Help Center> Relational Database Service> User Guide> Working with RDS for MySQL> Read Replicas> Changing a Single Read Replica to an HA Read Replica
Updated on 2023-09-26 GMT+08:00

Changing a Single Read Replica to an HA Read Replica

Scenarios

You can change a single read replica to an HA read replica as needed. For details about HA read replicas, see Introducing Read Replicas.

Constraints

  • If you want to change a single read replica to an HA read replica, the single read replica must use Cloud SSD as its storage type.
    • Cloud SSD: General-purpose, dedicated, and Kunpeng general-enhanced instance classes are supported.
  • If you are a DeC user, you can create HA read replicas or change single read replicas to HA read replicas. When you select DSS for Resource Type, only the storage type that you have selected when buying the DSS service is displayed by default.
  • To change a single read replica to an HA read replica, ensure that the SSL certificate, disk encryption, port, and subnet of the single read replica are the same as an existing HA read replica, or your primary instance if no HA read replica has been created.
  • Ensure that the subnet where your instance is located has sufficient IP addresses to be assigned to HA read replicas.
  • To ensure reliable operation of your workloads, do not modify parameters of HA read replicas.
  • For an HA read replica, do not change its port or change it to a single read replica.

Changing to an HA Read Replica

A single read replica can be changed to an HA read replica, but an HA read replica cannot be changed to a single read replica.

  1. Log in to the management console.
  2. Click in the upper left corner and select a region and a project.
  3. Click in the upper left corner of the page and choose Databases > Relational Database Service.
  4. In the DB instance list, click in front of the DB instance and click the target read replica.
  5. In the DB Information area on the Basic Information page, click Change to HA Read Replica next to the DB Instance Type field.

    Figure 1 DB information

  6. On the displayed page, confirm the information and click Submit.

    Figure 2 Changing to an HA read replica