Is there anyway to monitor one single (class) of object in terms of cache?

Question

I am trying to determine which implementation of the data structure would be best for the web application. Basically, I will maintain one set of "State" class for each unique user, and the State will be cached for some time when the user login, and after the non-sliding period, the state is saved to the db. So in order to balance the db load and the iis memory, I have to determine what is the best (expected) timeout for the cache.

My question is, how to monitor the particular cache activity for one set of object? I tried perfmon, and it gives roughly the % of total memory limit, but no idea on size or so (maybe even better, I could get a list of all cached objects and also the size and other performance issue data).

One last thing, I expect the program is going to handle 100,000+ cached user and each of them may do a request in about 10s-60s. So performance does matters to me.

Answer 1

What exactely are you trying to measure here? If you just want to get the size of your in-memory State instances at any given time, you can use an application-level counter and add/substract every time you create/remove an instance of State. So you know your State size, you know how many State instances you have. But if you already count on getting 100.000+ users each requesting at least once / minute you can actually do the math.