Can I Change the Replication Mode Between Primary DB Instances and Read Replicas?

A read replica uses a single-node architecture (without a standby node). Changes to the primary DB instance are also automatically synchronized to all associated read replicas through the native MySQL or MariaDB replication function. The synchronization is not affected by network latency. Even if a DB instance does not have a primary key ID, its data is synchronized to the associated read replicas.

The replication mode displayed on the RDS console indicates the data synchronization method between primary and standby DB instances. Semi-synchronous and asynchronous are both supported. The semi-synchronous mode is more secure but the asynchronous mode improves performance.

The default synchronization between primary DB instances and read replicas is asynchronous and cannot be changed.

The synchronous-commit mode is supported between primary and standby instances and cannot be modified.

The asynchronous-commit mode is supported between primary instances and read replicas and cannot be modified.

For more information, see official documentation.