Cluser Autoscaler

License: Apache 2.0

Cluster Autoscaler is a component that automatically adjusts the size of a Kubernetes Cluster so that all pods have a place to run and there are no unneeded nodes.

EKS-A

In EKS Anywhere cluster autoscaler is implemented using the cluster-api vsphere provider. This is used in EKS Anywhere along with the WorkerNodeGroups to provide autoscaling whereas in EKS, most node pools are done by Karpenter.

EKS

In EKS cluster autoscaler uses the AWS cloud provider. This is only used for the core node pool and legacy node pool. User/tenant node pools are managed by karpenter.

Links

• Code: https://github.com/kubernetes/autoscaler/cluster-autoscaler

• Releases: https://github.com/kubernetes/autoscaler/cluster-autoscaler/releases

• Documentation:

  • General Documentation(AWS): https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/aws/README.md
  • General Documentation(ClusterAPI): https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/clusterapi/README.md
  • FAQ: https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/FAQ.md

• Helm:

  • Releases: https://github.com/kubernetes/autoscaler/tree/master/charts/cluster-autoscaler

• Implementation:

  • EKS: AWS configurations

  https://code.vt.edu/it-common-platform/infrastructure/eks-cluster/-/blob/main/cluster-bootstrap/environments/aws/cluster-autoscaler.tf

  • EKS: AWS Autoscaler Node pools

  https://code.vt.edu/it-common-platform/infrastructure/eks-cluster/-/blob/main/eks/eks.tf

  • EKS-A:

  https://code.vt.edu/it-common-platform/infrastructure/eks-cluster/-/blob/main/cluster-bootstrap/environments/eksa/cluster-autoscaler.tf

  • EKS-A: Worker Node Groups

  https://code.vt.edu/it-common-platform/infrastructure/eksa-vsphere/-/blob/main/workloadcluster.yaml