Logical backup and recovery for PolarDB for MySQL - Data Management

Prerequisites

Before you begin, ensure that you have:

A PolarDB for MySQL instance with the necessary permissions
Binary logging enabled on the instance, if you need incremental backup — binary logging is disabled by default. See Enable binary logging
A backup schedule purchased with Data Source Type set to MySQL and Backup Method set to Logical Backup

For the backup and restore granularity supported for PolarDB for MySQL, see Supported database types and features.

Backup types

Data Disaster Recovery supports two types of backup for PolarDB for MySQL databases:

Full backup: Captures a complete snapshot of the selected databases or tables at a scheduled time. You can restore to the exact point in time when any full backup completed.
Incremental backup: Captures changes continuously using binary logs. With incremental backup enabled, you can restore to any point in time between the first full backup and the last incremental backup. Requires binary logging to be enabled on the PolarDB for MySQL instance.

Use both full and incremental backup together for the most flexible recovery options and the lowest recovery point objective (RPO).

Create a backup schedule

See Create a backup plan for instructions.

Configure a backup schedule

Log on to the Data Management (DMS) console V5.0.
In the top navigation bar, choose Security and Specifications (DBS) > Disaster Recovery for Data (DBS) > Backup Plan.

In simple mode, move the pointer over the icon in the upper-left corner and choose All Features > Security and Specifications (DBS) > Disaster Recovery for Data (DBS) > Backup Plan.
On the Backup Schedules page, find the backup schedule to configure and click Configure Backup Schedule in the Actions column.

In the Configure Backup Source and Destination step, set the following parameters and click Next.

For large data volumes, purchase a subscription storage plan to reduce costs compared to pay-as-you-go pricing.

Section	Parameter	Description
N/A	Schedule name	The name of the backup schedule. Data Disaster Recovery generates a name automatically. Enter a descriptive name for easy identification. Names do not need to be unique.
Backup source information	Backup mode	The backup method selected at purchase time. In this example, Logical Backup is displayed.
	Database location	The location of the source database. Select PolarDB.
	Instance region	The region where the source database instance resides.
	Database type	The type of the source database. Default: MySQL.
	PolarDB instance ID	The ID of the source PolarDB for MySQL database.
	Database account	The username of the account used to connect to the source database. The account must have backup permissions. See Required permissions for different types of database accounts.
	Password	The password of the database account. After entering the credentials, click Test Connection to verify. If the test passes, Test Passed appears. If it fails, click Check next to Test Failed and correct the configuration.
	Compliance warranty regarding cross-border data transfers	Read and accept the compliance commitment by selecting the check box.
Backup destination information	Backup storage type	Where backup data is stored. Options: <br>- DBS Storage (recommended): Data Disaster Recovery manages storage. Charged by volume. See Storage fees. <br>- OSS For User: Requires a pre-created OSS bucket in the Standard storage class. See Create buckets. If selected, configure the OSS Bucket Name parameter.
	Storage encryption	The encryption method for stored data. Options: <br>- Encrypted (recommended): AES-256 with OSS server-side encryption. See Server-side encryption. <br>- Non-encrypted: Data is stored without encryption.

In the Edit Backup Objects step, find the database or table to back up in the Available section, click the rightwards arrow to move it to the Selected section, and click Next.

- Data Disaster Recovery supports single-table, single-database, and multi-database backup. Click Select All in the lower-left corner of the Available section to select all databases. Supported backup objects vary by database type. See Supported database types and features. - Databases created after the backup schedule is set up are not backed up automatically. To include them, add the databases on the Configure Task page. See Modify backup objects.

In the Configure Backup Time step, set the following parameters and click Next.

Parameter	Description
Full-scale backup frequency	The backup schedule type. Options: Periodic Backup or Single Backup. Selecting Periodic Backup requires configuring Full Data Backup Recurrence and Start At.
Full data backup recurrence	The days of the week to run the backup. Select at least one day.
Start at	The start time for the backup. Schedule during off-peak hours — for example, 01:00. If a previous full backup has not completed by the next scheduled start time, Data Disaster Recovery skips the next backup.
Incremental backup	Whether to enable incremental backup. Requires binary logging on the PolarDB for MySQL instance. See Enable binary logging. Displayed only when Full-scale backup frequency is set to Periodic Backup.
Maximum concurrent threads for full data backup	The maximum number of concurrent threads for a full backup. Reduce this value to minimize impact on the database during backup.
Backup network speed limit	The network bandwidth limit. Default: `0` (no limit). Adjust based on your business requirements.

