IPVS is an alternative approach to in-cluster load balancing that uses in-kernel hash tables rather than the previous iptables approach, while CoreDNS is a replacement for kube-dns for service discovery.

### SIG Node

SIG-Node advanced several features and made incremental improvements in a few key topic areas this release.

- New `service.kubernetes.io/topology-mode` annotation has been introduced as a replacement for the `service.kubernetes.io/topology-aware-hints` annotation.
  - `service.kubernetes.io/topology-aware-hints` annotation has been deprecated.

### Network

In v1.9 SIG Network has implemented alpha support for IPv6, and alpha support for CoreDNS as a drop-in replacement for kube-dns. Additionally, SIG Network has begun the deprecation process for the extensions/v1beta1 NetworkPolicy API in favor of the networking.k8s.io/v1 equivalent.

### Node

PSP as an admission controller resource is being deprecated. Deployed PodSecurityPolicy's will keep working until version 1.25, their target removal from the codebase. A new feature, with a working title of "PSP replacement policy", is being developed in [KEP-2579](https://features.k8s.io/2579). To learn more, read [PodSecurityPolicy Deprecation: Past, Present, and Future](https://blog.k8s.io/2021/04/06/podsecuritypolicy-deprecation-past-present-and-future/).

* Add Japanese translation for kubectl ([#46756](https://github.com/kubernetes/kubernetes/pull/46756), [@girikuncoro](https://github.com/girikuncoro))
* federation: Add admission controller for policy-based placement ([#44786](https://github.com/kubernetes/kubernetes/pull/44786), [@tsandall](https://github.com/tsandall))

- Simple script based hyperkube image that bundles all the necessary binaries. This is an equivalent replacement for the image based on the go based hyperkube command + image. ([#84662](https://github.com/kubernetes/kubernetes/pull/84662), [@dims](https://github.com/dims))

- The following deprecated metrics are removed, please convert to the corresponding metrics:
  - The following replacement metrics are available from v1.14.0:
      - `rest_client_request_latency_seconds` -> `rest_client_request_duration_seconds`
      - `scheduler_scheduling_latency_seconds` -> `scheduler_scheduling_duration_seconds `

- Always create configmaps/extensions-apiserver-authentication from kube-apiserver. ([#67694](https://github.com/kubernetes/kubernetes/pull/67694), [@sttts](https://github.com/sttts))
- Switched certificate data replacement from "REDACTED" to "DATA+OMITTED" ([#66023](https://github.com/kubernetes/kubernetes/pull/66023), [@ibrasho](https://github.com/ibrasho))

- Kubeadm: remove the deprecated command `kubeadm config view`. A replacement for this command is `kubectl get cm -n kube-system kubeadm-config -o=jsonpath="{.data.ClusterConfiguration}"` ([#102071](https://github.com/kubernetes/kubernetes/pull/102071), [@neolit123](https://github.com/neolit123))

These extension points can now be abstracted away due to their irrelevance for most users.

### CSI Migration updates

CSI Migration enables the replacement of existing in-tree storage plugins such as `kubernetes.io/gce-pd` or `kubernetes.io/aws-ebs` with a corresponding CSI driver.
If CSI Migration is working properly, Kubernetes end users shouldn’t notice a difference.