RabbitMQ - purge a queue from all of its unacked messages

Question

I have thousands of unacked messages in my dev environment which I can\'t restart.
Is there a way to remove (purge) all messages even if they are unacknowledged?

Answer 1

One way this can happen is if the consumer is stuck recycling the same messages due to a processing error. In this case, the RabbitMQ queue management interface may show the messages as Unacked, but really they are being read from the queue and processed (to the point of the failure) then requeued (to enable a retry) at a rapid pace -- maybe thousands of times per second.

During this loop, the messages exist briefly in the Ready state, but are immediately removed again by you application -- and the cycle begins again. As an example, this auto-requeue behavior is the default for Spring AMQP.

Since the messages are never left in the Ready state, the Management Interface's Get Message(s) button is unlikely work. What can work, if you have queue access, is to run a separate custom consumer instance, perhaps locally, but with the specific intent of removing and not requeuing the messages in question.

By RabbitMQ's Fair Dispatch mechanism, your additional consumer will likely receive the messages in question and have the opportunity to perform your custom handling.

You might even write a custom utility to do this, with logic to filter, analyze, or deadletter the messages of interest.