Does ApsaraDB for RDS support read-only instances and read/write splitting?-ApsaraDB RDS(RDS)-阿里云帮助中心

ApsaraDB for RDS supports both read-only instances and read/write splitting, letting you offload read traffic from your primary instance and scale horizontally for read-heavy workloads.

Note ApsaraDB for RDS uses a primary/secondary architecture. The secondary instance does not serve read or write traffic — it exists solely as a standby to ensure high availability. Read-only instances are separate from the secondary instance and are the correct way to scale read capacity.

Read-only instances

Add read-only instances to your primary instance to distribute read traffic and increase query throughput. Common use cases include:

Handling read-heavy workloads that exceed the capacity of a single instance
Running reporting or analytics queries without affecting production traffic

Read-only instances are supported for the following engines:

Read/write splitting

Read/write splitting is available for MySQL, PostgreSQL, and SQL Server instances. After you add read-only instances to your primary instance, enable read/write splitting. A read/write splitting endpoint is automatically generated to centrally receive and route query requests.

For setup instructions, see the topic for your engine: