- `PodSpec.Container.Resources` became mutable for CPU and memory resource types.
  - `PodSpec.Container.ResizePolicy` (new object) gives users control over how their containers are resized.
  - `PodStatus.Resize` status describes the state of a requested Pod resize.
  - `PodStatus.ResourcesAllocated` describes node resources allocated to Pod.
  - `PodStatus.Resources` describes node resources applied to running containers by CRI.

  - go_gc_cycles_automatic_gc_cycles_total
  - go_gc_cycles_forced_gc_cycles_total
  - go_gc_cycles_total_gc_cycles_total
  - go_gc_heap_allocs_by_size_bytes
  - go_gc_heap_allocs_bytes_total
  - go_gc_heap_allocs_objects_total
  - go_gc_heap_frees_by_size_bytes
  - go_gc_heap_frees_bytes_total
  - go_gc_heap_frees_objects_total
  - go_gc_heap_goal_bytes
  - go_gc_heap_objects_objects

- Registered metric `apiserver_request_body_size_bytes` to track the size distribution of requests by `resource` and `verb`. ([#120474](https://github.com/kubernetes/kubernetes/pull/120474), [@YaoC](https://github.com/YaoC)) [SIG API Machinery and Instrumentation]