`autoscaling/v2alpha1`. The Horizontal Pod Autoscaler changes include support for status conditions, and autoscaling on memory and custom metrics.

* The metrics APIs, `custom-metrics.metrics.k8s.io` and `metrics`, were moved from `v1alpha1` to `v1beta1`, and renamed to `custom.metrics.k8s.io` and `metrics.k8s.io`, respectively. If you have deployed a custom metrics adapter, ensure that it supports the new API version. If you have deployed Heapster in aggregated API server mode, upgrade Heapster...

- Cloud controller manager's node controller now emits timing metrics for initial `Node` synchronization. These metrics measure the delay between the creation of a new `Node` and the node controller's initial management actions, such as removing the cloud provider taint. These metrics should be consulted when setting cloud controller manager's `--concurrent-node-syncs` flag. ([#119241](https://github.com/kubernetes/kubernetes/pull/119241),...

- HPA controller exposes the following metrics from the kube-controller-manager. 
  - `metric_computation_duration_seconds`: The time(seconds) that the HPA controller takes to calculate one metric.

- If `ComponentSLIs` feature gate is enabled, then `/metrics/slis` becomes available on kubelet, allowing you to scrape health check metrics. ([#113030](https://github.com/kubernetes/kubernetes/pull/113030), [@Richabanker](https://github.com/Richabanker)) [SIG Node]

- A new kubelet metric `image_pull_duration_seconds` was added. The metric tracks the duration (in seconds) it takes for an image to be pulled, including the time spent in the waiting queue of image puller. The metric is broken down by bucketed image size. ([#121719](https://github.com/kubernetes/kubernetes/pull/121719), [@ruiwen-zhao](https://github.com/ruiwen-zhao))

- Adds `apiserver_watch_list_duration_seconds` metrics. Which will measure response latency distribution in seconds for watch list requests broken by group, version, resource and scope ([#120490](https://github.com/kubernetes/kubernetes/pull/120490), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery and Instrumentation]