Scenarios

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

• You can change the DB instance class only when your account balance is more than ¥0.
• A DB instance cannot be deleted while its instance class is being changed.
• You can scale up or down the compute and memory capacity of Microsoft SQL Server DB instances as required.

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.
   Figure 1 Changing a DB instance class
   

   Changing the DB instance class will cause the DB instance to reboot. Select off-peak hours to avoid service interruption.

   DB instances in a DCC only support the general-enhanced instance class.

6. Confirm the specifications.
   • If you need to modify your settings, click Previous.
   • For pay-per-use DB instances, click Submit.

     To view the cost incurred by the DB instance class change, choose Billing > My Orders in the upper right corner.

   • For yearly/monthly DB instances:
     • If you intend to scale down the DB instance class, click Submit.

       The refund is automatically returned to your account. You can choose Billing > My Orders in the upper right corner to check the refund.

     • If you intend to scale up the DB instance class, click Pay Now. The scaling starts only after the payment is successful.

7. View the DB instance class change result.

   Changing the DB instance class takes 5–15 minutes. During this period, the status of the DB instance on the Instance Management page is Changing instance class. After a few minutes, click the DB instance and view the instance class on the displayed Basic Information page to check that the change is successful.

   

   After you change a SQL Server DB instance class, the value of max server memory will also be changed accordingly. You are advised to set it to a size equal to the memory size minus 520 MB. For example, if there is 1 GB of memory (1024 MB), you are advised to set max server memory to 504 MB (1024 MB – 520 MB).