preventing multiple logins

From: Sameer (sameer.gupta_at_jv.cmc.net.in)
Date: 10/20/03 

Date: Mon, 20 Oct 2003 03:11:34 -0700

one important problem i am facing is that my web solution
(asp.net) will be deployed on a webfarm. I am using sql
server session management on clustered sqlservers. but as
i need to prevent multiple logins through a
username/password (same credentials at a time) on the
website.

also session_end() event does not fire in sql server mode.

one solution is sychronized cache of webservers. and
maintaining usernames (loggedin) in the application cache.
This solution does not look like a robust solution.
suggest a standard solution.

please help me.

Regards
Sameer