If I add an object to the ObjectCache – at what level is this stored at? Would this be accessible by all users of the application or only a specific instance?
I’ve read articles that claim it is at application level but when I enumerate the cache, all I can see are the objects that instance of the application created.
As far as I know it depends on the application pool (since it stays on top of the ASP.NET stack).
This means that if you have multiple instances of the same cache on the same machine, each using a different app pool, you’ll have different caches. The same if you have multiple machines.
If you want a single cache on multiple machines use a distributed cache like Windows Server Appfabric.