[rabbitmq-discuss] Termination of queue after sending a message.

[Ernest Staszuk]

Hi,

while using RabbitMQ we encountered problems with queue termination.

I enclose log (with vulnerable parts censored). RabbitMQ version we used 
was 2.8.7 ran on Erlang R15B.
We ran into this issue while sending back to queue dead-lettered message 
as follows:

     1. Message from a queue named let's say "to-process" is delivered
         to consumer and then rejected due to failure.
     2. Since queue "to-process" has dead-letter exchange set to 
"failed-messages"
         it falls down there and then to queue "failed-messages-queue".
     3. Another consumer got this message while listening on 
"failed-messages-queue",
         stored content and headers in memory and sent acknowledgement.
     4. After a certain time there is made an attempt to sent message 
stored in memory
         to the queue form which it was rejected at first (explicitly 
saying to the "to-process" queue).
         To be more precise we are trying to send a message to exchange 
null with routing key "to-process".

And then queue "to-process" vanished unexpectedly. In logs of RabbitMQ 
we found error.

Due this we have some questions:
     - Why did that happen? Is something wrong with what we are doing?
     - Why queue terminated? In my opinion this should never happen 
(even if the message we sent back was broken, I mean isn't that a 
security issue?).
     - What did happened to the messages that was in "to-process" queue? 
Is there any way to find and restore them?
     - Does terminating a (durable) queue can result in messages lossing?

Thank you in advance for the time spent on my problem.

Best regards,
Ernest Staszuk