- When scaling down a ReplicaSet, delete doubled up replicas first, where a "doubled up replica" is defined as one that is on the same node as an active replica belonging to a related ReplicaSet.  ReplicaSets are considered "related" if they have a common controller (typically a Deployment). ([#80004](https://github.com/kubernetes/kubernetes/pull/80004),...

- The `endpoints` field in discovery.k8s.io/v1 EndpointSlice is now correctly defined as optional in the OpenAPI specification, matching the server's behavior. ([#136111](https://github.com/kubernetes/kubernetes/pull/136111), [@aojea](https://github.com/aojea)) [SIG Network]

       * template to be null (though we do handle that case gracefully at runtime). I've left this
       * one as it is because one of our users has defined a wrapper API around Preconditions,
       * declaring a checkState method that accepts a possibly null template. So we'd need to update
       * that user first.
       */
      @Nullable String errorMessageTemplate,

		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrOverlappingFilterNotification: {
		Code:           "InvalidArgument",
		Description:    "An object key name filtering rule defined with overlapping prefixes, overlapping suffixes, or overlapping combinations of prefixes and suffixes for the same event types.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrFilterNameInvalid: {

* 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].

	if err != nil {
		return arn.ARN{}, "", fmt.Errorf("RoleARN parse err: %v", err)
	}
	rolePolicy, ok := sys.rolesMap[roleArn]
	if !ok {
		return arn.ARN{}, "", fmt.Errorf("RoleARN %s is not defined.", arnStr)
	}
	return roleArn, rolePolicy, nil
}

// DeletePolicy - deletes a canned policy from backend. `notifyPeers` is true
// whenever this is called via the API. It is false when called via a

### **Auth**

	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 updatedAt, addedOrRemoved, effectivePolicies, err
			}
		}

- Supported fine-grained supplemental groups policy (KEP-3619), which enabled
  fine-grained control for supplementary groups in the first container processes.
  This allows you to choose whether to include groups defined in the container image (/etc/groups)
  for the container's primary UID or not. ([#117842](https://github.com/kubernetes/kubernetes/pull/117842), [@everpeace](https://github.com/everpeace)) [SIG API Machinery, Apps and Node]