Clear pod.Status.NominatedNodeName when pod is bound #132443

utam0k · 2025-06-22T12:39:11Z

What type of PR is this?

/kind feature
/sig scheduling
/cc sanposhiho

What this PR does / why we need it:

This PR implements the kube-apiserver side of KEP-5278 by clearing the NominatedNodeName field when a pod is successfully bound to a node through the binding API.

Previously, only the scheduler cleared NominatedNodeName, but with KEP-5278, external components like Cluster Autoscaler and Karpenter can also set this field. To prevent stale information from affecting scheduling decisions, the apiserver now clears this field upon successful binding, regardless of which component performed the scheduling.

Which issue(s) this PR is related to:

Fixes #132385

Previous implementation (scheduler side): KEP-5278: Change the scheduler not to clear NNN #132384

Special notes for your reviewer:

Does this PR introduce a user-facing change?

Whenever a pod is successfully bound to a node, the kube-apiserver now clears the pod's `nominatedNodeName` field. This prevents stale information from affecting external scheduling components.

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

k8s-ci-robot · 2025-06-22T12:39:19Z

This issue is currently awaiting triage.

If a SIG or subproject determines this is a relevant issue, they will accept it by applying the triage/accepted label and provide further guidance.

The triage/accepted label can be added by org members by writing /triage accepted in a comment.

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.

lmktfy · 2025-06-22T17:54:10Z

Changelog suggestion

-When a pod is successfully bound to a node, the kube-apiserver now clears the pod's NominatedNodeName field to prevent stale information from affecting external scheduling components.
+Whenever a pod is successfully bound to a node, the kube-apiserver now clears the pod's `nominatedNodeName` field. This prevents stale information from affecting external scheduling components.

utam0k · 2025-06-23T11:29:00Z

@imikushin Thanks for your review. Updated.

sanposhiho

We (i.e., including me in other PRs) forgot feature-gating the logic!!! 😅

sanposhiho · 2025-06-23T22:25:37Z

/cc @macsko @dom4ha

this is part of nnn kep

k8s-ci-robot · 2025-06-28T02:19:13Z

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: sanposhiho, utam0k
Once this PR has been reviewed and has the lgtm label, please ask for approval from dchen1107. For more information see the Code Review Process.

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

sanposhiho

still
/lgtm
from sig-scheduling

k8s-ci-robot · 2025-06-29T12:53:22Z

LGTM label has been added.

Git tree hash: d73c51eeab270fa51f422436dc477f9cf8f222c2

dom4ha · 2025-06-30T16:31:40Z

test/compatibility_lifecycle/reference/versioned_feature_list.yaml

@@ -973,6 +973,12 @@
    lockToDefault: false
    preRelease: Beta
    version: "1.30"
+- name: NominatedNodeNameForExpectation
+  versionedSpecs:
+  - default: false


I think it should be enabled by default?

dom4ha · 2025-06-30T17:05:45Z

pkg/features/kube_features.go

@@ -1379,6 +1389,10 @@ var defaultVersionedKubernetesFeatureGates = map[featuregate.Feature]featuregate
 		{Version: version.MustParse("1.30"), Default: true, PreRelease: featuregate.Beta},
 	},

+	NominatedNodeNameForExpectation: {
+		{Version: version.MustParse("1.34"), Default: false, PreRelease: featuregate.Beta},


Suggested change

{Version: version.MustParse("1.34"), Default: false, PreRelease: featuregate.Beta},

{Version: version.MustParse("1.34"), Default: true, PreRelease: featuregate.Beta},

Hi, @dom4ha 👋 Thanks for your review.
I believe that the default is set to true when approaching GA.
cc: @sanposhiho

During beta, the feature gate should be enabled by default, so the @dom4ha's comment is valid

I'm adding a feature gate for the first time and don't quite understand the process. Thanks for letting me know 🙏

I'm adding a feature gate for the first time and don't quite understand the process. Thanks for letting me know 🙏

AFAIK there is no rule regarding the default value in beta, but it's described in the KEP.

Signed-off-by: utam0k <[email protected]>

k8s-ci-robot · 2025-07-01T14:25:05Z

@utam0k: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-kubernetes-integration	`8192a1c`	link	true	`/test pull-kubernetes-integration`

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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. I understand the commands that are listed here.

dom4ha · 2025-07-01T14:39:50Z

/lgtm

k8s-ci-robot · 2025-07-01T14:39:58Z

LGTM label has been added.

Git tree hash: 19e0bf7e631766fe1c7768ff76f1ff54037ea53f

liggitt · 2025-07-01T16:40:05Z

pkg/registry/core/pod/storage/storage.go

@@ -256,6 +256,11 @@ func (r *BindingREST) setPodNodeAndMetadata(ctx context.Context, podUID types.UI
 			Type:   api.PodScheduled,
 			Status: api.ConditionTrue,
 		})
+		// Clear nomination hint to prevent stale information affecting external components.


does anything prevent setting this again via another status update after the pod is bound?

liggitt · 2025-07-01T17:18:01Z

pkg/registry/core/pod/storage/storage.go

@@ -256,6 +256,11 @@ func (r *BindingREST) setPodNodeAndMetadata(ctx context.Context, podUID types.UI
 			Type:   api.PodScheduled,
 			Status: api.ConditionTrue,
 		})
+		// Clear nomination hint to prevent stale information affecting external components.
+		if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.NominatedNodeNameForExpectation) {


not having read the KEP before reviewing this, this is a surprising behavior to associate with a feature named "NominatedNodeNameForExpectation" ... clearing the NominatedNode field after binding (and not letting it be set on an already-bound pod) makes a lot of sense... is there a clearer name we could use for the gate of this behavior change?

