CPU Spikes with WinHTTP Web Proxy Service
by admin on Mar.28, 2008, under Software, Systems
Ran across something interesting this week. I was looking into performance on some of our webservers and noticed that there would be unexplained CPU spikes every once in a while. No real spikes in traffic, no additional tasks going on.
In the event logs I did find something that correlated with the CPU spikes:
Event ID: 7036
“The WinHTTP Web Proxy Auto-Discovery Service service entered the running state.”
Event ID: 7036
“The WinHTTP Web Proxy Auto-Discovery Service service entered the stopped state.”
This happens many times a day, starting and stopping. When in transition it seemed to spike the CPU for a little while.
Service Description is the following:
Implements the Web Proxy Auto-Discovery (WPAD) protocol for Windows HTTP Services (WinHTTP). WPAD is a protocol to enable an HTTP client to automatically discover a proxy configuration. If this service is stopped or disabled, the WPAD protocol will be executed within the HTTP client’s process instead of an external service process; there would be no loss of functionality as a result.
In looking into this more I found this is not needed to run IIS or anything else on your server. Only needed for your browser on your server to detect a proxy for Internet browsing. So do yourself a favor and disable this service, you will see it most likely set as manual and stopped but don’t let this fool you. Check out your event logs and if you see it starting and stopping disable it.
May 29th, 2008 on 10:07 pm
Thanks for the information on this issue. I recently spent a lot of money on a new system, quad core cpu, 8gb ram etc.. It kept on freezing on my at any time of the day. I took it back to the shop for repairs but they couldn’t solve the problem (not suprized!!) so it was now up to me. On it’s first day home (today) it did it 3 times in the space of 3 hours so I started looking at the System Events in Event Viewer. Every time it froze I had to reboot and the LAST event in the log every time was - The WinHTTP Web Proxy Auto-Discovery Service service entered the stopped state. I have now disabled the Service and have been error free for a good hour.
Let’s hope you have solved my problems.
Thanks
Dave
May 29th, 2008 on 10:40 pm
Spoke too soon! This was now the last entry into the Event Log. The time service is now synchronizing the system time with the time source time.windows.com,0×9 (ntp.m|0×9|0.0.0.0:123->207.46.232.182:123).
August 26th, 2009 on 10:28 pm
I was having random ASP.net Application Errors. Seems that some of them these happend while this service was running. Thanks for the tip!