26.2. Using JMS

The property name used to identify the message group is JMSXGroupID. 
 // send 2 messages in the same group to ensure the same
 // consumer will receive both
 Message message = ...
 message.setStringProperty("JMSXGroupID", "Group-0");
 producer.send(message);

 message = ...
 message.setStringProperty("JMSXGroupID", "Group-0");
 producer.send(message);
Alternatively, you can set autogroup to true on the HornetQConnectionFactory which will pick a random unique id. This can also be set in the JBOSS_DIST/jboss-as/server/<PROFILE>/deploy/hornetq/hornetq-jms.xml file like this: 
<connection-factory name="NettyConnectionFactory">
   <connectors>
      <connector-ref connector-name="netty-connector"/>
   </connectors>
   <entries>
      <entry name="/ConnectionFactory"/>
   </entries>
   <autogroup>true</autogroup>
</connection-factory>
Alternatively you can set the group id via the connection factory. All messages sent with producers created via this connection factory will set the JMSXGroupID to the specified value on all messages sent. To configure the group id set it on the connection factory in the hornetq-jms.xml configuration file as follows: 
<connection-factory name="NettyConnectionFactory">
   <connectors>
      <connector-ref connector-name="netty-connector"/>
   </connectors>
   <entries>
      <entry name="/ConnectionFactory"/>
   </entries>
   <group-id>Group-0</group-id>
</connection-factory>