<p>I am planning to upgrade the kubernetes version of AWS EKS from 1.15 to 1.16. I understood that there is no downtime while upgrading the cluster plane of the kubernetes. But I am not sure if there is a downtime while upgrading the worker nodes of the kubernetes.</p>

<p>Is there any downtime while upgrading the kubernetes version?</p>

<p>It depends on how you have deployed your workload on the cluster and how you are planning to upgrade the worker nodes. Note the following items</p>

<ol>
<li>Drain each worker node one by one and upgrade each one by one.</li>
<li>Use deployment, statefulset, daemonset instead of bare pods directly. </li>
</ol>

<p><a href="https://kubernetes.io/docs/tasks/administer-cluster/safely-drain-node/" rel="nofollow noreferrer">https://kubernetes.io/docs/tasks/administer-cluster/safely-drain-node/</a></p>
