- Added a feature to report an event about a Pod if kubelet observes a failed attach operation, even if the kubelet is running with `--enable-controller-attach-detach=false`. ([#124884](https://github.com/kubernetes/kubernetes/pull/124884), [@carlory](https://github.com/carlory))

  // NodePhase is the recently observed lifecycle phase of the node.
  // More info: https://kubernetes.io/docs/concepts/nodes/node/#phase
  // The field is never populated, and now is deprecated.
  // +optional
  optional string phase = 3;

  // Conditions is an array of current observed node conditions.
  // More info: https://kubernetes.io/docs/concepts/nodes/node/#condition

## Urgent Upgrade Notes 

### (No, really, you MUST read this before you upgrade)

  - [Changelog since v1.18.17](#changelog-since-v11817)
  - [Important Security Information](#important-security-information)
    - [CVE-2021-25735: Validating Admission Webhook does not observe some previous fields](#cve-2021-25735-validating-admission-webhook-does-not-observe-some-previous-fields)
  - [Changes by Kind](#changes-by-kind-2)
    - [API Change](#api-change-1)
    - [Feature](#feature)
    - [Bug or Regression](#bug-or-regression-2)

- Kubernetes 1.24 bumped version of golang it is compiled with to go1.18, which introduced significant changes to its garbage collection algorithm. As a result, we observed an increase in memory usage for kube-apiserver in larger an heavily loaded clusters up to ~25% (with the benefit of API call latencies drop by up to 10x on 99th percentiles). If the memory increase is not acceptable for you you can mitigate by setting...

  - [Changelog since v1.20.5](#changelog-since-v1205)
  - [Important Security Information](#important-security-information-1)
    - [CVE-2021-25735: Validating Admission Webhook does not observe some previous fields](#cve-2021-25735-validating-admission-webhook-does-not-observe-some-previous-fields)
  - [Changes by Kind](#changes-by-kind-9)
    - [API Change](#api-change-2)
    - [Feature](#feature-5)
    - [Bug or Regression](#bug-or-regression-9)

* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))
* fixes a memory leak in the kube-controller-manager observed when large numbers of pods with tolerations are created/deleted ([#65339](https://github.com/kubernetes/kubernetes/pull/65339), [@liggitt](https://github.com/liggitt))

* fixes a memory leak in the kube-controller-manager observed when large numbers of pods with tolerations are created/deleted ([#65339](https://github.com/kubernetes/kubernetes/pull/65339), [@liggitt](https://github.com/liggitt))

- Added a kubelet socket which serves an grpc service containing the devices used by containers on the node. ([#70508](https://github.com/kubernetes/kubernetes/pull/70508), [@dashpole](https://github.com/dashpole))

## Known Issues