begins. Communication blocks until the send can proceed.
A send on an unbuffered channel can proceed if a receiver is ready.
A send on a buffered channel can proceed if there is room in the buffer.
A send on a closed channel proceeds by causing a <a href="#Run_time_panics">run-time panic</a>.
A send on a <code>nil</code> channel blocks forever.
</p>

<pre>
ch &lt;- 3  // send value 3 to channel ch
</pre>

<p>

- Reduce default NodeStatusReportFrequency to 5 minutes. With this change, periodic node status updates will be send every 5m if node status doesn't change (otherwise they are still send with 10s).

- Spedup kubectl by >10 when calling out to kube-apiserver for discovery information. ([#73345](https://github.com/kubernetes/kubernetes/pull/73345), [@sttts](https://github.com/sttts))
- Fixed 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))

and a suite of tests to validate that the CRI server implementation meets all the requirements. This allows the CRI runtime developers to verify that their runtime conforms to CRI, without needing to set up Kubernetes components or run Kubernetes end-to-end tests. ([docs](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-node/cri-validation.md) and [release notes](https://github.com/kubernetes-incubator/cri-tools/releases/tag/v0.1)) ([kubernetes/features#292](https://githu...

* Adds deleting pods created by DaemonSet assigned to not existing nodes. ([#73401](https://github.com/kubernetes/kubernetes/pull/73401), [@krzysztof-jastrzebski](https://github.com/krzysztof-jastrzebski))
* 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))

- The `AdmissionReview` API sent to and received from admission webhooks has been promoted to `admission.k8s.io/v1`. Webhooks can specify a preference for receiving `v1` AdmissionReview objects with `admissionReviewVersions: ["v1","v1beta1"]`, and must respond with an API object in the same `apiVersion` they are sent. When webhooks use `admission.k8s.io/v1`, the following additional validation is performed on their responses:...

* Update Cluster Autoscaler to version 1.3.7. ([#74136](https://github.com/kubernetes/kubernetes/pull/74136), [@jkaniuk](https://github.com/jkaniuk))
* 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))

- Introduced end-to-end tests to verify component invariant metrics across the entire test suite. ([#133394](https://github.com/kubernetes/kubernetes/pull/133394), [@BenTheElder](https://github.com/BenTheElder))

- Send an error on `ResultChan` and close the `RetryWatcher` when the client is forbidden or unauthorized from watching the resource. ([#126038](https://github.com/kubernetes/kubernetes/pull/126038), [@mprahl](https://github.com/mprahl)) [SIG API Machinery]

A security issue was discovered in Kubernetes where users may have access to secure endpoints in the control plane network. Kubernetes clusters are only affected if an untrusted user can to modify Node objects and send requests proxying through them.