RabbiMQ stomp auto delete queue - Precondition failed

[Boris Tuponja]

Greetings,

I wrote this question on stackoverflow (link), but I will repeat it here. 

I am writing application that uses STOMP for communication. Server side is written using Spring Boot 2.1.7 and as external broker RabbitMQ 3.7.1 is used. On client side, I am using StompJS.

When client subscribes to user destination, e.g. /user/queue/some-queue, Spring will map it to /queue/some-queue-user{sessionID}and RabbitMQ creates queue with name some-queue-user{sessionID}. That part is correct and works as expected.

On subscription I added header {'auto-delete': true}, as specified here in RabbitMQ Stomp Docs, and that created auto delete queue in RabbitMQ, which I can verify using manager plugin.

When I try to send something on that queue I receive error 

PRECONDITION_FAILED - inequivalent arg 'auto_delete' for queue 'some-queue-...

Am I doing something wrong here or did I misunderstood documentation for queue?

I created sample project that illustrates this issue (link). 

Thank you very much.

Best regards,

Boris Tuponja

[Luke Bakken]

Hi Boris,

After you create a queue, you can't change that queue's properties. In this case, you're trying to change the queue to auto-delete.

The code that originally creates the queue must create it as an auto-delete queue, or subsequent declare operations must not declare it as auto-delete.

Thanks,

Luke

[Boris Tuponja]

Hi Luke,

Thank you for the answer.

Unfortunately, I have not been clean enough in my explanation.

I am not trying to change queue properties. The queue is created on STOMP subscription to queue and headers control queue properties. So, on subscription I added header {'auto-delete': true} and correct queue is created. But when I try to send something to that queue, I receive the error.

Thanks.

Boris

[Luke Bakken]

Hi Boris,

I see that you found a solution by adding the auto-delete header to your publishing code - https://stackoverflow.com/q/57826317

That is the solution I was going to propose. I'm investigating why it is necessary and will follow up here.

Thank you very much for providing code to reproduce the issue.

Luke

[Luke Bakken]

Hi Boris,

Yes, it is required to add the auto-delete header when publishing messages.

This is due to the following code, which is part of sending a message - https://github.com/rabbitmq/rabbitmq-stomp/blob/master/src/rabbit_stomp_processor.erl#L753

The ensure_endpoint function declares the queue again to ensure it exists. Since the header is missing, the queue arguments are not the same and you see the precondition_failed message.

Thanks,

Luke

On Monday, September 9, 2019 at 8:18:40 AM UTC-7, Luke Bakken wrote:

Hi Boris,

[Boris Tuponja]

Hi Luke,

Thank you very much for clarification and support.

Best regards,

Boris