* Kubernetes json deserializer is now case-sensitive to restore compatibility with pre-1.8 servers. ([#65157](https://github.com/kubernetes/kubernetes/pull/65157), [@caesarxuchao](https://github.com/caesarxuchao))
    * If your config files contains fields with wrong case, the config files will be now invalid.

    available only after **training/evaluating the model on actual data** for
    functional models. `metrics` will **now include** model `loss` and output
    losses.`loss_functions` property has been removed from the model. This was
    an undocumented property that was accidentally public and has now been
    removed.

## Known Caveats

* In addition to restricting GCE metadata requests to known APIs, the metadata-proxy now restricts query strings to known parameters. ([#71094](https://github.com/kubernetes/kubernetes/pull/71094), [@dekkagaijin](https://github.com/dekkagaijin))

    - [Generic Ephemeral Volumes](#generic-ephemeral-volumes)
    - [CSI Service Account Token](#csi-service-account-token)
    - [CSI Health Monitoring](#csi-health-monitoring)
  - [Known Issues](#known-issues)
    - [<code>TopologyAwareHints</code> feature falls back to default behavior](#topologyawarehints-feature-falls-back-to-default-behavior)
  - [Urgent Upgrade Notes](#urgent-upgrade-notes)

      .timeout(100, TimeUnit.MILLISECONDS)
    assertContent("This comes after a busted connection", response2)

    // Check that a fresh connection was created, either immediately or after attempting reuse.
    // We know that a fresh connection was created if the server recorded a request with sequence
    // number 0. Since the client may have attempted to reuse the broken connection just before

## Known Issues

No Known Issues Reported

## Urgent Upgrade Notes

### (No, really, you MUST read this before you upgrade)

#### kube-apiserver:

- Warnings for the use of deprecated and known-bad values in pod specs are now sent. ([#101688](https://github.com/kubernetes/kubernetes/pull/101688), [@liggitt](https://github.com/liggitt))

      }
    callA.enqueue(callback)
    callB.enqueue(callback)
    assertThat(server.takeRequest().url.encodedPath).isEqualTo("/a")
    callback.await(requestA.url).assertBody("A")
    // At this point we know the callback is ready, and that it will receive a cancel failure.
    callback
      .await(requestB.url)
      .assertFailure("canceled", "Canceled", "Socket closed", "Socket is closed")
  }

  @Test

  - `spec.signerName` is now required, and requests for `kubernetes.io/legacy-unknown` are not allowed to be created via the `certificates.k8s.io/v1` API
  - `spec.usages` is now required, may not contain duplicate values, and must only contain known usages
  - `status.conditions` may not contain duplicate types
  - `status.conditions[*].status` is now required

## Known Issues

This section contains a list of known issues reported in Kubernetes 1.9 release. The content is populated from the [v1.9.x known issues and FAQ accumulator] [#57159](https://github.com/kubernetes/kubernetes/issues/57159).