- 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))

* The implicit registration of Prometheus metrics for workqueue has been removed, and a plug-able interface was added. If you were using workqueue in your own binaries and want these metrics, add the following to your imports in the main package: "k8s.io/pkg/util/workqueue/prometheus". ([#33792](https://github.com/kubernetes/kubernetes/pull/33792), [@caesarxuchao]...

* The implicit registration of Prometheus metrics for request count and latency have been removed, and a plug-able interface was added. If you were using our client libraries in your own binaries and want these metrics, add the following to your imports in the main package: "k8s.io/pkg/client/metrics/prometheus".  ([#30638](https://github.com/kubernetes/kubernetes/pull/30638), [@krousey](https://github.com/krousey))