* Kubernetes json deserializer is now case-sensitive to restore compatibility with pre-1.8 servers. ([#65157](https://github.com/kubernetes/kubernetes/pull/65157), [@caesarxuchao](https://github.com/caesarxuchao))
    * If your config files contains fields with wrong case, the config files will be now invalid.

    * To avoid that negative effect only use per pod metrics from pods that are:
    * - ready (so metrics about them should be valid), or
    * - unready but creation and last readiness change timestamps are apart more than 10s (pods that have formerly been ready and so metrics are in at least some cases (pod becoming unready because of overload) very useful).

Also, Job controller's constants for default backoff and maximal backoff are lowered down to 1s (from 10s) and 1min (from 6min), respectively. These constants are used to determine the backoff delay for the next Job controller sync in case of a request failure. ([#118615](https://github.com/kubernetes/kubernetes/pull/118615), [@mimowo](https://github.com/mimowo)) [SIG Apps and Testing]

        *   HostPorts are not supported.
*   An IPv6 network mask for pod or cluster cidr network must be /66 or longer. For example: 2001:db1::/66, 2001:dead:beef::/76, 2001:cafe::/118 are supported. 2001:db1::/64 is not supported

### Cluster Federation

#### [alpha] Federated Jobs

Federated Jobs that are automatically deployed to multiple clusters
are now supported. Cluster selection and weighting determine how Job
parallelism and completions are spread across clusters. Federated Job

- Fix azure disk naming matching issue due to case sensitive comparison ([#81720](https://github.com/kubernetes/kubernetes/pull/81720), [@andyzhangx](https://github.com/andyzhangx))
- Fix retry issues when the nodes are under deleting on Azure ([#80419](https://github.com/kubernetes/kubernetes/pull/80419), [@feiskyer](https://github.com/feiskyer))

- Node affinity, Node selectors, and tolerations are now mutable for Jobs that are suspended and have never been started ([#105479](https://github.com/kubernetes/kubernetes/pull/105479), [@ahg-g](https://github.com/ahg-g))

- Fixing issue with Winkernel Proxier - ClusterIP Loadbalancers are missing if the ExternalTrafficPolicy is set to Local and the available endpoints are all remoteEndpoints. ([#116000](https://github.com/kubernetes/kubernetes/pull/116000), [@princepereira](https://github.com/princepereira)) [SIG Network]

-...

- Fixing issue with Winkernel Proxier - ClusterIP Loadbalancers are missing if the ExternalTrafficPolicy is set to Local and the available endpoints are all remoteEndpoints. ([#115999](https://github.com/kubernetes/kubernetes/pull/115999), [@princepereira](https://github.com/princepereira)) [SIG Network]