source
The ID of source instance. If the source instance is a cloud database (such as RDS MySQL), you need to pass in the instance ID of the cloud database (such as the instance ID of RDS MySQL). If the source instance is a self-built database, the value of this parameter changes according to the value of source_endpoint_instance_type. For example, the value of source_endpoint_instance_type is: ** ECS, then this parameter needs to be passed into the instance ID of ECS. ** DG, then this parameter needs to be passed into the ID of database gateway. ** EXPRESS, CEN, then this parameter needs to be passed in the ID of VPC that has been interconnected with the source database. Note: when the value is CEN, you also need to pass in the ID of CEN instance in the cloud enterprise network with the reserved parameter reserve.