PolarDB allows you to use the backup and restoration features free of charge, but charges fees for the storage space consumed by backup files. This topic describes the billing rules of storage space consumed by PolarDB backup files.

Free quota

PolarDB offers a free storage quota for backup files. After this quota is exhausted, you are charged by PolarDB for the excess storage space consumed by backup files and the length of time for which the files are retained.

Backup type Free quota
Data backup Level-1 backup Database storage usage × 50%

For information about how to view the database storage usage, see View the database storage usage.

Level-2 backup None
Log backup 100 GB

Pay-as-you-go

After the free quota is exhausted, you are charged for the excess storage space consumed by backup files and the length of time for which the files are retained. The following tables describe the billing rules.
  • Billing rules for level-1 backups
    Storage type Regions in the Chinese mainland Regions outside the Chinese mainland Billing method
    PSL5

    USD 0.000464 per GB-hour

    USD 0.000650 per GB-hour

    		 Storage fee per hour = (Total physical storage of level-1 backups - Free quota) × Unit price per hour

    For example, assume that a PolarDB for MySQL cluster deployed in the Chinese mainland uses the PSL5 storage type. If the total size of level-1 backups (snapshots) is 700 GB and the database storage usage is 1,000 GB, the storage fee per hour is USD 0.0928.

    The fee is calculated based on the following formula: [700 GB - (1,000 GB × 50%)] × USD 0.000464/GB/hour = USD 0.0928/hour.

    Note For more information, see FAQ.
    PSL4

    USD 0.0003 per GB-hour

    USD 0.000433 per GB-hour
  • Billing rules for level-2 backups
    Regions in the Chinese mainland Regions outside the Chinese mainland Billing method

    USD 0.0000325 per GB-hour

    USD 0.0000455 per GB-hour

    		 Storage fee per hour = Total size of level-2 backups × Unit price per hour

    For example, assume that a PolarDB for MySQL cluster is deployed in the Chinese mainland. If the total size of level-2 backups is 1,000 GB, the storage fee per hour is USD 0.0325.

    The fee is calculated based on the following formula: 1,000 GB × USD 0.0000325/GB/hour = USD 0.0325/hour.

  • Billing rules for log backups
    Regions in the Chinese mainland Regions outside the Chinese mainland Billing method

    USD 0.0000325 per GB-hour

    USD 0.0000455 per GB-hour

    		 Storage fee per hour = (Total physical storage of log backups - 100 GB) × Unit price per hour

    For example, assume that a PolarDB for MySQL cluster is deployed in the Chinese mainland. If the total size of log backups is 1,000 GB, the hourly fee is USD 0.02925.

    The fee is calculated based on the following formula: (1,000 GB - 100 GB) × USD 0.0000325/GB/hour = USD 0.02925/hour.

Use storage plans to offset level-1 backup storage fees

The remaining capacity of a storage plan after offsetting the storage of PolarDB clusters is automatically used to offset the level-1 backup storage space that exceeds the free quota. The storage is offset based on the following rules:
Table 1. The amount of level-1 backup storage usage that can be offset by a 1 GB storage plan
Storage type Regions in the Chinese mainland Regions outside the Chinese mainland
PSL5 1.62 GB 1.62 GB
PSL4 2.5 GB 2.5 GB
Note After the free quota is consumed, you are charged for additional storage space on a pay-as-you-go basis. To reduce the costs of level-1 backups, we recommend that you use storage plans, which are cost-effective.

For example, assume that you purchase a storage plan of 100 GB for your cluster whose storage type is PSL5 and you have 50 GB of data. The data itself consumes 50 GB of the storage plan, which leaves 50 GB remaining. The level-1 backups of the cluster consume 50 GB of storage space beyond the free quota. In this case, 31.25 GB (50/1.6 = 31.25) of the storage plan is automatically used to offset the excess storage space consumed by the level-1 backups, which leaves a final size of 18.75 GB remaining in your storage plan.

If the remaining capacity of the storage plan is insufficient to offset the level-1 backup storage space, you are charged for additional storage space on a pay-as-you-go basis. For more information about storage plans, see Storage plans.