Several customers have reported a problem where they are using a JDBC store, the DBMS goes down and back up, but JMS can no longer use the store until WLS is shutdown and restarted. You can get around this problem by configuring the following attributes on the JDBC Connection Pool associated with the JMSJDBCStore:

TestConnectionsOnReserve="true"

TestTableName="[[[catalog.]schema.]prefix]JMSState"

If they are not set, then if the JDBC resource goes down and comes back up, JMS cannot re-use the connection pool until WLS is shutdown and restarted. This has been tested against WLS 6.0 SP02 and WLS 6.1.