Windows Server 2008 – Kill w3wp.exe if it is Working on 100% CPU Over a Period of Time

application-poolsasp.netcpu-usagewindows-server-2008

Im running a ASP.NET website on Windows 2008 and IIS7.

From time to time my w3wp.exe start spiking into 100% CPU, and the website hangs.
I have not found the reason for this, but that is irrelevant at the moment. All I want is to configure the application pool to kill the w3wp.exe process when it is working on 100% CPU over a short period of time. How can I do this?

These are my application pool CPU settings:
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Also, if I kill the process, will the process be running as normal upon next request to the website, or do I have to start the process manually after it is killed?

Best Answer

The strict answer to your question is to set the limit to 1000*CPUPercent that you want to be the hard upper limit, and set the Action to KillW3WP. For example, to limit it at 90%, you would set the limit to 90000

More info on CPU limits in an application pool can be found here: http://www.iis.net/ConfigReference/system.applicationHost/applicationPools/add/cpu

I must say, however, you're trying to cure the symptom and not the problem. Debugging the code to figure out why this is happening will fix this for good, but killing the process is just sticking a temporary band-aid over it.

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Iis – w3wp.exe using 50% CPU time when website is not doing anything

I would first verify that the application domainis not restarting. Sometimes this is due to files that are changing.

Add this to your master web.config located at:

C:\WINDOWS\Microsoft.NET\Framework\<version>\CONFIG or
C:\WINDOWS\Microsoft.NET\Framework64\<version>\CONFIG 

<add name="Application Lifetime Events Default" eventName="Application Lifetime Events"
    provider="EventLogProvider" profile="Default" minInstances="1"
    maxLimit="Infinite" minInterval="00:01:00" custom="" />

http://blogs.msdn.com/b/tess/archive/2006/08/02/asp-net-case-study-lost-session-variables-and-appdomain-recycles.aspx#686393

Windows 2003/2008 terminal server, Application using 95-100% CPU when crashed, auto kill process

I don't have a specific tool recommendation for what you want, but at least as a quick-and-dirty you can probably cobble something together with a couple of the Sysinternals tools. You might be able to run this non-interactively (scheduled), but it definitely wouldn't be a service.

Use Procdump to monitor CPU usage of processes with the appropriate process name (based on the executable). When a process hits the configured levels, generate a dump. Possibly start this from a looping .cmd file with a slight wait so each instance of procdump will only dump a single time, or possibly use the -n option to specify a very large number of dumps before it exits.
Monitor your dump output directory for new files. Parse out PIDs as required, then kill the files or not - it doesn't sound like you're going to be debugging and fixing the app.
Use PsKill to kill the relevant process.

As with anything cobbled together, this may or may not work well or be stable in the long run, but if the preferred option (fix the problem app) isn't viable then you're reduced to the second string anyway.

The Sysinternals tools are now available from Microsoft at http://technet.microsoft.com/en-us/sysinternals/default

Best Answer

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Iis – w3wp.exe using 50% CPU time when website is not doing anything

Windows 2003/2008 terminal server, Application using 95-100% CPU when crashed, auto kill process

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