.consumer] consumer.py:479 - Connected to amqp://celery:**#127.0.0.1:5672//
2019-02-11 22:31:20,308 ERROR 13003 [celery.worker.consumer] consumer.py:364 - consumer: Cannot connect to amqp://celery:**#127.0.0.1:5672//: [Errno 104] Connection res$
Trying again in 2.00 seconds...
</code>
After crashed rabbitmq i have restarted again using below command:
sudo service rabbitmq-server restart
Once rabbitmq restart i lost my all queues. My queue durability was Durable and message delivery mode was non-persistent.
Is there any way we can recover messages which was in queue ? It was having very important data of user which were under processing.

Answer 1

Nope. Non-persistent means they were in RAM, not stored on the disk.
A general comment - RabbitMQ is not a database. Even if you had set the queues to be persistent, expecting a message broker to reliably handle temporary storage of 200,000 messages is madness. Your system should be designed such that the broker is a buffer between tasks, with average queue length of zero. If you find such large numbers, either speed up processing or store in a database designed to be able to survive occasional restarts with little to no consequences.