The fee of a serverless ApsaraDB RDS for MySQL instance consist of the fees of the RDS Capacity Units (RCUs) and storage resources that are used by the serverless RDS instance. This topic describes the billing rules and billable items. This topic also provides a billing example.
Fee for a serverless RDS instance = Fee for an RDS instance x Number of RDS instances
The following table lists the fees for serverless RDS instances that run RDS Basic Edition and RDS High-availability Edition.
Number of nodes
RDS Basic Edition
Fee for a single node
RDS High-availability Edition
Fee for a single node × 2
Fee for an RDS instance
The fee for a serverless RDS instance consists of the fees that are generated for RDS Capacity Units (RCUs) and storage resources. The system separately issues bills for the RCUs and storage resources that are used by the serverless RDS instance on an hourly basis. The performance of an RCU is equivalent to that of an RDS instance that runs RDS Basic Edition and has 2 GB of memory. The minimum number of billable RCUs is 0.5. The number of RCUs that are consumed in an hour equals the total number of RCUs that are consumed per second of the hour. The fee for a serverless RDS instance varies based on the region. The following table provides a billing example for a serverless RDS instance in the Singapore region. For more information about the fee for a serverless RDS instance in a different region, visit the ApsaraDB RDS buy page.
USD 0.07455 per RCU-hour
USD 0.0004 per GB-hour
Formula: Fee for a serverless RDS instance = Fee for RCUs + Fee for storage resources
The storage capacity that you specified for a serverless RDS instance when you create the instance is the minimum storage capacity. For example, if you select 100 GB of storage capacity when you create a serverless RDS instance, you are charged based on 100 GB even if the storage usage is less than 100 GB. If the storage usage exceeds 100 GB, the system automatically scales up the storage capacity of the serverless RDS instance, and you are charged based on the actual usage.
After the storage capacity of a serverless RDS instance is automatically expanded, you cannot reduce the storage capacity and you are charged based on the storage capacity after the expansion. This ensures data integrity.
For example, you create a serverless RDS instance that runs RDS Basic Edition and has a storage capacity of 20 GB and available computing resources of 0.5 to 8 RCUs, and you experience a peak hour one day. A total of 8 RCUs are used during the peak hour, 1 RCU is used per hour for the rest of the day, and a total of 20 GB of storage is used for the day. In RDS Basic Edition, your database system consists of only one RDS instance. The fee for the serverless RDS instance in the day is calculated by using the following formulas:
Fee for RCUs = (0.07455 × 1 ×8) + (0.07455 × 23 × 1) = USD 2.31105
Fee for storage resources = 0.0004 × 24 × 20 = USD 0.192
Fee for the serverless RDS instance in the day = USD 2.31105 + USD 0.192 = USD 2.50305
In this example, the fee for the serverless RDS instance for one day is USD 2.50305, which is significantly less than the fee for a pay-as-you-go RDS instance for which fixed specifications are configured.
Fee for a serverless RDS instance in different states
Computing resource fee
Storage resource fee
Free of charge
Free of charge