Back up Data to GCS Using BR

Back up Data to GCS Using BR

This document describes how to back up the data of a TiDB cluster in Kubernetes to Google Cloud Storage (GCS).

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

Usage scenarios

If you have the following backup needs, you can use BR to make an ad-hoc backup or scheduled full backup of the TiDB cluster data to GCS.

To back up a large volume of data at a fast speed
To get a direct backup of data as SST files (key-value pairs)

For other backup needs, refer to Backup and Restore Overview to choose an appropriate backup method.

Note

BR is only applicable to TiDB v3.1 or later releases.
Data that is backed up using BR can only be restored to TiDB instead of other databases.

Ad-hoc backup

Ad-hoc backup supports both full backup and incremental backup.

To get an Ad-hoc backup, you need to create a Backup Custom Resource (CR) object to describe the backup details. Then, TiDB Operator performs the specific backup operation based on this Backup object. If an error occurs during the backup process, TiDB Operator does not retry, and you need to handle this error manually.

This document provides an example about how to back up the data of the demo1 TiDB cluster in the test1 Kubernetes namespace to GCS. The following are the detailed steps.

Step 1: Prepare for an ad-hoc backup

Download backup-rbac.yaml, and execute the following command to create the role-based access control (RBAC) resources in the test1 namespace:
```
kubectl apply -f backup-rbac.yaml -n test1
```
Grant permissions to the remote storage.

Refer to GCS account permissions.
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 backup database so that the Backup CR can adjust the GC time before and after the backup.
2. Create the backup-demo1-tidb-secret secret to store the root account and password to access the TiDB cluster:
```
kubectl create secret generic backup-demo1-tidb-secret --from-literal=password=<password> --namespace=test1
```

Step 2: Perform an ad-hoc backup

Create the Backup CR to back up cluster data to GCS as described below:
```
kubectl apply -f backup-gcs.yaml
```
The content of backup-gcs.yaml is as follows:
```
---
apiVersion: pingcap.com/v1alpha1
kind: Backup
metadata:
  name: demo1-backup-gcs
  namespace: test1
spec:
  # backupType: full
  # Only needed for TiDB Operator < v1.1.10 or TiDB < v4.0.8
  from:
    host: ${tidb-host}
    port: ${tidb-port}
    user: ${tidb-user}
    secretName: backup-demo1-tidb-secret
  br:
    cluster: demo1
    clusterNamespace: test1
    # logLevel: info
    # statusAddr: ${status-addr}
    # concurrency: 4
    # rateLimit: 0
    # checksum: true
    # sendCredToTikv: true
    # options:
    # - --lastbackupts=420134118382108673
  gcs:
    projectId: ${project_id}
    secretName: gcs-secret
    bucket: ${bucket}
    prefix: ${prefix}
    # location: us-east1
    # storageClass: STANDARD_IA
    # objectAcl: private
```
When configuring the backup-gcs.yaml, note the following:
- Since TiDB Operator v1.1.6, if you want to back up data incrementally, you only need to specify the last backup timestamp --lastbackupts in spec.br.options. For the limitations of incremental backup, refer to Use BR to Back up and Restore Data.
- Some parameters in spec.br are optional, such as logLevel and statusAddr. For more information about BR configuration, refer to BR fields.
- Some parameters in spec.gcs are optional, such as location, objectAcl, and storageClass. For more information about GCS configuration, refer to GCS fields.
- For v4.0.8 or a later version, BR can automatically adjust tikv_gc_life_time. You do not need to configure spec.tikvGCLifeTime and spec.from fields in the Backup CR.
- For more information about the Backup CR fields, refer to Backup CR fields.
After you create the Backup CR, TiDB Operator starts the backup automatically. You can view the backup status by running the following command:
```
kubectl get bk -n test1 -owide
```

Backup CR examples

Back up data of all clusters

---
apiVersion: pingcap.com/v1alpha1
kind: Backup
metadata:
  name: demo1-backup-gcs
  namespace: test1
spec:
  # backupType: full
  # Only needed for TiDB Operator < v1.1.10 or TiDB < v4.0.8
  # from:
    # host: ${tidb-host}
    # port: ${tidb-port}
    # user: ${tidb-user}
    # secretName: backup-demo1-tidb-secret
  br:
    cluster: demo1
    clusterNamespace: test1
  gcs:
    projectId: ${project_id}
    secretName: gcs-secret
    bucket: ${bucket}
    prefix: ${prefix}
    # location: us-east1
    # storageClass: STANDARD_IA
    # objectAcl: private

Back up data of a single database

The following example backs up data of the db1 database.

