sc-win32-status 121 and 1236 in IIS log

Question

I am trying to solve some performance problems.

We have a web server that calls another web server with WCF services installed.

There are about 20,000 calls in 1 hour, most are a few milliseconds.

But about 20 of them are 10 to 50 seconds

All of these have sc-win32-status 121 or 1236.

Question is what could be causing sc-win32-status 121 or 1236, and how could I solve this?

Answer 1

Could be a denial of service attack via and improperly set MinFileBytesPerSec metabase setting.

For details:

http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/0b447dba-6bcc-4238-a932-0e083170c3ab.mspx?mfr=true