- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.

- The `WaitFor` and `WaitForWithContext` functions in the wait package have now been marked private. Callers should use the equivalent `Poll*` method with a zero duration interval. ([#115116](https://github.com/kubernetes/kubernetes/pull/115116), [@smarterclayton](https://github.com/smarterclayton))

upgrading, and deleting clusters.

For the 1.8 release, SIG Cluster Lifecycle continued to focus on expanding the
capabilities of kubeadm, which is both a user-facing tool to manage clusters
and a building block for higher-level provisioning systems. Starting
with the 1.8 release, kubeadm supports a new upgrade command and includes alpha
support for self hosting the cluster control plane.

  This issue only could happen if you use custom plugins or if you change plugin set being used in your scheduler via the scheduler config. ([#122013](https://github.com/k...

to Services.
With the manual enablement of this feature, the cluster will prefer automatic assignment from
the pool of Service IP addresses thereby reducing the risk of collision.

A Service `ClusterIP` can be assigned:

* dynamically, which means the cluster will automatically pick a free IP within the configured Service IP range.

- Removed the recently re-introduced schedulability predicate ([#109706](https://github.com/kubernetes/kubernetes/pull/109706)) as to not have unschedulable nodes removed from load balancers back-end pools. ([#111691](https://github.com/kubernetes/kubernetes/pull/111691), [@alexanderConstantinescu](https://github.com/alexanderConstantinescu))

- Added a return value to `QueueingHint` to indicate an error. If `QueueingHint` returns an error,
  the scheduler logs it and treats the event as a `QueueAfterBackoff` so that
  the Pod won't be stuck in the unschedulable pod pool. ([#119290](https://github.com/kubernetes/kubernetes/pull/119290), [@carlory](https://github.com/carlory))
- Added apiserver identity to the following metrics: 

- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.