Backup and restore with metadata tool

StreamNative Platform is a distributed messaging system with multi-layer architecture and uses Apache ZooKeeper as the metadata service. Both StreamNative Platform storage layer and ZooKeeper provide multiple data replicas. To further enhance data fault tolerance and prevent data loss, you can backup and restore with the metadata tool. Currently, the tool enables you to backup and restore Pulsar cluster's metadata to or from the cloud storage.

Backup ZooKeeper metadata

By default, the backup service is disabled. To enable the backup service, you need to set the zookeeper.backup.enable to true, and set the bucket and secrets accordingly in the values.yaml file that you use to deploy your cluster.

To backup ZooKeeper metadata of your cluster, complete the following steps:

1. Create a bucket in AWS S3 to save the backup files.

2. Create the credential to access AWS S3.

3. Create a secret to save your AWS credentials with the following command.

   kubectl create secret generic aws-secret          --from-literal=AWS_ACCESS_KEY_ID=<YOUR_ACCESS_KEY_ID>    --from-literal=AWS_SECRET_ACCESS_KEY=<YOUR_AWS_SECRET_ACCESS_KEY>
   

4. Enable backup service in the zookeeper.customTools section in the values.yaml file.

   zookeeper:
     customTools:
       serviceAccount:
         use: true
         create: true
         name: ''
         annotations: {}
         clusterRole: true
       backup:
         component: 'backup'
         enable: true
         webServerPort: '8088'
         backupInterval: '600'
         bucket: 's3a://<your-bucket-name>'
         backupPrefix: 'pulsar-backup'
         managedLedgerPath: '/managed-ledgers'
         configData:
           OPTS: ''
         secrets:
           use: false
           aws:
             secretName: 'aws-secret'
   

   Note

   If you want to use the AWS Identity and Access Management (IAM) roles to operate the AWS resources, follow the AWS documentation to obtain the Amazon Resource Name (ARN) and then apply the ARN through the serviceAccount.annotations option. In addition, you need to set the backup.configData.secrets.use to false to disable the secret.

5. Create your cluster with the values.yaml file.

   helm install -f values.yaml <release_name> streamnative/sn-platform --set initialize=true -n <k8s_namespace>
   

6. Check whether the backup service is running.

   kubectl get pods <release_name>-restore-pulsar-backup-0
   

   If the status is running, the backup service starts. You can also check the backup files in your bucket.

Restore metadata from an old cluster

The restore service works only when you start a new cluster by using the old backup metadata, and it only restores data from tiered storage. If a cluster is running, you cannot restore it.

By default, the restore service is disabled. To restore your cluster to a backup point, complete the following steps:

1. Decide the restore point by finding a restore file from your bucket, for example: s3a://my-backuprestore/pulsar-backup-1623721488825.tar.gz.

2. Enable the restore service in the ZooKeeper customTools section in the values.yaml file that you use to deploy the cluster.

   restore:
     component: 'restore'
     enable: true
     restorePoint: 's3a://<your-bucket-name>/<backup-file>'
     restoreVersion: '1'
     bucket: 's3a://<your-bucket-name>'
     configData:
       OPTS: ''
     secrets:
       use: true
       aws:
         secretName: 'aws-secret'
   

3. Restore your cluster with the values.yaml.

   helm install -f values.yaml <release_name> streamnative/sn-platform  --set initialize=true -n <k8s_namespace>
   

4. Check the restore service and make sure that ZooKeeper pods start.

   kubectl get pods | grep zookeeper
   

   You can also check the topics and namespaces created in the new cluster.

Configuration

The following table lists the properties, description and default values of the backup and restore services.

Administration

The backup service provides some REST APIs for administration.

Monitor

The backup service provides the metrics endpoint to monitor the following metrics.