Which server? Application or database? If the application server crashes then I don't see how the user could do anything at all.
As far as not starting from scratch, many servers, take Amazon.com for example, record session information such as current shopping card in the database. It's a lot of extra information to store but the advantage is the user can return any time to see their shopping cart. [ March 27, 2008: Message edited by: Scott Selikoff ]
As far i know the clustering can be used here for rescue but i was looking for answer in single app server environment. I think you provided me good example of storing in database. Is there any other way?