replicateSourceDb

Specifies that this resource is a Replica database, and to use this value as the source database. If replicating an Amazon RDS Database Instance in the same region, use the identifier of the source DB, unless also specifying the db_subnet_group_name. If specifying the db_subnet_group_name in the same region, use the arn of the source DB. If replicating an Instance in a different region, use the arn of the source DB. Note that if you are creating a cross-region replica of an encrypted database you will also need to specify a kms_key_id. See instance-replication and Working with PostgreSQL and MySQL Read Replicas for more information on using Replication.