PolarDB clusters support two types of backup: data backup and redo log backup. Data backup creates a complete snapshot of all cluster data at a point in time. Redo log backup records changes generated after each snapshot, enabling point-in-time recovery between snapshots. Configure policies for both types to control backup frequency, retention periods, and storage locations.
How backup works
Each data backup creates a full snapshot of the cluster. Redo log backup captures ongoing changes between snapshots, so you can restore to any point within the retention window—not just snapshot times.
The backup tier available depends on your cluster's storage type:
Standard Edition Enhanced SSD — single-tier backup (no level distinction)
PSL4 or PSL5 — two-tier backup: level-1 (short-term, fast restore) and level-2 (long-term, same-region or cross-region storage)
Backup methods
PolarDB offers two data backup methods:
| Standard backup | High-frequency backup | |
|---|---|---|
| Frequency | Once per selected day of the week | Every 2, 3, or 4 hours |
| Best for | General workloads | Workloads requiring minimal data loss |
| Minimum recommended | At least twice a week | — |
| Retention (recent) | Per configured period | All backups in the last 24 hours |
| Retention (older) | Per configured period | First backup after 00:00 each day only |
Backup files cannot be deleted after creation.
Prerequisites
Before you begin, ensure that you have:
A PolarDB cluster
Access to the PolarDB console
Configure a backup policy
Log on to the PolarDB console.
In the upper-left corner, select the region where your cluster is deployed.
Find the cluster and click its ID.
In the left-side navigation pane, choose Settings and Management > Backup and Restoration.
On the Backup Policy Settings tab, click Modify.
In the Modify dialog box, configure the Data Backup, Log Backup, and General parameters, then click OK.
Data backup policy
Standard Edition Enhanced SSD
| Parameter | Description |
|---|---|
| Backup Method | Select Standard Backup (at specified intervals) or High-frequency Backup. |
| Backup Cycle | The days of the week on which automatic backups run. Required for Standard Backup only. |
| Backup Start Time Range | The time window within which automatic backups start. Required for Standard Backup only. |
| Backup Frequency | How often backups run within a 24-hour period. Valid values: Last 24 Hours, Every 2 Hours, Last 24 Hours, Every 3 Hours, and Last 24 Hours, Every 4 Hours. Required for High-frequency Backup only. |
| Backup Retention Period | How long to keep backups. Range: 3–730 days. Default: 7 days. |
To prevent data loss, run standard backup at least twice a week.
How High-frequency Backup retains data
All backups created within the last 24 hours are retained. For backups older than 24 hours, only the first backup created after 00:00 each day is kept permanently; the rest are deleted.
Example: You enable High-frequency Backup with a frequency of every 4 hours at 08:00 on March 1. At 16:00 on March 4, the retained backups are:
All backups from 16:00 on March 3 to 16:00 on March 4 (last 24 hours)
The backup created between 00:00 and 04:00 on March 3
The backup created between 00:00 and 04:00 on March 2
The backup created between 08:00 and 12:00 on March 1 (the first backup of the policy)
At 20:00 on March 4 (four hours later), the retained backups are:
All backups from 20:00 on March 3 to 20:00 on March 4 (last 24 hours)
The backup created between 00:00 and 04:00 on March 3
The backup created between 00:00 and 04:00 on March 2
The backup created between 08:00 and 12:00 on March 1
Log backup policy
Redo log backup is enabled by default and cannot be disabled.
| Parameter | Description |
|---|---|
| Backup Method | Select Same-region Backup, Cross-region Backup, or both. Cross-region log backup is only available when cross-region level-2 backup is enabled. |
| Same-region Backup and Retention | The retention period for same-region log backups. Range: 3–7,300 days. To keep logs indefinitely, select Long-term Retain Backups before Cluster Deletion. |
| Destination Backup Region | Auto-populated from the level-2 backup configuration. No action required. |
| Cross-region Backup and Retention | The retention period for cross-region log backups. Range: 3–7,300 days. To keep logs indefinitely, select Long-term Retain Backups before Cluster Deletion. |
General retention policy
Configure what happens to backup data when you delete the cluster.
| Option | Behavior |
|---|---|
| When the cluster is deleted, the cluster data is automatically backed up, and all backup sets of the cluster are retained for a long period of time | A final backup runs at deletion time. All existing backup sets are retained. |
| When the cluster is deleted, the cluster data is automatically backed up, and the backup set is retained for a long period of time | A final backup runs at deletion time. Only the most recent backup set is retained. |
| When the cluster is released, all backup sets of the cluster are deleted immediately | All backup sets are deleted immediately when the cluster is deleted. |
After you delete a cluster, level-1 backups automatically convert to level-2 backups. View retained backups on the Cluster Recycle Bin page. For more information, see Restore a released cluster.
If you have cross-region backup enabled and select When the cluster is released, all backup sets of the cluster are deleted immediately, all cross-region backup sets are also deleted at cluster deletion. If you select either of the other two options, the retention policies you configured apply to cross-region backups.
API reference
| Operation | Description |
|---|---|
| Queries the backup policies of a specified PolarDB cluster. | |
| Modifies the backup policies of a specified PolarDB cluster. |