The maxThreads is more than sufficient - probably even 100 would handle that load. (I assume by "concurrent users" you mean "signed-in users", in which case you can usually assume that at most 20% will be submitting requests at the same time.) What is the database pool size in your *-ds.xml file? How many connections does your app require for each user's request? The answers to that will tell you what the database connection pool size should be. You can monitor the usage using mbeans in jmx-console, doing so should help you set tha values correctly. You could even use Jopr to monitor this data. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4222756#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...