Scaling Nodes

This section applies only to worker Machines. You can add or remove compute capacity for your cluster workloads by creating or removing Machines. A Machine expresses intent to have a Node with a defined form factor.

Machines can be owned by scalable resources i.e. MachineSet and MachineDeployments.

You can scale MachineSets and MachineDeployments in or out by expressing intent via .spec.replicas or updating the scale subresource e.g kubectl scale machinedeployment foo --replicas=5.

If you need to prioritize which Machines get deleted during scale-down, add the cluster.x-k8s.io/delete-machine label to the Machine. KCP or a MachineSet will delete labeled control plane or worker Machines first, and this label has top priority over all delete policies.

Note: The label only affects MachineSet scale-down; in a MachineDeployment, the choice of MachineSet to scale-down may bypass labeled Machines.

When you delete a Machine directly or by scaling down, the same process takes place in the same order:

• The Node backed by that Machine will try to be drained indefinitely and will wait for any volume to be detached from the Node unless you specify a .spec.nodeDrainTimeout.
  • CAPI uses default kubectl draining implementation with -–ignore-daemonsets=true. If you needed to ensure DaemonSets eviction you’d need to do so manually by also adding proper taints to avoid rescheduling.
• The infrastructure backing that Node will try to be deleted indefinitely.
• Only when the infrastructure is gone, the Node will try to be deleted indefinitely unless you specify .spec.nodeDeletionTimeout.