Restore a MongoDB Cluster from Backup with Point-In-Time-Recovery(PITR) on KubeBlocks

This guide demonstrates how to perform Point-In-Time Recovery (PITR) for MongoDB clusters in KubeBlocks using:

1. A full base backup
2. Continuous WAL (Write-Ahead Log) backups
3. Two restoration methods:
   • Cluster Annotation (declarative approach)
   • OpsRequest API (operational control)

PITR enables recovery to any moment within the timeRange specified.

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

Prepare for PITR Restoration

To perform a PITR restoration, both a full backup and continuous backup are required. Refer to the documentation to configure these backups if they are not already set up.

• Completed full backup
• Active continuous WAL backup
• Backup repository accessible
• Sufficient resources for new cluster

To identify the list of full and continuous backups, you may follow the steps:

1. Verify Continuous Backup

Confirm you have a continuous WAL backup, either running or completed:

# expect EXACTLY ONE continuous backup per cluster
kubectl get backup -n demo -l dataprotection.kubeblocks.io/backup-type=Continuous,app.kubernetes.io/instance=mongo-cluster

2. Check Backup Time Range

Get the valid recovery window:

kubectl get backup <continuous-backup-name> -n demo -o yaml | yq '.status.timeRange'

Expected Output:

start: "2025-05-07T09:12:47Z"
end: "2025-05-07T09:22:50Z"

3. Identify Full Backup

Find available full backups that meet:

• Status: Completed
• Completion time after continuous backup start time

# expect one or more Full backups
kubectl get backup -n demo -l dataprotection.kubeblocks.io/backup-type=Full,app.kubernetes.io/instance=mongo-cluster

Option 1: Cluster Annotation Restoration

Step 1: Create Restored Cluster

Configure PITR parameters in cluster annotation:

Key parameters:

• name: Continuous backup name
• restoreTime: Target recovery time (within backup timeRange)

Apply this YAML configuration:

apiVersion: apps.kubeblocks.io/v1
kind: Cluster
metadata:
  name: mongo-cluster-restore-pitr
  namespace: demo
  annotations:
    # NOTE: replace <CONTINUOUS_BACKUP_NAME> with the continuouse backup name
    # NOTE: replace <RESTORE_POINT_TIME>  with a valid time within the backup timeRange.
    kubeblocks.io/restore-from-backup: '{"mongodb":{"name":"<CONTINUOUS_BACKUP_NAME>","namespace":"demo","restoreTime":"<RESTORE_POINT_TIME>","volumeRestorePolicy":"Parallel"}}'
spec:
  terminationPolicy: Delete
  clusterDef: mongodb
  topology: replicaset
  componentSpecs:
    - name: mongodb
      serviceVersion: "6.0.16"
      replicas: 3
      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

Step 2: Monitor Restoration

Track restore progress with:

# Watch restore status
kubectl get restore -n demo -w

# Watch cluster status
kubectl get cluster -n demo -w

Option 2: OpsRequest API Restoration

For operational control and monitoring, use the OpsRequest API:

apiVersion: operations.kubeblocks.io/v1alpha1
kind: OpsRequest
metadata:
  name: mongo-cluster-restore
  namespace: demo
spec:
  clusterName: mongo-cluster-restore
  force: false
  restore:
    backupName: <CONTINUOUS_BACKUP_NAME>
    backupNamespace: demo
    restorePointInTime: <RESTORE_POINT_TIME>
  type: Restore

Monitor Restoration

Track progress with:

# Watch restore operation
kubectl get restore -n demo -w

# Verify cluster status
kubectl get cluster -n demo -w

Cleanup

To remove all created resources, delete the MongoDB cluster along with its namespace:

kubectl delete cluster mongo-cluster -n demo
kubectl delete cluster mongo-cluster-restore -n demo
kubectl delete ns demo

Summary

This guide demonstrated how to restore a MongoDB cluster in KubeBlocks using a full backup and continuous backup for Point-In-Time Recovery (PITR). Key steps included:

• Verifying available backups.
• Extracting encrypted system account credentials.
• Creating a new MongoDB cluster with restoration configuration.
• Monitoring the restoration process.

With this approach, you can restore a MongoDB cluster to a specific point in time, ensuring minimal data loss and operational continuity.