This topic describes how to change the scaling range of RDS Capacity Units (RCUs) for a serverless ApsaraDB RDS for PostgreSQL instance.
RCUs are a representation of the performance of a serverless RDS instance. The system automatically adjusts the number of RCUs for a serverless RDS instance within the range that you specified based on your workloads.
If the value of the Database Capacity (RCUs per Second) parameter that is displayed on the Basic Information page of your serverless RDS instance reaches the upper limit during peak hours but still cannot meet your business requirements, you can increase the maximum number of RCUs.
The operations in this topic apply only to serverless RDS instances. Make sure that the billing method of your RDS instance is serverless.
If the maximum number of RCUs is set to 14, you cannot change the scaling range of RCUs based on this topic.
If you want to use more computing resources, we recommend that you create an RDS instance of a different deployment model to meet your business requirements. For more information, see Primary ApsaraDB RDS for PostgreSQL instance types.
The RCU scaling for a serverless RDS instance immediately takes effect and does not affect your workloads.
You are not charged for changing the scaling range of RCUs. The fee for RCUs depends only on the actual usage of RCUs. For more information, see Overview of serverless ApsaraDB RDS for PostgreSQL instances.
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.
In the Configuration Information section of the page that appears, click Modify Scaling Settings.
In the dialog box that appears, configure the Minimum and Maximum parameters in the RDS Capacity Units (RCUs) section.Note
The minimum number of RCUs is 0.5. The maximum number of RCUs is 14. You can configure the parameters based on your business requirements.
The maximum number of RCUs for my serverless RDS instance is 14 but cannot meet my business requirements. What do I do?
We recommend that you first purchase an RDS instance of a different deployment model. For example, the dedicated instance family for RDS High-availability Edition can provide a maximum of 104 CPU cores and 768 GB of memory. Then, migrate the workloads from the serverless RDS instance to the new RDS instance. For more information about instance types, see Primary ApsaraDB RDS for PostgreSQL instance types. For more information about data migration between RDS instances, see Use the cloud migration feature for an ApsaraDB RDS for PostgreSQL instance.
You can call the ModifyDBInstanceSpec operation to change the scaling range of RCUs for a serverless RDS instance. The following table describes the parameters.
The ID of the serverless instance for which you want to change the scaling range of RCUs.
The billing method of the serverless instance. Set the value to Serverless.
The specification change type of the instance. Set the value to Serverless.
The maximum number of RCUs.
The minimum number of RCUs.