Help Center/ TaurusDB/ User Guide/ Serverless Instances/ Changing the Maximum and Minimum Numbers of Read Replicas
Updated on 2024-11-06 GMT+08:00

Changing the Maximum and Minimum Numbers of Read Replicas

After buying a serverless instance, you can change the maximum and minimum numbers of read replicas. When certain trigger conditions are met, the number of read replicas of a serverless instance is automatically changed.

Conditions for Changing the Number of Read Replicas

If the compute has already been scaled up as much as possible but the CPU or memory usage still meets a compute scale-up condition, read replicas will be added.

If the compute has already been scaled down as much as possible but the CPU or memory usage still meets a compute scale-down condition, read replicas will be removed.

Constraints

  • If database proxy is not enabled for an instance, the number of read replicas cannot be adjusted.
  • To adjust the number of read replicas, there must be at least one proxy instance and new nodes will automatically be associated with the proxy instance. To associate new read replicas with a proxy instance, go to the Database Proxy page.
  • To prevent your workloads from being affected, you are advised not to use the private IP address for read to connect to your application.
  • After you set Scaling Type to Number of read replicas, the routing policy of the proxy instance will be changed to load balancing.
  • Manually created read replicas are affected by the configured auto scaling policy. For example, if you set the minimum number of read replicas to 1 and manually create four read replicas, when the CPU or memory usage meets the scale-down conditions, the manually created read replicas will be removed until there is only one read replica.

Changing the Maximum and Minimum Numbers of Read Replicas

  1. Log in to the management console.
  2. Click in the upper left corner and select a region and project.
  3. Click in the upper left corner of the page and choose Databases > GaussDB(for MySQL).
  4. On the Instances page, click the instance name to go to the Basic Information page.
  5. In the Serverless Information area, click Change under Compute Range.

    Figure 1 Changing serverless information

  6. In the displayed dialog box, set Scaling Type to Number of read replicas, change the maximum and minimum numbers of read replicas, and click OK.

    Figure 2 Changing the maximum and minimum numbers of read replicas

  7. Check the new maximum and minimum numbers of read replicas in the Serverless Information area.