400 concurrent users accessing the same data (very large) where we load in the memory at initialization time, users may very frequently update the data too. How can I make this scale very well with Hibernate – using Caching, and what type?

-To initialize the data at startup, initialize method is used very often – basically everywhere. (Better ways to do it?)
-We tried the Second-Level Caching, but it was kind of slow.
-If we use spring (templates …etc), is it like adding another layer of code, which will make it even slower?

We converted the application to work with Hibernate 3, same perfomance ...


Any notes, tips, or links will be appreciated.

Thanks.

-Hibernate rocks