Hibernate version: 2.1*

Hello,

I have a webapp that uses Hibernate, and I'm considering saving Hibernate Session in HttpSession, so I can benefit from the Session acting as a second level cache and thus avoid a few DB hits. Unfortunately, Session is not thread-safe, so a user hitting my webapp with multiple parallel requests (e.g. quickly opening multiple pages in new tabs) is likely to cause a HibernateException.

Hibernate in Action mentions this problem on page 328 (middle of the page), but there is no "recipe" given. So I am wondering how others handle this problem.

I can insert a servlet filter in the request chain, and ensure that only 1 request is processed at a time, but I am wondering if there is a better, more elegant approach.

How do others deal with this?

Thank you,
Otis

It must be better to create hibernate session per request and to use "global" cache for optimization. Heavy HttpSession can produce scalability problems.

this the right way to avoid concurrent httrequests.

Be sure to use a long session (storing it in httpSession) only if you really need it. This is called long-session-per-application-transaction pattern. As baliukas said, prefer short session with detached object if you need failover.

Even with long-session-per-application-transaction, you must take care of the session size and no consider it as a second level cache: it isn't