Restore Data from S3-Compatible Storage Using BR

This document describes how to restore the TiDB cluster data backed up using TiDB Operator on Kubernetes.

The restore method described in this document is implemented based on CustomResourceDefinition (CRD) in TiDB Operator. For the underlying implementation, BR is used to restore the data. BR stands for Backup & Restore, which is a command-line tool for distributed backup and recovery of the TiDB cluster data.

Usage Scenarios

After backing up TiDB cluster data to Amazon S3 using BR, if you need to recover the backup SST (key-value pairs) files from Amazon S3 to a TiDB cluster, you can follow steps in this document to restore the data using BR.

This document provides an example about how to restore the backup data from the spec.s3.prefix folder of the spec.s3.bucket bucket on Amazon S3 to the demo2 TiDB cluster in the test2 namespace. The following are the detailed steps.

Step 1: Prepare the restore environment

Before restoring backup data on a S3-compatible storage to TiDB using BR, take the following steps to prepare the restore environment:

1. Download backup-rbac.yaml, and execute the following command to create the role-based access control (RBAC) resources in the test2 namespace:

   kubectl apply -f backup-rbac.yaml -n test2
   

2. Grant permissions to the remote storage.

   If the data to be restored is in Amazon S3, you can grant permissions in three methods. For more information, see AWS account permissions.

   If the data to be restored is in other S3-compatible storage (such as Ceph and MinIO), you can grant permissions by using AccessKey and SecretKey.

3. For a TiDB version earlier than v4.0.8, you also need to complete the following preparation steps. For TiDB v4.0.8 or a later version, skip these preparation steps.

   1. Make sure that you have the SELECT and UPDATE privileges on the mysql.tidb table of the target database so that the Restore CR can adjust the GC time before and after the restore.

   2. Create the restore-demo2-tidb-secret secret to store the account and password to access the TiDB cluster:

      kubectl create secret generic restore-demo2-tidb-secret --from-literal=password=${password} --namespace=test2
      

Step 2: Restore the backup data to a TiDB cluster

Depending on which method you choose to grant permissions to the remote storage when preparing the restore environment, you can restore the data by doing one of the following:

• Method 1: If you grant permissions by importing AccessKey and SecretKey, create the Restore CR to restore cluster data as described below:

  kubectl apply -f restore-aws-s3.yaml
  

  The content of restore-aws-s3.yaml is as follows:

  ---
  apiVersion: pingcap.com/v1alpha1
  kind: Restore
  metadata:
    name: demo2-restore-s3
    namespace: test2
  spec:
    br:
      cluster: demo2
      clusterNamespace: test2
      # logLevel: info
      # statusAddr: ${status_addr}
      # concurrency: 4
      # rateLimit: 0
      # timeAgo: ${time}
      # checksum: true
      # sendCredToTikv: true
    # # Only needed for TiDB Operator < v1.1.10 or TiDB < v4.0.8
    # to:
    #   host: ${tidb_host}
    #   port: ${tidb_port}
    #   user: ${tidb_user}
    #   secretName: restore-demo2-tidb-secret
    s3:
      provider: aws
      secretName: s3-secret
      region: us-west-1
      bucket: my-bucket
      prefix: my-folder
  

• Method 2: If you grant permissions by associating IAM with Pod, create the Restore CR to restore cluster data as described below:

  kubectl apply -f restore-aws-s3.yaml
  

  The content of restore-aws-s3.yaml is as follows:

  ---
  apiVersion: pingcap.com/v1alpha1
  kind: Restore
  metadata:
   name: demo2-restore-s3
   namespace: test2
   annotations:
     iam.amazonaws.com/role: arn:aws:iam::123456789012:role/user
  spec:
   br:
     cluster: demo2
     sendCredToTikv: false
     clusterNamespace: test2
     # logLevel: info
     # statusAddr: ${status_addr}
     # concurrency: 4
     # rateLimit: 0
     # timeAgo: ${time}
     # checksum: true
   # Only needed for TiDB Operator < v1.1.10 or TiDB < v4.0.8
   to:
     host: ${tidb_host}
     port: ${tidb_port}
     user: ${tidb_user}
     secretName: restore-demo2-tidb-secret
   s3:
     provider: aws
     region: us-west-1
     bucket: my-bucket
     prefix: my-folder
  

• Method 3: If you grant permissions by associating IAM with ServiceAccount, create the Restore CR to restore cluster data as described below:

  kubectl apply -f restore-aws-s3.yaml
  

  The content of restore-aws-s3.yaml is as follows:

  ---
  apiVersion: pingcap.com/v1alpha1
  kind: Restore
  metadata:
    name: demo2-restore-s3
    namespace: test2
  spec:
    serviceAccount: tidb-backup-manager
    br:
      cluster: demo2
      sendCredToTikv: false
      clusterNamespace: test2
      # logLevel: info
      # statusAddr: ${status_addr}
      # concurrency: 4
      # rateLimit: 0
      # timeAgo: ${time}
      # checksum: true
    # Only needed for TiDB Operator < v1.1.10 or TiDB < v4.0.8
    to:
      host: ${tidb_host}
      port: ${tidb_port}
      user: ${tidb_user}
      secretName: restore-demo2-tidb-secret
    s3:
      provider: aws
      region: us-west-1
      bucket: my-bucket
      prefix: my-folder
  

When configuring restore-aws-s3.yaml, note the following:

• For more information about S3-compatible storage configuration, refer to S3 storage fields.
• Some parameters in .spec.br are optional, such as logLevel, statusAddr, concurrency, rateLimit, checksum, timeAgo, and sendCredToTikv. For more information about BR configuration, refer to BR fields.
• For v4.0.8 or a later version, BR can automatically adjust tikv_gc_life_time. You do not need to configure spec.to fields in the Restore CR.
• For more information about the Restore CR fields, refer to Restore CR fields.

After creating the Restore CR, execute the following command to check the restore status:

kubectl get rt -n test2 -o wide

Troubleshooting

If you encounter any problem during the restore process, refer to Common Deployment Failures.