You can change the resource requirements and limits (CPU and storage) by performing the vertical scale. For example, you can change the resource class from 1C2G to 2C4G.

This tutorial takes MySQL as an example to illustrate how to vertically scale a cluster.

NOTE

From v0.9.0, for MySQL and PostgreSQL, after vertical scaling is performed, KubeBlocks automatically matches the appropriate configuration template based on the new specification. This is the KubeBlocks dynamic configuration feature. This feature simplifies the process of configuring parameters, saves time and effort and reduces performance issues caused by incorrect configuration. For detailed instructions, refer to Configuration.

Before you start

Check whether the cluster status is Running. Otherwise, the following operations may fail.

kubectl get cluster mycluster
>
NAME        CLUSTER-DEFINITION   VERSION        TERMINATION-POLICY   STATUS    AGE
mycluster   mysql                mysql-8.0.33   Delete               Running   4d18h

Steps

There are two ways to apply vertical scaling.

Apply an OpsRequest to the specified cluster. Configure the parameters according to your needs.

kubectl apply -f - <<EOF
apiVersion: apps.kubeblocks.io/v1alpha1
kind: OpsRequest
metadata:
  name: ops-vertical-scaling
  namespace: demo
spec:
  clusterName: mycluster
  type: VerticalScaling
  verticalScaling:
  - componentName: mysql
    requests:
      memory: "2Gi"
      cpu: "1"
    limits:
      memory: "4Gi"
      cpu: "2"
EOF

Check the operation status to validate the vertical scaling.

kubectl get ops -n demo
>
NAMESPACE   NAME                   TYPE              CLUSTER     STATUS    PROGRESS   AGE
demo        ops-vertical-scaling   VerticalScaling   mycluster   Succeed   3/3        6m

If an error occurs, you can troubleshoot with kubectl describe ops -n demo command to view the events of this operation.

Check whether the corresponding resources change.
```
kubectl describe cluster mycluster -n demo
```

Change the configuration of spec.componentSpecs.resources in the YAML file. spec.componentSpecs.resources controls the requirement and limit of resources and changing them triggers a vertical scaling.

kubectl edit cluster mycluster -n demo

Edit the values of spec.componentSpecs.resources.

>
...
spec:
  clusterDefinitionRef: apecloud-mysql
  clusterVersionRef: ac-mysql-8.0.30
  componentSpecs:
  - name: mysql
    componentDefRef: mysql
    replicas: 3
    resources: # Change the values of resources
      requests:
        memory: "2Gi"
        cpu: "1"
      limits:
        memory: "4Gi"
        cpu: "2"
...

Check whether the corresponding resources change.
```
kubectl describe cluster mycluster -n demo
```

Vertical Scale