CPU Throttling High #

Meaning #

Processes experience elevated CPU throttling.

Impact #

The alert is purely informative and unless there is some other issue with the application, it can be skipped.

Diagnosis #

• Check if application is performing normally
• Check if CPU resource requests are adjusted accordingly to the app usage
• Check kernel version in the node

Mitigation #

Notice: User shouldn’t increase CPU limits unless the application is behaving erratically (another alert firing).

For this particular reason, the alert is inhibited by default in kube-prometheus and can be sent only if another alert in the same namespace is firing.

When mixed with other alerts:

Give specific container in the pod more CPU limits. Requests can stay the same.

In specific cases kubernetes node has too old kernel which is known to have issues with assigning CPU resources to the process see here

In certain scenarios ensure to use CPU Pinning and isolation - in short give to the container full CPU cores. Also ensure to update app so that it is aware it runs in cgroups, or explicitly set number of CPU it can use, or limit number of threads.

Longer and more detailed info - PDF from Intel