* kube-apiserver would return 400 Bad Request when it couldn't decode a json patch. ([#68346](https://github.com/kubernetes/kubernetes/pull/68346), [@CaoShuFeng](https://github.com/CaoShuFeng))
    * kube-apiserver would return 422 Unprocessable Entity when a json patch couldn't be applied to one object.

- Fixed bug in reflector that couldn't recover from `Too large resource version` errors with API servers before 1.17.0. ([#115093](https://github.com/kubernetes/kubernetes/pull/115093), [@xuzhenglun](https://github.com/xuzhenglun))

 
## Changes by Kind

### API Change

* fixes a validation error that could prevent updates to StatefulSet objects containing non-normalized resource requests ([#66165](https://github.com/kubernetes/kubernetes/pull/66165), [@liggitt](https://github.com/liggitt))

* Fix a race condition in the scheduler preemption logic that could cause nominatedNodeName of a pod not to be considered in one or more scheduling cycles. ([#72504](https://github.com/kubernetes/kubernetes/pull/72504), [@bsalamat](https://github.com/bsalamat))

* Fixed missing error checking that could cause kubelet to crash in a race condition. ([#60962](https://github.com/kubernetes/kubernetes/pull/60962), [@technicianted](https://github.com/technicianted))
* Bump Heapster to v1.5.2 ([#61396](https://github.com/kubernetes/kubernetes/pull/61396), [@kawych](https://github.com/kawych))

- Fixes a bug where a partial EndpointSlice update could cause node name information to be dropped from endpoints that were not updated. ([#108203](https://github.com/kubernetes/kubernetes/pull/108203), [@robscott](https://github.com/robscott)) [SIG Network]

* Fixes issue where you could not mount NFS or glusterFS volumes using hostnames on GCI/GKE with COS images. ([#42376](https://github.com/kubernetes/kubernetes/pull/42376), [@jingxu97](https://github.com/jingxu97))

- Fixed issue where kubectl-convert would fail when encountering resources that could not be converted to the specified api version. New behavior is to warn the user of the failed conversions...

### Other notable changes

* Fixed a regression where the kubelet would fail to update the ready status of pods. ([#84951](https://github.com/kubernetes/kubernetes/pull/84951), [@tedyu](https://github.com/tedyu))
* Fix nil pointer dereference in azure cloud provider ([#85975](https://github.com/kubernetes/kubernetes/pull/85975), [@ldx](https://github.com/ldx))