To use the singleton fail-over HA-JMS service, you must configure JMS services identically on all nodes in the cluster. That includes all JMS related service MBeans and all deployed JMS applications. The JMS server is configured to persist its data in the DefaultDS. By default, that is the embedded HSQLDB. In most cluster environments, however, all nodes need to persist data against a shared database. So, the first thing to do before you start clustered JMS is to setup a shared database for JMS. You need to do the following: ? Configure DefaultDS to point to the database server of your choice. That is to replace the deploy/ hsqlsb-ds.xml file with the xxx-ds.xml file in the docs/examples/jca directory, where xxx is the name of the target shared database (e.g., mysql-ds.xml). ? Replace the hsqldb-jdbc2-service.xml file under the server/all/deploy-hasingleton/jms directory with one tuned to the specific database. For example if you use MySQL the file is mysql-jdbc2-service.xml. Configuration files for a number of RDBMS are bundled with the JBoss AS distribution. They can be found under docs/examples/jms. Note There is no need to replace the hsqldb-jdbc-state-service.xml file under the server/ all/deploy-hasingleton/jms directory. Despite the hsql in its name, it works with all SQL92 compliant databases, including HSQL, MySQL, SQL Server, and more. It automatically uses the DefaultDS for storage, as we configured above. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4004459#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...