Create a Full Backup for a MySQL Cluster on KubeBlocks

This guide demonstrates how to create and validate full backups for a MySQL cluster deployed on KubeBlocks using XtraBackup through both Backup API and Ops API. The Ops API is essentially a wrapper around the Backup API, offering enhanced control and progress monitoring capabilities for backup operations.

We will cover how to restore data from a backup in the Restore From Full Backup guide.

Prerequisites

Before proceeding, ensure the following:

• Environment Setup:
  • A Kubernetes cluster is up and running.
  • The kubectl CLI tool is configured to communicate with your cluster.
  • KubeBlocks CLI and KubeBlocks Operator are installed. Follow the installation instructions here.
• Namespace Preparation: To keep resources isolated, create a dedicated namespace for this tutorial:

kubectl create ns demo
namespace/demo created

Deploy a MySQL Semi-Synchronous Cluster

KubeBlocks uses a declarative approach for managing MySQL clusters. Below is an example configuration for deploying a MySQL cluster with 2 nodes (1 primary, 1 replicas) in semi-synchronous mode.

Cluster Configuration

kubectl apply -f - <<EOF
apiVersion: apps.kubeblocks.io/v1
kind: Cluster
metadata:
  name: example-mysql-cluster
  namespace: demo
spec:
  clusterDef: mysql
  topology: semisync
  terminationPolicy: WipeOut
  componentSpecs:
    - name: mysql
      serviceVersion: 8.0.35
      replicas: 2
      resources:
        limits:
          cpu: '0.5'
          memory: 0.5Gi
        requests:
          cpu: '0.5'
          memory: 0.5Gi
      volumeClaimTemplates:
        - name: data
          spec:
            storageClassName: ""
            accessModes:
              - ReadWriteOnce
            resources:
              requests:
                storage: 20Gi
EOF

Key Notes:

• terminationPolicy: WipeOut:
  • When set to 'WipeOut', deleting the cluster also deletes all associated data, including backups.
  • For production environments, it is recommended to use terminationPolicy: Delete, which retains backup data even after the cluster is deleted.

Verifying the Deployment

Monitor the cluster status until it transitions to Running:

kubectl get cluster example-mysql-cluster -n demo

Example Output:

NAME                     CLUSTER-DEFINITION   TERMINATION-POLICY   STATUS    AGE
example-mysql-cluster   mysql                Delete               Running   36m

Identify Backup Policies

List available backup policies and schedules for the cluster:

# List backup policies
kubectl get backuppolicy -n demo

# List backup schedules
kubectl get backupschedule -n demo

Expected Output:

NAME                                            BACKUP-REPO   STATUS      AGE
example-mysql-cluster-mysql-backup-policy                      Available   58m

NAME                                              STATUS      AGE
example-mysql-cluster-mysql-backup-schedule        Available   60m

View supported backup methods in the BackupPolicy CR 'example-mysql-cluster-mysql-backup-policy':

kubectl get backuppolicy example-mysql-cluster-mysql-backup-policy -n demo -oyaml

Available Methods:

• 'xtrabackup': Full database backup using Percona XtraBackup
• 'volume-snapshot': Storage-level snapshot
• 'archive-binlog': Continuous binary log archiving

The following sections demonstrate how to perform a full backup using the 'xtrabackup' method.

Perform a Backup via Backup API

1. Initiate a Full Backup

Execute a full backup using the 'xtrabackup' method defined in the backup policy:

kubectl apply -f - <<EOF
apiVersion: dataprotection.kubeblocks.io/v1alpha1
kind: Backup
metadata:
  name: example-mysql-cluster-backup
  namespace: demo
spec:
  # Specifies the backup method name that is defined in the backup policy.
  # - xtrabackup
  # - volume-snapshot
  backupMethod: xtrabackup
  backupPolicyName: example-mysql-cluster-mysql-backup-policy
  # Determines whether the backup contents stored in the backup repository should be deleted when the backup custom resource(CR) is deleted. Supported values are 'Retain' and 'Delete'.
  # - 'Retain' means that the backup content and its physical snapshot on backup repository are kept.
  # - 'Delete' means that the backup content and its physical snapshot on backup repository are deleted.
  deletionPolicy: Delete
EOF

