The automatic scale-up feature of Database Autonomy Service (DAS) can automatically scale up your ApsaraDB RDS for MySQL instance based on your workloads to handle traffic spikes and ensure the stability of your RDS instance.
Prerequisites
- Your RDS instance runs RDS High-availability Edition with standard SSDs or enhanced
SSDs (ESSDs).
Note The automatic scale-up feature is not supported for RDS instances whose instance types are phased out. If the instance type of your RDS instance is phased out, you must change the instance type of the instance before you can enable the automatic scale-up feature. For more information about how to change the instance type of an RDS instance, see Change the specifications of an ApsaraDB RDS for MySQL instance.
- DAS is activated within your Alibaba Cloud account. For more information, see Autonomy center.
- The balance in your Alibaba Cloud account is sufficient for scale-ups.
Billing rules
By default, the automatic scale-up feature is disabled and does not produce fees. If you enable the automatic scale-up feature, you are charged based on the new instance type that is selected during the automatic scale-up. The price for a scale-up varies based on the instance configuration, such as the region and the new instance type. For more information, visit the ApsaraDB RDS buy page.
Automatic scale-up process

Impacts
- When the new specifications are being applied to an RDS instance, a transient connection that lasts approximately 30 seconds may occur. Make sure that your application is configured to automatically reconnect to the RDS instance.
- If an RDS instance does not run the latest minor engine version, DAS updates the minor engine version of the RDS instance to the latest version during a specification change. This ensures the performance and stability of the RDS instance.
- After you enable the automatic scale-up feature for an RDS instance, ApsaraDB RDS assigns the AliyunServiceRoleForDAS service-linked role to DAS. This way, DAS can access the resources that are related to ApsaraDB RDS.