`sync_proxy_rules_last_timestamp_seconds` metric no longer behaves the
  way it used to; now it will only change when services or endpoints actually
  change, rather than reliably updating every 60 seconds (or whatever). If you
  are trying to monitor for whether iptables updates are failing, the

- Kubelet TCP and HTTP probes are now more effective using networking resources:
  conntrack entries, sockets. This is achieved by reducing the `TIME-WAIT` state
  of the connection to 1 second, instead of the defaults 60 seconds. This allows
  kubelet to free the socket, and free conntrack entry and ephemeral port associated. ([#115143](https://github.com/kubernetes/kubernetes/pull/115143), [@aojea](https://github.com/aojea))

- Metric buckets for `pod_start_duration_seconds` were changed to `{0.5, 1, 2, 3, 4, 5, 6, 8, 10, 20, 30, 45, 60, 120, 180, 240, 300, 360, 480, 600, 900, 1200, 1800, 2700, 3600}`. ([#120680](https://github.com/kubernetes/kubernetes/pull/120680), [@ruiwen-zhao](https://github.com/ruiwen-zhao))

### Feature

- Kubelet TCP and HTTP probes are more effective using networking resources: conntrack entries, sockets, ... 
  This is achieved by reducing the TIME-WAIT state of the connection to 1 second, instead of the defaults 60 seconds. This allows kubelet to free the socket, and free conntrack entry and ephemeral port associated. ([#115143](https://github.com/kubernetes/kubernetes/pull/115143), [@aojea](https://github.com/aojea)) [SIG Network and Node]

- Deprecate `apiserver_longrunning_gauge`...

- The kubelet_runtime_operations_duration_seconds metric got additional buckets of 60, 300, 600, 900 and 1200 seconds ([#96054](https://github.com/kubernetes/kubernetes/pull/96054), [@alvaroaleman](https://github.com/alvaroaleman)) [SIG Instrumentation and Node]

### Feature

- Kubelet TCP and HTTP probes are more effective using networking resources: conntrack entries, sockets, ... 
  This is achieved by reducing the TIME-WAIT state of the connection to 1 second, instead of the defaults 60 seconds. This allows kubelet to free the socket, and free conntrack entry and ephemeral port associated. ([#115143](https://github.com/kubernetes/kubernetes/pull/115143), [@aojea](https://github.com/aojea)) [SIG Network and Node]

### Feature

- Kubelet TCP and HTTP probes are more effective using networking resources: conntrack entries, sockets, ... 
  This is achieved by reducing the TIME-WAIT state of the connection to 1 second, instead of the defaults 60 seconds. This allows kubelet to free the socket, and free conntrack entry and ephemeral port associated. ([#115143](https://github.com/kubernetes/kubernetes/pull/115143), [@aojea](https://github.com/aojea)) [SIG Network and Node]