- What's New
- Function Overview
- Product Bulletin
- Service Overview
- Billing
-
Getting Started
- Getting Started with RDS for MySQL
- Getting Started with RDS for MariaDB
- Getting Started with RDS for PostgreSQL
- Change History
- Huawei Cloud MySQL Kernel
-
User Guide
-
Working with RDS for MySQL
- Suggestions on Using RDS for MySQL
- Database Migration
- Performance Tuning
- Instance Lifecycle
-
Instance Modifications
- Upgrading a Minor Version
- Changing a DB Instance Name
- Changing a DB Instance Description
- Changing the Replication Mode
- Changing the Failover Priority
- Changing a DB Instance Class
- Scaling Up Storage Space
- Configuring Storage Autoscaling
- Changing the Maintenance Window
- Changing a DB Instance Type from Single to Primary/Standby
- Promoting a Read Replica to Primary
- Manually Switching Between Primary and Standby DB Instances
- Changing the AZ of a Standby DB Instance
- Read Replicas
- Data Backups
- Data Restorations
-
Parameter Templates
- Creating a Parameter Template
- Modifying Parameters of an RDS for MySQL Instance
- Exporting a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Connection Management
-
Database Proxy (Read/Write Splitting)
- Introducing Read/Write Splitting
- Suggestions on Using Database Proxy
- Kernel Versions
- Best Practices for Database Proxy
- Enabling Read/Write Splitting
- Configuring Transaction Splitting
- Configuring Connection Pools
- Configuring Multi-Statement Processing Modes
- Changing a Proxy from Pay-per-Use to Yearly/Monthly
- Configuring the Delay Threshold and Routing Policy
- Changing the Read/Write Splitting Address
- Changing the Read/Write Splitting Port
- Changing the Instance Class of a DB Proxy Instance
- Changing the Number of Proxy Nodes
- Upgrading the Kernel Version of Database Proxy
- Enabling or Disabling Access Control
- Restarting a Database Proxy
- Modifying Read/Write Splitting Parameters
- Disabling Read/Write Splitting
- Testing Read/Write Splitting Performance
- Database Management
- Account Management (Non-Administrator)
- Account and Network Security
- Metrics
- Interconnection with CTS
- Log Management
- Task Center
- Billing Management
- Managing Tags
-
Working with RDS for MariaDB
- Suggestions on Using RDS for MariaDB
- Instance Connection
- Parameter Tuning
- Instance Lifecycle
- Instance Modifications
- Read Replicas
- Data Backups
- Data Restorations
-
Parameter Templates
- Creating a Parameter Template
- Modifying RDS for MariaDB Instance Parameters
- Exporting a Parameter Template
- Importing a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Connection Management
- Database Management
- Account Management (Non-Administrator)
- Account and Network Security
- Metrics
- Interconnection with CTS
- Log Management
- Task Center
- Managing Tags
-
Working with RDS for PostgreSQL
- Suggestions on Using RDS for PostgreSQL
- Database Migration
- Performance Tuning
- Instance Lifecycle
-
Instance Modifications
- Upgrading a Minor Version
- Changing a DB Instance Name
- Changing a DB Instance Description
- Changing the Replication Mode
- Changing the Failover Priority
- Changing a DB Instance Class
- Scaling Storage Space
- Changing the Maintenance Window
- Changing a DB Instance Type from Single to Primary/Standby
- Manually Switching Between Primary and Standby DB Instances
- Changing the AZ of a Standby DB Instance
- Read Replicas
- Data Backups
- Data Restorations
-
Parameter Templates
- Creating a Parameter Template
- Modifying Parameters of an RDS for PostgreSQL Instance
- Exporting a Parameter Template
- Comparing Parameter Templates
- Viewing Parameter Change History
- Replicating a Parameter Template
- Resetting a Parameter Template
- Applying a Parameter Template
- Viewing Application Records of a Parameter Template
- Modifying a Parameter Template Description
- Deleting a Parameter Template
- Connection Management
- Extension Management
- Tablespace Management
- Account and Network Security
- Metrics
- Interconnection with CTS
- Log Management
- Task Center
- Billing Management
- Major Version Upgrade
- Managing Tags
-
Working with RDS for MySQL
- Best Practices
- Performance White Paper
-
API Reference
- Before You Start
- API Overview
- Calling APIs
- API v3.1 (Recommended)
-
API v3 (Recommended)
- Querying Version Information About APIs
- Querying Version Information About a DB Engine
- Querying Database Specifications
- Querying the Storage Type of a Database
-
DB Instance Management
- Creating a DB Instance
- Stopping an Instance
- Changing a DB Instance Name
- Changing the Description of a DB Instance
- Changing DB Instance Specifications
- Scaling Up Storage Space of a DB Instance
- Changing a Single DB Instance to Primary/Standby DB Instances
- Rebooting a DB Instance
- Deleting a DB Instance
- Querying DB Instances
- Binding and Unbinding an EIP
- Changing the Failover Priority
- Manually Switching Primary/Standby DB Instances
- Changing the Data Replication Mode of Primary/Standby DB Instances
- Configuring the Maintenance Window
- Database Security
- Backup and Restoration
- Log Information Queries
