- kube-scheduler

  - Migrate scheduler to use v1beta1 Event API. any tool targeting scheduler events needs to use v1beta1 Event API ([#78447](https://github.com/kubernetes/kubernetes/pull/78447), [@yastij](https://github.com/yastij))

- kubeadm

  - The `export` query parameter for list API calls, deprecated since v1.14, will be removed in v1.18.
  - The `series.state` field in the events.k8s.io/v1beta1 Event API is deprecated and will be removed in v1.18 ([#75987](https://github.com/kubernetes/kubernetes/pull/75987), [@yastij](https://github.com/yastij))

- kubeadm

- `client-go` event library allows customizing spam filtering function. 
  It is now possible to override `SpamKeyFunc`, which is used by event filtering to detect spam in the events. ([#103918](https://github.com/kubernetes/kubernetes/pull/103918), [@olagacek](https://github.com/olagacek))
- `client-go`, using log level 9, traces the following events of a HTTP request:
      - DNS lookup
      - TCP dialing

- Pod Security admission: the pod-security `warn` level will now default to the `enforce` level. ([#113491](https://github.com/kubernetes/kubernetes/pull/113491), [@tallclair](https://github.com/tallclair)) [SIG Auth and Security]
- Promote kubectl alpha events to kubectl events ([#113819](https://github.com/kubernetes/kubernetes/pull/113819), [@soltysh](https://github.com/soltysh)) [SIG CLI and Testing]

- Use table-driven test for `TestPerPodSchedulingMetrics`. ([#118842](https://github.com/kubernetes/kubernetes/pull/118842), [@helayoty](https://github.com/helayoty))
- When retrieving event resources, the `reportingController` and `reportingInstance` fields in the event will contain values. ([#116506](https://github.com/kubernetes/kubernetes/pull/116506), [@HirazawaUi](https://github.com/HirazawaUi)) [SIG API Machinery and Instrumentation]

- Fix a bug where events/v1 Events with similar event type and reporting instance were not aggregated by client-go. ([#112365](https://github.com/kubernetes/kubernetes/pull/112365), [@dgrisonnet](https://github.com/dgrisonnet)) [SIG API Machinery and Instrumentation]

* kube-proxy will emit "FailedToStartNodeHealthcheck" event when fails to start healthz server. ([#49267](https://github.com/kubernetes/kubernetes/pull/49267), [@MrHohn](https://github.com/MrHohn))

- Improved reboot event reporting. The kubelet will only emit one reboot Event when a server-level reboot 
is detected, even if the kubelet cannot write its status to the associated Node (which triggers a retry). ([#129151](https://github.com/kubernetes/kubernetes/pull/129151), [@rphillips](https://github.com/rphillips)) [SIG Node]

    * [prometheus-to-sd addon] Bump prometheus-to-sd to 0.3.1 to pick up security fixes, bug fixes and new features.
    * [event-exporter addon] Bump event-exporter to 0.2.3 to pick up security fixes.

    * [prometheus-to-sd addon] Bump prometheus-to-sd to 0.3.1 to pick up security fixes, bug fixes and new features.
    * [event-exporter addon] Bump event-exporter to 0.2.3 to pick up security fixes.