- What's New
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Getting Started
- Getting Started with RDS for MySQL
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- Huawei Cloud MySQL Kernel
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User Guide
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Working with RDS for MySQL
- Suggestions on Using RDS for MySQL
- Database Migration
- Performance Tuning
- Instance Lifecycle
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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
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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
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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
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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
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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
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Working with RDS for MySQL
- Best Practices
- Performance White Paper
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API Reference
- Before You Start
- API Overview
- Calling APIs
- API v3.1 (Recommended)
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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
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FAQs
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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
Configuring the Delay Threshold and Routing Policy
After read/write splitting is enabled and read replicas are created, you can configure the delay threshold and routing policy as required.
Parameter |
Description |
---|---|
Delay Threshold |
The maximum delay for data to be synchronized from primary DB instances to read replicas. This parameter is only applied when there are read replicas. To prevent data inconsistencies between primary DB instances and read replicas from lasting too long, if the delay of a read replica exceeds the configured threshold, read requests are not forwarded to the read replica regardless of the read weight distributed to it. When read/write splitting is enabled, the default delay threshold is 30s and the default value range is 0–7,200s. It is recommended that the threshold be greater than or equal to 30s. Traffic is not allocated to read replicas whose delay exceeds the configured threshold. |
Read Weight Distribution |
After read/write splitting is enabled, you can configure read weights for the primary DB instance and read replicas. If no read replicas are selected for the database proxy, read/write splitting cannot be used. The read weight ranges from 1 to 1,000. Read replicas with higher read weight distributions process more read requests. For example, if the read weights distributed to one primary DB instance and four read replicas are 0, 100, 200, 500, and 300, respectively, the primary DB instance does not process any read requests (write requests are still automatically routed to the primary DB instance) while the four read replicas process read requests with a ratio of 1:2:5:3. |
Constraints
To enable proxy load balancing, contact customer service.
Configuring Delay Threshold
- 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, click the target DB instance. The Basic Information page is displayed.
- In the navigation pane on the left, click Database Proxy.
- In the proxy information area, click
next to the Delay Threshold field.
Configuring Routing Policy in Multi-Proxy Mode
- 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, click the primary instance name. The Basic Information page is displayed.
- In the navigation pane on the left, click Database Proxy.
- In the proxy information area, click Configure next to the Routing Policy field. In the displayed dialog box, set required parameters.
- Weighted: You can distribute read weights for the DB instance and read replicas. For details, see Table 1.
NOTE:
The system automatically distributes weights to read replicas, including read replicas created afterwards, according to the default distribution rules. If a read replica breaks down or is deleted, the weight is automatically removed. After the read replica recovers, the weight is automatically restored.
Click OK and view the weights in the proxy information area.
- Load balancing: If selected, to balance the load among read replicas, read requests are automatically distributed to multiple read replicas based on the number of active connections.
In the Select DB Instance drop-down list, select the instances for load balancing.
NOTE:
To add new read replicas for load balancing, select the read replicas from the Select DB Instance drop-down list and click OK.
Click OK and view DB instances for load balancing in the proxy information area.
- Weighted: You can distribute read weights for the DB instance and read replicas. For details, see Table 1.
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