Automatic merge from submit-queue
Add node e2e density test using 60 QPS for benchmark
This PR adds a new benchmark node e2e density test which sets Kubelet API QPS limit from default 5 to 60, through ConfigMap.
The latency caused by API QPS limit is as large as ~30% when creating a large batch of pods (e.g. 105). It makes the pod startup latency, as well creation throughput underestimated. This test helps us to know the real performance of Kubelet core.