Help Center/ Document Database Service/ User Guide/ Data Backups/ Configuring an Incremental Backup Policy
Updated on 2024-08-08 GMT+08:00

Configuring an Incremental Backup Policy

Incremental backup is used to back up the data newly added or modified since the last full or incremental backup. DDS automatically backs up the updated data every 5-60 minutes since the last automated or incremental backup was made.

When you create a DDS DB instance, incremental backup is enabled by default for all DB instances except DB instances with fewer than 4 vCPUs. You can enable or disable the backup policy after an instance is created. For details, see Enabling or Modifying an Incremental Backup Policy and Disabling the Incremental Backup Policy.

After an incremental backup policy is enabled for a DDS instance, incremental files are not displayed on the DDS console.

Prerequisites

Before enabling the incremental backup policy, ensure that the automated backup policy has been enabled. For details, see Enabling or Modifying an Automated Backup Policy.

Only whitelisted users can use this function. You need to submit a service ticket to apply for this function. In the upper right corner of the management console, choose Service Tickets > Create Service Ticket to submit a service ticket.

Precautions

  • Incremental backup is performed on the hidden node. After an incremental backup policy is enabled, the CPU and memory usage of the hidden node increases, depending on the service model.
  • To ensure stable database running, you are advised to double the specifications of the hidden node when the CPU usage exceeds 60% or the memory usage exceeds 80%.

Constraints

  • Only cluster instances of versions 4.0, 4.2, and 4.4 and replica set instances of versions 3.4, 4.0, 4.2, and 4.4 support this function.
  • To minimize the impact of incremental backup on instances, incremental backup is disabled by default for DB instances with fewer than 4 vCPUs.
  • Incremental backup stops in any of the following scenarios and starts again after the next automated backup is complete:
    • rename operation
    • collmod operation
    • Creating a user
    • Deleting a user
    • Creating a role
    • Deleting a role
    • Enabling shard IP addresses of a cluster instance
    • Changing the password of the shard node user
    • Enabling config IP addresses of a cluster instance
    • Changing the password of the config node user
    • Changing the password of the rwuser user

Enabling or Modifying an Incremental Backup Policy

  1. Log in to the management console.
  2. Click in the upper left corner and select a region and a project.
  3. Click in the upper left corner of the page and choose Databases > Document Database Service.
  4. On the Instances page, click the instance name.
  5. In the navigation pane on the left, choose Backups & Restorations.
  6. On the Backups & Restorations page, click Set Backup Policy. To enable incremental backup, click . After incremental backup is enabled, a full backup is triggered.

    Figure 1 Set Backup Policy
    Table 1 Parameter description

    Parameter

    Description

    Automated Backup

    For details about automated backup parameters, see Table 2.

    Incremental Backup

    Before enabling the incremental backup policy, ensure that the automated backup policy has been enabled.

  7. Click OK.
  8. View the results.

    • During the creation of an automated backup, you can query the backup status on the Backups page or the Backups & Restorations tab. The backup status is Backing up.
    • In the upper right corner of the backup list, click to refresh the list. The backup status changes to Complete.

Disabling the Incremental Backup Policy

  1. Log in to the management console.
  2. Click in the upper left corner and select a region and a project.
  3. Click in the upper left corner of the page and choose Databases > Document Database Service.
  4. On the Instances page, click the instance name.
  5. In the navigation pane on the left, choose Backups & Restorations.
  6. On the Backups & Restorations page, click Set Backup Policy.
  7. In the displayed dialog box, click to the right of Incremental Backup to disable the incremental backup policy.

    Figure 2 Disabling incremental backup policy

  8. Click OK.

    • After you disable this incremental backup, the incremental backup task will be stopped, all incremental backup files will be deleted immediately, and operations related to incremental backup fail.
    • After a DB instance is deleted, all incremental backup files of the DB instance are retained. The retention period depends on the incremental backup retention period that you specified.