Add pod priority and preemption

[bsalamat]

Feature Description

• One-line feature description (can be used as a release note): Pod priority and preemption enables Kubernetes scheduler to schedule more important Pods first and when cluster is out of resources, it removes less important pods to create room for more important ones. The importance is specified by priority.
• Primary contact (assignee): @bsalamat
• Responsible SIGs: scheduling
• Design proposal link (community repo): https://github.com/kubernetes/community/blob/master/contributors/design-proposals/scheduling/pod-preemption.md
• Link to e2e and/or unit tests: https://github.com/kubernetes/kubernetes/blob/master/test/integration/scheduler/preemption_test.go
• Reviewer(s) - (for LGTM) recommend having 2+ reviewers (at least one from code-area OWNERS file) agreed to review. Reviewers from multiple companies preferred: @k82cn @davidopp
• Approver (likely from SIG/area to which feature belongs): @k82cn
• Feature target (which target equals to which milestone):
  • Alpha release target (x.y) 1.8
  • Beta release target (x.y) 1.11
  • Stable release target (x.y) 1.14

/stage beta
/sig scheduling
/kind feature

[justaugustus]

/assign @bsalamat

[justaugustus]

@bsalamat --
We're doing one more sweep of the 1.11 Features tracking spreadsheet.
Would you mind filling in any incomplete / blank fields for this feature's line item?

[kacole2]

@bsalamat This feature was worked on in the previous milestone, so we'd like to check in and see if there are any plans for this to graduate stages in Kubernetes 1.12.

If there are any updates, please explicitly ping @justaugustus, @kacole2, @robertsandoval, @rajendar38 to note that it is ready to be included in the Features Tracking Spreadsheet for Kubernetes 1.12.

---

Please note that the Features Freeze is July 31st, after which any incomplete Feature issues will require an Exception request to be accepted into the milestone.

In addition, please be aware of the following relevant deadlines:

• Docs deadline (open placeholder PRs): 8/21
• Test case freeze: 8/28

Please make sure all PRs for features have relevant release notes included as well.

Happy shipping!

[bsalamat]

This feature is built and graduated to Beta in 1.11. We don't have a clear milestone for GA at this point as we have not received enough feedback about it yet.

[fejta-bot]

Issues go stale after 90d of inactivity.
Mark the issue as fresh with /remove-lifecycle stale.
Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/lifecycle stale

[bsalamat]

/remove-lifecycle stale

[luxas]

When will this feature graduate to stable?

[bsalamat]

We recently encountered an issue with the new scheduling queue (which is needed for this feature to work correctly). We are addressing the issue. If we don't see further issues and once we have confidence in the feature, we can graduate it to stable. That could possibly be as early as 1.14 if things go well.

[claurence]

@bsalamat Hello - I’m the enhancement’s lead for 1.14 and I’m checking in on this issue to see what work (if any) is being planned for the 1.14 release. Enhancements freeze is Jan 29th and I want to remind that all enhancements must have a KEP

[bsalamat]

@claurence We want to move this feature to GA in 1.14. This feature is not new though. It has design docs/proposals merged a long time ago (here and here).

[liggitt]

I'll take the API review for this one

[liggitt]

@apelisse to shadow

[claurence]

@bsalamat looking over the KEP for this enhancement I don't see any testing plans - can someone help PR in testing plans for this enhancement? This information is helpful for knowing readiness of this feature for the release and is specifically useful for CI Signal.

If we don't have testing plans this enhancement will be at risk for being included in the 1.14 release

[bsalamat]

@claurence Could you please elaborate or refer me to an example of needed testing plans? This feature existed and already has unit, integration, and e2e tests and graduation to stable comes with no functionality change. So, there is no need to specifically add tests for the stable version.

[lachie83]

Hello @bsalamat, 1.14 enhancement shadow here. Code Freeze is March 7th and all PRs must be merged by then to your issue to make the 1.14 release. What open K/K PRs do you still have that need to merge? Thanks

[bsalamat]

Hi @lachie83, The only remaining PR is kubernetes/kubernetes#74465 which is actually just a comment update to mark older versions of the API deprecated. Other changes are already merged.

[claurence]

@bsalamat if the tests exist can you PR a link to them into the KEP so they are easy for CI Signal and others to find?

[lachie83]

@bsalamat can you please provide an update on the @claurence comment regarding tests?

[bsalamat]

@claurence @lachie83 I just sent a PR to add testing plan to the KEP.

[bsalamat]

Pod priority and preemption is in GA in 1.14. With that, we can close this enhancement request.

[RehanSaeed]

The docs still mention scheduling.k8s.io/v1beta1 as the apiVersion. Can we now switch to v1?

[bsalamat]

@RehanSaeed Yes. I will send a PR to change the example to v1. Thanks for reporting it.