This topic describes how to view and manage the backup size of an apsaradb RDS for MySQL instance.

Size of backup=size of data backup + size of log backup

How to view

In the lower-right corner of the basic information page of the instance, you can view the size of the backup.

For example, in the following figure, the size of a backup is 33.2GB (data backup) +20.19MB (log backup).

Note
  • In the figure, Archived backups refer to backups of data that have been retained for more than two years (730 days). data refers to non-archived backups.
  • After you update the minor engine version of your RDS instance, the Backup Size on the Basic Information page of the ApsaraDB RDS console may be displayed as 0. After the next scheduled backup is complete, this error is automatically fixed.
Backup size

Setting note

  • Relationship with storage usage
    • Data backup and log backup are stored in the backup space, and neither occupies storage space.
    • Logs are classified into local logs and log backups.
      Log management Setting note Billing management Function
      Local logs The raw logs of an instance, which are stored in the storage space of the instance. No fees are involved, but the instance storage space is occupied. For example, it can be used to build a master-slave architecture.
      Log backup When log backup is enabled, local logs are uploaded to the backup space in real time. In the backup space, logs are backed up. For more information, see Billing. Implements point-in-time recovery.
      Note
      • clearing local logs reduces the storage space it occupies, but does not affect the size of log backups.
      • You can view the storage space occupied by local logs on the monitoring and alerts page of the instance.Check local logs.
  • Relationship with data size

    The size of the backup may be larger than the amount of data, or it may be smaller than the amount of data.

    Cloud Disk instances are backed up by using snapshots. The size of a snapshot backup may be much larger than the size of the data. Therefore, the free backup quota of a cloud disk instance is four times that of an instance with local disks.
    Note When the snapshot backup size is calculated, the size of all non-empty blocks is calculated. If the writing time is scattered (for example, 3MB of data may occupy two, three, or even four blocks), this causes many non-empty blocks, and therefore leads to a large number of snapshot backups.
  • Relationship with the architecture of an instance

    The backup size is irrelevant to the instance architecture. For example, for high-availability instances and basic edition instances, if the data is consistent, the backup size is the same, and the backup size does not increase due to high availability.

Delete or reduce data backups

  • Manually delete data backup files.
    1. Go to the Backup and Restoration page.
    2. On the data backup tab, click delete for the target backup.
      Note If no delete button exists, the following conditions are not met:
      • When log backup is disabled, you can only manually delete data backups that have been retained for more than seven days.
      • When log backup is enabled, you can only manually delete data backups beyond the log backup retention period. For example, if the log backup retention period is seven days, you can delete data backups that have been retained for more than seven days.
  • automatically delete data backups (shorten the retention period of data backups)
    1. Go to the Backup and Restoration page.
    2. On the Backup settings tab, open the Settings dialog box to shorten the retention period of data backup.

      PolarDB-X deletes the backup files that are stored longer than the retention period. For example, if your instance keeps backups for 31 days, and you change the retention period from 30 days, the backups that have been retained for 31 days are automatically deleted.

  • reduce the number of data backups
    1. Go to the Backup and Restoration page.
    2. On the Backup settings tab, open the Settings dialog box to decrease the cycle for data backup.
  • delete or migrate data that does not need backup.

Delete or reduce log backups

  • Shorten log backup retention period
    1. Go to the Backup and Restoration page.
    2. On the Backup settings tab, open the Settings dialog box to shorten the log backup retention period.
      For example, if you set the log backup retention period to 30 days, log backups that have been retained for more than 30 days are automatically deleted.
      Note You can set the log backup retention period only when log backup is enabled.
  • disable log backup

    If you disable it, all log backups are automatically deleted and the restore by time point feature is unavailable.

    1. Go to the Backup and Restoration page.
    2. On the Backup settings tab, open the Settings dialog box and disable log backup.
  • reduces unnecessary additions, deletions, and modifications, and updates on large fields.
    Any addition, deletion, and modification of databases can increase the log backup size.
    Note You can use the Use the SQL Explorer feature on an ApsaraDB RDS for MySQL instance function to view the add, delete, modify, and query records of the database.