- Azure virtual machine scale sets (VMSS) allow you to create and manage identical load balanced VMs that automatically increase or decrease based on demand or a set schedule.

## Changelog since v1.8.13

### Other notable changes

* Bump version of prometheus-to-sd to 0.2.6 to decrease log noise and include latest security patches. ([#64963](https://github.com/kubernetes/kubernetes/pull/64963), [@loburm](https://github.com/loburm))

- Fixed a regression preventing garbage collection of RBAC role and binding objects ([#90534](https://github.com/kubernetes/kubernetes/pull/90534), [@apelisse](https://github.com/apelisse)) [SIG Auth]
- 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]

 - Fixes a regression in 1.17 that dropped cache-control headers on API requests ([#90468](https://github.com/kubernetes/kubernetes/pull/90468), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Testing]
 - 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]

- Number of errors reported to the metric `storage_operation_duration_seconds_count` for emptyDir decreased significantly because previously one error was reported for each projected volume created. ([#117022](https://github.com/kubernetes/kubernetes/pull/117022), [@mpatlasov](https://github.com/mpatlasov)) [SIG Storage]

## Changelog since v1.3.5

### Other notable changes

* Addresses vSphere Volume Attach limits ([#29881](https://github.com/kubernetes/kubernetes/pull/29881), [@dagnello](https://github.com/dagnello))
* Increase request timeout based on termination grace period ([#31275](https://github.com/kubernetes/kubernetes/pull/31275), [@dims](https://github.com/dims))

* AWS: Fix long-standing bug in stringSetToPointers ([#26331](https://github.com/kubernetes/kubernetes/pull/26331), [@therc](https://github.com/therc))
* AWS kube-up: Increase timeout waiting for docker start ([#25405](https://github.com/kubernetes/kubernetes/pull/25405), [@justinsb](https://github.com/justinsb))

Required

* ACTION REQUIRED: The node.k8s.io API group and runtimeclasses.node.k8s.io resource have been migrated to a built-in API. If you were using RuntimeClasses (an default-disabled alpha feature, as of Kubernetes v1.12), then you must recreate all RuntimeClasses after upgrading, and the runtimeclasses.node.k8s.io CRD should be manually deleted. RuntimeClasses can no longer be created without a defined handler. ([#74433](https://github.com/kubernetes/kubernetes/pull/74433), [@tallclair...

* In GCE with COS, increase TasksMax for Docker service to raise cap on number of threads/processes used by containers. ([#51986](https://github.com/kubernetes/kubernetes/pull/51986), [@yujuhong](https://github.com/yujuhong))

- Number of errors reported to the metric `storage_operation_duration_seconds_count` for emptyDir decreased significantly because previously one error was reported for each projected volume created. ([#117022](https://github.com/kubernetes/kubernetes/pull/117022), [@mpatlasov](https://github.com/mpatlasov)) [SIG Storage]