For Oracle, it is using the pingDatabase method to check if the database is available. You could see either a warning or a SQL exception in the log file if the ping fails. Look at the following files in the source: connector/src/main/org/jboss/resource/adapter/jdbc/vendor/OracleValidConnectionChecker.java connector/src/main/org/jboss/resource/adapter/jdbc/BaseWrapperManagedConnection.java (the checkValid method) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4067475#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...