Durable topic routing exchange being recreated on every application start

[rregout]

I have created a test application with a JMS durable topic. I added two JMS listeners for which a queue is created automatically.

On the first start I have:

• Exchange: jms.durable.topic
• Queue: test.topic.receiver.one & test.topic.receiver.two
• Routing exchange (x-jms-topic): two times jms-dutop-slx-

Every time I stop the application and start it again, two new x-jms-topic exchanges are created and binded to the corresponding queue and jms.durable.topic.

Why are x-jms-topic exchanges recreated on each startup?

@EnableJms
@Configuration
@EnableConfigurationProperties(RabbitProperties.class)
@RequiredArgsConstructor
public class RabbitConfig {

    private final RabbitProperties rabbitProperties;

    @Bean
    public RMQConnectionFactory connectionFactory(){
        RMQConnectionFactory factory = new RMQConnectionFactory();
        factory.setUsername(rabbitProperties.getUsername());
        factory.setPassword(rabbitProperties.getPassword());
        factory.setVirtualHost(rabbitProperties.getVirtualHost());
        factory.setHost(rabbitProperties.getHost());
        factory.setPort(rabbitProperties.getPort());
        return factory;
    }

    @Bean
    public DefaultJmsListenerContainerFactory jmsTopicListenerContainerFactory(ConnectionFactory connectionFactory) {
        DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory();
        factory.setConnectionFactory(connectionFactory);
        factory.setPubSubDomain(true);
        factory.setSubscriptionDurable(true);
        return factory;
    }

    @Bean
    public Destination jmsTopicDestination() {
        RMQDestination destination = new RMQDestination();
        destination.setAmqpExchangeName("jms.durable.topic");
        destination.setAmqp(false);
        destination.setQueue(false);
        destination.setAmqpRoutingKey("TestEventTopic");
        return destination;
    }

    @Bean
    public JmsTemplate jmsTemplateTopic(ConnectionFactory jmsTopicListenerContainerFactory, Destination jmsTopicDestination) {
        JmsTemplate jmsTemplate = new JmsTemplate(jmsTopicListenerContainerFactory);
        jmsTemplate.setPubSubDomain(true);
        jmsTemplate.setDefaultDestination(jmsTopicDestination);
        return jmsTemplate;
    }

}

@Component
@Slf4j
public class TopicReceiverOne {

  @JmsListener(destination = "TestEventTopic", containerFactory = "jmsTopicListenerContainerFactory",
          selector = "event = 'test1'", subscription = "test.topic.receiver.one")
  public void receiveMessage(TextMessage message) throws JMSException {
      log.info("Topic receiver one - received <{}>", message.getText());
  }

}

@Component
@Slf4j
public class TopicReceiverTwo {

  @JmsListener(destination = "TestEventTopic", containerFactory = "jmsTopicListenerContainerFactory",
          selector = "event = 'test2'", subscription = "test.topic.receiver.two")
  public void receiveMessage(TextMessage message) throws JMSException {
      log.info("Topic receiver two - received <{}>", message.getText());
  }

}

[acogoluegnes]

It seems like a bug. The selector exchanges are created with a UUID-based name to avoid conflicts, but then it is not possible to find whether they must be created or not on application restart. They are not supposed to be deleted between application restarts as they are for a durable subscription. So a fix would be to name them after the topic name and the subscription name, this way the application would re-create them on restart, which is idempotent if they already exist.

Note they should all go away when the subscriber unsubscribed (not a fix, I know :-) ).

[acogoluegnes]

I created a follow-up issue: #456.