### Scheduling

- Improved fairness of the scheduling queue by placing pods which are attempted recently behind other pods with the same priority. ([#73700](https://github.com/kubernetes/kubernetes/pull/73700), [@denkensk](https://github.com/denkensk))

* Change default value of deleting-pods-burst to 1 ([#27606](https://github.com/kubernetes/kubernetes/pull/27606), [@gmarek](https://github.com/gmarek))
* MESOS: fix race condition in contrib/mesos/pkg/queue/delay ([#24916](https://github.com/kubernetes/kubernetes/pull/24916), [@jdef](https://github.com/jdef))

  - apiserver_flowcontrol_current_r: R(the time of the last change in state of the queues)
  - apiserver_flowcontrol_dispatch_r: R(the time of the latest request dispatch)
  - apiserver_flowcontrol_latest_s: S(the request last dispatched) = R(when that request starts executing in the virtual world)
  - apiserver_flowcontrol_next_s_bounds: min and max next S among non-empty queues

### **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))

- Added `SchedulerPopFromBackoffQ` feature gate that is in beta and enabled by default. Improved scheduling queue behavior by popping pods from the backoffQ when the activeQ is empty. This allows to process potentially schedulable pods ASAP, eliminating a penalty effect of the backoff queue. ([#130772](https://github.com/kubernetes/kubernetes/pull/130772), [@macsko](https://github.com/macsko)) [SIG Scheduling and Testing]

    - `scheduler_async_api_call_duration_seconds`: histogram of API call execution duration by call type and result
    - `scheduler_pending_async_api_calls`: gauge showing current number of pending API calls in the queue. ([#133120](https://github.com/kubernetes/kubernetes/pull/133120), [@utam0k](https://github.com/utam0k)) [SIG Release and Scheduling]

    val response = client.newCall(request).execute()
    assertThat(response.body.string()).isEqualTo("B")
  }

  @Test
  fun requestOnlyIfCachedWithNoResponseCached() {
    // (no responses enqueued)
    val request =
      Request
        .Builder()
        .url(server.url("/"))
        .header("Cache-Control", "only-if-cached")
        .build()
    val response = client.newCall(request).execute()

	Maintenance    bool
	DeploymentType string
	NoLogging      bool
}

// HealthResult returns the current state of the system, also
// additionally with any specific heuristic information which
// was queried
type HealthResult struct {
	Healthy       bool
	HealthyRead   bool
	HealingDrives int
	ESHealth      []struct {
		Maintenance   bool
		PoolID, SetID int
		Healthy       bool

- Implemented scoring for DRA-backed extended resources. ([#134058](https://github.com/kubernetes/kubernetes/pull/134058), [@bart0sh](https://github.com/bart0sh)) [SIG Node, Scheduling and Testing]

- 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))