Raise the load and the HPA adds pods; when they no longer fit, the Cluster Autoscaler adds a node. Click node-2's label plate and node-3's taint barrier to see how pods are steered. Or press ▶ Guided tour.
| Pod | Placement rule | Placed on |
|---|
The Horizontal Pod Autoscaler sets a Deployment's replicas from a metric, here average CPU against a 50% target. It scales up quickly and down only after a stabilization window. When pods stay Pending because no node they are allowed on has room, the Cluster Autoscaler adds a node, and removes nodes that sit empty. A nodeSelector or node affinity pulls a pod to labelled nodes; a taint pushes pods away from a node unless they tolerate it.