4.2 Updating the NDB Cluster Configuration

Making changes in the configuration of an NDB Cluster running in Kubernetes, requires editing the NdbCluster YAML spec file, then applying the updated file to the Kubernetes Cluster.

Consider the example example-ndb, installed from the file docs/examples/example-ndb.yaml (see Section 3.1, “Setting the NDB Cluster's Configuration”), which provides two SQL nodes. To increase this number to five, update spec.mysqld.nodeCount in this file to the preferred value. The updated file should look like what is shown here (with the edited line in highlighted text):

apiVersion: mysql.oracle.com/v1
kind: NdbCluster
metadata:
  name: example-ndb
spec:
  redundancyLevel: 2
  dataNode:
    nodeCount: 2
  mysqlNode:
    nodeCount: 5

Now you can apply the updated YAML file to the Kubernetes Cluster, like this:

> kubectl apply -f docs/examples/example-ndb.yaml
ndbclusters.mysql.oracle.com/example-ndb configured

Once the change has been applied, NDB Operator picks up the changes and begins applying them to the NDB Cluster. In this particular case, it updates the management node configuration files, performs a rolling restart (see Performing a Rolling Restart of an NDB Cluster), and starts additional mysqld processes (SQL nodes).

The status and readiness of the NDB Cluster nodes can be observed as when they were first deployed.