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KubeBlocks for PostgreSQL

Introduction

PostgreSQL introduction

Cluster Management

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

Configuration

Configure cluster parameters

PostgreSQL Connection Pool

Connection pool

High Availability

High Availability for PostgreSQL
  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 -n demo get cluster mycluster
>
NAME        CLUSTER-DEFINITION   VERSION             TERMINATION-POLICY   STATUS    AGE
mycluster   postgresql           postgresql-14.8.0   Delete               Running   29m

kbcli cluster list mycluster -n demo
>
NAME        NAMESPACE   CLUSTER-DEFINITION   VERSION             TERMINATION-POLICY   STATUS    CREATED-TIME
mycluster   demo        postgresql           postgresql-14.8.0   Delete               Running   Sep 28,2024 16:47 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: postgresql
    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.components.volumeClaimTemplates.spec.resources in the cluster YAML file.

    spec.components.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: postgresql
  clusterVersionRef: postgresql-14.8.0
  componentSpecs:
  - name: postgresql
    componentDefRef: postgresql
    replicas: 1
    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 --components="postgresql" --volume-claim-templates="data" --storage="30Gi" -n demo
    • --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.

    • 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          postgresql                postgresql-14.8.0        Delete                    Updating        Sep 28,2024 16:47 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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