Iis – High CPU usage of IIS process (w3wp.exe) because of many slow clr.dll!CopyPDBs

asp.netiisiis-7.5netwindows-server-2008-r2

I am using Windows Server 2008 R2 Enterprise with IIS 7.5, hosting ASP.NET MVC 5 applications.

I've noticed lately that one of the w3wp.exe processes is using extremely high CPU bandwidth:

High CPU usage of w3wp.exe

After investigated little bit more, I've also noticed that the reason of this is the function clr.dll!CopyPDBs:

w3wp.exe threads details

Does anybody know what can be the problem?

If the reason is not related to .NET Framework and clr.dll!CopyPDBs how can I investigate further to find the actual reason for this

Best Answer

This is usually because you have a custom application on top of IIS. If it is an in house built application, speak with the Developers about it.

If it is not developed in house, please have a look at .net CLR with counters https://msdn.microsoft.com/en-us/library/x2tyfybc(v=vs.110).aspx and more tips on CLR performance https://msdn.microsoft.com/en-us/library/ee851764(v=vs.110).aspx and https://msdn.microsoft.com/en-us/magazine/cc163528.aspx .

Related Solutions

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

Iis – How to configure IIS 7.5 without restart + call a batch file on every ASP.NET restart

You can set IP restrictions in applicationHost.config in a location tag for your site. If you do that, then it won't cause an appdomain recycle. URL Rewrite at the global level is another option.

Week 12 and week 18 of my video series cover AppDomains and editing apphost.config.

To script it, use appcmd. The best way to do that is to start with Configuration Editor in IIS, make the change you want, then "Generate Script" from the actions pane on the right. The appcmd command will be there.

As for the 2nd question, you'll need to get a handle on your application startup within your project and have that trigger an event. An async call will allow it to start your startup script while allowing the page to continue, otherwise you'll run into a locking issue.

Best Answer

Related Solutions

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

Iis – How to configure IIS 7.5 without restart + call a batch file on every ASP.NET restart

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