ActiveMQ Mirrored Queue Performance Penalty

Question

I'm setting up an ActiveMQ instance and I'm interested in using Mirrored Queues to monitor a particular queue from time to time. However, from the linked documentation it appears that enabling Mirrored Queues will create a mirror topic for every queue in the system, of which there will be many. I have a few questions about this approach:

1. Is there a big performance impact to having topics with no subscribers? There won't always be a subscriber on the topic, I'm hoping that the impact will be minimal when no one's listening.
2. The queue's performance is obviously more important than the monitoring topic -- if the only subscribers to the mirror topic are non-durable, will that help to minimize any additional system load?

Thanks!

Answer 1

Typically no big issue when no one is subscribing the topics. And, yes, non durable subscribers generally is cheaper than the opposite. But I suggest you connect VisualVM to your specific setup and monitor resource usage under load with and without mirrored queues. That probably gives the best answer to this question