How to implement guide with spring boot 2.7 and rabbitmq: messages not being acknowledged under load
I've looked through the documentation and I'm still confused about I'm optimizing some code but I'm performance testing and Quick question that's been bugging me - I'm experiencing an scenario with my Spring Boot 2.7 application where messages sent to RabbitMQ are not getting acknowledged when the system is under heavy load..... The application uses the `@RabbitListener` annotation to process messages, and I've configured it with a concurrency setting to handle multiple messages simultaneously. However, during peak times, I can see in the RabbitMQ management interface that some messages remain in the queue, and the logs show the following behavior: ``` 2023-10-20 12:34:56.789 behavior [my-app] 12345 --- [ concurrent-1] o.s.amqp.rabbit.listener.SimpleMessageListenerContainer : Failed to process message. Message will be requeued. org.springframework.amqp.rabbit.listener.exception.ListenerExecutionFailedException: Listener method could not be invoked; nested exception is org.springframework.rabbit.listener.adapter.ListenerExecutionFailedException: Invocation of message listener failed; nested exception is java.lang.RuntimeException: Processing took too long ``` I've tried increasing the `prefetch` count in my `SimpleRabbitListenerContainerFactory` to allow more messages to be sent to the consumers, but that didn't seem to resolve the scenario. Here’s a snippet of the configuration I’m using: ```java @Bean public SimpleRabbitListenerContainerFactory rabbitListenerContainerFactory(ConnectionFactory connectionFactory) { SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory(); factory.setConnectionFactory(connectionFactory); factory.setConcurrentConsumers(5); factory.setMaxConcurrentConsumers(10); factory.setPrefetchCount(10); return factory; } ``` The `@RabbitListener` method is doing some processing that can take time, and I suspect it may be timing out under load. I’m currently not using any manual acknowledgment strategies, and I’m wondering if implementing manual acknowledgment could improve the situation. Would that be a good approach? Additionally, does anyone have suggestions on how to properly diagnose this scenario or improve the processing speed? Any insights would be greatly appreciated. I'm developing on Ubuntu 22.04 with Java. This is for a application running on Ubuntu 20.04. Any ideas how to fix this? I've been using Java for about a year now. I'd love to hear your thoughts on this.