Determining Which IIS Application Pool is Consuming Resources From Task Manager

Determining which IIS application pool is consuming resources like memory, CPU from task manager might not be an easy process if you have many websites running on the same web server.

Yesterday, one of my web servers entered ALARM state because of high CPU usage.

At first I thought the reason was the high traffic but then I realized the traffic could not be the reason of 100% CPU usage. When I checked the running processes from the Task Manager (by the way the server is a Windows Server 2012 with IIS8) I saw that one “IIS Worker Process” (i.e. “w3wp.exe”) is responsible from the high CPU and memory usage.

I had a clue for the problem but the sad news there were many IIS Worker Processes running and the task manager did not show which IIS Worker Processes belonged to which website.

However, it did show me the PID (Process ID) of each worker process and if I could match the PIDs with application pools I could find the problematic application pool and web site.

After searching the net I found the following command that uses appcmd.exe (the single command line tool for managing IIS 7 and above).

Appcmd enables you to easily list running worker processes like this:

%systemroot%\system32\inetsrv\appcmd.exe list wp

By using this command I get the list of all IIS Worker Processes with their names and PIDs. I used this information to find the problematic web site and then find the root reason causing high CPU and memory usage in that web site.

Hope it helps!

Originally published at http://www.weboideas.com on February 1, 2015.