Scenarios
When you create an RDS instance, an automated backup policy is enabled by default. For security purposes, the automated backup policy cannot be disabled. After the DB instance is created, you can customize the automated backup policy as required and then RDS backs up data based on the automated backup policy you configure.
RDS backs up data at the DB instance level, rather than the database level. If a DB instance fails or its data is corrupted, you can restore it from backups to ensure data availability. Backups are automatically stored as packages in OBS buckets to ensure data confidentiality and durability. Since backing up data affects database read and write performance, you are advised to set the automated backup time window to off-peak hours.
After an automated backup policy is configured, full backups are created based on the time window and backup cycle specified in the policy. The time required for creating a backup depends on how much data there is in the instance. Backups are stored for as long as you specified in the backup policy.
You do not need to set an interval for incremental backup because RDS automatically backs up incremental data every 5 minutes. Incremental backups can be used to restore data to a specific point in time.
Viewing or Modifying a Standard Backup Policy
- Log in to the management console.
- Click
in the upper left corner and select a region and a project. - Click
in the upper left corner of the page and choose Database > Relational Database Service. - On the Instances page, click the target instance name.
- In the navigation pane on the left, choose Backups & Restorations. On the displayed page, choose Modify Backup Policy > Configure Same-Region Backup Policy. The system shows the backup policies you have configured. To modify them, adjust the parameter settings as needed.
- Retention Period: How many days your automated full backups and incremental backups can be retained. The retention period is from 1 to 732 days and the default value is 7.
- Extending the retention period improves data reliability.
- Reducing the retention period takes effect for existing backups. Any backups (except manual backups) that have expired will be automatically deleted. Exercise caution when performing this operation.
Automatic deletion policy for full backups:
To ensure data integrity, the system keeps the most recent backup that has exceeded the retention period during automatic deletions. This ensures that data within the retention period can still be restored.
For example, if Backup Cycle was set to Monday and Tuesday and Retention Period was set to 2, the deletion behavior is as follows:
- The full backup created on Monday is automatically deleted on Thursday.
The full backup created on Monday expires on Wednesday, but according to the deletion policy, the system retains the most recent full backup that has exceeded the retention period. So it is retained until a new backup expires. The next full backup is created on Tuesday and expires on Thursday. Therefore, on Thursday, the Monday backup is deleted and the Tuesday backup is retained.
- The full backup created on Tuesday is automatically deleted on Wednesday of the following week.
The backup generated on Tuesday will expire on Thursday, but as it is the last backup, so it will be retained until a new backup expires. The next backup will be generated on the next Monday and will expire on the next Wednesday. So the full backup generated on Tuesday will not be automatically deleted until the next Wednesday.
- Manual Period
- Permanent: Manual backups are retained until you manually delete them.
- Custom: You can customize the retention period for manual backups from 1 to 732 days. Manual backups that exceed the retention period will be automatically deleted.
- Time Window: Set it to a one-hour period the backup will be scheduled, such as 01:00-02:00 or 12:00-13:00. It indicates when the backup starts, not the duration of the entire backup task. The backup duration depends on the data volume of your instance.Note
To minimize potential impact on workloads, set the time window to off-peak hours. The backup time is in UTC format. The backup time window changes with the time zone if the DST or standard time is switched.
- Backup Cycle: All options are selected by default, but you can change it. Select at least one day of the week.
- Retention Period: How many days your automated full backups and incremental backups can be retained. The retention period is from 1 to 732 days and the default value is 7.
- Click OK.