k8s-ci-robot requested a review from sanposhiho June 22, 2025 12:39

k8s-ci-robot added needs-priority Indicates a PR lacks a `priority/foo` label and requires one. sig/node Categorizes an issue or PR as relevant to SIG Node. labels Jun 22, 2025

github-project-automation bot added this to SIG Node: code and documentation PRs Jun 22, 2025

github-project-automation bot moved this to Triage in SIG Node: code and documentation PRs Jun 22, 2025

utam0k mentioned this pull request Jun 22, 2025

[Umbrella] KEP-5278: Nominated node name for an expected pod placement #132381

Open

7 tasks

lmktfy mentioned this pull request Jun 22, 2025

scheduler: stop clearing NominatedNodeName on all cases #132439

Open

utam0k force-pushed the clearn-nnn-bind-api branch from c2ade7a to 58b4179 Compare June 23, 2025 11:28

k8s-ci-robot added area/test sig/testing Categorizes an issue or PR as relevant to SIG Testing. labels Jun 23, 2025

github-project-automation bot added this to SIG Node CI/Test Board Jun 23, 2025

github-project-automation bot moved this to Triage in SIG Node CI/Test Board Jun 23, 2025

sanposhiho reviewed Jun 23, 2025

View reviewed changes

k8s-ci-robot requested review from dom4ha and macsko June 23, 2025 22:25

utam0k force-pushed the clearn-nnn-bind-api branch from 58b4179 to 0d030b4 Compare June 24, 2025 12:25

k8s-ci-robot added size/M Denotes a PR that changes 30-99 lines, ignoring generated files. and removed size/S Denotes a PR that changes 10-29 lines, ignoring generated files. labels Jun 24, 2025

utam0k requested a review from sanposhiho June 24, 2025 12:46

utam0k force-pushed the clearn-nnn-bind-api branch from 0d030b4 to 5ae0d94 Compare June 26, 2025 10:49

k8s-ci-robot removed the lgtm "Looks good to me", indicates that a PR is ready to be merged. label Jun 28, 2025

k8s-ci-robot requested review from dchen1107 and sanposhiho June 28, 2025 02:18

k8s-ci-robot added the needs-rebase Indicates a PR cannot be merged because it has merge conflicts with HEAD. label Jun 28, 2025

utam0k requested a review from macsko June 28, 2025 02:19

utam0k force-pushed the clearn-nnn-bind-api branch from 3106b92 to 395d168 Compare June 28, 2025 02:42

k8s-ci-robot removed the needs-rebase Indicates a PR cannot be merged because it has merge conflicts with HEAD. label Jun 28, 2025

utam0k force-pushed the clearn-nnn-bind-api branch 2 times, most recently from ff52974 to 603b4f9 Compare June 28, 2025 12:07

sanposhiho reviewed Jun 29, 2025

View reviewed changes

k8s-ci-robot added the lgtm "Looks good to me", indicates that a PR is ready to be merged. label Jun 29, 2025

dom4ha reviewed Jun 30, 2025

View reviewed changes

Clear pod.Status.NominatedNodeName when pod is bound

8192a1c

Signed-off-by: utam0k <[email protected]>

utam0k force-pushed the clearn-nnn-bind-api branch from 603b4f9 to 8192a1c Compare July 1, 2025 13:20

k8s-ci-robot removed the lgtm "Looks good to me", indicates that a PR is ready to be merged. label Jul 1, 2025

k8s-ci-robot requested a review from sanposhiho July 1, 2025 13:20

utam0k requested a review from dom4ha July 1, 2025 13:21

k8s-ci-robot assigned dom4ha Jul 1, 2025

k8s-ci-robot added the lgtm "Looks good to me", indicates that a PR is ready to be merged. label Jul 1, 2025

liggitt reviewed Jul 1, 2025

View reviewed changes

liggitt self-assigned this Jul 1, 2025

liggitt added the api-review Categorizes an issue or PR as actively needing an API review. label Jul 1, 2025

github-project-automation bot added this to API Reviews Jul 1, 2025

liggitt moved this to Changes requested in API Reviews Jul 1, 2025

	{Version: version.MustParse("1.34"), Default: false, PreRelease: featuregate.Beta},
	{Version: version.MustParse("1.34"), Default: true, PreRelease: featuregate.Beta},

Clear pod.Status.NominatedNodeName when pod is bound #132443

Are you sure you want to change the base?

Clear pod.Status.NominatedNodeName when pod is bound #132443

Conversation

utam0k commented Jun 22, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

What type of PR is this?

What this PR does / why we need it:

Which issue(s) this PR is related to:

Special notes for your reviewer:

Does this PR introduce a user-facing change?

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

Uh oh!

k8s-ci-robot commented Jun 22, 2025

Uh oh!

lmktfy commented Jun 22, 2025

Uh oh!

utam0k commented Jun 23, 2025

Uh oh!

sanposhiho left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

sanposhiho commented Jun 23, 2025

Uh oh!

k8s-ci-robot commented Jun 28, 2025

Uh oh!

sanposhiho left a comment

Choose a reason for hiding this comment

Uh oh!

k8s-ci-robot commented Jun 29, 2025

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

k8s-ci-robot commented Jul 1, 2025

Uh oh!

dom4ha commented Jul 1, 2025

Uh oh!

k8s-ci-robot commented Jul 1, 2025

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

utam0k commented Jun 22, 2025 •

edited

Loading

sanposhiho left a comment •

edited

Loading