Defined in github.com/aws/aws-sdk-go/service/rds/api.go
The ARN for the IAM role that permits RDS to send enhanced monitoring metrics to CloudWatch Logs. For example, arn:aws:iam:123456789012:role/emaccess. For information on creating a monitoring role, go to To create an IAM role for Amazon RDS Enhanced Monitoring (http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_Monitoring.html#USER_Monitoring.OS.IAMRole).
If MonitoringInterval is set to a value other than 0, then you must supply a MonitoringRoleArn value.