In the Edit Lifecycle step, configure the lifecycle for full backup data in the Configure Full Data Backup Lifecycle section. If you enabled Incremental Backup in the previous step, also configure the lifecycle for incremental backup data. For lifecycle rule details, see How do I manage the lifecycle rules of backup sets?
Click Precheck in the lower-right corner.
When Precheck Passed appears, click Start Task.

- The backup schedule is active when its status changes to Running. - If an error occurs, troubleshoot it promptly. See How do I fix errors for an abnormal backup schedule? If the issue persists, contact technical support in the DingTalk group (ID: 35585947).

Restore a PolarDB for MySQL database

After restoring, any tables with naming conflicts are renamed in the format job_info_dbs_<Restore task ID>_<Timestamp>. For example, a conflict on the job_info table produces job_info_dbs_<Restore task ID>_<Timestamp>.

Log on to the DMS console V5.0.
In the top navigation bar, choose Security and Specifications (DBS) > Disaster Recovery for Data (DBS) > Backup Plan.

In simple mode, move the pointer over the icon in the upper-left corner and choose All Features > Security and Specifications (DBS) > Disaster Recovery for Data (DBS) > Backup Plan.
On the Backup Schedules page, find the backup schedule and click Manage in the Actions column.
On the Configure Task page, click Restore Database in the upper-right corner.

In the Set Time Restored To step of the Create Restore Task wizard, set the following parameters and click Next.

Section	Parameter	Description
N/A	Task name	The name of the restore task. Data Disaster Recovery generates a name automatically. Enter a descriptive name for easy identification. Names do not need to be unique.
Set time restored to	Time range available to restore	The restorable time range, from when the first full backup set is created to when the latest full backup set is created.
	Restore to	The target point in time. Must fall within the Time range available to restore. With incremental backup enabled, you can restore to any point from the first full backup completion to the last incremental backup completion. Without incremental backup, restoration is limited to points when a full backup completed.
Configure destination database	Target database instance type	The type of the destination database instance. Select Use Exists. In this example, the backup set is restored to the source PolarDB cluster.
	Database location	The location of the destination database. Select PolarDB.
	Instance region	The region where the destination database resides.
	Database type	The type of the destination database. Default: MySQL.
	PolarDB instance ID	The ID of the destination PolarDB for MySQL cluster.
	Database account	The username of the account used to connect to the destination database. The account must have write permissions.
	Password	The password of the account used to connect to the destination database.
	Compliance warranty regarding cross-border data transfers	Read and accept the compliance commitment by selecting the check box.

In the Configure Objects to Restore step, set the following parameters and click Precheck.

Parameter	Description
Conflict handling	Default: Rename Object with the Same Name. Conflicting tables are renamed in the format `<table_name>_dbs_<Restore task ID>_<Timestamp>`.
Objects to restore	Select the database or table in the Available section and click the rightwards arrow to move it to the Selected section. Data Disaster Recovery supports database-level and table-level restoration, which reduces the amount of data restored and shortens the recovery time objective (RTO). See Supported database types and features.

When Precheck Passed appears in the Precheck dialog box, click Start Task. To monitor restoration progress, click Restore Tasks in the left-side navigation pane.

Restoration time depends on the backup schedule specifications and the size of the database. Higher schedule specifications result in faster restoration. See Performance tests on logical backup and physical backup.

Next steps

Manage your backup schedule via API: Call CreateBackupPlan to create a backup schedule, or CreateAndStartBackupPlan to create, configure, and start one in a single operation. See CreateBackupPlan or CreateAndStartBackupPlan.
Update backup configuration: Modify the backup source, backup objects, backup schedule, or retention policy. See Manage a backup plan.
Review billing: Check the fees associated with your backup schedule. See Billing FAQ.
Pause a backup schedule: Temporarily stop a backup schedule that is no longer needed to reduce costs. See Pause or start a backup schedule.

FAQ

The precheck failed with a binary logging error. What do I do?

Binary logging is disabled on the PolarDB for MySQL instance. Enable it in the PolarDB console. See Enable binary logging.