What types of exchanges are supported in RabbitMQ and where are they used?

RabbitMQ supports the following types of exchanges, which determine the message routing logic:

• Direct Exchange — routes messages to queues where the routing key matches the binding key. Used for point-to-point delivery.

• Fanout Exchange — sends messages to all queues bound to this exchange, ignoring the routing key. Used for broadcast messaging.

• Topic Exchange — routes messages to queues based on routing key patterns with support for wildcards (* and #). Used for flexible topic-based routing.

• Headers Exchange — routes messages based on headers rather than routing keys. Allows for more complex filtering rules.

Example of using a direct exchange in Python with the pika library:

channel.exchange_declare(exchange='direct_logs', exchange_type='direct')
channel.basic_publish(exchange='direct_logs', routing_key='error', body='Error message')

Each exchange type is suitable for different scenarios: from simple delivery to complex routing by topics and filtering.