Optional: Configuring dedicated OpenShift worker nodes for Db2 Big SQL

You can provision Db2® Big SQL on dedicated Red Hat® OpenShift® worker nodes.

About this task

Do this advanced configuration only when it is necessary. Constraining Db2 Big SQL to a specific set of nodes can complicate activities, including upgrades and maintenance at the OpenShift level. In general, it is recommended that you allow Db2 Big SQL to be scheduled across all available OpenShift worker nodes.

This task assumes that all Db2 Big SQL instances share the same set of dedicated nodes. That is, the nodes are labeled as icp4data=database-bigsql.

Procedure

Log in to your OpenShift cluster as a project administrator:
```
oc login <OpenShift_URL>:<port>
```
Retrieve the name of the worker node that you want to dedicate to Db2 Big SQL:
```
oc get nodes
```

Label and taint the nodes:

oc adm taint node node name icp4data=database-bigsql:PreferNoSchedule
oc label node node name icp4data=database-bigsql

Change to the project where the Cloud Pak for Data control plane is installed:
```
oc project ${PROJECT_CPD_INSTANCE}
```
Note: This command uses an environment variable so that you can run the command exactly as written. For information about sourcing environment variables, see Setting up installation environment variables.

Identify the Cloud Pak for Data pod that holds the Db2 Big SQL Custom Resource (CR) template:

pod=$(oc get pod -o custom-columns=NAME:.metadata.name --no-headers | grep ibm-nginx-[0-9a-h]*-[0-9a-z]* | head -n 1)

On the local host, back up the Db2 Big SQL CR template from the pod:

oc cp $pod:/user-home/_zen-addons/bigsql/7.4.4/yamls/bigsql-cr.yaml /tmp/bigsql-cr.yaml

On the pod, update the Db2 Big SQL CR template file:

oc exec -it $pod -- sed -i -e 's/^spec:/spec:\n  affinity:\n    nodeAffinity:\n      requiredDuringSchedulingIgnoredDuringExecution:\n        nodeSelectorTerms:\n        - matchExpressions:\n          - key: icp4data\n            operator: In\n            values:\n            - database-bigsql\n  tolerations:\n  - key: "icp4data"\n    operator: "Equal"\n    value: "database-bigsql"\n    effect: "PreferNoSchedule"/' /user-home/_zen-addons/bigsql/7.4.4/yamls/bigsql-cr.yaml

What to do next

Provision Db2 Big SQL