- Previously, the pod name and namespace were eliminated in the event log message. This PR attempts to add the preemptor pod UID in the preemption event message logs for easier debugging and safer transparency. ([#119971](https://github.com/kubernetes/kubernetes/pull/119971), [@kwakubiney](https://github.com/kwakubiney)) [SIG Scheduling]

- Changed kubectl describe to compute age of an event using the `EventSeries.count` and `EventSeries.lastObservedTime`. ([#104482](https://github.com/kubernetes/kubernetes/pull/104482), [@harjas27](https://github.com/harjas27))

- Scheduler now registers event handlers dynamically. ([#101394](https://github.com/kubernetes/kubernetes/pull/101394), [@Huang-Wei](https://github.com/Huang-Wei)) [SIG Scheduling and Testing]

ParameterList = ParameterDecl { "," ParameterDecl } .
ParameterDecl = [ IdentifierList ] [ "..." ] Type .
</pre>

<p>
Within a list of parameters or results, the names (IdentifierList)
must either all be present or all be absent. If present, each name
stands for one item (parameter or result) of the specified type and
all non-<a href="#Blank_identifier">blank</a> names in the signature
must be <a href="#Uniqueness_of_identifiers">unique</a>.

* Bump event-exporter to 0.2.2 to pick up security fixes. ([#66157](https://github.com/kubernetes/kubernetes/pull/66157), [@loburm](https://github.com/loburm))

* Fixed an issue with informers missing an `Added` event if a recently deleted object was immediately recreated at the same time the informer dropped a watch and relisted. ([#83911](https://github.com/kubernetes/kubernetes/pull/83911), [@matte21](https://github.com/matte21))

 - Fixed a 1.18 regression in wait.Forever that skips the backoff period on the first repeat ([#90476](https://github.com/kubernetes/kubernetes/pull/90476), [@zhan849](https://github.com/zhan849)) [SIG API Machinery]

* kubectl apply now supports explicitly clearing values not present in the config by setting them to null ([#40630](https://github.com/kubernetes/kubernetes/pull/40630), [@liggitt](https://github.com/liggitt))

### Other notable changes

* Connections from Pods to Services with 0 endpoints will now ICMP reject immediately, rather than blackhole and timeout. ([#72534](https://github.com/kubernetes/kubernetes/pull/72534), [@thockin](https://github.com/thockin))

* Scheduler should be able to read from config file if configmap is not present. ([#59386](https://github.com/kubernetes/kubernetes/pull/59386), [@ravisantoshgudimetla](https://github.com/ravisantoshgudimetla))
* Add apiserver metric for current inflight-request usage. ([#58342](https://github.com/kubernetes/kubernetes/pull/58342), [@gmarek](https://github.com/gmarek))