* For Deployment, ReplicaSet, and DaemonSet, selectors are now immutable when updating via the new `apps/v1beta2` API. For backward compatibility, selectors can still be changed when updating via `apps/v1beta1` or `extensions/v1beta1`. ([#50719](https://github.com/kubernetes/kubernetes/pull/50719), [@crimsonfaith91](https://github.com/crimsonfaith91))

* Fix AWS NLB security group updates where valid security group ports were incorrectly removed ([#68422](https://github.com/kubernetes/kubernetes/pull/68422), [@kellycampbell](https://github.com/kellycampbell))
    * when updating a service or when node changes occur.
* Fix scheduling starvation of pods in cluster with large number of unschedulable pods. ([#72619](https://github.com/kubernetes/kubernetes/pull/72619), [@everpeace](https://github.com/everpeace))

- Fix invalid VMSS updates due to incorrect cache ([#89002](https://github.com/kubernetes/kubernetes/pull/89002), [@ArchangelSDY](https://github.com/ArchangelSDY)) [SIG Cloud Provider]
- Fix the VMSS name and resource group name when updating Azure VMSS for LoadBalancer backendPools ([#89337](https://github.com/kubernetes/kubernetes/pull/89337), [@feiskyer](https://github.com/feiskyer)) [SIG Cloud Provider]

- All api-server log request lines in a more greppable format. ([#87203](https://github.com/kubernetes/kubernetes/pull/87203), [@lavalamp](https://github.com/lavalamp)) [SIG API Machinery]
- Azure VMSS LoadBalancerBackendAddressPools updating has been improved with sequential-sync + concurrent-async requests. ([#88699](https://github.com/kubernetes/kubernetes/pull/88699), [@feiskyer](https://github.com/feiskyer)) [SIG Cloud Provider]

* Adding lock files for kubeconfig updating ([#28034](https://github.com/kubernetes/kubernetes/pull/28034), [@krousey](https://github.com/krousey))
* federation service controller: fixing the logic to update DNS records ([#27999](https://github.com/kubernetes/kubernetes/pull/27999), [@quinton-hoole](https://github.com/quinton-hoole))

- The `matchLabelKeys/mismatchLabelKeys` feature is introduced to the hard/soft `PodAffinity/PodAntiAffinity`. ([#116065](https://github.com/kubernetes/kubernetes/pull/116065), [@sanposhiho](https://github.com/sanposhiho))
- When updating a CRD, per-expression cost limit check are now skipped for `x-kubernetes-validations` rules of versions that are not mutated. ([#121460](https://github.com/kubernetes/kubernetes/pull/121460), [@jiahuif](https://github.com/jiahuif))

* Add missing argument to log message in federated ingress controller. ([#34158](https://github.com/kubernetes/kubernetes/pull/34158), [@quinton-hoole](https://github.com/quinton-hoole))
* Fix issue in updating device path when volume is attached multiple times ([#33796](https://github.com/kubernetes/kubernetes/pull/33796), [@jingxu97](https://github.com/jingxu97))

- Metrics for `RetroactiveDefaultStorageClass` feature are now available. To see an attempt count for updating PVC retroactively with a default StorageClass see `retroactive_storageclass_total` metric and for total numer of errors see `retroactive_storageclass_errors_total`. ([#113323](https://github.com/kubernetes/kubernetes/pull/113323), [@RomanBednar]...

* Allow kubernetes components to react to SIGTERM signal and shutdown gracefully. ([#57756](https://github.com/kubernetes/kubernetes/pull/57756), [@mborsz](https://github.com/mborsz))
* Fix scheduler cache panic when updating pod conditions. ([#56733](https://github.com/kubernetes/kubernetes/pull/56733), [@bsalamat](https://github.com/bsalamat))

- Added consistent vanity import to files and provided tooling for verifying and updating them. ([#120642](https://github.com/kubernetes/kubernetes/pull/120642), [@jcchavezs](https://github.com/jcchavezs))