The Start RDS Instances action starts your RDS Instances on demand.
It does this using the following endpoints in AWS’s RDS API:
Access to all four endpoints is required.
You may need the Start RDS Instances action to confirm the targeted RDS Instances have finish starting before moving onto the next action in a rule.
You can achieve this using the Start RDS Instances action’s Wait panel, pictured:
If you select Wait for RDS Instances to Start, the action will wait until the
describeDBInstances endpoint returns