Quick update: Looking at the source the problem seems to be with method searchUsers in class LDAPExtUserModuleImpl. I added some debugging to verify that ldapContext.close() is been called - and it is. Having pooling logging turned on I can see that even though ldapContext.close() is called the connection isn't released. On the other hand ldapContext.close() in method getProperty in LDAPUserProfileModuleImpl is releasing the connection. Then I read this: http://blogs.warwick.ac.uk/kieranshaw/entry/ldap_connection_pooling/ It's says there that one should close NamingEnumeration - which you don't do in searchUsers. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4141841#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...