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Hibernate version:3.1

I am using ehCache to do the second level caching for H3. Should I divide the cache into functional regions (for example, user registration objects are in one cache, sample requests in another and sweepstakes entries in a third) or should they be divided by time (short duration, long duration) or by something else? What is the best practice for caching under H3?

Thanks.

You shouldn't have to do anything like this, unless you're very very performance-concious. Or maybe if you're planning on using items in the cache independently of hibernate. Have you read section 19 of the ref docs? Sections 19.2 and 19.3 are mostly likely to be of interest to you.

Actually I have read these parts. When I first setup H3 and started getting items from the database, it promptly blew up. This lead me to download ehCache and start cache regions.

Fair enough.

I've never seen a best practice being metioned anywhere around here, but I would imagine that it depends on how you're using the cache. If you're intending to do some cache management (specifically, you want to be able to evict chunks of cache based on age), then you'll probably want to follow java's model: eden, survivor1, survivor2, old. If you don't want that functionality, then you're probably using the cache to assist with LRU or MRU algorithms, so division by logical grouping would be best. If you're not "manually" using the cache at all, and are only setting it up to allow hibernate to make use of it, then you shouldn't have to worry about dividing it up.

Well, that does give me some ideas. I very rarely will need to deal with the cache manually and need it mostly for writing. For regular traffic areas, I will use a default cache, unless I start getting errors. For the higher traffic input areas (promotions and the like), I will use a named cache for each, size based on the size of the objects and the expected traffic. Since the higher areas are usually input only, the time to live for these objects will be small (a minute or less).

Who knows, perhaps this discussion will be the start of caching best practices.