When the scheduling queue receives a cluster event, before moving each Pod from unschedulable pod pool to activeQ/backoffQ, it will call QueueingHintFn of plugins that rejected each Pod in the previous scheduling cycle.
  Depending on the value returned from QueueingHintFn, the scheduling queue changes how it queues each Pod:
  - if more than one QueueingHintFn returns QueueImmediately, it queues Pod to activeQ.

- Refactor scheduler's framework permit API. ([#83756](https://github.com/kubernetes/kubernetes/pull/83756), [@hex108](https://github.com/hex108))
- Add incoming pods metrics to scheduler queue. ([#83577](https://github.com/kubernetes/kubernetes/pull/83577), [@liu-cong](https://github.com/liu-cong))

* scheduler: use incremental scheduling cycle in PriorityQueue to put all in-flight unschedulable pods back to active queue if we received move request ([#73309](https://github.com/kubernetes/kubernetes/pull/73309), [@cofyc](https://github.com/cofyc))

* scheduler: use incremental scheduling cycle in PriorityQueue to put all in-flight unschedulable pods back to active queue if we received move request ([#73309](https://github.com/kubernetes/kubernetes/pull/73309), [@cofyc](https://github.com/cofyc))

* Webhook always retries connection reset error. ([#53947](https://github.com/kubernetes/kubernetes/pull/53947), [@crassirostris](https://github.com/crassirostris))
* Adjust batching audit webhook default parameters: increase queue size, batch size, and initial backoff. Add throttling to the batching audit webhook. Default rate limit is 10 QPS. ([#53417](https://github.com/kubernetes/kubernetes/pull/53417), [@crassirostris](https://github.com/crassirostris))

- Sometimes, the scheduler incorrectly placed a pod in the "unschedulable" queue instead of the "backoff" queue. This happened when some plugin previously declared the pod as "unschedulable" and then in a later attempt encounters some other error. Scheduling of that pod then got delayed by up to five minutes, after which periodic flushing moved the pod back into the "active" queue. ([#120334](https://github.com/kubernetes/kubernetes/pull/120334), [@pohly](https://github.com/pohly))...

### **Instrumentation**

#### **Audit**

*   Adjust batching audit webhook default parameters: increase queue size, batch size, and initial backoff. Add throttling to the batching audit webhook. Default rate limit is 10 QPS. ([#53417](https://github.com/kubernetes/kubernetes/pull/53417),[ @crassirostris](https://github.com/crassirostris))

- Migrate proxy/winkernel/proxier.go logs to structured logging ([#98001](https://github.com/kubernetes/kubernetes/pull/98001), [@JornShen](https://github.com/JornShen)) [SIG Network and Windows]
- Migrate scheduling_queue.go to structured logging ([#98358](https://github.com/kubernetes/kubernetes/pull/98358), [@tanjing2020](https://github.com/tanjing2020)) [SIG Scheduling]

- Added a `Processing` condition for the `workqueue` API.
  Changed `Shutdown` for the `workqueue` API to wait until the work queue finishes processing all in-flight items. ([#101928](https://github.com/kubernetes/kubernetes/pull/101928), [@alexanderConstantinescu](https://github.com/alexanderConstantinescu))

- Sometimes, the scheduler incorrectly placed a pod in the "unschedulable" queue instead of the "backoff" queue. This happened when some plugin previously declared the pod as "unschedulable" and then in a later attempt encounters some other error. Scheduling of that pod then got delayed by up to five minutes, after which periodic flushing moved the pod back into the "active" queue. ([#120334](https://github.com/kubernetes/kubernetes/pull/120334), [@pohly](https://github.com/pohly))...