2. Monitor Backup Progress

Check the backup status until it shows 'Completed':

kubectl get backup example-mysql-cluster-backup  -n demo -w

Example Output:

NAME                           POLICY                                      METHOD       REPO      STATUS    TOTAL-SIZE   DURATION   DELETION-POLICY   CREATION-TIME          COMPLETION-TIME   EXPIRATION-TIME
example-mysql-cluster-backup   example-mysql-cluster-mysql-backup-policy   xtrabackup   s3-repo   Running                           Delete            2025-03-07T01:39:05Z
example-mysql-cluster-backup   example-mysql-cluster-mysql-backup-policy   xtrabackup   s3-repo   Completed   1524515      18s        Delete            2025-03-07T01:39:05Z   2025-03-07T01:39:23Z

3. Validate Backup Artifacts

Verify the backup files in the configured S3 bucket:

aws s3 ls s3://kubeblocks-backup-repo/ --recursive

Example Output:

2025-03-07 09:39:10    1524515 demo/example-mysql-cluster-cb1b0f47-e310-4f63-9537-dacb6cbac499/mysql/example-mysql-cluster-backup/example-mysql-cluster-backup.xbstream.zst
2025-03-07 09:39:20       5642 demo/example-mysql-cluster-cb1b0f47-e310-4f63-9537-dacb6cbac499/mysql/example-mysql-cluster-backup/kubeblocks-backup.json

Perform a Backup via Ops API

1. Initiate a Full Backup

Execute a full backup using the 'xtrabackup' method defined in the backup policy:

kubectl apply -f - <<EOF
apiVersion: operations.kubeblocks.io/v1alpha1
kind: OpsRequest
metadata:
  name: example-mysql-cluster-backup
  namespace: demo
spec:
  clusterName: example-mysql-cluster
  force: false
  backup:
    backupPolicyName: example-mysql-cluster-mysql-backup-policy
    backupMethod: xtrabackup
    deletionPolicy: Delete
    retentionPeriod: 1mo
  type: Backup
EOF

2. Monitor Backup Progress

Step 1: Verify Backup Operation Status

Execute the following command to monitor the backup operation status in real-time:

kubectl get ops example-mysql-cluster-backup  -n demo -w

Expected Output:

NAME                           TYPE     CLUSTER                 STATUS    PROGRESS   AGE
example-mysql-cluster-backup   Backup   example-mysql-cluster   Succeed   -/-        3m34s

• A STATUS of 'Succeed' indicates the backup operation completed successfully.

Step 2: Confirm Backup Completion

Check the final backup status with:

kubectl get backup  -n demo -w

Example Output:

NAME                                               POLICY                                      METHOD           REPO      STATUS      TOTAL-SIZE   DURATION   DELETION-POLICY   CREATION-TIME          COMPLETION-TIME        EXPIRATION-TIME
backup-demo-example-mysql-cluster-20250307013939   example-mysql-cluster-mysql-backup-policy   xtrabackup   s3-repo   Completed   1549449      18s        Delete            2025-03-07T01:39:39Z   2025-03-07T01:39:57Z   2025-04-06T01:39:57Z

• The backup status should show 'Completed'.

3. Validate Backup Artifacts

Verify the backup files in the configured S3 bucket:

aws s3 ls s3://kubeblocks-backup-repo/ --recursive

Example Output:

2025-03-07 09:39:44    1549449 demo/example-mysql-cluster-cb1b0f47-e310-4f63-9537-dacb6cbac499/mysql/backup-demo-example-mysql-cluster-20250307013939/backup-demo-example-mysql-cluster-20250307013939.xbstream.zst
2025-03-07 09:39:54       5529 demo/example-mysql-cluster-cb1b0f47-e310-4f63-9537-dacb6cbac499/mysql/backup-demo-example-mysql-cluster-20250307013939/kubeblocks-backup.json

Summary

This guide demonstrated how to:

• Deploy a semi-synchronous MySQL cluster on KubeBlocks.
• Create a full backup using the 'xtrabackup' method.
• Monitor and validate backup artifacts. By following this guide, you can ensure your MySQL cluster data is securely backed up and easily restorable.