SimpleMessageListenerContainer Error Handling

2019-03-02 17:21发布

问题:

I'm using a SimpleMessageListenerContainer as a basis for remoting over AMQP. Everything goes smooth provided that the RabbitMQ broker can be reached at process startup. However, if by any reason it can't be reached (network down, permissions problem, etc...) the container just keeps retrying to connect forever. How can I set up a retry behaviour in this case (for example, try at most 5 times with an exponential backoff and then abort, killing the process)? I've had a look at this, but it doesn't seem to work for me on container startup. Can anyone please shed some light?

At the very least, I'd like to be able to catch the exception and provide a log message, instead of printing the exception itself as is the default behaviour.

回答1:

How can I set up a retry behaviour in this case

There is no sophisticated connection retry, just a simple recoveryInterval. The assumption is that the broker unavailability is temporary. Fatal errors (such as bad credentials) stop the container.

You could use some external process to try connectionFactory.createConnection() and stop() the SimpleMessageListenerContainer when you deem it's time to give up.

You could also subclass CachingConnectionFactory, override createBareConnection catch the exception and increment the recoveryInterval, then call stop() when you want.

EDIT

Since 1.5, you can now configure a backOff. Here's an example using Spring Boot...

@SpringBootApplication
public class RabbitBackOffApplication {

    public static void main(String[] args) {
        SpringApplication.run(RabbitBackOffApplication.class, args);
    }

    @Bean(name = "rabbitListenerContainerFactory")
    public SimpleRabbitListenerContainerFactory simpleRabbitListenerContainerFactory(
            SimpleRabbitListenerContainerFactoryConfigurer configurer,
            ConnectionFactory connectionFactory) {
        SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory();
        configurer.configure(factory, connectionFactory);
        BackOff recoveryBackOff = new FixedBackOff(5000, 3);
        factory.setRecoveryBackOff(recoveryBackOff);
        return factory;
    }

    @RabbitListener(queues = "foo")
    public void listen(String in) {

    }

}

and

2018-04-16 12:08:35.730  INFO 84850 --- [           main] com.example.RabbitBackOffApplication     : Started RabbitBackOffApplication in 0.844 seconds (JVM running for 1.297)
2018-04-16 12:08:40.788  WARN 84850 --- [cTaskExecutor-1] o.s.a.r.l.SimpleMessageListenerContainer : Consumer raised exception, processing can restart if the connection factory supports it. Exception summary: org.springframework.amqp.AmqpConnectException: java.net.ConnectException: Connection refused (Connection refused)
2018-04-16 12:08:40.788  INFO 84850 --- [cTaskExecutor-1] o.s.a.r.l.SimpleMessageListenerContainer : Restarting Consumer@57abad67: tags=[{}], channel=null, acknowledgeMode=AUTO local queue size=0
2018-04-16 12:08:40.789  INFO 84850 --- [cTaskExecutor-2] o.s.a.r.c.CachingConnectionFactory       : Attempting to connect to: [localhost:1234]
2018-04-16 12:08:45.851  WARN 84850 --- [cTaskExecutor-2] o.s.a.r.l.SimpleMessageListenerContainer : Consumer raised exception, processing can restart if the connection factory supports it. Exception summary: org.springframework.amqp.AmqpConnectException: java.net.ConnectException: Connection refused (Connection refused)
2018-04-16 12:08:45.852  INFO 84850 --- [cTaskExecutor-2] o.s.a.r.l.SimpleMessageListenerContainer : Restarting Consumer@3479ea: tags=[{}], channel=null, acknowledgeMode=AUTO local queue size=0
2018-04-16 12:08:45.852  INFO 84850 --- [cTaskExecutor-3] o.s.a.r.c.CachingConnectionFactory       : Attempting to connect to: [localhost:1234]
2018-04-16 12:08:50.935  WARN 84850 --- [cTaskExecutor-3] o.s.a.r.l.SimpleMessageListenerContainer : Consumer raised exception, processing can restart if the connection factory supports it. Exception summary: org.springframework.amqp.AmqpConnectException: java.net.ConnectException: Connection refused (Connection refused)
2018-04-16 12:08:50.935  INFO 84850 --- [cTaskExecutor-3] o.s.a.r.l.SimpleMessageListenerContainer : Restarting Consumer@2be60f67: tags=[{}], channel=null, acknowledgeMode=AUTO local queue size=0
2018-04-16 12:08:50.936  INFO 84850 --- [cTaskExecutor-4] o.s.a.r.c.CachingConnectionFactory       : Attempting to connect to: [localhost:1234]
2018-04-16 12:08:50.938  WARN 84850 --- [cTaskExecutor-4] o.s.a.r.l.SimpleMessageListenerContainer : stopping container - restart recovery attempts exhausted