search

kubernetes-sigs / descheduler

Descheduler for Kubernetes
https://sigs.k8s.io/descheduler
Apache License 2.0
4.26k stars 650 forks source link

feat: Implement preferredDuringSchedulingIgnoredDuringExecution for RemovePodsViolatingNodeAffinity #1210

Closed jordipiqueselles closed 11 months ago

jordipiqueselles commented 11 months ago

Now, the descheduler can detect and evict pods that are not optimally allocated according to the "preferred..." node affinity. It only evicts a pod if it can be scheduled on a node that scores higher in terms of preferred node affinity than the current one.

This can be activated by enabling the RemovePodsViolatingNodeAffinity plugin and passing "preferredDuringSchedulingIgnoredDuringExecution" in the args.

For example, imagine we have a pod that prefers nodes with label "key1: value1" with a weight of 10. If this pod is scheduled on a node that doesn't have "key1: value1" as label but there's another node that has this label and where this pod can potentially run, then the descheduler will evict the pod.

Another effect of this commit is that the RemovePodsViolatingNodeAffinity plugin will not remove pods that don't fit in the current node but for other reasons than violating the node affinity. Before that, enabling this plugin could cause evictions on pods that were running on tainted nodes without the necessary tolerations.

This commit also fixes the wording of some tests from node_affinity_test.go and some parameters and expectations of these tests, which were wrong.

linux-foundation-easycla[bot] commented 11 months ago

CLA Signed

The committers listed above are authorized under a signed CLA.

k8s-ci-robot commented 11 months ago

Hi @jordipiqueselles. Thanks for your PR.

I'm waiting for a kubernetes-sigs 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](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [kubernetes/test-infra](https://github.com/kubernetes/test-infra/issues/new?title=Prow%20issue:) repository.
jordipiqueselles commented 11 months ago

@a7i @ingvagabund Could you review this PR? Thanks!

a7i commented 11 months ago

/ok-to-test

a7i commented 11 months ago

/cc @knelasevero

a7i commented 11 months ago

Thank you @jordipiqueselles this is a great addition!

/lgtm

a7i commented 11 months ago

/label tide/merge-method-squash

knelasevero commented 11 months ago

Thanks for this!

/approve

k8s-ci-robot commented 11 months ago

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: knelasevero

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: - ~~[OWNERS](https://github.com/kubernetes-sigs/descheduler/blob/master/OWNERS)~~ [knelasevero] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment