CPU Spikes stalling IIS frequently

Posted By RajeshP on 11/15/2022 1:11 AM

Hi,

Can anyone help in diagnosing and resolving the root cause that is creating intermittent CPU spikes on my IIS server. We are running 10.9.1 version. Even if it is a paid service do let me know.

Regards

Rajesh

Any monitoring software you can procure should help you with this.  Some of the most popular ones that we know and see are listed below (in no particular order).  

• New Relic
• Site24x7
• Solar Winds

There are at least hundreds more out there... Also, if you're on any cloud provider's platform, they should have some built-in options for you to turn on.  In many cases, it doesn't require much more than that.  

 

Oh, and it might be time for you to do some routine maintenance. Usually, performance is something that's been an issue for a long time, and it finally began to be visibly apparent.  These kinds of things should be done semi-regularly.  

Some maintenance tasks to perform include:  

• Reviewing and potentially archiving log files in the /Portals/_default/Logs/ folder.    
• Reviewing and potentially archiving log entries in the Admin Log.  
• Review the log files for any and all exceptions and fix as many as you can.  
• Uninstall any extensions that are no longer being used.  
• Rebuilding/reorganizing the index of the database.  
• Moving large portal folders to a cloud folder provider.  
• Deleting the /Install/Temp/ folder.  
• Increase caching in the DNN performance settings. 
• Increase/improve caching with a CDN/WAF (e.g., CloudFlare, Imperva, etc.).  
• Upgrade all extensions currently installed on the website. 
• Upgrade DNN to the most current version.  
• Update any custom code to use the latest DNN API endpoints.  
• Remove dead code from the web.config (usually done by performing a diff/merge).  
• Remove dead code from your custom extensions.  

As well as all of Will's very helpful info above, check for errors in your server's Event Viewer, particularly for multiple System Interrupts. If you get many frequent errors from failing hardware such as a drive or drive controller it can hit the CPU heavily while trying to write to the system event logs.