Performance tweak: Optimizing StaticFileHandler in EPiServer CMS 5 (part 2)
This is a update to my previous post.
EPiServer CMS 5 Release 2 will support kernel-mode response caching when you enable expirationTime on a VPP in web.config. Kernel mode response caching is handled by http.sys which is the HTTP protocol stack in Windows. This cache kicks in when static content with a valid cache policy defined is accessed multiple times witin a specific time period (by default 2 anonymous requests within 10 seconds). This cache was introduced in IIS 6 and was specifically designed to improve performance for static files by skipping the user-mode transition, and in our case we are also skipping ASP.NET and all it's modules.
The list when kernel-mode caching is not used is very very long, read more here. For example visitors must be anonymous and URL's cannot have querystrings.
IIS 7 have a nice way of looking into the kernel-cache by typing:
c:\>netsh http show cachestate
I was hoping to publish some performance stats whenever we get our new MS Visual Studio 2008 Team Test Load Agents, the server kind of responds to fast right now ;-)
06 May 2008