ApsaraDB RDS:Change the scaling range of RCUs for a serverless ApsaraDB RDS for SQL Server instance

Scenarios

• Traffic spikes are expected to occur and may affect the load and cause performance jitters. In this case, you can increase the minimum number of RCUs to prevent this issue.

• If you want to reduce costs, you can reduce the maximum number of RCUs. This operation may affect the performance of the serverless RDS instance. Proceed with caution.

Feature description

The scaling of RCUs for a serverless RDS instance depends on the CPU utilization, memory usage, and average active sessions (AAS) metrics of the serverless RDS instance. If one of the prceding metrics reaches the threshold for a scale-up, the system automatically scales up the number of RCUs within 5 to 10 seconds. If one of the preceding metrics reaches the threshold for a scale-down, the system automatically scales down the number of RCUs within 15 to 20 seconds.

Impacts

• The RCU scaling for a serverless RDS instance takes effect within approximately 1 minute.

• The scaling of RCUs causes the following impacts:

  • Change the maximum number of RCUs

    • If the current number of RCUs is smaller than the new maximum number of RCUs, the number of RCUs remains unchanged.

    • If the current number of RCUs is greater than the new maximum number of RCUs, the number of RCUs is immediately decreased to the new maximum number after the configuration takes effect.

    • If the current maximum number of RCUs does not meet your business requirements, the number of RCUs is immediately increased to the new maximum number after the configuration takes effect.

      For example, a traffic spike occurs, the current maximum number of RCUs is 6 and cannot meet your business requirements, and the new maximum number of RCUs is 8. The system immediately increases the number of RCUs to 8 after the configuration takes effect.

  • Change the minimum number of RCUs

    • If the current number of RCUs is greater than the new minimum number of RCUs, the number of RCUs remains unchanged.

    • If the current number of RCUs is smaller than the new minimum number of RCUs, the number of RCUs is immediately increased to the new minimum number after the configuration takes effect.

Billing rules

You are not charged for changing the number of RCUs. The fee for a serverless RDS instance depends only on the actual usage of RCUs and storage resources. For more information, see Pricing of a serverless ApsaraDB RDS for SQL Server instance.

Procedure

1. Log on to the ApsaraDB RDS console and go to the Instances page. In the top navigation bar, select the region in which the RDS instance resides. Then, find the RDS instance and click the ID of the instance.

2. In the Configuration Information section of the Basic Information page, click Adjust Elastic Settings.

3. In the Resource Scaling Range (RCU) section of the panel that appears, configure the Minimum and Maximum parameters.

   Note

   The minimum value of Minimum is 2. The maximum value of Maximum is 8. You can configure the parameters based on your business requirements.

4. Click OK.

References

• Expand the storage capacity of a serverless ApsaraDB RDS for SQL Server instance

• Stop an ApsaraDB RDS for SQL Server instance

• Release or unsubscribe from an ApsaraDB RDS for SQL Server instance