2. If you were previously overriding the kube-proxy configuration for performance reasons, this may no longer be necessary. See https://kubernetes.io/docs/reference/networking/virtual-ips/#optimizing-iptables-mode-performance. ([#115138](https://github.com/kubernetes/kubernetes/pull/115138), [@danwinship](https://github.com/danwinship))

- Significant kube-proxy performance improvements for non UDP ports. ([#83208](https://github.com/kubernetes/kubernetes/pull/83208), [@robscott](https://github.com/robscott))

- Improved yaml parsing performance ([#85458](https://github.com/kubernetes/kubernetes/pull/85458), [@cjcullen](https://github.com/cjcullen)) [SIG API Machinery, CLI, Cloud Provider, Cluster Lifecycle, Instrumentation and Node]

* Improve scheduler performance of MatchInterPodAffinity predicate. ([#57476](https://github.com/kubernetes/kubernetes/pull/57476), [@misterikkit](https://github.com/misterikkit))
* Improve scheduler performance of MatchInterPodAffinity predicate. ([#57477](https://github.com/kubernetes/kubernetes/pull/57477), [@misterikkit](https://github.com/misterikkit))

* Fix a scalability issue where high rates of event writes degraded etcd performance. ([#64539](https://github.com/kubernetes/kubernetes/pull/64539), [@ccding](https://github.com/ccding))

- Add 'cascade delete' support for Octavia load balancers to improve performance.
- Add improved load balancer naming.

### SIG-scheduling

SIG Scheduling development efforts have been primarily focused on improving performance and reliability of the scheduler.
- Performance of the inter-pod affinity/anti-affinity feature is improved over 100X via algorithmic optimization.

### Node

SIG Node iterated on the ability to support more workloads with better performance and improved reliability.  Alpha features were improved around hardware accelerator support, device plugins enablement, and cpu pinning policies to enable us to graduate these features to beta in a future release.  In addition, a number of reliability and performance enhancements were made across the node to help operators in production.

### OpenStack

- Improved scheduler performance when no scoring plugins were defined.
   ([#122058](https://github.com/kubernetes/kubernetes/pull/122058), [@aleksandra-malinowska](https://github.com/aleksandra-malinowska))
- Improved scheduler performance when no scoring plugins were defined.

    * Disable the metadata agent for monitored resource construction in logging.
    * Disable timestamp adjustment in logs to optimize performance.
    * Reduce logging agent buffer chunk limit to 512k to optimize performance.
* Fix a bug on GCE that /etc/crictl.yaml is not generated when crictl is preloaded. ([#66877](https://github.com/kubernetes/kubernetes/pull/66877), [@Random-Liu](https://github.com/Random-Liu))

A security issue was discovered in kube-apiserver that could allow an attacker controlled aggregated API server to redirect client traffic to any URL.  This could lead to the client performing unexpected actions as well as leaking the client's credentials to third parties.