Database Autonomy Service (DAS) provides the automatic performance scaling feature. During peak hours, DAS automatically scales up a database instance to handle peak-hour traffic and ensure business stability. DAS monitors the CPU utilization of the database instance in real time. If the CPU utilization per unit time decreases, DAS automatically scales down the database instance. This topic describes how to enable the automatic performance scaling feature.

Prerequisites

  • An ApsaraDB RDS for MySQL instance of the High-availability Edition or a PolarDB for MySQL instance of the Cluster Edition is connected to DAS. The ApsaraDB RDS for MySQL instance uses enhanced SSDs.
  • The billing method of the ApsaraDB RDS for MySQL instance or the PolarDB for MySQL instance is pay-as-you-go.
  • The Enable Autonomy Service switch is turned on for the database instance for which you want to enable the automatic performance scaling. For more information, see Autonomy center.
  • A RAM role that is linked to DAS is created to enable automatic performance scaling. For more information, see AliyunServiceRoleForDAS role.
    Note If you have not created a RAM role that is linked to DAS when you enable automatic performance scaling, DAS creates a role for you before automatic performance scaling.

Scenario examples

If you use DAS to enable automatic performance scaling for a database instance, DAS automatically scales up the instance. This operation doubles the read/write throughput and lowers the CPU utilization from higher than 90% to 25%. This allows the instance to run under heavy load for nearly 10 consecutive hours. After the traffic decreases and the CPU utilization drops to lower than 25%, DAS automatically scales down the instance specifications to those before the scale-up.

This way, DAS ensures the stability of online business.

Procedure

  1. Log on to the DAS console.
  2. In the left-side navigation pane, click Instance Monitoring.
  3. On the Instance Monitoring page, find the instance for which you want to enable the automatic performance scaling feature and click the instance ID. The instance details page appears.
  4. In the left-side navigation pane, click Autonomy Center.
  5. In the upper-right corner of the Autonomy Center page, click Autonomy Service Settings.
  6. In the Settings dialog box, turn on the automatic performance scaling switch and configure the following parameters.
    s
    Parameter Description
    Average CPU Utilization The CPU utilization threshold that triggers automatic performance scaling. If the average CPU utilization is greater than or equal to the specified value, the automatic performance scaling operation is triggered.
    Maximum Specifications The upper limit to which the instance specifications can be upgraded for automatic performance scaling. DAS upgrades the specifications of a database instance by one level at a time. For example, DAS scales up the instance specification from 4 cores to 8 cores and then to 16 cores based on business requirements. This process continues until the instance specifications reach the specified upper limit.
    Observation Window The time window during which DAS monitors the CPU utilization of the database instance. If the CPU utilization reaches the threshold within an observation window, DAS triggers automatic scaling at the end of the observation window. By default, the CPU utilization reaches the threshold if it remains higher than 70% for longer than half the duration of an observation window.
  7. Click OK.

Learn more

For more information about automatic performance scaling, see AutoScale.