Auto scaling

Feature overview

• Prediction-based auto scaling: Uses the historical data of an instance from the past 10 days to predict its performance metric usage for the next 24 hours. When the predicted value meets or exceeds your defined target, it provides a scale-up recommendation.

• Scheduled auto scaling: Scales up the specifications of a database instance at a scheduled time based on a predefined policy. After the specified duration, it automatically scales back to the original specifications. This feature helps you manage predictable, cyclical changes in your database workload to meet business demands while controlling costs.

• Automatic scaling for local resources: When the average CPU utilization of a database instance reaches a set threshold within an observation window, DAS scales up the instance's CPU cores by using available resources on the local host.

• Automatic storage expansion: When the used storage space of a database instance meets or exceeds a set expansion threshold, the system automatically expands the storage to ensure uninterrupted service.

Create a policy

1. Log on to the DAS console.

2. In the navigation pane on the left, click Resource Management > Auto Scaling Settings.

3. In the Auto Scaling Policies section, click Add Policy on the right. On the Add Policy page, select a Mode for the new policy and configure its parameters as described in the following topics:

   • Prediction-based auto scaling

   • Scheduled auto scaling

   • Automatic scaling for local resources

   • Automatic storage expansion

Apply a policy

1. Log on to the DAS console.

2. In the navigation pane on the left, click Resource Management > Auto Scaling Settings.

3. In the Auto Scaling Policies section, find the target policy and click Apply in the Actions column.

4. On the Apply Policies page, select the database instances for this policy, and click .

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

Remove a policy from an instance

1. Log on to the DAS console.

2. In the navigation pane on the left, click Resource Management > Auto Scaling Settings.

3. In the Auto Scaling Policies section, find the target policy and click the number in the Applied Instances column.

4. On the Instance Details page, find the target instance and click Cancel in the Actions column.

5. Click OK.

Modify a policy

1. Log on to the DAS console.

2. In the navigation pane on the left, click Resource Management > Auto Scaling Settings.

3. In the Auto Scaling Policies section, find the target policy and click Modify in the Actions column.

4. On the Update Policy page, modify the policy's settings.

   Note

   • Changes to a policy affect all database instances to which it is applied.

   • Modifying a scheduled auto scaling policy affects its ongoing operations.

     • If you modify the Operation setting of a scheduled auto scaling policy during an execution cycle, the system will not perform the scale-back. This is because the instance specifications no longer match the scale-back requirements defined in the policy.

     • If you modify the Valid From and Recurrence settings of a scheduled auto scaling policy during an execution cycle and the Scale-back Time changes as a result, the system will not perform the scale-back.

5. Click OK.

Delete a policy

1. Log on to the DAS console.

2. In the navigation pane on the left, click Resource Management > Auto Scaling Settings.

3. To delete one or more policies:

   Note

   • You can only delete policies that are not applied to any instances. To remove a policy from an instance, see Remove a policy from an instance.

   • If you delete a scheduled auto scaling policy during its execution cycle, the system will not perform the corresponding scale-back.

   • To delete multiple policies: Select the policies you want to delete and click Batch Delete.

   • To delete a single policy: Find the policy you want to delete and click Delete in the Actions column.