system.web.caching - At what level is the cache maintained?

I am looking at implementing caching in a .net Web App. Basically... I want to cache some data that is pulled in on every page, but never changes on the database.

Is my Cache Element unique to each:

• Session?
• App Pool?
• Server?

If it is session, this could get out of hand if thousands of people are hitting my site and each 开发者_如何学Ccache is ~5k.

If App Pool, and I had several instances of one site running (say with a different DB backend, all on one server, though) then I'd need individual App Pools for each instance.

Any help would be appreciated... I think this data is probably out there I just don't have the right google combination to pull it up.

By default it is stored in memory on the server. This means that it will be shared among all users of the web site. It also means that if you are running your site in a web farm, you will have to use an out-of-process cache storage to ensure that all nodes of the farm share the same cache. Here's an article on MSDN which discusses this.

"One instance of this class is created per application domain, and it remains valid as long as the application domain remains active" - MSDN