KEP-6371keps/sig-node/6371-external-node-liveness-detection

External Node Liveness Detection

implementablealphasig-nodelatest v1.38

KEP on GitHub kep.yaml Ask about this KEP

This KEP makes node liveness detection replaceable with a custom implementation. A cluster operator can turn off the detector built into the node lifecycle controller, disable kubelet Lease heartbeats, and supply an external detector that writes Ready=Unknown. The node lifecycle controller retains responsibility for all other lifecycle management, such as eviction and zone disruption handling. This is implemented by a --node-liveness-source=external flag on the kube-controller-manager, which stops the controller from checking liveness and changes how it reacts to Ready=Unknown when the condition is written by an external node liveness detector. An enableNodeLease: false field is added to the kubelet for configurations that do not need node lease heartbeats.

Facts

Authors: @jpbetz
Approvers: @mrunalp
Reviewers: @mrunalp
PRR approvers: @johnbelamaricalpha
Tracking issue: #6371(opens GitHub in a new tab) openmilestone v1.38sig/nodestage/alphatracked/yeskind/keplead-opted-in
Milestones: alpha v1.38
Participating SIGs: sig-scalability sig-cloud-provider sig-api-machinery
Feature gates: ExternalNodeLivenessDetection
Created / last updated: 2026-09-14 / none

Who decided each state, with the evidence.
Decided	Decision	Deciders	Evidence
2026-09-15 17:43 UTC	prr_approval johnbelamaric gave the production readiness approval for KEP-6371 at alpha on 2026-09-15.	@johnbelamaric prr_approver	Document 6371.yaml(opens GitHub in a new tab)
2026-09-28 17:26 UTC	stage_graduation KEP-6371 set milestone.alpha to v1.38 in PR #6373, approved by mrunalp, johnbelamaric; merged by automation (kubernetes-prow) on 2026-09-28.	@mrunalp approver @johnbelamaric approve_command @johnbelamaric lgtm @jpbetz author @kubernetes-prow merger	Commit kubernetes/enhancements@469de898a77d780883a8e04b9df019e4514dd385(opens GitHub in a new tab) StatusChange milestone.alpha ∅ → v1.38 (2026-09-15)(opens GitHub in a new tab) PullRequest kubernetes/enhancements#6373 KEP-6371: External Node Liveness Detection(opens GitHub in a new tab) Review kubernetes/enhancements/pulls/reviews/5342290650(opens GitHub in a new tab) Review kubernetes/enhancements/pulls/reviews/5332901186(opens GitHub in a new tab)
2026-09-28 17:26 UTC	stage_graduation KEP-6371 graduated to alpha in PR #6373, approved by mrunalp, johnbelamaric; merged by automation (kubernetes-prow) on 2026-09-28.	@mrunalp approver @johnbelamaric approve_command @johnbelamaric lgtm @jpbetz author @kubernetes-prow merger	Commit kubernetes/enhancements@469de898a77d780883a8e04b9df019e4514dd385(opens GitHub in a new tab) StatusChange stage ∅ → alpha (2026-09-15)(opens GitHub in a new tab) PullRequest kubernetes/enhancements#6373 KEP-6371: External Node Liveness Detection(opens GitHub in a new tab) Review kubernetes/enhancements/pulls/reviews/5342290650
2026-09-28 17:26 UTC	status_transition KEP-6371 status set to implementable in PR #6373, approved by mrunalp, johnbelamaric; merged by automation (kubernetes-prow) on 2026-09-28.	@mrunalp approver @johnbelamaric approve_command @johnbelamaric lgtm @jpbetz author @kubernetes-prow merger	Commit kubernetes/enhancements@469de898a77d780883a8e04b9df019e4514dd385(opens GitHub in a new tab) StatusChange status ∅ → implementable (2026-09-15)(opens GitHub in a new tab) PullRequest kubernetes/enhancements#6373 KEP-6371: External Node Liveness Detection(opens GitHub in a new tab) Review kubernetes/enhancements/pulls/reviews/5342290650

Metadata, label and milestone changes, oldest first.Showing 1–10 of 17Rows

Status history
At	Kind	Field	Change	Actor	Evidence
2026-09-15 15:20 UTC	label	needs-sig added	none → needs-sig	@kubernetes-prow	source(opens GitHub in a new tab)
2026-09-15 17:43 UTC	metadata	approvers set	none → ["mrunalp"]	none

Relationships as stored, Person → KEP, from kep.yaml(opens GitHub in a new tab)
Person	Relationship
@jpbetz GitHub(opens GitHub in a new tab)	—AUTHORED→
@mrunalp GitHub(opens GitHub in a new tab)	—REVIEWS→
@mrunalp GitHub(opens GitHub in a new tab)	—APPROVES→
@johnbelamaric

How they connect

Shortest paths in the graph between this KEP and its SIG or one of its people, up to four hops.

