HPA External Metrics Fallback on Retrieval Failure

[omerap12]

Enhancement Description

• One-line enhancement description (can be used as a release note): HPAs can now specify fallback values for external metrics to continue scaling when metric retrieval fails
• Kubernetes Enhancement Proposal:
• Discussion Link:
  https://kubernetes.slack.com/archives/C09R1LV8S/p1736868782365929
• Primary contact (assignee): @omerap12 , @adrianmoisey
• PRs by stage and milestone:
  • Alpha - v1.36
    • KEP (k/enhancements) update PR(s): KEP-5679: Fallback for HPA on failure to retrieve metrics #5680
    • Code (k/k) update PR(s):
    • Docs (k/website) update PR(s):

Please keep this description up to date. This will help the Enhancement Team to track the evolution of the enhancement efficiently.

[omerap12]

/sig autoscaling