Changing the Maximum and Minimum Numbers of Read Replicas

Conditions for Changing the Number of Read Replicas

When the compute power has been scaled up to the specified upper limit and the CPU or memory usage still meets a compute power scale-up condition, read replicas will be scaled out.

When the compute power has been scaled down as much as possible and the CPU or memory usage still meets a compute power scale-down condition, read replicas will be scaled in.

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. If you require that read replicas can be automatically associated with the 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.
   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.