add intro to metrics stability extension kep

Author: Han Kang

keps/sig-instrumentation/4242-additional-stability-classes/README.md renamed to keps/sig-instrumentation/4242-extending-stability/README.md

@@ -1,82 +1,6 @@
-<!--
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-# KEP-NNNN: Your short, descriptive title
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-<!--
-This is the title of your KEP. Keep it short, simple, and descriptive. A good
-title can help communicate what the KEP is and should be considered as part of
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-<!-- toc -->
+# KEP-4242: Extending Metrics Stability
+
+
 - [Release Signoff Checklist](#release-signoff-checklist)
 - [Summary](#summary)
 - [Motivation](#motivation)
@@ -104,24 +28,9 @@ tags, and then generate with `hack/update-toc.sh`.
 - [Drawbacks](#drawbacks)
 - [Alternatives](#alternatives)
 - [Infrastructure Needed (Optional)](#infrastructure-needed-optional)
-<!-- /toc -->
 
 ## Release Signoff Checklist
 
-<!--
-**ACTION REQUIRED:** In order to merge code into a release, there must be an
-issue in [kubernetes/enhancements] referencing this KEP and targeting a release
-milestone **before the [Enhancement Freeze](https://git.k8s.io/sig-release/releases)
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-
 Items marked with (R) are required *prior to targeting to a milestone / release*.
 
 - [ ] (R) Enhancement issue in release milestone, which links to KEP dir in [kubernetes/enhancements] (not the initial KEP PR)
@@ -139,9 +48,6 @@ Items marked with (R) are required *prior to targeting to a milestone / release*
 - [ ] User-facing documentation has been created in [kubernetes/website], for publication to [kubernetes.io]
 - [ ] Supporting documentation—e.g., additional design documents, links to mailing list discussions/SIG meetings, relevant PRs/issues, release notes
 
-<!--
-**Note:** This checklist is iterative and should be reviewed and updated every time this enhancement is being considered for a milestone.
--->
 
 [kubernetes.io]: https://kubernetes.io/
 [kubernetes/enhancements]: https://git.k8s.io/enhancements
@@ -150,60 +56,27 @@ Items marked with (R) are required *prior to targeting to a milestone / release*
 
 ## Summary
 
-<!--
-This section is incredibly important for producing high-quality, user-focused
-documentation such as release notes or a development roadmap. It should be
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-A good summary is probably at least a paragraph in length.
+The metric stability framework was originally introduced with the intent of safeguarding significant metrics from being broken downstream. Metrics could be deemed `stable` or `alpha`, and only `stable` metrics would have stability guarantees. 
 
-Both in this section and below, follow the guidelines of the [documentation
-style guide]. In particular, wrap lines to a reasonable length, to make it
-easier for reviewers to cite specific portions, and to minimize diff churn on
-updates.
-
-[documentation style guide]: https://github.com/kubernetes/community/blob/master/contributors/guide/style-guide.md
--->
+This KEP intends to propose additional stability classes to extend on the existing metrics stability framework, such that we can achieve parity with the various stages of the feature release cycle.
 
 ## Motivation
 
-<!--
-This section is for explicitly listing the motivation, goals, and non-goals of
-this KEP.  Describe why the change is important and the benefits to users. The
-motivation section can optionally provide links to [experience reports] to
-demonstrate the interest in a KEP within the wider Kubernetes community.
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-[experience reports]: https://github.com/golang/go/wiki/ExperienceReports
--->
+It's become more obvious recently that we need additional stability classes, particularly in respect to various stages of feature releases. This has become more obvious with the advent of PRR (production readiness reviews) and mandated production readiness metrics. 
 
 ### Goals
 
-<!--
-List the specific goals of the KEP. What is it trying to achieve? How will we
-know that this has succeeded?
--->
+Introduce two more metric classes: `beta`, corresponding to the `beta` stage of feature release, and `internal` which corresponds to internal development related metrics. 
+
+Additionally we propose forced upgrades of metrics stability classes in the similar vein that features are not allowed to languish in `alpha` or `beta` stages. In order to respect the fact that there may be classes of metrics which do not correspond to features, we reserve the `internal` metrics stability class.
 
 ### Non-Goals
 
-<!--
-What is out of scope for this KEP? Listing non-goals helps to focus discussion
-and make progress.
--->
+
 
 ## Proposal
 
-<!--
-This is where we get down to the specifics of what the proposal actually is.
-This should have enough detail that reviewers can understand exactly what
-you're proposing, but should not include things like API designs or
-implementation. What is the desired outcome and how do we measure success?.
-The "Design Details" section below is for the real
-nitty-gritty.
--->
+
 
 ### User Stories (Optional)
 
@@ -252,23 +125,9 @@ proposal will be implemented, this is the place to discuss them.
 
 ### Test Plan
 
-<!--
-**Note:** *Not required until targeted at a release.*
-
-Consider the following in developing a test plan for this enhancement:
-- Will there be e2e and integration tests, in addition to unit tests?
-- How will it be tested in isolation vs with other components?
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-No need to outline all of the test cases, just the general strategy. Anything
-that would count as tricky in the implementation, and anything particularly
-challenging to test, should be called out.
+We have static analysis testing for stable metrics, we will extend our test coverage 
+to include metrics which are `ALPHA` and `BETA` while ignoring `INTERNAL` metrics.
 
-All code is expected to have adequate tests (eventually with coverage
-expectations). Please adhere to the [Kubernetes testing guidelines][testing-guidelines]
-when drafting this test plan.
-
-[testing-guidelines]: https://git.k8s.io/community/contributors/devel/sig-testing/testing.md
--->
 
 ### Graduation Criteria
 

keps/sig-instrumentation/4242-additional-stability-classes/kep.yaml renamed to keps/sig-instrumentation/4242-extending-stability/kep.yaml

@@ -1,19 +1,19 @@
 id: "2306"
 prnumber: ""
-name: additional-stability-classes
-title: Additional Metrics Stability Classes
+name: extending-stability
+title: Extending Metrics Stability
 kep-number: "4242"
-authors: ['@logicalhan,brancz,coffeepac']
+authors: ['@logicalhan', '@dgrisonnet', '@coffeepac']
 owning-sig: sig-instrumentation
 participating-sigs: [sig-architecture, sig-instrumentation]
-reviewers: ['@dashpole']
+reviewers: ['@dashpole', '@ehashman']
 approvers: []
-prr-approvers: []
+prr-approvers: ['@ehashman']
 creation-date: "2021-06-27"
-last-updated: v1.19
+last-updated: v1.24
 status: provisional
-stage: ""
-latest-milestone: ""
+stage: "ALPHA"
+latest-milestone: "v1.24"
 milestone:
     alpha: ""
     beta: ""