Merge pull request #63251 from liggitt/namespace-controller-qps

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Bump QPS on namespace controller

https://github.com/kubernetes/kubernetes/pull/62913 switched from using a client pool, where each groupVersionResource got its own rest client, to a single client.

This increases the QPS to account for increased requests using a single rest client rate limiter.

Fixes #63240

```release-note
NONE
```

cmd/kube-controller-manager/app/core.go

@@ -296,8 +296,8 @@ func startNamespaceController(ctx ControllerContext) (bool, error) {
 	// the ratelimiter negatively affects its speed.  Deleting 100 total items in a namespace (that's only a few of each resource
 	// including events), takes ~10 seconds by default.
 	nsKubeconfig := ctx.ClientBuilder.ConfigOrDie("namespace-controller")
-	nsKubeconfig.QPS *= 10
-	nsKubeconfig.Burst *= 10
+	nsKubeconfig.QPS *= 20
+	nsKubeconfig.Burst *= 100
 	namespaceKubeClient := clientset.NewForConfigOrDie(nsKubeconfig)
 
 	discoverResourcesFn := namespaceKubeClient.Discovery().ServerPreferredNamespacedResources