OpenShift Container Platform

Configuring node pools for availability zones

To improve the high availability of your hosted cluster, you can distribute node pools across multiple Red Hat OpenStack Platform (RHOSP) Nova availability zones.

Availability zones do not necessarily correspond to fault domains and do not inherently provide high availability benefits.

Prerequisites

You created a hosted cluster.
You have access to the management cluster.
The hcp and oc command-line interfaces (CLIs) are installed.

Procedure

Set environment variables that are appropriate for your needs. For example, if you want to create two additional machines in the az1 availability zone, you could enter:
```
$ export NODEPOOL_NAME="${CLUSTER_NAME}-az1" \
  && export WORKER_COUNT="2" \
  && export FLAVOR="m1.xlarge" \
  && export AZ="az1"
```

Create the node pool by using your environment variables by entering the following command:

$ hcp create nodepool openstack \
  --cluster-name <cluster_name> \
  --name $NODEPOOL_NAME \
  --replicas $WORKER_COUNT \
  --openstack-node-flavor $FLAVOR \
  --openstack-node-availability-zone $AZ

where:

<cluster_name>: Specifies the name of your hosted cluster.

Check the status of the node pool by listing nodepool resources in the clusters namespace by running the following command:

$ oc get nodepools --namespace clusters

Example output

NAME                      CLUSTER         DESIRED NODES   CURRENT NODES   AUTOSCALING   AUTOREPAIR   VERSION   UPDATINGVERSION   UPDATINGCONFIG   MESSAGE
example                   example         5               5               False         False        4.17.0
example-az1               example         2                               False         False                  True              True             Minimum availability requires 2 replicas, current 0 available

Observe the notes as they start on your hosted cluster by running the following command:

$ oc --kubeconfig $CLUSTER_NAME-kubeconfig get nodes

Example output

NAME                      STATUS   ROLES    AGE     VERSION
...
example-extra-az-zh9l5    Ready    worker   2m6s    v1.27.4+18eadca
example-extra-az-zr8mj    Ready    worker   102s    v1.27.4+18eadca
...

Verify that the node pool is created by running the following command:

$ oc get nodepools --namespace clusters

Example output

NAME              CLUSTER         DESIRED   CURRENT   AVAILABLE   PROGRESSING   MESSAGE
<node_pool_name>  <cluster_name>  2         2         2           False         All replicas are available