<p>I know that with Azure AKS , master components are fully managed by the service. But I'm a little confused here when it comes to pick the node pools. I understand that there are two kind of pools system and user, where the user nodes pool offer hosting my application pods. I read on official documentation that <strong>System node pools serve the primary purpose of hosting critical system pods such as CoreDNS and tunnelfront.</strong> And i'm aware that we can only rely on system nodes to create and run our kubernetes cluster.</p>
<p>My question here, do they mean here by the system node the <strong>MASTER node</strong> ? If it is so, why then we have the option to not create the user nodes (worker node by analogy) ? because as we know -in on prem kubernetes solution- we cannot create a kubernetes cluster with master nodes only.</p>
<p><a href="https://i.stack.imgur.com/IHNyo.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IHNyo.png" alt="enter image description here" /></a></p>
<p>I'll appreciate any help</p>

<p>System node pools in AKS does not contain Master nodes. Master nodes in AKS are 100% managed by Azure and are outside your VNet. A system node pool contains worker nodes on which AKS automatically assigns the label <code>kubernetes.azure.com/mode: system</code>, that's about it. AKS then use that label to deploy critical pod like <code>tunnelfront</code>, which is use to create a secure communication from your nodes to the control plane. You need at least 1 system node pool per cluster and they have the <a href="https://learn.microsoft.com/en-us/azure/aks/use-system-pools#system-and-user-node-pools" rel="nofollow noreferrer">following restrictions</a> :</p>
<ul>
<li>System pools osType must be Linux.</li>
<li>System pools must contain at least one node, and user node pools may contain zero or more nodes.</li>
<li>System node pools require a VM SKU of at least 2 vCPUs and 4GB memory. But burstable-VM(B series) is not recommended.</li>
<li>System node pools must support at least 30 pods as described by the minimum and maximum value formula for pods.</li>
</ul>
