Microsoft's IIS 6.0 comes with kernel mode caching for helping to speed up web page load times. Unfortunately, the kernel mode caching seems to have some side effects that are affecting my index.xml RSS feed that many of my blog readers subscribe to. You may have noticed that my blog web pages had blog entries that didn't show up in my index.xml feed until hours later. The kernel mode cache was designed to take heavily accessed files and stick them in the kernel for faster retrieval.
According to Microsoft:
"The IIS 6.0 kernel-mode cache is designed speed up static file performance significantly by bypassing the need to do a kernel-to-usermode transition to generate and serve the response," says Eric Deilly, IIS 6.0 program manager with Microsoft. "Instead, the kernel mode listener is able to receive the connection request, receive the new connection, check the kernel-mode cache, and serve the response from the cache on a cache hit."
During some troubleshooting I noticed that if I open the XML file locally on the Windows IIS server, the file is current. However, if I go to another PC which has never loaded the index.xml feed (not cached by the browser), it often loads an older version of the file. The only way I can see that happening is if the kernel is holding the file in memory using Microsoft's new kernel mode caching.
If I manually stop and start (restart) IIS, then the correct, most up-to-date index.xml file loads.
Even stranger, I can DELETE the index.xml file fom the IIS server and IIS will continue to "serve" the file as though it still exists. Weird, eh? I should get a 404 error on my browser after deleting.
If I then stop/start IIS then I get a file not found error on my browser. (or if I didn't delete the file, restarting IIS makes sure the most recent XML file is served)
I assume since the kernel cache caches heavily accessed files, such as my blog's RSS feed, that the kernel is keeping the file in memory and thus serving it from the kernel instead of the hard disk. However, it's supposed to detect changes in the file and then let the most recent version be loaded into the cache. I certainly can't restart IIS after after blog entry, so I will have to continue to work on this problem. Damn you Microsoft and damn your kernel mode caching!
Damn you Kernel Mode Caching!
Categories:
Technorati
Del.icio.us
Slashdot
Digg
twitter- Related Entries to Damn you Kernel Mode Caching!
- HTTP Error 500 19 when upgrading Office Communicator Phone Edition firmware URLs on Windows 2008 - Jan 19, 2009
- Installing and Upgrading to Movable Type 3.2 - Apr 11, 2006
- MovableType Trackback on Microsoft Windows IIS gives 404 error SOLVED! - May 13, 2004
- To Appear Offline or Not to Appear Offline, that is the Presence Question - Aug 19, 2009
- Office Communications Server 2007 R2 Web Scheduler - Aug 15, 2009
- Microsoft Releases Two New UC OCS 2007 Training Tools - Aug 13, 2009
- Judge orders Microsoft to stop Selling Microsoft Word + pay $290 million - Aug 12, 2009
- Office Communications Server Team Blog's Top 118 UC & OCS Blogs - Aug 12, 2009
- Microsoft OCS 2007 R2 Documentation - Jul 29, 2009
- Microsoft OCS 2007 R2 XMPP Gateway? - Jul 24, 2009
Listed below are links to sites that reference Damn you Kernel Mode Caching!:
Damn you Kernel Mode Caching! TrackBack URL : http://blog.tmcnet.com/mt/mt-tb.cgi/18233
4 Comments
Leave a comment
Related Entries
- HTTP Error 500 19 when upgrading Office Communicator Phone Edition firmware URLs on Windows 2008
- Installing and Upgrading to Movable Type 3.2
- MovableType Trackback on Microsoft Windows IIS gives 404 error SOLVED!
- To Appear Offline or Not to Appear Offline, that is the Presence Question
- Office Communications Server 2007 R2 Web Scheduler
- Microsoft Releases Two New UC OCS 2007 Training Tools
- Judge orders Microsoft to stop Selling Microsoft Word + pay $290 million
- Office Communications Server Team Blog's Top 118 UC & OCS Blogs
- Microsoft OCS 2007 R2 Documentation
- Microsoft OCS 2007 R2 XMPP Gateway?
I have same problem with IIS, however sometimes restarting the service doesn't fix it. I have to restart the whole OS
http://support.microsoft.com/?id=820129
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\HTTP\Parameters
UriEnableCache=0
have a nice day!
Yeah I tried this reg entry and it didn't work.
There is an interesting blog on Kernel Mode Caching by David Wang:
http://blogs.msdn.com/david.wang/archive/2005/07/07/HOWTO_Use_Kernel_Response_Cache_with_IIS_6.aspx