KubeBlocks
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KubeBlocks for Redis

Cluster Management

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

Configuration

Configure cluster parameters

High Availability

High Availability for Redis
Redis Cluster Mode
  1. Before you start
  2. Steps

Expand volume

You can expand the storage volume size of each pod.

NOTE

Volume expansion triggers a concurrent restart and the pod role may change after the operation.

Before you start

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

kubectl -n demo get cluster mycluster
>
NAME           CLUSTER-DEFINITION   VERSION        TERMINATION-POLICY   STATUS     AGE
mycluster      redis                               Delete               Running    19m

kbcli cluster list mycluster -n demo
>
NAME        NAMESPACE   CLUSTER-DEFINITION   VERSION   TERMINATION-POLICY   STATUS    CREATED-TIME
mycluster   demo        redis                          Delete               Running   Sep 29,2024 09:46 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: redis
    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.

    kubectl edit cluster mycluster -n demo

    Edit the value of spec.componentSpecs.volumeClaimTemplates.spec.resources.requests.storage.

    ...
spec:
  affinity:
    podAntiAffinity: Preferred
    topologyKeys:
    - kubernetes.io/hostname
  clusterDefinitionRef: redis
  componentSpecs:
  - componentDef: redis
    enabledLogs:
    - running
    disableExporter: true
    name: redis
    replicas: 1
    resources:
      limits:
        cpu: "0.5"
        memory: 0.5Gi
      requests:
        cpu: "0.5"
        memory: 0.5Gi
    serviceAccountName: kb-redis
    volumeClaimTemplates:
    - name: data
      spec:
        accessModes:
        - ReadWriteOnce
        resources:
          requests:
            storage: 40Gi # Change the volume storage size
...

  2. Check whether the corresponding cluster resources change.

    kubectl describe cluster mycluster -n demo

    View the value of spec.componentSpecs.volumeClaimTemplates.spec.resources.requests.storage.

    ...
Volume Claim Templates:
   Name:  data
   Spec:
     Access Modes:
       ReadWriteOnce
     Resources:
       Requests:
         Storage:   40Gi

  1. Change configuration.

    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="redis" --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.

    • 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-ih2r4 -n demo

    • View the cluster status.

      kbcli cluster list mycluster -n demo
>
NAME                CLUSTER-DEFINITION        VERSION           TERMINATION-POLICY        STATUS          CREATED-TIME
redis-cluster        redis                                      Delete                    Updating        Sep 29,2024 09:46 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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