How can I run multiple listeners in Spring Boot Java?

Question

I am continuously receiving data feed from third party and want to process around 100k messages in less than a minute. So thinking to implement a messaging queue through which I can offload the processing part and will push the message to a queue, where one worker out of 100 (or whatever number) picks the job and process it.

I've read about JMS and Redis based messaging, but I am not sure how to run multiple listeners. The single listener is already configured.

Answer 1

Spring JMS allows you to specify concurrency limits via a "lower-upper" String, eg "5-10", or a simple upper limit String, eg "10" (the lower limit will be 1 in this case).

The listener container will always hold on to the minimum number of consumers (setConcurrentConsumers(int)) and will slowly scale up to the maximum number of consumers

See:

[1] https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/jms/config/DefaultJmsListenerContainerFactory.html#setConcurrency-java.lang.String-

[2] https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/jms/listener/DefaultMessageListenerContainer.html#setConcurrency-java.lang.String-

An example in a Spring boot configuration bean:

@Configuration
@EnableJms
public class AppConfig {

    @Bean
    public DefaultJmsListenerContainerFactory jmsListenerContainerFactory() {
        DefaultJmsListenerContainerFactory factory 
          = new DefaultJmsListenerContainerFactory();
        factory.setConnectionFactory(connectionFactory());
        factory.setConcurrency("3-10");
        return factory;
    }
}