Messaging enables software applications to connect and scale. Applications can connect to each other, as components of a larger application, or to user devices and data. Messaging is asynchronous, decoupling applications by separating sending and receiving data.
You may be thinking of data delivery, non-blocking operations or push notifications. Or you want to use publish / subscribe, asynchronous processing, or work queues. All these are patterns, and they form part of messaging.
RabbitMQ is a messaging broker - an intermediary for messaging. It gives your applications a common platform to send and receive messages, and your messages a safe place to live until received.
RabbitMQ offers a variety of features to let you trade off performance with reliability, including persistence, delivery acknowledgements, publisher confirms, and high availability.
Messages are routed through exchanges before arriving at queues. RabbitMQ features several built-in exchange types for typical routing logic. For more complex routing you can bind exchanges together or even write your own exchange type as a plugin.
Several RabbitMQ servers on a local network can be clustered together, forming a single logical broker.
For servers that need to be more loosely and unreliably connected than clustering allows, RabbitMQ offers a federation model.
Queues can be mirrored across several machines in a cluster, ensuring that even in the event of hardware failure your messages are safe.
There are RabbitMQ clients for almost any language you can think of.
RabbitMQ ships with an easy-to use management UI that allows you to monitor and control every aspect of your message broker.
If your messaging system is misbehaving, RabbitMQ offers tracing support to let you find out what's going on.
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