About the pod scale issue 【autoscale_target_utilization】

Question

We deployed pod that automatically scale

autoscale_target_utilization: 55

https://github.com/Azure/aml-deploy/blob/master/README.md#aks-deployment
autoscale_target_utilizationint: [1, 100]70The target utilization (in percent out of 100) the autoscaler should attempt to maintain for this Webservice.

May I ask how this parameter is calculated?
Originally, it was thought that when the node cpu reached 55%, it would trigger automatic scale,

but later it was found that the node cpu would also scale if it did not reach 55%

Our pod only has request without limit

Is it based on request? Is it based on request 55%?

In this example, the cpu Max 209 and then there's a pod that scales
thanks

Answer 1

Hello Yongchao Liu (Neusoft America Inc)

Welcome to Microsoft Q&A Platform, thanks for posting your query here.

Based on your ask looks like your query is about the behavior of Horizontal Pod Autoscalers.

If so you can find the detailed explanation here: https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/

Basically HPAs measure utilization against pod requests, in order to decide if scale-in or scale-out is needed. Please check the document for more details.

Hope this helps.