Managing hosted control planes | Hosted control planes

Scaling down the data plane to zero
Deleting a hosted cluster

After you configure your environment for hosted control planes and create a hosted cluster, you can further manage your clusters and nodes.

Scaling down the data plane to zero

If you are not using the hosted control plane, to save the resources and cost you can scale down a data plane to zero.

Ensure you are prepared to scale down the data plane to zero. Because the workload from the worker nodes disappears after scaling down.

Procedure

Set the kubeconfig file to access the hosted cluster by running the following command:
```
$ export KUBECONFIG=<install_directory>/auth/kubeconfig
```
Get the name of the NodePool resource associated to your hosted cluster by running the following command:
```
$ oc get nodepool --namespace <HOSTED_CLUSTER_NAMESPACE>
```

Optional: To prevent the pods from draining, add the nodeDrainTimeout field in the NodePool resource by running the following command:

$ oc edit NodePool <nodepool> -o yaml --namespace <HOSTED_CLUSTER_NAMESPACE>

Example output

apiVersion: hypershift.openshift.io/v1alpha1
kind: NodePool
metadata:
# ...
  name: nodepool-1
  namespace: clusters
# ...
spec:
  arch: amd64
  clusterName: clustername (1)
  management:
    autoRepair: false
    replace:
      rollingUpdate:
        maxSurge: 1
        maxUnavailable: 0
      strategy: RollingUpdate
    upgradeType: Replace
  nodeDrainTimeout: 0s (2)
# ...

1	Defines the name of your hosted cluster.
2	Specifies the total amount of time that the controller spends to drain a node. By default, the `nodeDrainTimeout: 0s` setting blocks the node draining process.

To allow the node draining process to continue for a certain period of time, you can set the value of the nodeDrainTimeout field accordingly, for example, nodeDrainTimeout: 1m.

Scale down the NodePool resource associated to your hosted cluster by running the following command:

$ oc scale nodepool/<NODEPOOL_NAME> --namespace <HOSTED_CLUSTER_NAMESPACE> --replicas=0

After scaling down the data plan to zero, some pods in the control plane stay in the Pending status and the hosted control plane stays up and running. If necessary, you can scale up the NodePool resource.

Optional: Scale up the NodePool resource associated to your hosted cluster by running the following command:
```
$ oc scale nodepool/<NODEPOOL_NAME> --namespace <HOSTED_CLUSTER_NAMESPACE> --replicas=1
```
After rescaling the NodePool resource, wait for couple of minutes for the NodePool resource to become available in a Ready state.

Verification

Verify that the value for the nodeDrainTimeout field is greater than 0s by running the following command:

$ oc get nodepool -n <hosted_cluster_namespace> <nodepool_name> -ojsonpath='{.spec.nodeDrainTimeout}'

Deleting a hosted cluster

The steps to delete a hosted cluster differ depending on which provider you use.

Procedure

If the cluster is on AWS, follow the instructions in Destroying a hosted cluster on AWS.
If the cluster is on bare metal, follow the instructions in Destroying a hosted cluster on bare metal.
If the cluster is on OKD Virtualization, follow the instructions in Destroying a hosted cluster on OpenShift Virtualization.

Next steps

If you want to disable the hosted control plane feature, see Disabling the hosted control plane feature.