KubeBlocks
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KubeBlocks for MySQL

Cluster Management

Create and connect
Scale
Expand volume
Restart
Stop/Start
Switchover
Delete protection

Configuration

Configuration

High Availability

Failure simulation and automatic recovery
  1. Before you start
  2. Steps

Expand volume

You can expand the storage volume size of each pod.

Before you start

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

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

kbcli cluster list mycluster
>
NAME        NAMESPACE   CLUSTER-DEFINITION   VERSION        TERMINATION-POLICY   STATUS    CREATED-TIME
mycluster   demo        mysql                mysql-8.0.33   Delete               Running   Jul 05,2024 18:46 UTC+0800

Steps

  1. Apply an OpsRequest. Change the value of storage according to your need and run the command below to expand the volume of a cluster.

    kubectl apply -f - <<EOF
apiVersion: apps.kubeblocks.io/v1alpha1
kind: OpsRequest
metadata:
  name: ops-volume-expansion
  namespace: demo
spec:
  clusterName: mycluster
  type: VolumeExpansion
  volumeExpansion:
  - componentName: mysql
    volumeClaimTemplates:
    - name: data
      storage: "40Gi"
EOF

  2. Validate the volume expansion operation.

    kubectl get ops -n demo
>
NAMESPACE   NAME                   TYPE              CLUSTER     STATUS    PROGRESS   AGE
demo        ops-volume-expansion   VolumeExpansion   mycluster   Succeed   3/3        6m

  3. Check whether the corresponding cluster resources change.

    kubectl describe cluster mycluster -n demo
>
...
Volume Claim Templates:
   Name:  data
   Spec:
     Access Modes:
       ReadWriteOnce
     Resources:
       Requests:
         Storage: 40Gi
...

  1. Change the value of spec.componentSpecs.volumeClaimTemplates.spec.resources in the cluster YAML file.

    spec.componentSpecs.volumeClaimTemplates.spec.resources is the storage resource information of the pod and changing this value triggers the volume expansion of a cluster.

    apiVersion: apps.kubeblocks.io/v1alpha1
kind: Cluster
metadata:
  name: mycluster
  namespace: demo
spec:
  clusterDefinitionRef: mysql
  clusterVersionRef: mysql-8.0.33
  componentSpecs:
  - name: mysql
    componentDefRef: mysql
    replicas: 2
    volumeClaimTemplates:
    - name: data
      spec:
        accessModes:
          - ReadWriteOnce
        resources:
          requests:
            storage: 40Gi # Change the volume storage size
  terminationPolicy: Delete

  2. Check whether the corresponding cluster resources change.

    kubectl describe cluster mycluster -n demo
>
...
Volume Claim Templates:
   Name:  data
   Spec:
     Access Modes:
       ReadWriteOnce
     Resources:
       Requests:
         Storage:   40Gi

  1. Configure the values of --components, --volume-claim-templates, and --storage, and run the command below to expand the volume.

    kbcli cluster volume-expand mycluster -n demo --components="mysql" --volume-claim-templates="data" --storage="40Gi"
    • --components describes the component name for volume expansion.
    • --volume-claim-templates describes the VolumeClaimTemplate names in components.
    • --storage describes the volume storage size.

  2. Validate the volume expansion operation. There are two options.

    • View the OpsRequest progress.

      KubeBlocks outputs a command automatically for you to view the details of the OpsRequest progress. The output includes the status of this OpsRequest and PVC. When the status is Succeed, this OpsRequest is completed.

      kbcli cluster describe-ops mycluster-volumeexpansion-8257f -n demo

    • View the cluster status.

      kbcli cluster list mycluster -n demo
>
NAME        NAMESPACE   CLUSTER-DEFINITION   VERSION        TERMINATION-POLICY   STATUS    CREATED-TIME
mycluster   demo        mysql                mysql-8.0.33   Delete               Running   Jul 05,2024 18:46 UTC+0800
      • STATUS=Updating: it means the volume expansion is in progress.
      • STATUS=Running: it means the volume expansion operation has been applied.

  3. After the OpsRequest status is Succeed or the cluster status is Running again, check whether the corresponding resources change.

    kbcli cluster describe mycluster -n demo

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