[rabbitmq-discuss] Dead-Lettering Queue Contents On Queue Expiration

Fri Jan 17 01:06:16 GMT 2014

On 17/01/14 00:57, Matthias Radestock wrote:
> How would you prevent messages from getting lost that are en-route to a
> queue that is about to expire?

And on a related note, since you said you are using the 
consistent-hash-exchange, be mindful of the following (from 
https://github.com/rabbitmq/rabbitmq-consistent-hash-exchange)

<quote>
Each message gets delivered to at most one queue. Normally, each message 
gets delivered to exactly one queue, but there is a race between the 
determination of which queue to send a message to, and the 
deletion/death of that queue that does permit the possibility of the 
message being sent to a queue which then disappears before the message 
is processed. Hence in general, at most one queue.
</quote>

In other words, the consistent-hash-exchange can lose messages when 
queues disappear.

Matthias