Impact of change

Rows returned by the tool
Kep	Depth	Reached	By hop	Open pull requests	Hop	Feature gates	Sigs	People	Open issues
{ "label": "KEP", "key": "keps/sig-node/6371-external-node-liveness-detection", "title": "External Node Liveness Detection", "url": "https://github.com/kubernetes/enhancements/tree/5b503a75369bdfdd494a2c2c72107a41bf6dd1a8/keps/sig-node/6371-external-node-liveness-detection", "evidence_id": "33zedzargdhr", "number": 6371, "owning_sig": "sig-node", "status": "implementable", "stage": "alpha", "latest_milestone": "v1.38", "milestone_alpha": "v1.38", "creation_date": "2026-09-14", "metadata_invalid": false }	2	5	{ "1": { "feature_gates": 1, "sigs": 1, "people": 2, "open_issues": 1 } }	not in graph (merged pull requests only)	none	none	none	none	none
none	none	none	none	none	1	[ { "label": "FeatureGate", "key": "ExternalNodeLivenessDetection", "title": "ExternalNodeLivenessDetection", "url": "https://github.com/kubernetes/enhancements/blob/5b503a75369bdfdd494a2c2c72107a41bf6dd1a8/keps/sig-node/6371-external-node-liveness-detection/kep.yaml", "evidence_id": "cdg7sytyshtq", "name": "ExternalNodeLivenessDetection" } ]	[ { "label": "SIG", "key": "sig-node", "title": "Node", "url": "https://github.com/kubernetes/community/tree/440e496d3a172234d81728df1bfe43849b589adf/sig-node", "evidence_id": "nrsuxu2xcxa7", "display_name": "Node", "sig_label": "node", "in_scope": true } ]	[ { "label": "Person", "key": "jpbetz", "title": "jpbetz", "url": "https://github.com/jpbetz", "evidence_id": "kmutsyrrrwir", "login": "jpbetz", "is_bot": false }, { "label": "Person", "key": "mrunalp", "title": "mrunalp", "url": "https://github.com/mrunalp", "evidence_id": "oysq4hgp6yuk", "login": "mrunalp", "is_bot": false } ]	[ { "label": "Issue", "key": "kubernetes/enhancements#6371", "title": "External Node Liveness Detection", "url": "https://github.com/kubernetes/enhancements/issues/6371", "evidence_id": "uun32euy7ttv", "number": 6371, "state": "open", "created_at_iso": "2026-09-15T15:20:34Z", "labels_current": [ "sig/node", "stage/alpha", "tracked/yes", "kind/kep", "lead-opted-in" ], "milestone_current": "v1.38", "is_tracking_issue": true } ]

Rows returned by the tool
Kep	Depth	Reached	By hop	Open pull requests	Hop	Feature gates	Sigs	People	Open issues
{ "label": "KEP", "key": "keps/sig-node/6371-external-node-liveness-detection", "title": "External Node Liveness Detection", "url": "https://github.com/kubernetes/enhancements/tree/5b503a75369bdfdd494a2c2c72107a41bf6dd1a8/keps/sig-node/6371-external-node-liveness-detection", "evidence_id": "33zedzargdhr", "number": 6371, "owning_sig": "sig-node", "status": "implementable", "stage": "alpha", "latest_milestone": "v1.38", "milestone_alpha": "v1.38", "creation_date": "2026-09-14", "metadata_invalid": false }	2	5	{ "1": { "feature_gates": 1, "sigs": 1, "people": 2, "open_issues": 1 } }	not in graph (merged pull requests only)	none	none	none	none	none
none	none	none	none	none	1	[ { "label": "FeatureGate", "key": "ExternalNodeLivenessDetection", "title": "ExternalNodeLivenessDetection", "url": "https://github.com/kubernetes/enhancements/blob/5b503a75369bdfdd494a2c2c72107a41bf6dd1a8/keps/sig-node/6371-external-node-liveness-detection/kep.yaml", "evidence_id": "cdg7sytyshtq", "name": "ExternalNodeLivenessDetection" } ]	[ { "label": "SIG", "key": "sig-node", "title": "Node", "url": "https://github.com/kubernetes/community/tree/440e496d3a172234d81728df1bfe43849b589adf/sig-node", "evidence_id": "nrsuxu2xcxa7", "display_name": "Node", "sig_label": "node", "in_scope": true } ]	[ { "label": "Person", "key": "jpbetz", "title": "jpbetz", "url": "https://github.com/jpbetz", "evidence_id": "kmutsyrrrwir", "login": "jpbetz", "is_bot": false }, { "label": "Person", "key": "mrunalp", "title": "mrunalp", "url": "https://github.com/mrunalp", "evidence_id": "oysq4hgp6yuk", "login": "mrunalp", "is_bot": false } ]	[ { "label": "Issue", "key": "kubernetes/enhancements#6371", "title": "External Node Liveness Detection", "url": "https://github.com/kubernetes/enhancements/issues/6371", "evidence_id": "uun32euy7ttv", "number": 6371, "state": "open", "created_at_iso": "2026-09-15T15:20:34Z", "labels_current": [ "sig/node", "stage/alpha", "tracked/yes", "kind/kep", "lead-opted-in" ], "milestone_current": "v1.38", "is_tracking_issue": true } ]

