Types of Exchanges

RabbitMQ supports several types of exchanges, each serving a different routing strategy.

In my experience, direct and topic are the most commonly useful in backend Pub/Sub architectures. I rarely have a use for sending all messages to all queues, or for routing based on the message headers.

We'll talk more about the intricacies of routing keys later.

Breakdown

• Direct: Messages are routed to the queues based on the message routing key exactly matching the binding key of the queue.
• Topic: Messages are routed to queues based on wildcard matches between the routing key and the routing pattern specified in the binding.
• Fanout: It routes messages to all of the queues bound to it, ignoring the routing key.
• Headers: Routes based on header values instead of the routing key. It's similar to topic but uses message header attributes for routing.