As part of our efforts to improve the resilience of OpenStack within sites, we are moving to a multi controller architecture. I decided to tackle the underlying, stateful infrastructure services first. The first of those I looked into was RabbitMQ. RabbitMQ supports clustering, and HA queues, as well as durable queues (queues that persist to disk). The setup seems fairly simple, but unfortunately many things still assume IP means IPv4, and that's exactly where this got interesting.