---
apiVersion: pingcap.com/v1alpha1
kind: Backup
metadata:
  name: demo1-backup-gcs
  namespace: test1
spec:
  # backupType: full
  # Only needed for TiDB Operator < v1.1.10 or TiDB < v4.0.8
  # from:
    # host: ${tidb-host}
    # port: ${tidb-port}
    # user: ${tidb-user}
    # secretName: backup-demo1-tidb-secret
  tableFilter:
  - "db1.*"
  br:
    cluster: demo1
    clusterNamespace: test1
  gcs:
    projectId: ${project_id}
    secretName: gcs-secret
    bucket: ${bucket}
    prefix: ${prefix}
    # location: us-east1
    # storageClass: STANDARD_IA
    # objectAcl: private

Back up data of a single table

The following example backs up data of the db1.table1 table.

---
apiVersion: pingcap.com/v1alpha1
kind: Backup
metadata:
  name: demo1-backup-gcs
  namespace: test1
spec:
  # backupType: full
  # Only needed for TiDB Operator < v1.1.10 or TiDB < v4.0.8
  # from:
    # host: ${tidb-host}
    # port: ${tidb-port}
    # user: ${tidb-user}
    # secretName: backup-demo1-tidb-secret
  tableFilter:
  - "db1.table1"
  br:
    cluster: demo1
    clusterNamespace: test1
  gcs:
    projectId: ${project_id}
    secretName: gcs-secret
    bucket: ${bucket}
    prefix: ${prefix}
    # location: us-east1
    # storageClass: STANDARD_IA
    # objectAcl: private

Back up data of multiple tables using the table filter

The following example backs up data of the db1.table1 table and db1.table2 table.

---
apiVersion: pingcap.com/v1alpha1
kind: Backup
metadata:
  name: demo1-backup-gcs
  namespace: test1
spec:
  # backupType: full
  # Only needed for TiDB Operator < v1.1.10 or TiDB < v4.0.8
  # from:
    # host: ${tidb-host}
    # port: ${tidb-port}
    # user: ${tidb-user}
    # secretName: backup-demo1-tidb-secret
  tableFilter:
  - "db1.table1"
  - "db1.table2"
  br:
    cluster: demo1
    clusterNamespace: test1
  gcs:
    projectId: ${project_id}
    secretName: gcs-secret
    bucket: ${bucket}
    prefix: ${prefix}
    # location: us-east1
    # storageClass: STANDARD_IA
    # objectAcl: private

Scheduled full backup

You can set a backup policy to perform scheduled backups of the TiDB cluster, and set a backup retention policy to avoid excessive backup items. A scheduled full backup is described by a custom BackupSchedule CR object. A full backup is triggered at each backup time point. Its underlying implementation is the ad-hoc full backup.

Step 1: Prepare for a scheduled full backup

The steps to prepare for a scheduled full backup are the same as that of Prepare for an ad-hoc backup.

Step 2: Perform a scheduled full backup

Create a BackupSchedule CR to back up cluster data as described below:

kubectl apply -f backup-schedule-gcs.yaml

The content of backup-schedule-gcs.yaml is as follows:

---
apiVersion: pingcap.com/v1alpha1
kind: BackupSchedule
metadata:
  name: demo1-backup-schedule-gcs
  namespace: test1
spec:
  #maxBackups: 5
  #pause: true
  maxReservedTime: "3h"
  schedule: "*/2 * * * *"
  backupTemplate:
    # Only needed for TiDB Operator < v1.1.10 or TiDB < v4.0.8
    from:
      host: ${tidb_host}
      port: ${tidb_port}
      user: ${tidb_user}
      secretName: backup-demo1-tidb-secret
    br:
      cluster: demo1
      clusterNamespace: test1
      # logLevel: info
      # statusAddr: ${status-addr}
      # concurrency: 4
      # rateLimit: 0
      # checksum: true
      # sendCredToTikv: true
    gcs:
      secretName: gcs-secret
      projectId: ${project_id}
      bucket: ${bucket}
      prefix: ${prefix}
      # location: us-east1
      # storageClass: STANDARD_IA
      # objectAcl: private

From the above in backup-schedule-gcs.yaml, you can see that the backupSchedule configuration consists of two parts. One is the unique configuration of backupSchedule, and the other is backupTemplate.

For the unique configuration of backupSchedule, refer to BackupSchedule CR fields.
backupTemplate specifies the configuration related to the cluster and remote storage, which is the same as the spec configuration of the Backup CR.

After creating the scheduled full backup, use the following command to check the backup status:
```
kubectl get bks -n test1 -owide
```
Use the following command to check all the backup items:
```
kubectl get bk -l tidb.pingcap.com/backup-schedule=demo1-backup-schedule-gcs -n test1
```