Is the session id I get from HttpSession.getId() unique, I mean even if I change my servlet container, am I assured to get a unique id... I dont think so. Actually I have to store some session info in the database alongwith the session id. So I dont want to mix up the session info. Can I rely on the getId() API or do I need to generate my own unique number for each session, and thus I am assured not to have any problem even if I change my container. SHankar.