* **Tolerations**

#### **Other**

### SIG Scheduling

- Added metrics for volume scheduling operations ([#59529](https://github.com/kubernetes/kubernetes/pull/59529), [@wackxu](https://github.com/wackxu))
- Improved memory use and performance when processing large numbers of pods containing tolerations ([#65350](https://github.com/kubernetes/kubernetes/pull/65350), [@liggitt](https://github.com/liggitt))

    * of DaemonSet Pod already exists, it will be replaced.
    * DaemonSet controller will only perform these operations when creating DaemonSet Pods;
    * and those operations will only modify the Pods of DaemonSet, no changes are made to the
    * `.spec.template` of DaemonSet.

* Time for attach/detach retry operations has been decreased from 10-12s to 2-6s ([#56974](https://github.com/kubernetes/kubernetes/pull/56974), [@gnufied](https://github.com/gnufied))

### Auth

* Contexts must be named in kubeconfigs. ([#56769](https://github.com/kubernetes/kubernetes/pull/56769), [@dixudx](https://github.com/dixudx))

* Fix cluster autoscaler addon permissions so it can access batch/job. ([#69858](https://github.com/kubernetes/kubernetes/pull/69858), [@losipiuk](https://github.com/losipiuk))
* Add tolerations for Stackdriver Logging and Metadata Agents. ([#69737](https://github.com/kubernetes/kubernetes/pull/69737), [@qingling128](https://github.com/qingling128))

     ([#73977](https://github.com/kubernetes/kubernetes/pull/73977), [@khenidak](https://github.com/khenidak))
- Add scheduling support for RuntimeClasses. RuntimeClasses can now specify nodeSelector constraints & tolerations, which are merged into the PodSpec for pods using that RuntimeClass. ([#80825](https://github.com/kubernetes/kubernetes/pull/80825), [@tallclair](https://github.com/tallclair))

  This allows the scheduler to handle cluster events faster with less memory.

  Specific node events include updates to taints, tolerations or allocatable.

- Revised the logic for `DaemonSet` rolling update to exclude nodes if scheduling constraints are not met. This eliminates the problem of rolling updates to a `DaemonSet` getting stuck around tolerations. ([#119317](https://github.com/kubernetes/kubernetes/pull/119317), [@mochizuki875](https://github.com/mochizuki875))

### Scheduling

- Tolerations with the same key and effect will be merged into one that has the value of the latest toleration for best effort pods. ([#75985](https://github.com/kubernetes/kubernetes/pull/75985), [@ravisantoshgudimetla](https://github.com/ravisantoshgudimetla))