- `apiserver_flowcontrol_upper_limit_seats`: Configured upper bound on number of execution seats available to each priority level
    - `apiserver_flowcontrol_demand_seats`: Observations, at the end of every nanosecond, of (the number of seats each priority level could use) / (nominal number of seats for that level)
    - `apiserver_flowcontrol_demand_seats_high_watermark`: High watermark, over last adjustment period, of demand_seats

  you want to set the equivalent of any of the `--iptables-xxx` options.)
  
  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))

* Adds the Categories []string field to API resources, which represents the list of group aliases (e.g. "all") that every resource belongs to. ([#43338](https://github.com/kubernetes/kubernetes/pull/43338), [@fabianofranz](https://github.com/fabianofranz))