I have a very interesting story to tell everyone. The story is about the accidental mistake by one of my clients who hired me to help with the Comprehensive Database Performance Health Check. Today we will talk about a very funny Confusing Story of CPU in Task Manager.
My client had a very interesting situation every single day, at 1 PM the server become unresponsive for over a few minutes and it only comes back to after a while. There were occasions that they had to reboot the server as SQL Server did not respond to them. I was hired to help them to tune their SQL Server. I worked with them on various aspects of their server and eventually we were able to reach the point at 1 PM server ran as smooth as any other time. I will in detail write a blog post in the future where I will discuss what are the different things which I changed to help them achieve the situation where their server ran very fast all the time.
However, yesterday, I got an email from their Senior DBA that they are facing a very interesting situation. They are facing no performance degradation but their server is showing them a constant spike of the CPU. Additionally, they were really surprised that the CPU patter was repeating itself continuously. They were worried about if their system was hacked or running malicious code. Here is the image they had sent to me.
When I looked at the image I could not understand what exactly is going on with their system until I actually jumped on the call and started to work with them via gotomeeting. Honestly, it was indeed a very funny situation. When we looked at their task manager, we realized that accidentally they had paused the updates for the task manager and that is why they were seeing static information there.
Here is the image which created confusion about the task manager and its various statistics.
Once we changed the frequency of updating the task manager to normal everything was indeed normal.
Reference: Pinal Dave (https://blog.sqlauthority.com)