Random Pod selection on ReplicaSet downscaling

[alculquicondor]

Enhancement Description

• One-line enhancement description (can be used as a release note): When a ReplicaSet is downscaled, victim Pods are selected randomly
• Kubernetes Enhancement Proposal: https://git.k8s.io/enhancements/keps/sig-apps/2185-random-pod-select-on-replicaset-downscale
• Discussion Link: kubernetes/kubernetes#96748
• Primary contact (assignee): alculquicondor@, damemi@
• Responsible SIGs: sig-apps, sig-scheduling
• Enhancement target (which target equals to which milestone):
  • Alpha release target (x.y): 1.21
  • Beta release target (x.y): 1.22
  • Stable release target (x.y): 1.31
• [x] Alpha
  • [x] KEP (k/enhancements) update PR(s): #2233
  • [x] Code (k/k) update PR(s): kubernetes/kubernetes#99212
  • [x] Docs (k/website) update PR(s): kubernetes/website#27221
• [x] Beta
  • [x] KEP (k/enhancements) update PR(s): #2691
  • [x] Code (k/k) update PR(s): https://github.com/kubernetes/kubernetes/pull/101767
  • [x] Docs (k/website) update(s): https://github.com/kubernetes/website/pull/27221
• [ ] Stable
  • [x] KEP (k/enhancements) update PR(s): https://github.com/kubernetes/enhancements/pull/4649
  • [x] Code (k/k) update PR(s): https://github.com/kubernetes/kubernetes/pull/125459
  • [ ] Docs (k/website) update(s):

[alculquicondor]

/sig apps /sig scheduling

[alculquicondor]

cc @damemi

[damemi]

/assign

[damemi]

Haven't fogotten about this, just didn't get it in time for the new year... will open a PR soon based on @alculquicondor's draft

[damemi]

Filled out most of the sections and opened a KEP here: https://github.com/kubernetes/enhancements/pull/2233

Looking for anything I missed or could improve on. Pretty straightforward mostly since it's not affecting a user-documented behavior

[jrsapi]

Greetings @damemi! Since your Enhancement is scheduled to be in 1.21, please keep in mind the important upcoming dates: • Tuesday, March 9th: Week 9 - Code Freeze • Tuesday, March 16th: Week 10 - Docs Placeholder PR deadline • If this enhancement requires new docs or modification to existing docs, please follow the steps in the Open a placeholder PR doc to open a PR against k/website repo. As a reminder, please link all of your k/k PR(s) and k/website PR(s) to this issue so we can track them. Thanks!

[damemi]

xref - wip PR https://github.com/kubernetes/kubernetes/pull/96898

I'll be picking up this PR and working to get that merged for code freeze. Thanks for the update @jrsapi !

[damemi]

Opened new PR in https://github.com/kubernetes/kubernetes/pull/99212

[jrsapi]

Greetings @damemi,

A friendly reminder that Code freeze is 5 days away, March 9th EOD PST Any enhancements that are NOT code complete by the freeze will be removed from the milestone will require an exception to be added back. Please also keep in mind that if this enhancement requires new docs or modification to existing docs, you'll need to follow the steps in the Open a placeholder PR doc to open a PR against k/website repo by March 16th EOD PST. Thanks!

[alculquicondor]

Should we consider any updates to documentation for this? https://kubernetes.io/docs/concepts/workloads/controllers/replicaset/#scaling-a-replicaset

Current documentation doesn't give any details about internal selection, which might still be desired.

@janetkuo @soltysh

[janetkuo]

Yes, please update docs and the feature gate for this.

[PI-Victor]

Hello @damemi, 1.21 Docs shadow here. Does this enhancement work planned for 1.21 require any new docs or modification to existing docs? If so, please follows the steps here to open a PR against dev-1.21 branch in the k/website repo. This PR can be just a placeholder at this time and must be created by March 16 EOD PST Also take a look at Documenting for a release to get yourself familiarize with the docs requirement for the release. Thank you!

[damemi]

Yeah, I will open a PR to update the docs Aldo linked above

[damemi]

Docs PR opened at https://github.com/kubernetes/website/pull/26993, which just copies the comments from code into the docs

[ahg-g]

@alculquicondor can you update the description checklist?

@damemi do you plan on submitting a KEP update to graduate the feature to Beta?

[alculquicondor]

Updated alpha links

[damemi]

@ahg-g yes, I'll update the KEP with what's necessary for Beta graduation

[reylejano]

Hi @damemi ,

1.22 release team here. After reviewing the kep there are a few things that need to be complete before the 1.22 Enhancements Freeze which starts at 23:59:59 pst on Thursday, May 13:

• Update the Monitoring Requirements section in the kep README.md
• The kep requires an approved PRR for beta before Enhancements Freeze, please submit for a PRR after updating the requirements for beta
• In the kep.yaml, update the value for latest-milestone to "v1.22"
• Update the metrics section in the kep.yaml

[damemi]

@reylejano thanks for the update, we have a PR to update the KEP that is currently undergoing review at https://github.com/kubernetes/enhancements/pull/2691 to make the changes you have listed. This should be able to make the enhancements freeze

[reylejano]

Hi @damemi , I see that sig scheduling is a participating sig for this enhancement. Does sig scheduling need to do anything for this enhancement for the 1.22 release?

[alculquicondor]

sig-scheduling, in particular @damemi and me, proposed the change. But there's no AI on sig-scheduling.

[reylejano]

Hi @damemi, With the merge of PR 2691, this enhancement is all set for the 1.22 Enhancements Freeze 🎉 Thank you!

[chrisnegus]

Hi @damemi ! I'm @chrisnegus , a Docs Shadow for release 1.22. This enhancement is marked as Needs Docs for the 1.22 release.

Please follow the steps detailed in the documentation to open a PR against dev-1.22 branch in the kubernetes/website repo. This PR can be just a placeholder at this time and must be created before Fri July 9, 11:59 PM PDT.

Also, take a look at Documenting for a release to familiarize yourself with the docs requirement for the release.

Thank you!

[damemi]

Hi @chrisnegus, I opened the placeholder PR here: https://github.com/kubernetes/website/pull/28102 Besides the status change from Alpha to Beta, I think the only other user-facing change for this release will be a KCM metric we planned to add (from the discussion in https://github.com/kubernetes/enhancements/pull/2691). Do those get documented as well?

[reylejano]

Hi @dememi,

With about 2 weeks until code freeze (July 8, 2021), Can you confirm if the following k/k PR is all that is needed for the implementation of this enhancement for the 1.22 release?

• https://github.com/kubernetes/kubernetes/pull/101767

[damemi]

@reylejano yes, that and the docs PR (https://github.com/kubernetes/website/pull/28102) are all that is needed for this. Thanks!

[reylejano]

Hi @damemi ,

Just a reminder that the 1.22 code freeze starts next week on July 8, 2021. We're tracking https://github.com/kubernetes/kubernetes/pull/101767 for 1.22. Looks like you're set for the 1.22 Docs Placeholder PR deadline (July 9, 2021) with https://github.com/kubernetes/website/pull/28102

[reylejano]

Hi @damemi ,

The 1.22 code freeze starts in a few days on Thursday, July 8 at 18:00 PDT. The following PR and any other PR required for this enhancement for 1.22 has to merge by then:

• https://github.com/kubernetes/kubernetes/pull/101767

This enhancement is currently at-risk of falling out of 1.22 with kubernetes/kubernetes#101767 open

[damemi]

@reylejano that PR was tagged for merge this morning and should have no issues making it in by Thursday 🙂

[reylejano]

Hi @damemi ,

This enhancement is all set for the 1.22 code freeze 🎉