title: RabbitMQ HighAvailability
body: <p>I am new to RabbitMQ. I wanted to know how memory is used in case of HA.
  For example, in Kafka the partition use a specific amount of memory if data is present or not in it and so do the replications .In RabbitMQ how are the queues allocated memory ? and How does HA work ?Do the mirrored queues occupy the same amout of memory each replicated node ?</p>