RabbitMQ, on the other hand, is written in Erlang and is based on the Advanced Message Queuing Protocol (AMQP) protocol. AMQP is significantly more powerful and complicated than JMS, as it allows peer-to-peer messaging, request/reply, and publish/subscribe models for one-to-one or one-to-many message consumption.

RabbitMQ has gained popularity in the past 5 years, and is now the most searched-for queuing system.

RabbitMQ's architecture is outlined as follows:

Scaling in RabbitMQ systems is performed by creating a cluster of RabbitMQ servers. Clusters share data and state, which are replicated, but message queues are distinct per node. To achieve high availability we can also replicate queues in different nodes.