Backup Storages
TiDB supports storing backup data to Amazon S3, Google Cloud Storage (GCS), Azure Blob Storage, and NFS. Specifically, you can specify the URI of backup storage in the --storage or -s parameter of br commands. This document introduces the URI format and authentication of different external storage services, and server-side encryption.
Send credentials to TiKV
| CLI parameter | Description | Default value | 
|---|---|---|
| --send-credentials-to-tikv | Controls whether to send credentials obtained by BR to TiKV. | true | 
By default, BR sends a credential to each TiKV node when using Amazon S3, GCS, or Azure Blob Storage as the storage system. This behavior simplifies the configuration and is controlled by the parameter --send-credentials-to-tikv(or -c in short).
Note that this operation is not applicable to cloud environments. If you use IAM Role authorization, each node has its own role and permissions. In this case, you need to configure --send-credentials-to-tikv=false (or -c=0 in short) to disable sending credentials:
./br backup full -c=0 -u pd-service:2379 --storage 's3://bucket-name/prefix'
If you back up or restore data using the BACKUP and RESTORE statements, you can add the SEND_CREDENTIALS_TO_TIKV = FALSE option:
BACKUP DATABASE * TO 's3://bucket-name/prefix' SEND_CREDENTIALS_TO_TIKV = FALSE;
URI format
URI format description
This section describes the URI format of the storage services:
[scheme]://[host]/[path]?[parameters]
- Amazon S3
- GCS
- Azure Blob Storage
- scheme:- s3
- host:- bucket name
- parameters:- access-key: Specifies the access key.
- secret-access-key: Specifies the secret access key.
- session-token: Specifies the temporary session token. BR does not support this parameter yet.
- use-accelerate-endpoint: Specifies whether to use the accelerate endpoint on Amazon S3 (defaults to- false).
- endpoint: Specifies the URL of custom endpoint for S3-compatible services (for example,- <https://s3.example.com/>).
- force-path-style: Use path style access rather than virtual hosted style access (defaults to- true).
- storage-class: Specifies the storage class of the uploaded objects (for example,- STANDARDor- STANDARD_IA).
- sse: Specifies the server-side encryption algorithm used to encrypt the uploaded objects (value options: `- ,AES256- , oraws:kms`).
- sse-kms-key-id: Specifies the KMS ID if- sseis set to- aws:kms.
- acl: Specifies the canned ACL of the uploaded objects (for example,- privateor- authenticated-read).
- role-arn: When you need to access Amazon S3 data from a third party using a specified IAM role, you can specify the corresponding Amazon Resource Name (ARN) of the IAM role with the- role-arnURL query parameter, such as- arn:aws:iam::888888888888:role/my-role. For more information about using an IAM role to access Amazon S3 data from a third party, see AWS documentation.
- external-id: When you access Amazon S3 data from a third party, you might need to specify a correct external ID to assume the IAM role. In this case, you can use this- external-idURL query parameter to specify the external ID and make sure that you can assume the IAM role. An external ID is an arbitrary string provided by the third party together with the IAM role ARN to access the Amazon S3 data. Providing an external ID is optional when assuming an IAM role, which means if the third party does not require an external ID for the IAM role, you can assume the IAM role and access the corresponding Amazon S3 data without providing this parameter.
 
- scheme:- gcsor- gs
- host:- bucket name
- parameters:- credentials-file: Specifies the path to the credentials JSON file on the migration tool node.
- storage-class: Specifies the storage class of the uploaded objects (for example,- STANDARDor- COLDLINE)
- predefined-acl: Specifies the predefined ACL of the uploaded objects (for example,- privateor- project-private)
 
- scheme:- azureor- azblob
- host:- container name
- parameters:- account-name: Specifies the account name of the storage.
- account-key: Specifies the access key.
- sas-token: Specifies the shared access signature (SAS) token.
- access-tier: Specifies the access tier of the uploaded objects, for example,- Hot,- Cool, or- Archive. The default value is the default access tier of the storage account.
- encryption-scope: Specifies the encryption scope for server-side encryption.
- encryption-key: Specifies the encryption key for server-side encryption, which uses the AES256 encryption algorithm.
 
