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

• A DB instance cannot be deleted when its instance class is being changed.

• After you change instance classes, the DB instances will be rebooted and service will be interrupted. Therefore, you are advised to change instance classes during off-peak hours.
• Set the recovery model of your database to FULL instead of SIMPLE.
  • In the SIMPLE recovery model, no incremental backup is performed for the database, so the database cannot be restored to a specified time point.
  • For primary/standby or cluster instances, if the recovery model is set to SIMPLE, no replication relationship will be established for the instances. As a result, a primary/standby switchover or instance class change cannot be performed.

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 Instances 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.

   Changing the DB instance class takes 5–15 minutes. During this period, the status of the DB instance on the Instances 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 Microsoft 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 (1,024 MB), you are advised to set max server memory to 504 MB (1,024 MB – 520 MB).