Changing a DB Instance Class

Scenarios

You can change the instance class (CPU or memory) of a DB instance as required. If the status of a DB instance changes from Changing instance class to Available, the change is successful.

Constraints

• An instance cannot be deleted while its instance class is being changed.
• The following operations cannot be performed on an instance whose instance class is being changed: rebooting the instance, scaling up storage space, modifying parameter groups, creating a manual backup, creating a database account, and creating a database.
• After the instance class is changed, some parameters are automatically changed to the default values defined in the new instance class. The parameters are threadpool_size, innodb_buffer_pool_size, innodb_io_capacity, innodb_io_capacity_max, innodb_buffer_pool_instances, back_log, and max_connections.
• After you change instance classes, the DB instances will reboot and services will be interrupted. Therefore, you are advised to change instance classes during off-peak hours.
• Changing the instance class takes 5 to 15 minutes. Service downtime only occurs during the primary/standby switchover.

Procedure

1. Log in to the management console.
2. Click in the upper left corner and select a region and a project.
3. Click Service List. Under Database, click Relational Database Service. The RDS console is displayed.
4. On the Instance Management page, locate the target DB instance and choose More > Change Instance Class in the Operation column.

   Alternatively, click the target DB instance to go to the Basic Information page. In the DB Information area, click Change in the Instance Class field.

5. On the displayed page, specify the new instance class and click Next.
6. View the DB instance class change result.

   Return to the Instance Management page and view the instance status. During the change period, the instance status is Changing instance class. You can view the execution progress of Changing a MySQL DB instance class on the Task Center page. After a few minutes, view the DB instance class on the Basic Information page to check that the change is successful.

   

   After you change an RDS for MySQL instance class, the values of the following parameters will be changed accordingly: back_log, innodb_buffer_pool_size, innodb_log_buffer_size, innodb_log_files_in_group, max_connections, innodb_page_cleaners, innodb_buffer_pool_instances, threadpool_size, and slave_parallel_workers.