Enabling cluster Auto scalar in AKS

Question

I heard in AWS we do use deployment file kind cluster Role to deploy auto scalar in EKS

so in azure AKS do we need to same step or it is available in the AKS?

Answer 1

Hello @Varma

In Azure Kubernetes Service (AKS), the cluster autoscaler is already built in. Unlike AWS EKS (where you must deploy the autoscaler yourself using Kubernetes YAML files), AKS manages the autoscaler for you. You don’t need to install or deploy anything manually with kubectl commands/helm charts.

You simply turn it on using the Azure CLI, and AKS handles the rest.

How to Enable It on a New Cluster

When creating a new AKS cluster, add these options:

az aks create \
  --resource-group myResourceGroup \
  --name myAKSCluster \
  --node-count 1 \
  --enable-cluster-autoscaler \
  --min-count 1 \
  --max-count 3 \
  --generate-ssh-keys

What does the parameters mean in the above command:

-> The cluster will start with 1 node

-> It can automatically scale up to 3 nodes

-> AKS adds nodes when workloads need more resources

-> AKS removes nodes when they are no longer needed

How to Enable It on an Existing Cluster

If the cluster already exists, run:

az aks update \
  --resource-group myResourceGroup \
  --name myAKSCluster \
  --enable-cluster-autoscaler \
  --min-count 1 \
  --max-count 3

This turns on autoscaling for the existing node pool with the limits you set.

Please note:

• You need Azure CLI version 2.0.76 or later
• Once autoscaler is enabled, do not manually scale the Virtual Machine Scale Set
• Always manage scaling through AKS to avoid conflicts in Azure Kubernetes Service (AKS), the cluster autoscaler is already built in.

References:

• https://learn.microsoft.com/en-us/azure/aks/cluster-autoscaler-overview

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Answer 2

Hi,

in aks the cluster autoscaler is native and managed by the platform. U configure it through Azure settings, not by deploying YAML manifests like in EKS.

U simply enable it on a node pool either when creating the cluster or by updating an existing node pool. For example u can enable autoscaling with min and max node count using the Azure CLI when creating or updating the node pool. There is no need to deploy a separate autoscaler pod or manage RBAC yourself because Azure handles that internally.

rgds,

Alex