Database Autonomy Service (DAS) provides the automatic storage expansion feature for ApsaraDB RDS for MySQL. The feature monitors the storage of your ApsaraDB RDS for MySQL instance and automatically expands the storage capacity of the RDS instance when the remaining storage is insufficient. This helps ensure the stability of your workloads.
Prerequisites
The following requirements are met:
The RDS instance runs MySQL 8.0 or MySQL 5.7.
The RDS instance runs RDS High-availability Edition or RDS Cluster Edition.
The RDS instance uses cloud disks.
NoteThis feature is not supported for cost-effective RDS instances that originally use the ARM architecture.
You can enable the feature for RDS instances that run RDS Basic Edition and use cloud disks in the DAS console. For more information, see Automatic space expansion.
For more information about how to configure automatic storage expansion for RDS instances that run different database engines, see the following topics:
ApsaraDB RDS for PostgreSQL instances: Use the automatic storage expansion feature for an ApsaraDB RDS for PostgreSQL instance
ApsaraDB RDS for SQL Server instances: Configure automatic storage expansion for an ApsaraDB RDS for SQL Server instance
The balance in your Alibaba Cloud account is sufficient.
A service-linked role is created for DAS. For more information, see AliyunServiceRoleForDAS role.
NoteIf the role does not exist, a service-linked role is automatically created for DAS when you enable the automatic storage expansion feature.
Usage notes
After the storage capacity of your RDS instance is expanded, the storage capacity cannot be automatically reduced. However, you can manually reduce the storage capacity by changing the instance specifications. For more information, see Change the specifications of an ApsaraDB RDS for MySQL instance.
Starting February 28, 2023, the system optimizes the rules for automatic storage expansion in regions in phases. If your RDS instance is a primary RDS instance and has read-only RDS instances, the system checks the storage capacity of each read-only instance when automatic storage expansion is triggered for the primary RDS instance. If the storage capacity of a read-only RDS instance is less than the storage capacity of the primary RDS instance after the capacity expansion, the system preferentially expands the storage capacity of the read-only instance. After the storage capacity of each read-only RDS instance that is attached to the primary RDS instance is expanded, the system automatically expands the storage capacity of the primary RDS instance. For more information, see [Notice] Optimization of automatic storage expansion for ApsaraDB RDS for MySQL instances and ApsaraDB RDS for PostgreSQL instances.
Billing rules
The billing rules for automatic storage expansion are the same as the billing rules for manual storage expansion. For more information, see Specification changes.
Procedure
- 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.
Use one of the following methods to go to the Autonomous Function Management panel:
In the left-side navigation pane, choose Autonomy Service > Diagnostics. On the page that appears, click the Autonomy Center tab. On the Autonomy Center tab, click Autonomy Service Settings.
In the left-side navigation pane, choose Autonomy Service > Dashboard. On the Dashboard tab of the page that appears, click Autonomy Service Settings.
On the Autonomous Function Settings tab of the Autonomous Function Management panel, enable the autonomy service.
On the Optimization and Throttling tab, select Automatic Space Expansion and configure the following parameters.
Parameter
Description
Available Storage Space
The available storage of your RDS instance. When the remaining storage of your RDS instance is less than or equal to the value that is specified by the Available Storage Space parameter, the system automatically expands the storage capacity of your RDS instance based on the larger value of the following items:
Storage of 5 GB
15% of the current storage of your RDS instance
Maximum Storage of Automatic Expansion
The maximum storage capacity that is allowed by automatic storage expansion. The value of this parameter must be greater than or equal to the current storage capacity of your RDS instance.
If your RDS instance uses the enhanced SSD (ESSD) storage type, the maximum value of this parameter can be 32,000 GB.
If your RDS instance uses the standard SSD storage type, the maximum value of this parameter can be 6,000 GB.
NoteThe standard SSD storage type is phased out. We recommend that you upgrade the storage type to ESSDs. For more information, see Upgrade the storage type of an ApsaraDB RDS for MySQL instance from standard SSDs to ESSDs.
NoteThe minimum interval between consecutive storage expansion events is 10 minutes.
Click OK.
View the details of automatic storage expansion events
- 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 left-side navigation pane, choose Autonomy Service > Diagnostics.
On the Autonomy Center tab, select a time range to view the auto scaling events that occurred in the selected time range.
Click Details in the Auto-Scaling Events section to view the details of auto scaling events.
