topic Re: How is CPU saturation really calculated? in Open Q&A

How is CPU saturation really calculated?

AntonioSousa — Wed, 23 Aug 2023 19:19:11 GMT

The documentation says:

By default, Dynatrace alerts when average CPU usage is higher than 95% in 3 of 5 consecutive one-minute intervals or when usage is higher than 90% in a single five-minute interval.

But, when we look at how we define custom settings for the CPU saturation settings, it seems to be based on the 10-second samples that are taken each minute:

Now, even though the two approaches might seem similar, there are cases where it will not happen. Given that we don't have visibility into the 10-second samples (we do have the min/avg/max values), how do we know what is exactly happening with CPU saturation detection?

BTW, remembers me of this Product Idea: https://community.dynatrace.com/t5/Product-ideas/RFE-Increase-resolution-of-data/idi-p/166920

Re: How is CPU saturation really calculated?

bradley_danyo — Wed, 06 Sep 2023 21:44:18 GMT

Hi,

What documentation exactly are you looking at? The documentation here discusses event thresholds using 10 second intervals. I believe 10 second intervals are used for infra alerting, and one minute intervals are used for graphing. If you provide me the documentation where it says that, I can get clarification from product team and get updated appropriately.

Regards,

Bradley

Re: How is CPU saturation really calculated?

AntonioSousa — Wed, 06 Sep 2023 22:01:15 GMT

@bradley_danyo,

The reference from documentation is here: https://www.dynatrace.com/support/help/platform/davis-ai/basics/events/event-types/resource-events

Re: How is CPU saturation really calculated?

bradley_danyo — Wed, 06 Sep 2023 22:18:25 GMT

Thanks. I've reached out to confirm and will let you know once I have more information.

Regards,

Bradley

Re: How is CPU saturation really calculated?

bradley_danyo — Fri, 08 Sep 2023 14:03:25 GMT

Hi Antonio,

I've confirmed that the documentation you shared should be changed. The CPU alerting now uses 10 second intervals. Thank you for bringing this to our attention.

Regards,

Bradley