### Bug or Regression

- Added jitter factor to lease controller that better smears load on kube-apiserver over time. ([#101652](https://github.com/kubernetes/kubernetes/pull/101652), [@marseel](https://github.com/marseel)) [SIG API Machinery and Scalability]

    - [Node Binaries](#node-binaries-13)
  - [Major Themes](#major-themes)
    - [Node](#node)
    - [Storage](#storage)
    - [Windows](#windows)
    - [OpenStack](#openstack)
    - [API-machinery](#api-machinery)
    - [Auth](#auth)
    - [Azure](#azure)
    - [CLI](#cli)
    - [Network](#network)
  - [Before Upgrading](#before-upgrading)
  - [Known Issues](#known-issues)
  - [Deprecations](#deprecations)

### Other (Cleanup or Flake)

- Build etcd image v3.5.12 ([#123069](https://github.com/kubernetes/kubernetes/pull/123069), [@bzsuni](https://github.com/bzsuni)) [SIG API Machinery and Etcd]

## Dependencies

### Added
_Nothing has changed._

[#57159](https://github.com/kubernetes/kubernetes/issues/57159).

*   If you are adding Windows Server Virtual Machines as nodes to your Kubernetes environment, there is a compatibility issue with certain virtualization products. Specifically the Windows version of the kubelet.exe calls `GetPhysicallyInstalledSystemMemory` to get the physical memory installed on Windows machines and reports it as part of node metrics to heapster. This API call fails for VMware and VirtualBox virtualization environments....

- Supporting Cross RG resources (disks, Azure File and node [Experimental]

Besides the above new features, support for Azure Virtual Machine Scale Sets (VMSS) and Cluster-Autoscaler is now stable and considered GA:

- Azure virtual machine scale sets (VMSS) allow you to create and manage identical load balanced VMs that automatically increase or decrease based on demand or a set schedule.

- Fixes issue where you can't attach more than 15 GCE Persistent Disks to c2, n2, m1, m2 machine types. ([#88602](https://github.com/kubernetes/kubernetes/pull/88602), [@yuga711](https://github.com/yuga711)) [SIG Storage]
- Fixes kubelet crash in client certificate rotation cases ([#88079](https://github.com/kubernetes/kubernetes/pull/88079), [@liggitt](https://github.com/liggitt)) [SIG API Machinery, Auth and Node]

  - [Urgent Upgrade Notes](#urgent-upgrade-notes)
    - [(No, really, you MUST do this before you upgrade)](#no-really-you-must-do-this-before-you-upgrade)
  - [Major Themes](#major-themes)
    - [SIG API Machinery](#sig-api-machinery)
    - [SIG Auth](#sig-auth)
    - [SIG CLI](#sig-cli)
    - [SIG Cluster Lifecycle](#sig-cluster-lifecycle)
    - [SIG Instrumentation](#sig-instrumentation)
    - [SIG Network](#sig-network)

- Fixes a regression with clients prior to 1.15 not being able to update podIP in pod status, or podCIDR in node spec, against >= 1.16 API servers ([#88505](https://github.com/kubernetes/kubernetes/pull/88505), [@liggitt](https://github.com/liggitt)) [SIG Apps and Network]

  - [Known Issues](#known-issues)
  - [Deprecations](#deprecations)
  - [Major Themes](#major-themes)
    - [SIG API Machinery](#sig-api-machinery)
    - [SIG Auth](#sig-auth)
    - [SIG AWS](#sig-aws)
    - [SIG Azure](#sig-azure)
    - [SIG Big Data](#sig-big-data)
    - [SIG CLI](#sig-cli)
    - [SIG Cloud Provider](#sig-cloud-provider)

trigger automatic volume detach).
  * In very large clusters it may happen that a few nodes won’t register in API
server in a given timeframe for whatever reasons (networking issue, machine
failure, etc.). Normally when kube-up script will encounter even one NotReady
node it will fail, even though the cluster most likely will be working. We
added an environmental variable to kube-up ALLOWED\_NOTREADY\_NODES that