Use Mixed SKU Node Pools (Preview) in Azure Kubernetes Services (AKS)

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Hello, fellow Kubernetes enthusiasts! Today, we’re diving into an exciting new feature in Azure Kubernetes Services (AKS) – Mixed SKU Node Pools. This feature, currently in preview, allows you to deploy multiple VM SKUs from a SKU family within a single node pool, providing more flexibility and reducing the need for multiple node pools.

Prerequisites

Before we get started, make sure you have the following:

• An Azure subscription.
• AKS-preview extension (v4.0.0b4 or later).
• Minimum Kubernetes version 1.26.

Installation and Registration

First things first, let’s get the AKS-preview extension installed or updated. Open your Azure Cloud ell and run:

Next, set your subscription and register the VMsAgentPoolPreview feature flag. This will enable the mixed SKU node pools feature for your subscription:

After a few minutes, verify that the feature is registered:

Finally, refre the registration of the Microsoft.ContainerService resource provider:

Limitations

Before you jump in, note these limitations:

• Cluster autoscaler isn’t available.
• InfiniBand and Windows node pools aren’t supported.
• Management is only via CLI or REST APIs.
• VM sizes must be from the same family.

Create a Mixed SKU Node Pool

Now, let’s create a new AKS cluster with a mixed SKU node pool. Here’s how you do it:

This command sets up a new AKS cluster named aks-mixed-pools with two nodes in the rg-aks-mixed-pools resource group. If you look at the managed resource group you will see Virtual machines rather than a Virtual Machine Scale Set (VMSS).

Add a Mixed SKU Node Pool to an Existing Cluster

To add a mixed SKU node pool to an existing cluster, run:

This adds a new node pool named mixedpool to your aks-mixed-pools cluster with three nodes of Standard_D4s_v3 VM SKU. One cool thing to note is --vm-size can have more than one vm size, it accepts comma seperated lists like: "Standard_D4s_v3,Standard_D8s_v3"

Manage Scale Profiles

You can also manage scale profiles for your mixed SKU node pools. Here’s how to add, update, and delete scale profiles:

Add a Manual Scale Profile

To add a manual scale profile to a node pool, use the following command. This example adds a profile to mixedpool with two nodes of Standard_D2s_v3:

After running this command you will notice that the mixedpool node pool now has 5 nodes in it, 3 “Standard_D4s_v3” and 2 “Standard_D2s_v3”. You can check with the following command:

Update an Existing Manual Scale Profile

To update an existing manual scale profile, use this command. This example updates mixedpool to change from Standard_D4s_v3 to Standard_D8s_v3 and sets the node count to five:

Delete a Manual Scale Profile

To delete a manual scale profile, use this command. This example deletes the profile using Standard_D8s_v3 in mixedpool:

Conclusion

Mixed SKU node pools are a powerful addition to AKS, enabling greater flexibility and efficiency in managing diverse workloads. While currently in preview, this feature promises to streamline your AKS deployments significantly.