Product Introduction
The RDS currently supports read-only instances (read-only instances are currently only supported in Chongqing 2).
In the application scenario where there are a few write requests but a large number of read requests to the database, a single instance may not be able to properly deal with the read stress and even have an impact on the main business. In order to scale the read ability and balance the load on the database, you can create one or more read-only instances in a certain region, and use these read-only instances to meet a large number of read requests to the database, thereby increasing the throughput of your application. You need to configure the connection address of the active instance and each read-only instance in the application so that the write request can be sent to the active instance and the read request can be sent to the read-only instances.
A read-only instance is an architecture with a single physical node (no backup node). The native replication function of MySQL is used to synchronize the changes to the active instance to all read-only instances, and the data synchronization between the active instance and read-only instances is not affected by network latency.
Functional Features
The specification can differ from that of the active instance, but must be greater than or equal to that of the active instance, and the specification can be changed at any time (no time limit) to facilitate flexible upgrading.
Accounts and databases are maintenance free and synchronized from the active instance.
System performance metrics are monitored.
The RDS provides nearly 20 performance monitoring views, such as disk capacity, IOPS, number of connections, CPU utilization, and network traffic. Users can easily view the load of instances.
Functional Restrictions
Up to 5 read-only instances can be created for one active instance.
Backup setting: Backup setting and temporary backup are not available.
Instance recovery: Users cannot create temporary instances from backup files or at any point in time, or overwrite instances by backup sets.
Data migration: Users cannot migrate data to read-only instances.
Database management: Users cannot create or delete databases.
Account management: For read-only instances, users cannot create accounts. To add accounts for read-only instances, please add them on the active instance.