### **Instrumentation**

#### **Audit**

*   Adjust batching audit webhook default parameters: increase queue size, batch size, and initial backoff. Add throttling to the batching audit webhook. Default rate limit is 10 QPS. ([#53417](https://github.com/kubernetes/kubernetes/pull/53417),[ @crassirostris](https://github.com/crassirostris))

administrators will be able to place limits by using the new kubelet command line parameter --pod-max-pids. Note that since this is a alpha feature they will need to enable the "SupportPodPidsLimit" feature. By default, we do not set any maximum limit, If an administrator wants to enable this, they should enable SupportPodPidsLimit=true in the --feature-gates= parameter to kubelet and specify the limit using the --pod-max-pids parameter. The limit set is the total count of all processes running in all containers...

- `diskformat` storage class parameter for in-tree vSphere volume plugin is deprecated as of v1.21 release. Please consider updating storageclass and remove `diskformat` parameter. vSphere CSI Driver does not support diskformat storageclass parameter.
  

- Resolves a spurious "Unknown discovery response content-type" error in client-go discovery requests by tolerating extra content-type parameters in API responses ([#117637](https://github.com/kubernetes/kubernetes/pull/117637), [@seans3](https://github.com/seans3)) [SIG API Machinery]

* Created a new `dryRun` query parameter for mutating endpoints. If the parameter is set, then the query will be rejected, as the feature is not implemented yet. This will allow forward compatibility with future clients; otherwise, future clients talking with older apiservers might end up modifying a resource even if they include the `dryRun` query parameter. ([#63557](https://github.com/kubernetes/kubernetes/pull/63557), [@apelisse](https://...

* Bump Heapster to v1.6.0-beta.1 ([#67074](https://github.com/kubernetes/kubernetes/pull/67074), [@kawych](https://github.com/kawych))

* Fixed pod cleanup when /var/lib/kubelet is a symlink. ([#68741](https://github.com/kubernetes/kubernetes/pull/68741), [@jsafrane](https://github.com/jsafrane))
* Add "only_cpu_and_memory" GET parameter to /stats/summary http handler in kubelet. If parameter is true then only cpu and memory will be present in response. ([#67829](https://github.com/kubernetes/kubernetes/pull/67829), [@krzysztof-jastrzebski](https://github.com/krzysztof-jastrzebski))

* Fix mounting of UNIX sockets(and other special files) in subpaths ([#61480](https://github.com/kubernetes/kubernetes/pull/61480), [@gnufied](https://github.com/gnufied))
* Fix GCE etcd scripts to pass in all required parameters for the etcd migration utility to correctly perform HA upgrades and downgrades ([#61957](https://github.com/kubernetes/kubernetes/pull/61957), [@jpbetz](https://github.com/jpbetz))

- The deprecated flag `--lock-object-namespace` and `--lock-object-name` have been removed from kube-scheduler. Please use `--leader-elect-resource-namespace` and `--leader-elect-resource-name` or ComponentConfig instead to configure those parameters. ([#119130](https://github.com/kubernetes/kubernetes/pull/119130), [@SataQiu](https://github.com/SataQiu)) [SIG Scheduling]

  - HardPodAffinityWeight moved from a top level ComponentConfig parameter to a PluginConfig parameter of InterPodAffinity Plugin in `kubescheduler.config.k8s.io/v1alpha2` ([#88002](https://github.com/kubernetes/kubernetes/pull/88002), [@alculquicondor](https://github.com/alculquicondor)) [SIG Scheduling and Testing]