Changing the vCPUs or Memory of a DB Instance or Node

Scenarios

You can change the the specifications (vCPUs and memory) of a yearly/monthly or pay-per-use DB instance or node as needed. If the status of a DB instance or node changes from Changing instance specifications to Available, the change is successful.

You can scale up or down the specifications of your DB instance or node.

Constraints

A DB instance or node cannot be deleted when its specifications are being changed.
You can change the specifications of a DB instance or just a single node within the instance. To change the specifications of a single node, submit an application by choosing Service Tickets > Create Service Ticket in the upper right corner of the management console.
Instance specifications can only be changed from the general-purpose edition to the dedicated edition.
You can change the specifications of yearly/monthly or pay-per-use DB instances immediately or during a maintenance window. Serverless DB instances do not support specification changes.
If you want to change instance specifications during a maintenance window, you can cancel the task before it starts. Once started, the task cannot be canceled.
During an instance specification change, a read replica will be promoted to primary. To prevent service interruptions, perform the operation during off-peak hours.
The time required for modifying specifications depends on factors such as the number of nodes, database load, and number of database tables.
Changing instance specifications will change the private IP addresses for read of the primary node and read replicas. The connection addresses in your application need to be changed to prevent your services from being affected. You are advised to use the private IP address of a DB instance to connect your application.
The specifications of the primary node and read replicas can be changed separately. When the specifications of the primary node are changed separately, the specifications of synchronous nodes are also changed.

Procedure

Log in to the management console.
Click in the upper left corner and select a region and project.
Click in the upper left corner of the page and choose Databases > GaussDB(for MySQL).
Change specifications.
- Changing the specifications of a DB instance
  On the Instances page, locate the DB instance whose specifications you want to change and choose More > Change Instance Specifications in the Operation column.
  
  Alternatively, click the instance name to go to the Basic Information page. In the Configuration area, click Change under Instance Specifications.
- Changing the specifications of the primary node
  On the Instances page, click the instance name to go to the Basic Information page. In the Node List area, locate the primary node and click Change in the Operation column.
- Changing the specifications of a read replica
  On the Instances page, click the instance name to go to the Basic Information page. In the Node List area, locate a read replica and click Change in the Operation column.
On the displayed page, select the desired specifications. You can scale up or down the specifications as required.

You can change the specifications immediately or during the maintenance window.
- Upon submission: The specifications will be changed immediately after the task is submitted.
- In maintenance window: The specifications will be changed during the maintenance window you specify.
Click Next. On the displayed page, confirm the specifications.
- If you need to modify your settings, click Previous to go back to the page where you specify details.
- For pay-per-use instances, click Submit.
  To view the cost incurred by the instance specifications change, choose Billing Center > Billing Dashboard in the upper right corner.
- For yearly/monthly instances:
  - Scaling down the specifications: click Submit.
    The refund is automatically returned to your account. You can click Billing Center in the upper right corner and then choose Orders > My Orders in the navigation pane on the left to view the details.
  - Scaling up the specifications: click Submit. The scaling starts only after the payment is successful.
View the results.

Changing the instance specifications takes 5–15 minutes. During this period, the status of the instance on the Instances page is Changing instance specifications. After a few minutes, you can click the instance name to view the new instance specifications on the displayed Basic Information page.
- After the instance specifications of GaussDB(for MySQL) 8.0 are changed, the system will change the values of the following parameters accordingly: innodb_buffer_pool_size, innodb_log_buffer_size, max_connections, innodb_buffer_pool_instances, innodb_page_cleaners, innodb_parallel_read_threads, innodb_read_io_threads, innodb_write_io_threads, and threadpool_size.
- The default value of innodb_parallel_select_count is OFF for instance with 16 vCPUs or less and ON for instances with more than 16 vCPUs.
  If you have modified value of the parameter, the parameter value remains unchanged after the specifications are changed, or the default value is used.