This topic describes the offset rules of storage plans in ApsaraDB MyBase.

Offset rules

After you purchase a storage plan for a region, ApsaraDB MyBase automatically calculates the amount of storage used by your pay-as-you-go instances that are deployed in the region. Then, the system uses the storage plan to offset your storage costs before the storage plan expires. If the amount of the storage that is used exceeds the capacity of your storage plan, you are billed for the additional storage based on the pay-as-you-go billing method. The minimum specification of storage plans that you can purchase contains one node and a PL1 enhanced SSD (ESSD). If you use other types of storage devices, the specification must be multiplied by an offset factor to calculate fees. The following offset rules are applied to database instances:
  • For a Basic Edition instance that contains one node, the offset factor is 1.
  • For a High-availability Edition instance that contains the primary and secondary nodes, the offset factor is 2.
  • For an ApsaraDB MyBase for MySQL instance that contains three nodes, the offset factor is 2.
Note The preceding offset factors are used together with the offset factors of disk types.

Offset factors

The offset capacity of a storage plan varies based on the type of storage resources to which the storage plan is applied. The offset factor of a storage plan varies based on the disk type. The offset factor indicates the capacity of the storage plan that is consumed per GB of ESSDs. For example, 1 GB of the storage plan can offset 1 GB of the storage that is used by PL1 ESSDs.

Disk type Offset factor Description
PL3 ESSD 4 Each GB of storage that is used by PL3 ESSDs consumes 4 GB of a storage plan.
PL2 ESSD 2 Each GB of storage that is used by PL2 ESSDs consumes 2 GB of a storage plan.
PL1 ESSD 1 Each GB of storage that is used by PL1 ESSDs consumes 1 GB of a storage plan.

Examples

If you purchase a 10 TB storage plan for a region, you can use the storage plan to offset the pay-as-you-go bills for up to 10 TB of PL1 ESSDs, 5 TB of PL2 ESSDs, or 2.5 TB of PL3 ESSDs in the region. You can also use a storage plan to offset the bills for a combination of disks of different types. For more information, see the following examples:

  • The storage plan can offset the bills for 10 TB of PL1 ESSDs.
  • The storage plan can offset the bills for 1 TB of PL3 ESSDs, 2 TB of PL2 ESSDs, and 2 TB of PL1 ESSDs.
Note You can view the hourly offset records of storage plans in the Billing Management console.