I don’t consider myself a message broker specialist and I spent only about a day or two on each so, I may have done some big mistakes configuration wise. I’ll take the blame if something is misconfigured or not used correctly.
RabbitMQ is well known and popular message broker and it has many powerful features. The documentation on the RabbitMQ web site is excellent and there are many books available. RabbitMQ is written in Erlang, not a widely used programming language but well adapted to such tasks. The company Pivotal develops and maintains RabbitMQ. I reviewed version 3.2.2 on CentOS 6 servers.
With the mesh of brokers setup, I got an insert rate of about 5000 msg/s over 15 threads and a single consumer was able to read 2000 msg/s. I let it run for a while and got 150M messages. At this point though, I lost the web interface and the publishing rate was much slower.