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Billy Tat
25 lines
1.6 KiB
Markdown
25 lines
1.6 KiB
Markdown
---
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title: Cluster Autoscaler
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---
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In this section, you'll learn how to install and use the [Kubernetes cluster-autoscaler](https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/) on Rancher custom clusters using AWS EC2 Auto Scaling Groups.
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The cluster autoscaler is a tool that automatically adjusts the size of the Kubernetes cluster when one of the following conditions is true:
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* There are pods that failed to run in the cluster due to insufficient resources.
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* There are nodes in the cluster that have been underutilized for an extended period of time and their pods can be placed on other existing nodes.
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To prevent your pod from being evicted, set a `priorityClassName: system-cluster-critical` property on your pod spec.
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Cluster Autoscaler is designed to run on Kubernetes master nodes. It can run in the `kube-system` namespace. Cluster Autoscaler doesn't scale down nodes with non-mirrored `kube-system` pods running on them.
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It's possible to run a customized deployment of Cluster Autoscaler on worker nodes, but extra care needs to be taken to ensure that Cluster Autoscaler remains up and running.
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## Cloud Providers
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Cluster Autoscaler provides support to distinct cloud providers. For more information, go to [cluster-autoscaler supported cloud providers.](https://github.com/kubernetes/autoscaler/tree/master/cluster-autoscaler#deployment)
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### Setting up Cluster Autoscaler on Amazon Cloud Provider
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For details on running the cluster autoscaler on Amazon cloud provider, refer to [this page.](../how-to-guides/new-user-guides/manage-clusters/install-cluster-autoscaler/use-aws-ec2-auto-scaling-groups.md)
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