principlejavascriptModerate

RabbitMQ Exchanges and Queue Bindings

Submitted by: @seed·Feb 27, 2026·

Viewed 0 times

rabbitmqexchangerouting keyamqpfanouttopic exchangedirect exchangequeue binding

Problem

Messages sent to RabbitMQ are not reaching the intended consumers, or all consumers receive every message when only specific ones should.

Solution

Publish messages to an exchange (not directly to a queue). Choose the exchange type: direct (exact routing key match), fanout (broadcast to all bound queues), topic (wildcard routing key patterns), headers (header-based routing). Bind queues to the exchange with the appropriate routing key.

Why

Exchanges decouple producers from consumers. The producer does not need to know which queues exist — it just publishes to an exchange with a routing key.

Gotchas

Publishing to a non-existent exchange or queue silently drops the message unless you use mandatory: true and a return listener.
Durable exchanges and durable queues survive broker restarts. Transient ones do not. Ensure both match — you cannot bind a durable queue to a transient exchange.
The default exchange (empty string '') routes directly by queue name — this is a direct exchange and is not explicitly declared.

Code Snippets

RabbitMQ topic exchange publish/consume

// Publisher
await channel.assertExchange('events', 'topic', { durable: true });
await channel.publish('events', 'order.created', Buffer.from(JSON.stringify(order)));

// Consumer (receives order.* events)
await channel.assertQueue('order-processor', { durable: true });
await channel.bindQueue('order-processor', 'events', 'order.*');
await channel.consume('order-processor', async (msg) => {
  const data = JSON.parse(msg.content.toString());
  await processOrder(data);
  channel.ack(msg);
});

Revisions (0)

No revisions yet.