Relational Database ServiceRelational Database Service

Elastic Cloud Server
Bare Metal Server
Auto Scaling
Image Management Service
Dedicated Host
Virtual Private Cloud
Elastic IP
Elastic Load Balance
NAT Gateway
Direct Connect
Virtual Private Network
Domain Name Service
VPC Endpoint
Cloud Connect
Enterprise Switch
Security & Compliance
Web Application Firewall
Host Security Service
Data Encryption Workshop
Database Security Service
Advanced Anti-DDoS
Data Security Center
Container Guard Service
Situation Awareness
Managed Threat Detection
Cloud Certificate Manager
Anti-DDoS Service
Relational Database Service
Document Database Service
Data Admin Service
Data Replication Service
GaussDB(for MySQL)
Distributed Database Middleware
GaussDB(for openGauss)
Developer Services
Distributed Cache Service
Simple Message Notification
Application Performance Management
Application Operations Management
Blockchain Service
API Gateway
Cloud Performance Test Service
Distributed Message Service for Kafka
Distributed Message Service for RabbitMQ
Distributed Message Service for RocketMQ
Cloud Service Engine
Cloud Communications
Message & SMS
Cloud Ecosystem
Partner Center
User Support
My Account
Billing Center
Cost Center
Resource Center
Enterprise Management
Service Tickets
HUAWEI CLOUD (International) FAQs
ICP License Service
Support Plans
Customer Operation Capabilities
Partner Support Plans
Professional Services
Intelligent EdgeFabric
SDK Developer Guide
API Request Signing Guide
Koo Command Line Interface
Updated at: Apr 02, 2022 GMT+08:00

Changing a DB Instance Class


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.


  • A DB instance cannot be deleted when its instance class is being changed.
  • You can scale up or down the compute and memory capacity of Microsoft SQL Server DB instances as needed.
  • 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.


  1. Log in to the management console.
  2. Click in the upper left corner and select a region and a project.
  3. Click in the upper left corner of the page and choose Database > 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

    You can change the DB instance class as required.

    Changing the instance class will cause the DB instance to reboot. To prevent service interruption, perform the operation during off-peak hours. Rebooting a DB instance will clear the cached memory in it. To prevent traffic congestion during peak hours, you are advised to reboot the DB instance during off-peak hours.

    DB instances in a DeC 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 Center > Cost Bills 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 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.

      • 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 RDS for 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).

Did you find this page helpful?

Failed to submit the feedback. Please try again later.

Which of the following issues have you encountered?

Please complete at least one feedback item.

Content most length 200 character

Content is empty.

OK Cancel