If we let Cluster Autoscaler do its "magic" without defining any thresholds, our cluster or our wallet might be at risk.
We might, for example, misconfigure HPA and end up scaling Deployments or StatefulSets to a huge number of replicas. As a result, Cluster Autoscaler might add too many nodes to the cluster. As a result, we could end up paying for hundreds of nodes, even though we need much less. Luckily, AWS, Azure, and GCP limit how many nodes we can have so we cannot scale to infinity. Nevertheless, we should not allow Cluster Autoscaler to go over some limits.
Similarly, there is a danger that Cluster Autoscaler will scale down to too few nodes. Having zero nodes is almost impossible since that would mean that we have no Pods in the cluster. Still, we should maintain a healthy minimum of nodes, even if that means...