- Added a return value to `QueueingHint` to indicate an error. If `QueueingHint` returns an error,
  the scheduler logs it and treats the event as a `QueueAfterBackoff` so that
  the Pod won't be stuck in the unschedulable pod pool. ([#119290](https://github.com/kubernetes/kubernetes/pull/119290), [@carlory](https://github.com/carlory))

  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.Time timeAdded = 4;
}

// The pod this Toleration is attached to tolerates any taint that matches
// the triple <key,value,effect> using the matching operator <operator>.
message Toleration {
  // Key is the taint key that the toleration applies to. Empty means match all taint keys.

* Mark multi-scheduler graduation to beta and then v1. ([#38871](https://github.com/kubernetes/kubernetes/pull/38871), [@k82cn](https://github.com/k82cn))
* Scheduler treats StatefulSet pods as belonging to a single equivalence class. ([#39718](https://github.com/kubernetes/kubernetes/pull/39718), [@foxish](https://github.com/foxish))

- SSA treats certain structs as atomic ([#100684](https://github.com/kubernetes/kubernetes/pull/100684), [@Jefftree](https://github.com/Jefftree)) [SIG API Machinery, Auth, Node and Storage]

- Server Side Apply now treats LabelSelector fields as atomic (meaning the entire selector is managed by a single writer and updated together), since they contain interrelated and inseparable fields that do not merge in intuitive ways. ([#93901](https://github.com/kubernetes/k...

- Fixed Pod stuck in `Terminating` because of `GenerateUnmapVolumeFunc` missing `globalUnmapPath` when kubelet tries to clean up all volumes that failed reconstruction. ([#123032](https://github.com/kubernetes/kubernetes/pull/123032), [@carlory](https://github.com/carlory))

* This fix prevents a GCE PD volume from being mounted if the udev device link is stale and tries to correct the link. ([#66832](https://github.com/kubernetes/kubernetes/pull/66832), [@msau42](https://github.com/msau42))

- This fix prevents a GCE PD volume from being mounted if the udev device link is stale and tries to correct the link. ([#66832](https://github.com/kubernetes/kubernetes/pull/66832), [@msau42](https://github.com/msau42))

- kubeadm commands now print warnings if input YAML documents contain unknown or duplicate fields.
- kubeadm now properly recognizes Docker 18.09.0 and newer, but still treats 18.06 as the default supported version.
- kubeadm now automatically sets the `--pod-infra-container-image` flag when starting the kubelet.

### SIG IBM Cloud

    * [Path Parameters and Numeric Validations - Order the parameters as you need, tricks](https://fastapi.tiangolo.com/tutorial/path-params-numeric-validations/#order-the-parameters-as-you-need-tricks)
        * [Better with `Annotated`](https://fastapi.tiangolo.com/tutorial/path-params-numeric-validations/#better-with-annotated)