collection algorithm. As a result, we observed an increase in memory usage for kube-apiserver in larger an heavily loaded clusters up to ~25% (with the benefit of API call latencies drop by up to 10x on 99th percentiles). If the memory increase is not acceptable for you you can mitigate by setting GOGC env variable (for our tests using GOGC=63 brings memory usage back to original value, although the exact value may depend on usage patterns on your cluster). ([#108870](https://github.com/kubernetes/kube...

    * If the serialization type is application/vnd.kubernetes.protobuf, and protobuf marshaling is not implemented for the requested API resource type, a '406 Not Acceptable is returned'.
    * If the serialization type is 'application/json':
    * If serialization fails, and the original status code was an failure (e.g. 4xx or 5xx), the original status code will be returned.

### SIG OpenStack

SIG-OpenStack continued to build out testing, with eleven acceptance tests covering a wide-range of scenarios and use-cases. During the 1.11 cycle our reporting back to test-grid has qualified the OpenStack cloud provider as a gating job for the Kubernetes release.