* Deployments are updated to use (1) a more stable hashing algorithm (fnv) than the previous one (adler) and (2) a hashing collision avoidance mechanism that will ensure new rollouts will not block on hashing collisions anymore. ([#44774](https://github.com/kubernetes/kubernetes/pull/44774), [@kargakis](https://github.com/kargakis))

* Allows kubectl to use http caching mechanism for the OpenAPI schema. The cache directory can be configured through `--cache-dir` command line flag to kubectl. If set to empty string, caching will be disabled. ([#50404](https://github.com/kubernetes/kubernetes/pull/50404), [@apelisse](https://github.com/apelisse))

* kubectl: --resource-version now works properly in label/annotate/set selector commands when racing with other clients to update the target object ([#85285](https://github.com/kubernetes/kubernetes/pull/85285), [@liggitt](https://github.com/liggitt))

* Limit use of tags when calling EC2 API to prevent API throttling for very large clusters ([#76749](https://github.com/kubernetes/kubernetes/pull/76749), [@mcrute](https://github.com/mcrute))

#### kube-apiserver:
- in an `--encryption-provider-config` config file, an explicit `cacheSize: 0` parameter previously silently defaulted to caching 1000 keys. In Kubernetes 1.18, this now returns a config validation error. To disable caching, you can specify a negative cacheSize value in Kubernetes 1.18+.

* Move private key parsing from serviceaccount/jwt.go to client-go/util/cert ([#40907](https://github.com/kubernetes/kubernetes/pull/40907), [@cblecker](https://github.com/cblecker))
* Caching added to the OIDC client auth plugin to fix races and reduce the time kubectl commands using this plugin take by several seconds. ([#38167](https://github.com/kubernetes/kubernetes/pull/38167), [@ericchiang](https://github.com/ericchiang))

- Limit use of tags when calling EC2 API to prevent API throttling for very large clusters. ([#76749](https://github.com/kubernetes/kubernetes/pull/76749), [@mcrute](https://github.com/mcrute))

message NodeSystemInfo {
  // MachineID reported by the node. For unique machine identification
  // in the cluster this field is preferred. Learn more from man(5)
  // machine-id: http://man7.org/linux/man-pages/man5/machine-id.5.html
  optional string machineID = 1;

  // SystemUUID reported by the node. For unique machine identification
  // MachineID is preferred. This field is specific to Red Hat hosts

- Avoid caching the Azure VMSS instances whose network profile is nil ([#100948](https://github.com/kubernetes/kubernetes/pull/100948), [@feiskyer](https://github.com/feiskyer)) [SIG Cloud Provider]

    * when updating a service or when node changes occur.
* Allow for watching objects larger than 1MB given etcd accepts objects of size up to 1.5MB ([#72053](https://github.com/kubernetes/kubernetes/pull/72053), [@wojtek-t](https://github.com/wojtek-t))