Can server recognize disconnection between clients and serve

[changemylife]

Hi all!

I use "jboss-4.0.5.GA" and EJB3.0.

My client is standard alone. I use DatabaseLoginModule to authenticate a particular client.
When the client login success, I can get some informations such as username and role.
Can the server maintain connection between clients and server ? How server can recognize that a particular client has logout (disconnect).

have some ideas ?

Thank.