Another very minor detail, but you mention that RabbitMQ can do priority based on multiple queues. While that's certainly a fine way to do it, it's worth noting that AMQP also supports per-message priorities within one queue:

http://www.rabbitmq.com/amqp-0-9-1-reference.html#class.basi...

> The server MUST implement at least 2 priority levels for basic messages, where priorities 0-4 and 5-9 are treated as two distinct levels.

Depending on your client, it may be difficult to prioritize consumption of one queue over another, so this solution could be preferred.

Thanks! I'll update the post. A quick search found this RabbitMQ plugin https://github.com/rabbitmq/rabbitmq-priority-queue , which specifies: "In contrast to the AMQP spec, RabbitMQ queues by default do not support priorities. When creating priority queues using this plugin, you can specify as many priority levels as you like."

Your are correct. The sentence you referenced is in the section that describes RabbitMQ without clustering. The next section talks about the tradeoffs of RabbitMQ clustering.

OK. Fair enough. But that's merely a configuration choice and not really a shortcoming of RabbitMQ and even without a cluster, persistent queues are at your disposal, it's just that a HA cluster would be able to give you more of a guarantee.

Really enjoyed reading your post by the way...

thanks. The Pros/Cons were supposed to refer to the complete architecture setup, and not to the Q component by itself. I can see how that could have been read that way...