In the following test I'm trying to simulate the following scenario:
But my test fails and the message is not redelivered to the new consumer. I'll appreciate any hints on this.
MessageProcessingFailureAndReprocessingTest.java
@ContextConfiguration(locations="com.prototypo.queue.MessageProcessingFailureAndReprocessingTest$ContextConfig",
loader=JavaConfigContextLoader.class)
public class MessageProcessingFailureAndReprocessingTest extends AbstractJUnit4SpringContextTests {
@Autowired
private FailureReprocessTestScenario testScenario;
@Before
public void setUp() {
testScenario.start();
}
@After
public void tearDown() throws Exception {
testScenario.stop();
}
@Test public void
should_reprocess_task_after_processing_failure() {
try {
Thread.sleep(20*1000);
assertThat(testScenario.succeedingWorker.processedTasks, is(Arrays.asList(new String[]{
"task-1",
})));
} catch (InterruptedException e) {
fail();
}
}
@Configurable
public static class FailureReprocessTestScenario {
@Autowired
public BrokerService broker;
@Autowired
public MockTaskProducer mockTaskProducer;
@Autowired
public FailingWorker failingWorker;
@Autowired
public SucceedingWorker succeedingWorker;
@Autowired
public TaskScheduler scheduler;
public void start() {
Date now = new Date();
scheduler.schedule(new Runnable() {
public void run() { failingWorker.start(); }
}, now);
Date after1Seconds = new Date(now.getTime() + 1*1000);
scheduler.schedule(new Runnable() {
public void run() { mockTaskProducer.produceTask(); }
}, after1Seconds);
Date after2Seconds = new Date(now.getTime() + 2*1000);
scheduler.schedule(new Runnable() {
public void run() {
failingWorker.stop();
succeedingWorker.start();
}
}, after2Seconds);
}
public void stop() throws Exception {
succeedingWorker.stop();
broker.stop();
}
}
@Configuration
@ImportResource(value={"classpath:applicationContext-jms.xml",
"classpath:applicationContext-task.xml"})
public static class ContextConfig {
@Autowired
private ConnectionFactory jmsFactory;
@Bean
public FailureReprocessTestScenario testScenario() {
return new FailureReprocessTestScenario();
}
@Bean
public MockTaskProducer mockTaskProducer() {
return new MockTaskProducer();
}
@Bean
public FailingWorker failingWorker() {
TaskListener listener = new TaskListener();
FailingWorker worker = new FailingWorker(listenerContainer(listener));
listener.setProcessor(worker);
return worker;
}
@Bean
public SucceedingWorker succeedingWorker() {
TaskListener listener = new TaskListener();
SucceedingWorker worker = new SucceedingWorker(listenerContainer(listener));
listener.setProcessor(worker);
return worker;
}
private DefaultMessageListenerContainer listenerContainer(TaskListener listener) {
DefaultMessageListenerContainer listenerContainer = new DefaultMessageListenerContainer();
listenerContainer.setConnectionFactory(jmsFactory);
listenerContainer.setDestinationName("tasksQueue");
listenerContainer.setMessageListener(listener);
listenerContainer.setAutoStartup(false);
listenerContainer.initialize();
return listenerContainer;
}
}
public static class FailingWorker implements TaskProcessor {
private Logger LOG = Logger.getLogger(FailingWorker.class.getName());
private final DefaultMessageListenerContainer listenerContainer;
public FailingWorker(DefaultMessageListenerContainer listenerContainer) {
this.listenerContainer = listenerContainer;
}
public void start() {
LOG.info("FailingWorker.start()");
listenerContainer.start();
}
public void stop() {
LOG.info("FailingWorker.stop()");
listenerContainer.stop();
}
@Override
public void processTask(Object task) {
LOG.info("FailingWorker.processTask(" + task + ")");
try {
Thread.sleep(1*1000);
throw Throwables.propagate(new Exception("Simulate task processing failure"));
} catch (InterruptedException e) {
LOG.log(Level.SEVERE, "Unexpected interruption exception");
}
}
}
public static class SucceedingWorker implements TaskProcessor {
private Logger LOG = Logger.getLogger(SucceedingWorker.class.getName());
private final DefaultMessageListenerContainer listenerContainer;
public final List<String> processedTasks;
