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javatomcatrabbitmqamqpspring-rabbit

DirectMessageListenerContainer without a configured Task Executor on TomCat?

I'm setting a DirectMessageListenerContainer for my messaging application. I am working with Tomcat, Spring, AMQP.

The docs have this warning https://docs.spring.io/spring-amqp/reference/#threading

With the DirectMessageListenerContainer, you need to ensure that the connection factory is configured with a task executor that had sufficient threads to support your desired concurrency across all listener containers that use that factory. The default pool size is only five.

In my application, I haven't configured any executor so I am using the default. The reason I have not done so is because I am operating over tomcat which is set with 10000 max threads. Am I going to end up bottlenecked with a pool size of five?

Solution

  • The listener threads have nothing to do with tomcat threads. I just looked at the latest amqp-client (the RabbitMQ java client that Spring AMQP uses) and the default number of threads is now...

    DEFAULT_NUM_THREADS = Runtime.getRuntime().availableProcessors() * 2;

    Whether that is enough for your application entirely depends on your application, how long it takes to process a message, and how much concurrency you configure (consumersPerQueue).