Automatic merge from submit-queue (batch tested with PRs 40746, 41699, 42108, 42174, 42093)
Switch kube-proxy to informers & save 2/3 of cpu & memory of non-iptables related code.
Fix#42000
This PR should be no-op from the behavior perspective.
It is changing KubeProxy to use standard "informer" framework instead of combination of reflector + undelta store.
This is significantly reducing CPU usage of kube-proxy and number of memory allocations.
Previously, on every endpoints/service update, we were copying __all__ endpoints/services at least 3 times, now it is once (which should also be removed in the future).
In Kubemark-500, hollow-proxies were processing backlog from load test for an hour after the test was finishing. With this change, it is keeping up with the load.
@thockin @ncdc @derekwaynecarr
49e80116b7