RabbitMQ Tutorial: Exchange Types, Routing Rules, and Practical Code Examples

The article revisits the general RabbitMQ usage flow: establishing a connection, creating a channel, declaring an exchange, declaring a queue, binding the exchange to the queue, publishing and consuming messages, and finally closing the channel and connection.

It then introduces the four exchange types:

fanout : broadcasts messages to all queues bound to the exchange.

direct : routes messages to queues whose binding key exactly matches the routing key.

topic : uses pattern matching with '.'‑separated words, where '*' matches a single word and '#' matches zero or more words.

headers : routes based on message header attributes (mentioned but not covered due to high resource cost).

Following the overview, the article presents three practical examples focusing on different exchange types.

01 – Publish/Subscribe (fanout) : Demonstrates a consumer script (receive_log.js) and a producer script (emit_log.js) that broadcast messages without specifying binding or routing keys.

02 – Routing (direct) : Shows a consumer script (receive_log_direct.js) and a producer script (emit_log_direct.js) where messages are routed using matching binding and routing keys.

03 – Topics (topic) : Provides a consumer script (receive_log_topic.js) and a producer script (emit_log_topic.js) illustrating pattern‑based routing with wildcard keys.

The examples also discuss durable exchanges, temporary exclusive queues, and the importance of matching binding and routing keys for direct and topic exchanges.

In conclusion, the article emphasizes that while the core steps remain similar across examples, the main differences lie in how binding and routing keys are handled for each exchange type, guiding readers to design appropriate routing rules.