K8s Vertical Pod Autoscaler
VPA는 K8s에서 Scale-in/out에 대한 기능을 제공.
현재 동작하고 있는 pod에 대해 pod restart 없이 할당된 resource를 변경하는 것은 아직 미지원인듯
github의 VPA repo
https://github.com/kubernetes/autoscaler/tree/master/vertical-pod-autoscaler
Updating running pods is an experimental feature of VPA. Whenever VPA updates the pod resources the pod is recreated, which causes all running containers to be restarted. The pod may be recreated on a different node.
In-place updates
In-place Pod updates (#5774) is a planned feature to allow changing resources (request/limit) of existing containers without killing them, assuming sufficient free resources available on the node. Vertical Pod Autoscaler will greatly benefit from this ability, however it is not considered a blocker for the MVP.
Google Cloud 지원 상태
https://cloud.google.com/kubernetes-engine/docs/concepts/verticalpodautoscaler
Due to Kubernetes limitations, the only way to modify the resource requests of a running Pod is to recreate the Pod. If you create a VerticalPodAutoscaler with an updateMode of “Auto”, the VerticalPodAutoscaler evicts a Pod if it needs to change the Pod’s resource requests.
To limit the amount of Pod restarts, use a Pod disruption budget.
https://livewyer.io/blog/2019/06/24/vertical-pod-autoscaling/ 24 June 2019
Auto Will assign request values both at pod startup and while the pod is live using the specified update mechanism. At the moment, this is equivalent to “recreate”, as there isn’t currently an “in-place” mechanism for updating request values on live pods