RabbitMQ Message Broker

RabbitMQ is a free and open-source message broker software that implements the Advanced Message Queuing Protocol (AMQP) for reliable asynchronous communication between distributed applications. Originally developed by RabbitMQ Technologies Ltd (founded by Alexis Richardson and Matthias Radestock in 2007 in London), acquired by SpringSource (now VMware/Broadcom) in 2010, RabbitMQ is one of the most popular message brokers in the world, used by millions of organizations including Adidas, T-Mobile, NASA, and the UK Government. Key features: AMQP 0-9-1 protocol: the primary protocol, providing exchanges (direct, fanout, topic, headers), queues, bindings, and message properties. Messages are published to exchanges, routed to queues via bindings, and consumed by workers. Multi-protocol support: also supports STOMP, MQTT, and AMQP 1.0. Reliable delivery: publisher confirms and consumer acknowledgements ensure no messages are lost during crashes. Persistent messages stored to disk. Dead letter exchanges: automatically route messages that expire, are rejected, or exceed queue length limits for error handling. Flexible routing: topic exchanges support wildcard pattern matching (log.*.error matching log.app.error, log.db.error), enabling complex routing topologies. Clustering: multiple RabbitMQ nodes form a cluster with replicated queue metadata and mirrored queues for high availability. Federation and Shovel plugins: connect brokers across datacenters. Management UI: a web-based dashboard for monitoring queues, exchanges, bindings, connections, and message rates, with a management HTTP API. Erlang-based: built on the Erlang/OTP platform, inheriting its fault tolerance, hot code upgrades, and massive concurrency (millions of lightweight processes). Cross-platform. MPL 2.0.