In place vertical scaling

[bbuchthal]

Hello KWOK team,

First off, thank you for all the work you’ve put into KWOK — it has been a very helpful tool for us. I’ve been testing the in-place Pod vertical scaling feature. I followed the documentation by:

• Enabling enableInPlacePodVerticalScaling: true in my kwok.yaml
• Adding the label kwok.x-k8s.io/in-place-scaling=true to my test Pods
• Attempted to patch container resources using kubectl patch.

However, I’m still observing that new Pods are being created rather than existing Pods being updated in place. Looking at the KWOK release, it seems the project is currently running with Kubernetes v1.28. From the Kubernetes release notes, I see that in-place vertical scaling graduated to beta and is enabled by default in v1.33. That makes me wonder:

• Does this mean KWOK does not yet support in-place Pod vertical scaling?
• Is there a plan or timeline to update KWOK to Kubernetes v1.33 (or newer)?
• Is there any way to test this feature today with the current KWOK release?

Thanks again for your time and for maintaining this project. I’d be grateful for any guidance.

Best,
Brandon

[wzshiming]

https://kwok.sigs.k8s.io/docs/technical-outcomes/scalability/scale-using-vpa/

I think you can refer to this document, which makes a simple VPA example.

Is there a plan or timeline to update KWOK to Kubernetes v1.33 (or newer)?

No plans yet.

[bbuchthal]

hello: thanks for the follow up. i want to clarify that the thing I am looking to do is in-place scaling, not VPA setup. Is that possible now currently? My initial testing has suggested that it is not.

[wzshiming]

The updater of VPA is used for in-place scaling operations.

https://kubernetes.io/blog/2025/05/16/kubernetes-v1-33-in-place-pod-resize-beta/
This is actually an apiserver feature that kwok already supports without adapting it.

[wzshiming]

I'm guessing that you're missing the subresource

kubectl edit pod <pod-name> --subresource resize