public SucceedingWorker(DefaultMessageListenerContainer listenerContainer) {
this.listenerContainer = listenerContainer;
this.processedTasks = new ArrayList<String>();
}
public void start() {
LOG.info("SucceedingWorker.start()");
listenerContainer.start();
}
public void stop() {
LOG.info("SucceedingWorker.stop()");
listenerContainer.stop();
}
@Override
public void processTask(Object task) {
LOG.info("SucceedingWorker.processTask(" + task + ")");
try {
TextMessage taskText = (TextMessage) task;
processedTasks.add(taskText.getText());
} catch (JMSException e) {
LOG.log(Level.SEVERE, "Unexpected exception during task processing");
}
}
}
}
TaskListener.java
public class TaskListener implements MessageListener {
private TaskProcessor processor;
@Override
public void onMessage(Message message) {
processor.processTask(message);
}
public void setProcessor(TaskProcessor processor) {
this.processor = processor;
}
}
MockTaskProducer.java
@Configurable
public class MockTaskProducer implements ApplicationContextAware {
private Logger LOG = Logger.getLogger(MockTaskProducer.class.getName());
@Autowired
private JmsTemplate jmsTemplate;
private Destination destination;
private int taskCounter = 0;
public void produceTask() {
LOG.info("MockTaskProducer.produceTask(" + taskCounter + ")");
taskCounter++;
jmsTemplate.send(destination, new MessageCreator() {
@Override
public Message createMessage(Session session) throws JMSException {
TextMessage message = session.createTextMessage("task-" + taskCounter);
return message;
}
});
}
@Override
public void setApplicationContext(ApplicationContext applicationContext)
throws BeansException {
destination = applicationContext.getBean("tasksQueue", Destination.class);
}
}
Apparently the source of documentation I was looking yesterday Creating Robust JMS Applications mislead me in a way (or I might have understood it incorrectly). Especially that excerpt:
Until a JMS message has been acknowledged, it is not considered to be successfully consumed. The successful consumption of a message ordinarily takes place in three stages.
- The client receives the message.
- The client processes the message.
- The message is acknowledged. Acknowledgment is initiated either by the JMS provider or by the client, depending on the session acknowledgment mode.
I assumed AUTO_ACKNOWLEDGE does exactly that - acknowledged the message after the listener method returns a result. But according to the JMS specification it is a bit different and Spring listener containers as expected do not try to alter the behavior from the JMS specification. This is what the javadoc of AbstractMessageListenerContainer has to say - I've emphasized the important sentences:
The listener container offers the following message acknowledgment options:
- "sessionAcknowledgeMode" set to "AUTO_ACKNOWLEDGE" (default): Automatic message acknowledgment before listener execution; no redelivery in case of exception thrown.
- "sessionAcknowledgeMode" set to "CLIENT_ACKNOWLEDGE": Automatic message acknowledgment after successful listener execution; no redelivery in case of exception thrown.
- "sessionAcknowledgeMode" set to "DUPS_OK_ACKNOWLEDGE": Lazy message acknowledgment during or after listener execution; potential redelivery in case of exception thrown.
- "sessionTransacted" set to "true": Transactional acknowledgment after successful listener execution; guaranteed redelivery in case of exception thrown.
So the key to my solution is listenerContainer.setSessionTransacted(true);
Another issue I faced was that the JMS provider keeps redelivering the failed message back to the same consumer that had failed during the processing of the message. I don't know if the JMS specification gives a prescription what the provider should do in such situations, but what have worked for me was to use listenerContainer.shutdown();
in order to disconnect the failing consumer and allow the provider to redeliver the message and give a chance to another consumer.
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