Database Autonomy Service:Automatic storage expansion

Usage notes

• After the storage capacity of your database 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 instance specifications.

• From February 28, 2023, the automatic storage expansion feature is optimized for database instances in different regions. If your database instance has read-only instances, DAS automatically checks the storage capacity of each read-only instance when automatic storage expansion is triggered for the primary instance. If the storage capacity of one or more read-only instances is smaller than the desired storage capacity of the primary instance, DAS first expands the storage capacity of the read-only instances. After the storage capacity of each read-only instance is expanded, DAS automatically expands the storage capacity of the primary instance. For more information, see [Notice] Optimization of automatic storage expansion for ApsaraDB RDS for MySQL instances and ApsaraDB RDS for PostgreSQL instances.

• If a database instance is being backed up when automatic storage expansion is triggered, the automatic storage expansion task is postponed until the backup is complete.

Billing

The billing rules for automatic storage expansion are the same as the billing rules for manual storage expansion of an ApsaraDB RDS instance. For more information, see Change instance specifications.

Procedure

1. Log on to the DAS console.

2. Add an automatic storage expansion policy.

   • Add an automatic storage expansion policy on the Management and Settings page.

     1. In the left-side navigation pane, click Management and Settings.

     2. In the Auto Scaling Policies section, click Add Policy. In the Add Policy panel, configure the following parameters.

        Table 1. Parameters

        Parameter	Description
        Policy Name	The name of the policy.
        Mode	The mode of the policy. Select Automatic Storage Expansion from the Mode drop-down list.
        Engine Type	The type of the database engine. Set the value to RDS PostgreSQL.
        Specifications	The specifications of the database engine. Set the value to Disks.
        Used Storage Space ≥	The ratio of the used storage space to the total storage capacity. Valid values: 50 to 90. Default value: 50. Unit: percentage. When the percentage of the used storage capacity of the database instance is greater than or equal to the value of this parameter, the system automatically expands the storage capacity by the larger one of the following values: 5 GB Note If the storage capacity of the database instance is less than 50 GB and the available storage is less than 10% of the total storage capacity, the step size for storage capacity expansion is adjusted to 10 GB. 15% of the current storage capacity of the database instance. The result is the nearest integer that is a multiple of 5. Note The interval between two storage expansion operations is at least 10 minutes.
        Maximum Storage	The maximum storage capacity of the database instance after automatic expansion. The specified value must be greater than or equal to the current total storage capacity. If the database instance uses ESSDs, you can set this parameter up to 32,000 GB. If the database instance uses standard SSDs, you can set this parameter up to 6,000 GB.

     3. Click Next Step.

     4. In the Apply Policies dialog box, select the database instances to which you want to apply the policy, and click the icon.

     5. Click Confirm to apply the policy to the selected database instances.

   • Add an automatic storage expansion policy on the Autonomous Function Settings tab of the Autonomous Function Management panel.

     1. In the left-side navigation pane, click Instance Monitoring.

     2. On the page that appears, find the database instance that you want to manage and click the instance ID. The instance details page appears.

     3. On the instance details page, click Autonomy Service Settings in the upper-right corner.

     4. On the Autonomous Function Settings tab of the Autonomous Function Management panel, click the Auto Scaling tab. On the Auto Scaling tab, click Add Policy. In the Add Policy panel, add an automatic storage expansion policy. For more information about how to configure the parameters, see the Parameters section of this topic.

     5. In the Recommended Policies section, find the policy that you want to apply and click Apply in the Actions column.

        Note

        • In the Recommended Policies section, find the policy that you want to apply and click Apply in the Actions column.

        • To cancel a policy for the database instance, find the policy and click Cancel in the Actions column in the Applied Policies section.

     6. Click OK.

View the results of automatic storage expansion

1. In the left-side navigation pane of the DAS console, click Instance Monitoring.

2. On the page that appears, find the database instance that you want to view and click the instance ID. The instance details page appears.

3. On the instance details page, click Autonomy Center in the left-side navigation pane.

4. On the Autonomy Center page, select a time range to view the auto scaling events that occurred during the selected time range.

5. Click Details in the Elastic Scaling Events section to view the details of automatic storage capacity expansion.

   

References

Auto Scaling