*  Fix: Release the connection if `Authenticator` throws an exception.
 *  Fix: Change the declaration of `OkHttpClient.cache()` to return a `@Nullable Cache`. The return
    value has always been nullable but it wasn't declared properly.
 *  Fix: Reverse suppression of connect exceptions. When both a call and its retry fail, we now
    throw the initial exception which is most likely to be actionable.

* Performance test framework and basic tests for the IPAM controller, to simulate behavior of the four supported modes under lightly loaded and loaded conditions, where load is defined as the number of operations to perform as against the configured kubernetes. ([#61143](https://github.com/kubernetes/kubernetes/pull/61143), [@satyasm](https://github.com/satyasm))

For the 1.8 release, SIG Scalability focused on automating large cluster
scalability testing in a continuous integration (CI) environment. The SIG
defined a concrete process for scalability testing, created
documentation for the current scalability thresholds, and defined a new set of
Service Level Indicators (SLIs) and Service Level Objectives (SLOs) for the system.
Here's the release [scalability validation report].

- 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://githu...

- 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://githu...

* Fix controller-manager race condition issue which cause endpoints flush during restart ([#23035](https://github.com/kubernetes/kubernetes/pull/23035), [@xinxiaogang](https://github.com/xinxiaogang))
* MESOS: forward globally declared cadvisor housekeeping flags ([#22974](https://github.com/kubernetes/kubernetes/pull/22974), [@jdef](https://github.com/jdef))

	if isAttach {
		// new policies to attach => inputPolicies - existing (set difference)
		policiesToUpdate = policiesToUpdate.Difference(existingPolicySet)
		// validate that new policies to add are defined.
		for _, p := range policiesToUpdate.ToSlice() {
			if _, found := cache.iamPolicyDocsMap[p]; !found {
				err = errNoSuchPolicy
				return
			}
		}

			break
		}
	}()

	if markDelete && (opts.Versioned || opts.VersionSuspended) {
		if !deleteMarker {
			// versioning suspended means we add `null` version as
			// delete marker, if its not decided already.
			deleteMarker = opts.VersionSuspended && opts.VersionID == ""
		}
		fi := FileInfo{
			Name:             object,
			Deleted:          deleteMarker,
			MarkDeleted:      markDelete,

		}
	}
}

func tenRunes(r rune) string {
	runes := make([]rune, 10)
	for i := range runes {
		runes[i] = r
	}
	return string(runes)
}

// User-defined self-inverse mapping function
func rot13(r rune) rune {
	const step = 13
	if r >= 'a' && r <= 'z' {
		return ((r - 'a' + step) % 26) + 'a'
	}
	if r >= 'A' && r <= 'Z' {

### **Auth**