- Scheduler: in 1.29 pre-releases, enabling contextual logging slowed down pod scheduling. ([#121715](https://github.com/kubernetes/kubernetes/pull/121715), [@pohly](https://github.com/pohly)) [SIG Instrumentation and Scheduling]

- Revised `OpenAPI v2` fetching for CustomResourceDefinitions. CRDs are now aggregated lazily,
  which improves resource usage during installation of many CRDs. As a result, the first request
  to fetch the OpenAPI may be slower. ([#118808](https://github.com/kubernetes/kubernetes/pull/118808), [@Jefftree](https://github.com/Jefftree))

- Kubeadm: increase robustness for "kubeadm join" when adding etcd members on slower setups ([#90645](https://github.com/kubernetes/kubernetes/pull/90645), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

- The `controller.kubernetes.io/pod-deletion-cost` annotation can be set to offer a hint on the cost of deleting a `Pod` compared to other pods belonging to the same ReplicaSet. Pods with lower deletion cost are deleted first. This is an alpha feature. ([#99163](https://github.com/kubernetes/kubernetes/pull/99163), [@ahg-g](https://github.com/ahg-g))

- Fixed the issue where pod with ordinal number lower than the rolling partitioning number was being deleted it was coming up with updated image. ([#120731](https://github.com/kubernetes/kubernetes/pull/120731), [@adilGhaffarDev](https://github.com/adilGhaffarDev)) [SIG Apps and Testing]

    * Default value for expendable pod priority cutoff in GCP deployment of Cluster Autoscaler changed from 0 to -10.
    * action required: users deploying workloads with priority lower than 0 may want to use priority lower than -10 to avoid triggering scale-up.
* [action required] kubeadm: The `v1alpha1` config API has been removed. ([#65628](https://github.com/kubernetes/kubernetes/pull/65628), [@luxas](https://github.com/luxas))

 - Kubeadm: increase robustness for "kubeadm join" when adding etcd members on slower setups ([#90645](https://github.com/kubernetes/kubernetes/pull/90645), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

* Experimental support to reserve a pod's memory request from being utilized by
  pods in lower QoS tiers.
  ([#41149](https://github.com/kubernetes/kubernetes/pull/41149),
  [@sjenning](https://github.com/sjenning))
* Port forwarding can forward over websockets or SPDY.

    * Default value for expendable pod priority cutoff in GCP deployment of Cluster Autoscaler changed from 0 to -10.
    * action required: users deploying workloads with priority lower than 0 may want to use priority lower than -10 to avoid triggering scale-up.

### Other notable changes

- Enhanced the daemonset sync logic to avoid a problem where pods are thought to be unavailable when the controller's clock is slower than the node's clock. ([#77208](https://github.com/kubernetes/kubernetes/pull/77208), [@DaiHao](https://github.com/DaiHao))