Merge pull request #4605 from p0lyn0mial/kep-watch-list-update-1-31

Update KEP 3157 (watch-list) for milestone 1.31

Author: k8s-ci-robot

keps/sig-api-machinery/3157-watch-list/README.md

@@ -101,6 +101,7 @@ tags, and then generate with `hack/update-toc.sh`.
     - [Alpha](#alpha)
     - [Beta](#beta)
     - [GA](#ga)
+    - [Post-GA](#post-ga)
   - [Upgrade / Downgrade Strategy](#upgrade--downgrade-strategy)
   - [Version Skew Strategy](#version-skew-strategy)
 - [Production Readiness Review Questionnaire](#production-readiness-review-questionnaire)
@@ -678,15 +679,21 @@ We expect no non-infra related flakes in the last month as a GA graduation crite
   Whether it is safe to use the RequestWatchProgress API call 
   or if the experimental-watch-progress-notify-interval flag has been set.
   Knowing etcd configuration will be used to automatically disable the streaming feature.
+- Use WatchProgressRequester to request progress notifications directly from etcd.
+  This mechanism was developed in [Consistent Reads from Cache KEP](https://github.com/kubernetes/enhancements/tree/master/keps/sig-api-machinery/2340-Consistent-reads-from-cache#use-requestprogress-to-enable-automatic-watch-updates)
+  and will reduce the overall latency for watchlist requests.
 
 #### GA
-- Consider using WatchProgressRequester to request progress notifications directly from etcd.
-  This mechanism was developed in [Consistent Reads from Cache KEP](https://github.com/kubernetes/enhancements/tree/master/keps/sig-api-machinery/2340-Consistent-reads-from-cache#use-requestprogress-to-enable-automatic-watch-updates)
-  and could reduce the overall latency for watchlist requests.
 - [Switch](https://github.com/kubernetes/kubernetes/blob/a07b1aaa5b39b351ec8586de800baa5715304a3f/staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go#L416) 
   the `storage/cacher` to use streaming directly from etcd 
   (This will also allow us to [remove](https://github.com/kubernetes/kubernetes/blob/a07b1aaa5b39b351ec8586de800baa5715304a3f/staging/src/k8s.io/client-go/tools/cache/reflector.go#L110) the `reflector.UseWatchList` field).
 
+#### Post-GA
+- Make  **list** calls expensive in APF. 
+  Once all supported releases have the streaming list enabled by default (client-go, control plane components)
+  and the feature itself is locked to its default value, we can increase the cost of regular list requests in APF. 
+  This ensures that the fallback mechanism, which switches back to the standard list when streaming has issues, will not be affected.
+
 <!--
 **Note:** *Not required until targeted at a release.*
 

keps/sig-api-machinery/3157-watch-list/kep.yaml

@@ -20,24 +20,24 @@ stage: beta
 # The most recent milestone for which work toward delivery of this KEP has been
 # done. This can be the current (upcoming) milestone, if it is being actively
 # worked on.
-latest-milestone: "v1.30"
+latest-milestone: "v1.31"
 
 # The milestone at which this feature was, or is targeted to be, at each stage.
 milestone:
   alpha: "v1.27"
-  beta: "v1.30"
+  beta: "v1.31"
 
 # The following PRR answers are required at alpha release
 # List the feature gate name and the components for which it must be enabled
 feature-gates:
   - name: WatchList
     components:
       - kube-apiserver
-  - name: WatchListClient (the actual name might be different because it hasn't been added yet))
+  - name: WatchListClient
     components:
       - kube-controller-manager via client-go library
 disable-supported: true
 
 # The following PRR answers are required at beta release
 metrics:
-  - my_feature_metric
+  - apiserver_watch_list_duration_seconds