- Kube-apiserver: fixed a 1.27+ regression watching a single namespace via the deprecated /api/v1/watch/namespaces/$name endpoint where watch events were not delivered after the watch was established. ([#125145](https://github.com/kubernetes/kubernetes/pull/125145), [@xyz-li](https://github.com/xyz-li)) [SIG API Machinery, Node and Testing]

- Added metric `apiserver_watch_events_total` that can be used to understand the number of watch events in the system. ([#78732](https://github.com/kubernetes/kubernetes/pull/78732), [@mborsz](https://github.com/mborsz))
- Added metric `apiserver_watch_events_sizes` that can be used to estimate sizes of watch events in the system. ([#80477](https://github.com/kubernetes/kubernetes/pull/80477), [@mborsz](https://github.com/mborsz))

 │  fastapi run                                        │
 │                                                     │
 ╰─────────────────────────────────────────────────────╯

INFO:     Will watch for changes in these directories: ['/home/user/code/awesomeapp']
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [2248755] using WatchFiles

- The watch API endpoints prefixed with `/watch` are deprecated and will be removed in a future release. These standard method for watching resources (supported since v1.0) is to use the list API endpoints with a `?watch=true` parameter. All client-go clients have used the parameter method since v1.6.0. ([#65147](https://github.com/kubernetes/kubernetes/pull/65147),...

 *
 * ```java
 * HttpUrl base = HttpUrl.parse("https://www.youtube.com/user/WatchTheDaily/videos");
 * HttpUrl link = base.resolve("../../watch?v=cbP2N1BQdYc");
 * System.out.println(link);
 * ```
 *
 * which prints:
 *
 * ```
 * https://www.youtube.com/watch?v=cbP2N1BQdYc
 * ```
 *
 * ## What's in a URL?
 *
 * A URL has several components.
 *
 * ### Scheme
 *

 │  fastapi run                                        │
 │                                                     │
 ╰─────────────────────────────────────────────────────╯

INFO:     Will watch for changes in these directories: ['/home/user/code/awesomeapp']
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [2248755] using WatchFiles

* Fix watch to not send the same set of events multiple times causing watcher to go back in time ([#73845](https://github.com/kubernetes/kubernetes/pull/73845), [@wojtek-t](https://github.com/wojtek-t))

wondered at this, but at the time it all seemed quite natural);
but when the Rabbit actually TOOK A WATCH OUT OF ITS WAISTCOAT-
POCKET, and looked at it, and then hurried on, Alice started to
her feet, for it flashed across her mind that she had never
before seen a rabbit with either a waistcoat-pocket, or a watch to
take out of it, and burning with curiosity, she ran across the

* Fix watch to not send the same set of events multiple times causing watcher to go back in time ([#73845](https://github.com/kubernetes/kubernetes/pull/73845), [@wojtek-t](https://github.com/wojtek-t))

### Client
* Use Prometheus instrumentation conventions ([#36704](https://github.com/kubernetes/kubernetes/pull/36704), [@fabxc](https://github.com/fabxc))
* Clients now use the `?watch=true` parameter to make watch API calls, instead of the `/watch/` path prefix ([#41722](https://github.com/kubernetes/kubernetes/pull/41722), [@liggitt](https://github.com/liggitt))