• Relational Database Service

rds
  1. Help Center
  2. Relational Database Service
  3. User Guide
  4. Managing DB Instances
  5. DB Instance Operations
  6. Changing the CPU or Memory of a DB Instance

Changing the CPU or Memory of a DB Instance

Scenarios

You can change the 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.

For details about how to scale up storage space of a DB instance, see section Scaling Up Storage Space.

NOTE:

A DB instance cannot be deleted while its CPU or memory is being changed.

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 to go to the RDS console.
  4. On the Instance Management page, locate the target DB instance and click Scale in the Operation column.
  5. On the displayed page, click CPU/Memory, specify the desired CPU and memory, and click Submit.
  6. View the DB instance CPU or memory modification result.

    Changing the CPU or memory takes 5-15 minutes. During this time, the status of the DB instance on the Instance Management page will be Changing instance class. To verify that the change has succeeded, click the DB instance and view the instance class on the displayed Basic Information page.

    • After you change the CPU or memory of a MySQL instance, the values of the following parameters will also be changed accordingly: back_log (only for MySQL 5.7), 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.
    • After you change the CPU or memory of a PostgreSQL instance, the values of the following parameters will also be changed: shared_buffers, max_connections, maintenance_work_mem, and effective_cache_size.
    • After you change the CPU or memory of an RDS for Microsoft SQL Server instance, the system will change the value of max server memory 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, you are advised to set max server memory to 504 MB.