* Fixed missing error checking that could cause kubelet to crash in a race condition. ([#60962](https://github.com/kubernetes/kubernetes/pull/60962), [@technicianted](https://github.com/technicianted))
* Introduced `--http2-max-streams-per-connection` command line flag on api-servers and set default to 1000 for aggregated API servers. ([#60054](https://github.com/kubernetes/kubernetes/pull/60054), [@MikeSpreitzer](https://github.com/MikeSpreitzer))

message PodExecOptions {
  // Redirect the standard input stream of the pod for this call.
  // Defaults to false.
  // +optional
  optional bool stdin = 1;

  // Redirect the standard output stream of the pod for this call.
  // +optional
  optional bool stdout = 2;

  // Redirect the standard error stream of the pod for this call.
  // +optional
  optional bool stderr = 3;

- Added options for configuring `nf_conntrack_udp_timeout`, and `nf_conntrack_udp_timeout_stream` variables of netfilter conntrack subsystem. ([#120808](https://github.com/kubernetes/kubernetes/pull/120808), [@aroradaman](https://github.com/aroradaman))

- Implemented API streaming for the `watch-cache`
  
  When `sendInitialEvents` `ListOption` is set together with `watch=true`, it begins the watch stream with synthetic init events followed by a synthetic "Bookmark" after which the server continues streaming events. ([#110960](https://github.com/kubernetes/kubernetes/pull/110960), [@p0lyn0mial](https://github.com/p0lyn0mial))

## 0.66.0

### Features

</pre>

<p>
In <a href="https://www.unicode.org/versions/Unicode8.0.0/">The Unicode Standard 8.0</a>,
Section 4.5 "General Category" defines a set of character categories.
Go treats all characters in any of the Letter categories Lu, Ll, Lt, Lm, or Lo
as Unicode letters, and those in the Number category Nd as Unicode digits.
</p>

<h3 id="Letters_and_digits">Letters and digits</h3>

<p>

- Added a method `StreamWithContext` to `remotecommand.Executor` to support cancelable SPDY executor stream. ([#103177](https://github.com/kubernetes/kubernetes/pull/103177), [@arkbriar](https://github.com/arkbriar))