Database Autonomy Service (DAS) provides the auto scaling feature. This feature allows DAS to provide suggestions for scaling database instances based on your preset policies and to scale instances when their workloads reach specified thresholds.

Prerequisites

Note Starting from February 18, 2022, this feature will be gradually rolled out to eventually cover all DAS users.

Features

  • Prediction-based auto scaling: DAS predicts the metric values of an instance in the next 24 hours based on the historical data of the instance over the last 10 days. If the predicted value of a metric is greater than or equal to the predefined value, scaling suggestions are provided.
  • Scheduled auto scaling: DAS scales up or down the specifications of database instances based on your scheduled auto scaling policies. This feature allows you to cope with predictable periodic changes in database loads and control costs while meeting business requirements.
  • Automatic scaling for local resources: When the average CPU utilization of a database instance reaches the specified threshold within an observation window, DAS utilizes available resources on the local host to increase the number of CPU cores of the database instance to the specified value.
  • Automatic storage capacity expansion: When the used storage space of a database instance is greater than or equal to the specified scaling threshold, the system automatically increases the storage space to ensure that your business is stably running.

Create a policy

  1. Log on to the DAS console.
  2. In the left-side navigation pane, click Management and Settings.
  3. In the Auto Scaling Policies section, click Add Policy. In the Add Policy panel, set Mode and configure the relevant parameters.

Apply a policy

  1. Log on to the DAS console.
  2. In the left-side navigation pane, click Management and Settings.
  3. In the Auto Scaling Policies section, click Apply in the Actions column corresponding to the policy that you want to apply.
  4. In the Apply Policies dialog box, select the database instances to which you want to apply the policy, and click p20220214.
  5. Click Confirm to apply the policy to the selected database instances.

Cancel the application of a policy

  1. Log on to the DAS console.
  2. In the left-side navigation pane, click Management and Settings.
  3. In the Auto Scaling Policies section, click the number in the Applied Instances column corresponding to the policy that you want to cancel for an instance.
  4. In the Instance Details dialog box, click Cancel in the Actions column corresponding to the instance for which you want to cancel the policy.
  5. In the message that appears, click OK.

Modify a policy

  1. Log on to the DAS console.
  2. In the left-side navigation pane, click Management and Settings.
  3. In the Auto Scaling Policies section, click Modify in the Actions column corresponding to the policy that you want to modify.
  4. In the Update Policy panel, update the policy settings.
    Note If you modify the policy, all database instances to which the policy is applied are affected.
    Mode Configurable parameter
    Prediction-based auto scaling
    • Policy Name
    • Destination Value
    Scheduled auto scaling
    • Policy Name
    • Operation
    • Valid From
    • Recurrence
    Automatic scaling for local resources
    • Policy Name
    • Average CPU Utilization
    • Scale-up Observation Window
    • CPU Scale-up Step Size
    • Scale-down Observation Window
    Automatic storage scale-out
    • Policy Name
    • Used Storage Space
    • Maximum Storage of Automatic Expansion
    Note If you modify a scheduled auto scaling policy, ongoing tasks associated with the policy are affected.
    • If the Operation value of a scheduled auto scaling policy is modified within an execution period, the system does not scale the instances back to their original specifications at scale-back time because the instance specifications are different from those specified by the original policy.
    • If the Scale-back Time value changes after the Valid From and Recurrence values of a scheduled auto scaling policy is modified within an execution period, the system does not scale the instances back to their original specifications.
  5. In the message that appears, click OK.

Delete a policy

  1. Log on to the DAS console.
  2. In the left-side navigation pane, click Management and Settings.
  3. Delete one or more created policies by using the following methods.
    Note
    • Only policies that are not applied to instances can be deleted. For more information about how to cancel the application of a policy, see Cancel the application of a policy.
    • If you delete a scheduled auto scaling policy, ongoing tasks associated with the policy are affected. If a scheduled auto scaling policy is deleted within an execution period, the system does not scale the instances back to their original specifications.
    • To delete multiple policies at a time, select the policies and click Batch Delete.
    • To delete a single policy, click Delete in the Actions column corresponding to the policy.