- Fixed a regression in default configurations, which enabled PodDisruptionConditions by default, 

- APIServerTracing now collects spans from etcd client calls, and propagates context to etcd. ([#103216](https://github.com/kubernetes/kubernetes/pull/103216), [@dashpole](https://github.com/dashpole)) [SIG API Machinery, Cloud Provider and Instrumentation]

  - A cluster-scoped object with an ownerReference referencing a uid of a namespaced kind is now consistently treated as though that owner is not resolvable, and the child object is ignored by the garbage collector. ([#92743](https://github.com/kubernetes/kubernetes/pull/92743), [@liggitt](https://github.com/liggitt)) [SIG API Machinery, Apps and Testing]


## Changes by Kind

### Deprecation

- Fixed a bug in the API server where empty collections of ValidatingAdmissionPolicies did not have an `items` field. ([#124568](https://github.com/kubernetes/kubernetes/pull/124568), [@xyz-li](https://github.com/xyz-li)) [SIG API Machinery]

- The kubelet now only collects cgroups metrics for the node, container runtime, kubelet, pods, and containers. ([#72787](https://github.com/kubernetes/kubernetes/pull/72787), [@dashpole](https://github.com/dashpole))

#### Storage

    * The `admissionregistration.k8s.io/v1beta1` versions of `MutatingWebhookConfiguration` and `ValidatingWebhookConfiguration` are deprecated and will no longer be served in v1.19.
* The garbage collector and generic object quota controller have been updated to use the metadata client which improves memory ([#78742](https://github.com/kubernetes/kubernetes/pull/78742), [@smarterclayton](https://github.com/smarterclayton))

* bazel deb package bugfix: The kubeadm deb package now reloads the kubelet after installation ([#65554](https://github.com/kubernetes/kubernetes/pull/65554), [@rdodev](https://github.com/rdodev))
* The garbage collector now supports CustomResourceDefinitions and APIServices. ([#65915](https://github.com/kubernetes/kubernetes/pull/65915), [@nikhita](https://github.com/nikhita))

- Garbage collector now can correctly orphan ControllerRevisions when StatefulSets are deleted with orphan propagation policy. ([#84984](https://github.com/kubernetes/kubernetes/pull/84984), [@cofyc](https://github.com/cofyc)) [SIG Apps]

*   Updates `sqlite3` to `3.33.00` to handle
    [CVE-2020-15358](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-15358).
*   Fixes deprecated usage of `collections` API
*   Removes `scipy` dependency from `setup.py` since TensorFlow does not need it
    to install the pip package

# Release 2.2.1

## Bug Fixes and Other Changes

## Changelog since v1.30.3

## Changes by Kind

### API Change

- Fixed a bug in the API server where empty collections of ValidatingAdmissionPolicies did not have an `items` field. ([#126146](https://github.com/kubernetes/kubernetes/pull/126146), [@xyz-li](https://github.com/xyz-li)) [SIG API Machinery]