Open Stack

On 10/14/2014 09:39 AM, Sandy Walsh wrote:
> Sort of.
>
> Openstack RPC-over-AMQP (oslo.messaging) automatically ack()'s all
> messages that are received. So, it becomes the responsibility of the
> sender to retry. For example, the scheduler in Nova does this. However,
> if the client fails before getting the message, AMQP will automatically
> requeue it and send it to another client. But that's an unlikely
> occurrence as it's queue-per-host so there wouldn't be a second client.
> Therefore, queues should be configured to be durable.

Oddly, the default in oslo.messaging is for them to not be durable.

And as Gordon pointed out, queues are auto-deleted leading to this bug:
https://bugs.launchpad.net/oslo.messaging/+bug/1349301

And then there are issues about who should re-create queues on amqp 
server failover:
https://bugs.launchpad.net/oslo.messaging/+bug/1338732

Chris