Hi,

I am using only 1 nhibernate session in the application scope, and I load into its 1st level cache some objects.
The application performs various computations ... one of them lasts for about 10 minutes. When I wanted to retrieve the objects from the 1st level cache, I found out that they are not there anymore, the 1st level cache has expired them.

I need to know whether an object in the cache 1L can expire, and if so, how can this be undo (prohibit the objects in the cache 1L expire).

Thank you,
C.

Objects do not expire in 1st level cache, only in 2nd level cache.
When objects in 1st level cache do dissappear, then probably because you have detached them previously from from persistent context (= 1st level cache). Objects get detached either when you call session.evict(object) or when you call session.clear()