System Architecture
RDS provides primary and secondary availability architectures by default, and there are two available deployment, namely, single-availability zone deployment and multiple availability zone deployment:
Single Availability Zone Deployment

Multiple Availability Zone Deployment

Architecture Analysis
- DNS: Domain Name Resolution service, used to access RDS instance through domain name in the intranet.
- DMS: Database Management service, providing a WEB management interface, convenient for simple management on cloud database instances.
- Console: JD Cloud console service, providing RDS management interface.
- Master Node and Subnode: The default master node provides external services, and the subnode exists as a disaster recovery instance. When the master node fails to provide services, the subnode can be promoted as a new master node to ensure uninterrupted user services.
- Monitoring Service: To collect RDS instance information and physical machine information.
- Account Management Service: It is responsible for the creation, deletion and authorization of the RDS instance account.
- Database Management Service: It is responsible for the creation, deletion, and authorization of the RDS instance database.
- Backup Service: Automatic scheduled backup, supporting customized backup.
- Performance Optimization Service: To collect RDS slow log information for analysis and system optimization.
- SQL Audit: It is responsible for collecting SQL execution statements for safety audit.