URI examples
This section provides some URI examples by using external as the host parameter (bucket name or container name in the preceding sections).
- Amazon S3
- GCS
- Azure Blob Storage
Back up snapshot data to Amazon S3
./br backup full -u "${PD_IP}:2379" \
--storage "s3://external/backup-20220915?access-key=${access-key}&secret-access-key=${secret-access-key}"
Restore snapshot data from Amazon S3
./br restore full -u "${PD_IP}:2379" \
--storage "s3://external/backup-20220915?access-key=${access-key}&secret-access-key=${secret-access-key}"
Back up snapshot data to GCS
./br backup full --pd "${PD_IP}:2379" \
--storage "gcs://external/backup-20220915?credentials-file=${credentials-file-path}"
Restore snapshot data from GCS
./br restore full --pd "${PD_IP}:2379" \
--storage "gcs://external/backup-20220915?credentials-file=${credentials-file-path}"
Back up snapshot data to Azure Blob Storage
./br backup full -u "${PD_IP}:2379" \
--storage "azure://external/backup-20220915?account-name=${account-name}&account-key=${account-key}"
Restore the test database from snapshot backup data in Azure Blob Storage
./br restore db --db test -u "${PD_IP}:2379" \
--storage "azure://external/backup-20220915account-name=${account-name}&account-key=${account-key}"
Authentication
When storing backup data in a cloud storage system, you need to configure authentication parameters depending on the specific cloud service provider. This section describes the authentication methods used by Amazon S3, GCS, and Azure Blob Storage, and how to configure the accounts used to access the corresponding storage service.
- Amazon S3
- GCS
- Azure Blob Storage
Before backup, configure the following privileges to access the backup directory on S3.
- Minimum privileges for TiKV and Backup & Restore (BR) to access the backup directories during backup: s3:ListBucket,s3:PutObject, ands3:AbortMultipartUpload
- Minimum privileges for TiKV and BR to access the backup directories during restore: s3:ListBucket,s3:GetObject, ands3:PutObject. BR writes checkpoint information to the./checkpointssubdirectory under the backup directory. When restoring log backup data, BR writes the table ID mapping relationship of the restored cluster to the./pitr_id_mapssubdirectory under the backup directory.
If you have not yet created a backup directory, refer to Create a bucket to create an S3 bucket in the specified region. If necessary, you can also create a folder in the bucket by referring to Create a folder.
It is recommended that you configure access to S3 using either of the following ways:
- Method 1: Specify the access key - If you specify an access key and a secret access key in the URI, authentication is performed using the specified access key and secret access key. Besides specifying the key in the URI, the following methods are also supported: - BR reads the environment variables $AWS_ACCESS_KEY_IDand$AWS_SECRET_ACCESS_KEY.
- BR reads the environment variables $AWS_ACCESS_KEYand$AWS_SECRET_KEY.
- BR reads the shared credentials file in the path specified by the environment variable $AWS_SHARED_CREDENTIALS_FILE.
- BR reads the shared credentials file in the ~/.aws/credentialspath.
 
- BR reads the environment variables 
- Method 2: Access based on the IAM role - Associate an IAM role that can access S3 with EC2 instances where the TiKV and BR nodes run. After the association, BR can directly access the backup directories in S3 without additional settings. br backup full --pd "${PD_IP}:2379" \ --storage "s3://${host}/${path}"
You can configure the account used to access GCS by specifying the access key. If you specify the credentials-file parameter, the authentication is performed using the specified credentials-file. Besides specifying the key in the URI, the following methods are also supported:
- BR reads the file in the path specified by the environment variable $GOOGLE_APPLICATION_CREDENTIALS
- BR reads the file ~/.config/gcloud/application_default_credentials.json.
- BR obtains the credentials from the metadata server when the cluster is running in GCE or GAE.
- Method 1: Specify the shared access signature - If you specify - account-nameand- sas-tokenin the URI, the authentication is performed using the specified account name and shared access signature (SAS) token. Note that the SAS token contains the- &character. You need to encode it as- %26before appending it to the URI. You can also directly encode the entire- sas-tokenusing percent-encoding.
- Method 2: Specify the access key - If you specify - account-nameand- account-keyin the URI, the authentication is performed using the specified account name and account key. Besides the method of specifying the key in the URI, BR can also read the key from the environment variable- $AZURE_STORAGE_KEY.
- Method 3: Use Azure AD for backup and restore - Configure the environment variables - $AZURE_CLIENT_ID,- $AZURE_TENANT_ID, and- $AZURE_CLIENT_SECRETon the node where BR is running.- When the cluster is started using TiUP, TiKV uses the systemd service. The following example shows how to configure the preceding three environment variables for TiKV: - Suppose that the TiKV port on this node is - 24000, that is, the name of the systemd service is- tikv-24000:systemctl edit tikv-24000
- Edit the TiKV configuration file to configure the three environment variables: [Service] Environment="AZURE_CLIENT_ID=aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa" Environment="AZURE_TENANT_ID=aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa" Environment="AZURE_CLIENT_SECRET=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
- Reload the configuration and restart TiKV: systemctl daemon-reload systemctl restart tikv-24000
 
- To configure the Azure AD information for TiKV and BR started with command lines, you only need to check whether the environment variables - $AZURE_CLIENT_ID,- $AZURE_TENANT_ID, and- $AZURE_CLIENT_SECRETare configured in the operating environment by running the following commands:echo $AZURE_CLIENT_ID echo $AZURE_TENANT_ID echo $AZURE_CLIENT_SECRET
- Use BR to back up data to Azure Blob Storage: ./br backup full -u "${PD_IP}:2379" \ --storage "azure://external/backup-20220915?account-name=${account-name}"
 
Server-side encryption
Amazon S3 server-side encryption
BR supports server-side encryption when backing up data to Amazon S3. You can also use an AWS KMS key you create for S3 server-side encryption using BR. For details, see BR S3 server-side encryption.
Azure Blob Storage server-side encryption
BR supports specifying the Azure server-side encryption scope or providing the encryption key when backing up data to Azure Blob Storage. This feature lets you establish a security boundary for different backup data of the same storage account. For details, see BR Azure Blob Storage server-side encryption.
Other features supported by the storage service
BR v6.3.0 supports AWS S3 Object Lock. You can enable this feature to prevent backup data from being tampered with or deleted.