<p>I'd like to run the kubernetes cluster autoscaler so that unneeded nodes will be removed automatically, but I don't want the autoscaler to add nodes automatically. I prefer to handle scaling up myself. Is this possible?</p>

<p>I found maxNodesTotal, but I worry the semantics of setting this to 0 might mean all my nodes will go away. I also found scaleDownEnabled, but no corresponding option for scaling up.</p>

Jesse Shieh
<p>Kubernetes Cluster Autoscaler or CA will attempt scale up whenever it will identify pending pods waiting to be scheduled to run but request more resources(CPU/RAM) than any available node can serve.</p>

<p>You can use the parameter maxNodeTotal to limit the maximum number of nodes CA would be allowed to spin up.</p>

<p>For example if you don't want your cluster to consist of any more than 3 nodes during peak utlization than you would set maxNodeTotal to 3.</p>

<p>There are different considerations that you should be aware of in terms of cost savings, performance and availability.</p>

<p>I would try to list some related to cost savings and efficient utilization as I suspect you might be more interested in that aspect.
Make sure you size your pods in consistency to their actual utlization, because scale up would get triggered by Pods resource request and not actual Pod resource utilization.
Also, bigger Pods are less likely to fit together on the same node, and in addition CA won't be able to scale down any semi-utilised nodes, resulting in resource spending.</p>
