OpenShift Container Platform

Scale the node pool

After you approve your agents, you can scale the node pools. The agentLabelSelector value that you configured in the node pool ensures that only matching agents get added to the cluster. This also helps scale down the node pool.

To remove specific architecture nodes from the cluster, scale down the corresponding node pool.

Procedure

Scale the node pool by running the following command:

$ oc -n <clusters_namespace> scale nodepool <nodepool_name> --replicas 2

The Cluster API agent provider picks two agents randomly to assign to the hosted cluster. These agents pass through different states and then join the hosted cluster as OpenShift Container Platform nodes. The various agent states are binding, discovering, insufficient, installing, installing-in-progress, and added-to-existing-cluster.

Verification

List the agents by running the following command:

$ oc -n <hosted_control_plane_namespace> get agent

Example output

NAME                                   CLUSTER         APPROVED   ROLE          STAGE
4dac1ab2-7dd5-4894-a220-6a3473b67ee6   hypercluster1   true       auto-assign
d9198891-39f4-4930-a679-65fb142b108b                   true       auto-assign
da503cf1-a347-44f2-875c-4960ddb04091   hypercluster1   true       auto-assign

Check the status of a specific scaled agent by running the following command:

$ oc -n <hosted_control_plane_namespace> get agent -o jsonpath='{range .items[*]}BMH: {@.metadata.labels.agent-install\.openshift\.io/bmh} Agent: {@.metadata.name} State: {@.status.debugInfo.state}{"\n"}{end}'

Example output

BMH: ocp-worker-2 Agent: 4dac1ab2-7dd5-4894-a220-6a3473b67ee6 State: binding
BMH: ocp-worker-0 Agent: d9198891-39f4-4930-a679-65fb142b108b State: known-unbound
BMH: ocp-worker-1 Agent: da503cf1-a347-44f2-875c-4960ddb04091 State: insufficient

After the agents reach the added-to-existing-cluster state, verify that the OpenShift Container Platform nodes are ready by running the following command:

$ oc --kubeconfig <hosted_cluster_name>.kubeconfig get nodes

Example output

NAME           STATUS   ROLES    AGE     VERSION
ocp-worker-1   Ready    worker   5m41s   v1.24.0+3882f8f
ocp-worker-2   Ready    worker   6m3s    v1.24.0+3882f8f

Adding workloads to the nodes can reconcile some cluster operators. The following command displays the creation of two machines that happened after scaling up the node pool:

$ oc -n <hosted_control_plane_namespace> get machines

Example output

NAME                            CLUSTER               NODENAME       PROVIDERID                                     PHASE     AGE   VERSION
hypercluster1-c96b6f675-m5vch   hypercluster1-b2qhl   ocp-worker-1   agent://da503cf1-a347-44f2-875c-4960ddb04091   Running   15m   4.11.5
hypercluster1-c96b6f675-tl42p   hypercluster1-b2qhl   ocp-worker-2   agent://4dac1ab2-7dd5-4894-a220-6a3473b67ee6   Running   15m   4.11.5