Hi, I wrote a simple message grouping example to illustrate the effect of 'JMSXGroupID', but it doesn't always work as expected. All I do is create two consumers and send out 10 messages with JMSXGroupID set, and inspect that all the messages will went to only one of the consumers. But the result is random: sometimes all messages went to consumer1, sometimes consumer2 and sometimes both. I don't know what's wrong?
The code :
MessageConsumer consumer1 = session.createConsumer(queue);
consumer1.setMessageListener(new SimpleMessageListener("consumer-1"));
MessageConsumer consumer2 = session.createConsumer(queue);
consumer2.setMessageListener(new SimpleMessageListener("consumer-2"));
//Step 8. Create and send 10 text messages with group id 'Group-0'
int msgCount = 10;
TextMessage[] groupMessages = new TextMessage[msgCount];
for (int i = 0; i < msgCount; i++)
{
groupMessages = session.createTextMessage("Group-0 message " + i);
groupMessages.setStringProperty(JBossMessage.JMSXGROUPID, "Group-0");
producer.send(groupMessages);
System.out.println("Sent message: " + groupMessages.getText());
}
And I added the config
<address-settings match="jms.queue.exampleQueue">
<distribution-policy-class>org.jboss.messaging.core.server.impl.GroupingRoundRobinDistributor</distribution-policy-class>
</address-settings>
