Is System.Web.Caching or System.Runtime.Caching preferable for a .NET 4 web application

Solution 1:

Microsoft recommends using System.Runtime.Caching for all caching purposes. See this: http://msdn.microsoft.com/en-us/library/dd997357.aspx

Although, I have come across a couple threads where people are having issues with the MemoryCache.Default instance. After a while, it stops working properly. Any item you add using the Add or Set method does not actually get added to the cache. I tried the same and was able to reproduce this issue with explicitly calling MemoryCache.Default.Dispose() method.

Here are the links: MemoryCache Empty : Returns null after being set

http://forums.asp.net/t/1736572.aspx/1

My recommendation is to use the System.Web.Caching (HttpContext.Current.Cache)

UPDATE:

This issue has been fixed by MS. Check the accepted answer in the post below: Runtime Cache Issue Resolved

Solution 2:

System.Runtime.Caching allows you to cache across all .Net apps, not just the IIS worker process. So if you have a requirement that will access the cache in multiple scenarios, use System.Runtime. Also you can check this cache adapter which allows you to swap between runtime, web, and app fabric caching. https://bitbucket.org/glav/cacheadapter

One more thing, if you have a multi-server farm, with a load balanced configuration make sure you have sticky-sessions or a distributed cache model.