-
Database and Account Management (MySQL)
- Creating a Database
- Querying Details About a Database
- Querying Databases
- Querying Authorized Databases of a Specified User
- Deleting a Database
- Creating a Database Account
- Querying Database Users
- Querying Authorized Users of a Specified Database
- Deleting a Database Account
- Configuring a Password for a Database Account
- Authorizing a Database Account
- Revoking Permissions of a Database Account
- Resetting the Password for User root
- Database and Account Management (PostgreSQL)
-
Parameter Management
- Obtaining a Parameter Template List
- Creating a Parameter Template
- Modifying a Parameter Template
- Applying a Parameter Template
- Modifying Parameters of a Specified DB Instance
- Obtaining the Parameter Template of a Specified DB Instance
- Obtaining Parameters in a Specified Parameter Template
- Deleting a Parameter Template
- Recycling a DB Instance
- Tag Management
- Obtaining Task Information
- Appendix
- Change History
- SDK Reference
-
FAQs
- Product Consulting
- Resource and Disk Management
-
Database Connection
- What Should I Do If I Can't Connect to My RDS DB Instance?
- Can an External Server Access the RDS Database?
- What Do I Do If the Number of RDS Database Connections Reaches the Upper Limit?
- What Is the Maximum Number of Connections to an RDS DB Instance?
- How Can I Create and Connect to an ECS?
- What Should I Do If an ECS Cannot Connect to an RDS DB Instance Through a Private Network?
- What Should I Do If a Database Client Problem Causes a Connection Failure?
- What Should I Do If an RDS Database Problem Causes a Connection Failure?
- How Do My Applications Access an RDS DB Instance in a VPC?
- Do Applications Need to Support Reconnecting to the RDS DB Instance Automatically?
- Why Cannot I Ping My EIP After It Is Bound to a DB Instance?
- How Can I Obtain the IP Address of an Application?
- Can I Access an RDS DB Instance Over an Intranet Connection Across Regions?
- Is an SSL Connection to a DB Instance Interrupted After a Primary/Standby Switchover or Failover?
- Database Migration
- Database Permission
- Database Storage
- Client Installation
- Backup and Restoration
- Database Monitoring
- Capacity Expansion and Specification Change
- Database Parameter Modification
- Network Security
- Change History
- Troubleshooting
- Videos
Changing a DB Instance Class
Scenarios
You can change the instance class (vCPU 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
- The instance class can be changed only when the DB instance is available.
- The instance class of a DR instance cannot be changed.
- A DB instance cannot be deleted when its instance class is being changed.
- If a DB instance has a read replica, the new instance class must be no larger than the read replica class. When changing the read replica class, ensure that the selected class is no smaller than the DB instance class.
- After the instance class is changed, some parameters are automatically changed to the default values defined in the new instance class. The parameters are max_connections, max_worker_processes, max_wal_senders, max_prepared_transactions, and max_locks_per_transaction.
- After you change instance classes, the DB instances will be rebooted and services will be interrupted. You are advised to change instance classes during off-peak hours.
- The time required for changing an instance class (during off-peak hours) is as follows:
- This process takes 5 to 15 minutes.
- When you are changing an instance class, service downtime only occurs during the primary/standby switchover. The duration of the downtime varies based on the replication delay and the number of temporary files.
Parameter Changes
After the instance class is changed, RDS will change the values of the following parameters accordingly:
- shared_buffers
- max_connections
- maintenance_work_mem
- effective_cache_size
For RDS for PostgreSQL 11 and later versions, in addition to the preceding parameters, the values of the following parameters will also be changed:
- max_prepared_transactions
- max_wal_size
- work_mem
Procedure
- Log in to the management console.
- Click
in the upper left corner of the page and choose Databases > Relational Database Service.
- 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 next to the Instance Class field.
- On the displayed page, specify the new instance class and click Next.
- Confirm the specifications.
- If you need to modify your settings, click Previous.
- For pay-per-use DB instances, click Submit.
- 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 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.
- If you intend to scale down the DB instance class, click Submit.
- View the DB instance class change result.
Return to the Instances page and view the instance status. During the change period, the instance status is Changing instance class. After a few minutes, click the DB instance and view its instance class on the displayed Basic Information page to check that the change is successful.
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