RabbitMQ — asynchronous messaging in practice

The user clicks “Generate report”. Synchronous processing takes 30 seconds. The solution? Move the heavy work to the background. RabbitMQ is our tool for asynchronous processing and service decoupling.

Why RabbitMQ¶

AMQP standard, a rich management UI, excellent Java support via Spring AMQP. The producer sends a message, the consumer processes it. Better UX, scalability, and resilience.

Exchanges, queues, bindings¶

@Bean
public Queue reportQueue() {
    return new Queue("reports.generate", true);
}

@RabbitListener(queues = "reports.generate")
public void handleReport(ReportRequest request) {
    byte[] pdf = reportService.generate(request);
    emailService.sendReport(request.getUserEmail(), pdf);
}

Error handling and the dead letter queue¶

Three attempts with exponential backoff, then a move to the DLQ. DLQ monitoring is part of alerting. The Management Plugin on port 15672 provides an overview of queues and throughput.

Messaging is an architectural pattern¶

Instead of synchronous calls you think in events and queues. The result: a more resilient, more scalable system.