As I understand, if the second level cache is configured, an object is placed in it immediately after reading from a database. An object in the second level cache outlives the session in which it was retrieved. So the question is when an object is deleted from the second level cache?
I understand that I can explicitly evict it from the cache. But in a web application it is not convenient, I would prefer if it is done automatically, based on some expiration mechanism.

Thanks,
Lev

It was a stupid question on my part. Obviously every cache implementation have to have a parameter that specifies a maximum idling time after which an object is deleted from cache.
At least EhCache has it. I found this information in
http://blog.upcom.eu/2009/01/19/improving-hibernate-performance-using-second-level-cache/

Lev Tannen