- Improved scheduler performance when no scoring plugins were defined.
   ([#122058](https://github.com/kubernetes/kubernetes/pull/122058), [@aleksandra-malinowska](https://github.com/aleksandra-malinowska))
- Improved scheduler performance when no scoring plugins were defined.

* Bump GCI to gci-stable-56-9000-84-2: Fixed google-accounts-daemon breaks on GCI when network is unavailable. Fixed iptables-restore performance regression. ([#41831](https://github.com/kubernetes/kubernetes/pull/41831), [@freehan](https://github.com/freehan))

* Resolves bottleneck in internal API server communication that can cause increased goroutines and degrade API Server performance ([#80465](https://github.com/kubernetes/kubernetes/pull/80465), [@answer1991](https://github.com/answer1991))

#### Docker Known Issues

##### 1.9.1

  * Listing containers can be slow at times which will affect kubelet performance.
More information [here](https://github.com/docker/docker/issues/17720)
  * Docker daemon restarts can fail. Docker checkpoints have to deleted between

  
  As this code is still very new, it has not been heavily optimized yet;
  while it is expected to _eventually_ have better performance than the
  iptables backend, very little performance testing has been done so far. ([#121046](https://github.com/kubernetes/kubernetes/pull/121046), [@danwinship](https://github.com/danwinship))

* Resolves bottleneck in internal API server communication that can cause increased goroutines and degrade API Server performance ([#80465](https://github.com/kubernetes/kubernetes/pull/80465), [@answer1991](https://github.com/answer1991))
* Update to go 1.12.10 ([#83139](https://github.com/kubernetes/kubernetes/pull/83139), [@cblecker](https://github.com/cblecker))

    * handle gracefully problem when kubelet reports duplicated stats for the same container (see [#47853](https://github.com/kubernetes/kubernetes/pull/47853)) on Heapster side
    * fixed bugs and improved performance in Stackdriver Sink

mitigation to avoid disrupting load balancer → kube-apiserver connections if http/2 requests from multiple clients share the same backend connection. An API server on a private network may choose not to enable the kube-apiserver mitigation to prevent performance regressions for unauthenticated clients. Authenticated requests rely on the fix in golang.org/x/net v0.17.0 alone. https://issue.k8s.io/121197 tracks further mitigation of http/2 attacks by authenticated clients. ([#121200](https://github.com/k...