The server/default/lib directory is the correct location for the JDBC driver JAR files. If both MySQL and JBossAS are showing CPU usage, then you can at least be assured that the database connection was made. You might want to enable the general query log in MySQL to see what is going on http://dev.mysql.com/doc/refman/5.0/en/query-log.html During the "hang" you should take thread dumps of JBossAS to see what your code is doing. I suggest taking three or more, perhaps a second or two apart. If your code is in a loop, this should point it out. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4172661#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...