Skip to content

fix: Cluster Autoscaler not scaling down nodes where Pods with hard topology spread constraints are scheduled #8164

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Conversation

MenD32
Copy link
Contributor

@MenD32 MenD32 commented May 24, 2025

What type of PR is this?

/kind fix

What this PR does / why we need it:

Nodes are mistakenly marked as unremovable with specific configurations of topology spread constraints

Which issue(s) this PR fixes:

Fixes #8093
Fixes #8162

Special notes for your reviewer:

Does this PR introduce a user-facing change?

deployments with topology spread constraints will no longer block scale down if the removable node changes the global minimum

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:


Signed-off-by: MenD32 <amit.mendelevitch@gmail.com>
@k8s-ci-robot
Copy link
Contributor

@MenD32: The label(s) kind/fix cannot be applied, because the repository doesn't have them.

In response to this:

What type of PR is this?

/kind fix

What this PR does / why we need it:

Nodes are mistakenly marked as unremovable with specific configurations of topology spread constraints

Which issue(s) this PR fixes:

Fixes #8093
Fixes #8162

Special notes for your reviewer:

Does this PR introduce a user-facing change?


Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:


Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

@k8s-ci-robot k8s-ci-robot added cncf-cla: yes Indicates the PR's author has signed the CNCF CLA. area/cluster-autoscaler labels May 24, 2025
@k8s-ci-robot
Copy link
Contributor

Hi @MenD32. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

@k8s-ci-robot k8s-ci-robot added the needs-ok-to-test Indicates a PR that requires an org member to verify it is safe to test. label May 24, 2025
@k8s-ci-robot k8s-ci-robot added the size/XS Denotes a PR that changes 0-9 lines, ignoring generated files. label May 24, 2025
…constraints

Signed-off-by: MenD32 <amit.mendelevitch@gmail.com>
@k8s-ci-robot k8s-ci-robot added size/M Denotes a PR that changes 30-99 lines, ignoring generated files. and removed size/XS Denotes a PR that changes 0-9 lines, ignoring generated files. labels May 24, 2025
@@ -226,6 +226,7 @@ func (r *RemovalSimulator) findPlaceFor(removedNode string, pods []*apiv1.Pod, n
klog.Errorf("Simulating removal of %s/%s return error; %v", pod.Namespace, pod.Name, err)
}
}
r.clusterSnapshot.RemoveNodeInfo(removedNode)
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

nit: Could you add a comment explaining that this is necessary for pod topology spread to work correctly?

@towca
Copy link
Collaborator

towca commented May 27, 2025

Thanks for picking up the fix!

Could you fill out the "Does this PR introduce a user-facing change?" section? This PR does change behavior, CA will now scale down in scenarios where it previously wouldn't.

/ok-to-test

@k8s-ci-robot k8s-ci-robot added ok-to-test Indicates a non-member PR verified by an org member that is safe to test. and removed needs-ok-to-test Indicates a PR that requires an org member to verify it is safe to test. labels May 27, 2025
Signed-off-by: MenD32 <amit.mendelevitch@gmail.com>
@MenD32 MenD32 changed the title fix: Cluster Autoscaler not scaling down Nodes where Pods with hard topology spread constraints are scheduled fix: Cluster Autoscaler not scaling down nodes where Pods with hard topology spread constraints are scheduled May 29, 2025
@towca
Copy link
Collaborator

towca commented May 30, 2025

/lgtm
/approve

@k8s-ci-robot k8s-ci-robot added the lgtm "Looks good to me", indicates that a PR is ready to be merged. label May 30, 2025
@k8s-ci-robot
Copy link
Contributor

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: MenD32, towca

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

@k8s-ci-robot k8s-ci-robot added the approved Indicates a PR has been approved by an approver from all required OWNERS files. label May 30, 2025
@k8s-ci-robot k8s-ci-robot merged commit 2511e44 into kubernetes:master May 30, 2025
7 checks passed
@MenD32 MenD32 deleted the fix/hard-topology-spread-constraints-stop-scaledown branch May 30, 2025 13:22
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
approved Indicates a PR has been approved by an approver from all required OWNERS files. area/cluster-autoscaler cncf-cla: yes Indicates the PR's author has signed the CNCF CLA. lgtm "Looks good to me", indicates that a PR is ready to be merged. ok-to-test Indicates a non-member PR verified by an org member that is safe to test. size/M Denotes a PR that changes 30-99 lines, ignoring generated files.
Projects
None yet
3 participants