* Add validation for CustomResources via JSON Schema. ([#47263](https://github.com/kubernetes/kubernetes/pull/47263), [@nikhita](https://github.com/nikhita))
* enqueue a sync task to wake up jobcontroller to check job ActiveDeadlineSeconds in time ([#48454](https://github.com/kubernetes/kubernetes/pull/48454), [@weiwei04](https://github.com/weiwei04))

* Add validation for CustomResources via JSON Schema. ([#47263](https://github.com/kubernetes/kubernetes/pull/47263), [@nikhita](https://github.com/nikhita))
* enqueue a sync task to wake up jobcontroller to check job ActiveDeadlineSeconds in time ([#48454](https://github.com/kubernetes/kubernetes/pull/48454), [@weiwei04](https://github.com/weiwei04))

- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.

- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.

    /**
     * Get the value for the key 'index.document.crawler.queue.number_of_shards'. <br>
     * The value is, e.g. 10 <br>
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getIndexDocumentCrawlerQueueNumberOfShards();

    /**
     * Get the value for the key 'index.document.crawler.queue.number_of_shards' as {@link Integer}. <br>

- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.

- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.

- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.

- 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))...

- Implement the scheduling framework with `Reserve`, `Prebind`, `Permit`, `Post-bind`, `Queue sort` and `Unreserve` extension points.
([#77567](https://github.com/kubernetes/kubernetes/pull/77567), [@wgliang](https://github.com/wgliang))