Kep

Depth

Reached

By hop

Open pull requests

Hop

Feature gates

Sigs

People

Open issues

{
  "label": "KEP",
  "key": "keps/sig-node/6371-external-node-liveness-detection",
  "title": "External Node Liveness Detection",
  "url": "https://github.com/kubernetes/enhancements/tree/5b503a75369bdfdd494a2c2c72107a41bf6dd1a8/keps/sig-node/6371-external-node-liveness-detection",
  "evidence_id": "33zedzargdhr",
  "number": 6371,
  "owning_sig": "sig-node",
  "status": "implementable",
  "stage": "alpha",
  "latest_milestone": "v1.38",
  "milestone_alpha": "v1.38",
  "creation_date": "2026-09-14",
  "metadata_invalid": false
}

{
  "1": {
    "feature_gates": 1,
    "sigs": 1,
    "people": 2,
    "open_issues": 1
  }
}

not in graph (merged pull requests only)

[
  {
    "label": "FeatureGate",
    "key": "ExternalNodeLivenessDetection",
    "title": "ExternalNodeLivenessDetection",
    "url": "https://github.com/kubernetes/enhancements/blob/5b503a75369bdfdd494a2c2c72107a41bf6dd1a8/keps/sig-node/6371-external-node-liveness-detection/kep.yaml",
    "evidence_id": "cdg7sytyshtq",
    "name": "ExternalNodeLivenessDetection"
  }
]

[
  {
    "label": "SIG",
    "key": "sig-node",
    "title": "Node",
    "url": "https://github.com/kubernetes/community/tree/440e496d3a172234d81728df1bfe43849b589adf/sig-node",
    "evidence_id": "nrsuxu2xcxa7",
    "display_name": "Node",
    "sig_label": "node",
    "in_scope": true
  }
]

[
  {
    "label": "Person",
    "key": "jpbetz",
    "title": "jpbetz",
    "url": "https://github.com/jpbetz",
    "evidence_id": "kmutsyrrrwir",
    "login": "jpbetz",
    "is_bot": false
  },
  {
    "label": "Person",
    "key": "mrunalp",
    "title": "mrunalp",
    "url": "https://github.com/mrunalp",
    "evidence_id": "oysq4hgp6yuk",
    "login": "mrunalp",
    "is_bot": false
  }
]

[
  {
    "label": "Issue",
    "key": "kubernetes/enhancements#6371",
    "title": "External Node Liveness Detection",
    "url": "https://github.com/kubernetes/enhancements/issues/6371",
    "evidence_id": "uun32euy7ttv",
    "number": 6371,
    "state": "open",
    "created_at_iso": "2026-09-15T15:20:34Z",
    "labels_current": [
      "sig/node",
      "stage/alpha",
      "tracked/yes",
      "kind/kep",
      "lead-opted-in"
    ],
    "milestone_current": "v1.38",
    "is_tracking_issue": true
  }
]

MATCH (k:KEP {key: $key}) RETURN k LIMIT 1 ; MATCH (k:KEP {key: $key}) MATCH path = (k)-[:REPLACES|SUPERSEDED_BY|SEE_ALSO|GATED_BY*1..2]-(n) WHERE n <> k AND (n:KEP OR n:FeatureGate) AND all(x IN nodes(path)[1..-1] WHERE x <> k AND (x:KEP OR (x:FeatureGate AND NOT x.key IN $placeholders))) WITH n, path ORDER BY length(path), [x IN nodes(path) | x.key] WITH n, collect(path)[0] AS path RETURN n AS node, length(path) AS hop, path ORDER BY hop, n.key LIMIT 150 ; UNWIND $keys AS kk MATCH (k:KEP {key: kk}) RETURN k.key AS kep, [(k)-[r_0:OWNED_BY]->(s_0:SIG) WHERE coalesce(r_0.valid_to, $open) = $open | s_0] AS sigs, [(p_1:Person)-[r_1:AUTHORED]->(k) WHERE coalesce(r_1.valid_to, $open) = $open AND coalesce(p_1.is_bot, false) = false | p_1] AS authors, [(p_2:Person)-[r_2:APPROVES]->(k) WHERE coalesce(r_2.valid_to, $open) = $open AND coalesce(p_2.is_bot, false) = false | p_2] AS approvers, [(k)-[r_3:TRACKED_BY]->(i_3:Issue) WHERE coalesce(r_3.valid_to, $open) = $open AND i_3.state = 'open' | i_3] AS open_issues LIMIT 200

External Node Liveness Detection

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