We are defining an architecture to collect log information by Logstash shippers which are installed in various machines and index the data in one elasticsearch server centra
I have been wondering the same thing. Earlier recommendations by the Logstash folks recommend Redis over RabbitMQ (http://logstash.net/docs/1.1.1/tutorials/getting-started-centralized), however that section of the notes no longer exists in the current documentation although there are generic notes on using a broker to deal with spikes here https://www.elastic.co/guide/en/logstash/current/deploying-and-scaling.html.
While I am also using RabbitMQ quite happily, I'm currently exploring a Redis broker, since the AMQP protocol is likely overkill for my logging use case.