Automatic space expansion

Usage notes

• When automatic space expansion is triggered for a primary instance with read-only instances, the system first expands any read-only instance whose storage is smaller than the primary instance's target size. Only after expanding all required read-only instances does the system expand the primary instance.

• Due to Windows driver limitations, this feature is unavailable for some instances. We recommend that you upgrade the minor engine version of SQL Server.

Billing

The billing rules are the same as those for manually upgrading the storage space of an RDS instance. For more information, see Billing rules for configuration changes.

Procedure

1. Log on to the DAS console.

2. In the navigation pane on the left, click Intelligent O&M Center > Instance Monitoring .

3. Find the target instance and click the instance ID to open the instance details page.

4. In the navigation pane on the left, click Autonomy Center.

5. On the Autonomy Center page, click Autonomy Service Settings on the right.

6. On the Autonomous Function Management > Autonomous Function Settings tab, enable the autonomy service.

7. On the Optimization and Throttling tab, select the Automatic Space Expansion checkbox and configure the following parameters.

   Parameter	Description
   Available Storage Space ≤	The expansion threshold. When the available storage space of your instance is less than or equal to this threshold, the system expands the storage by the larger of the following two values: 5 GB Note If the total storage space of the instance is less than 50 GB and the available storage space is less than 10% of the total storage, the expansion step is adjusted to 10 GB. 15% of the current total storage of the instance (rounded to the nearest multiple of 5). For example, if your total storage is 100 GB, the expansion increment is 15 GB (15% of 100 GB, which is greater than the 5 GB minimum). After a successful expansion, the total storage will be 115 GB. Note For PolarDB for MySQL Standard Edition database instances, the expansion threshold is set by the system and does not require manual configuration. For details about the thresholds, see Scale-out thresholds for PolarDB for MySQL Standard Edition.
   Maximum Storage of Automatic Expansion	The maximum total storage space the instance can reach through automatic expansion. This value must be greater than or equal to the instance's current total storage. Important For PolarDB for MySQL Standard Edition database instances, the expansion step size is a multiple of 10. We recommend that you set Maximum Storage of Automatic Expansion to a multiple of 10. Otherwise, the expansion may fail or may not reach the specified Maximum Storage of Automatic Expansion.

   Note

   The minimum interval between successive expansion operations is 10 minutes.

8. Click OK.

9. Configure an Alert Template to receive notifications about automatic space expansions.

   The system recommends an alert template with the appropriate alert rules. Follow the prompts to complete the configuration.

   Note

   • If you have already configured an alert template for the instance, follow the prompts to add alert rules for the corresponding autonomous events to the template.

   • If you need to configure the alert template and rules yourself, see Configure alert templates and Configure alert rules.

10. Select a Alert Contact Group to receive alert notifications.

    • Click Add Contact to add a new alert contact.

    • Click Create Contact Group to add a new contact group.

    • Click Modify or Remove next to a contact to modify or delete their information.

    For more information, see Manage alert contacts.

11. Click Submit Configuration and confirm the settings in the subsequent dialog box.

View automatic expansion results

1. Log on to the DAS console.

2. In the navigation pane on the left, click Intelligent O&M Center > Instance Monitoring .

3. Find the target instance and click the instance ID to open the instance details page.

4. In the navigation pane on the left, click Autonomy Center.

5. On the Autonomy Center page, view the Auto-Scaling Events for the selected time range.

6. Click Details to view the details of the automatic space expansion. In the event list, a record named Auto-scaling event with an event level of Notice is displayed. Click the Details button on its right.

PolarDB for MySQL Standard Edition scale-out thresholds

The expansion threshold depends on the instance's total storage space, as shown in the table below:

Related documents

• After an automatic space expansion, automatic space shrinking is not currently supported. To shrink the space, you must manually change the configuration. For more information, see Change configuration.

  Note

  Manual scale-in is not supported for ApsaraDB RDS for SQL Server or PolarDB for MySQL Standard Edition instances.

• You can enable automatic fragment reclamation to clean up table space fragments and reduce wasted storage space.

• You can use the storage analysis and capacity assessment features to analyze your storage usage.

• If your database instance is ApsaraDB RDS for PostgreSQL, see Automatic storage expansion.

• If your database instance is PolarDB for MySQL, see Set automatic expansion for ESSD cloud disks.