*`preferred_backup_window` - (Optional) The daily time range during which automated backups are created if automated backups are enabled using the BackupRetentionPeriod parameter.
Default: A 30-minute window selected at random from an 8-hour block of time per region. e.g. 04:00-09:00
*`preferred_maintenance_window` - (Optional) The weekly time range during which system maintenance can occur, in (UTC) e.g. wed:04:00-wed:04:30
*`port` - (Optional) The port on which the DB accepts connections
*`vpc_security_group_ids` - (Optional) List of VPC security groups to associate
with the Cluster
*`apply_immediately` - (Optional) Specifies whether any cluster modifications
are applied immediately, or during the next maintenance window. Default is
`false`. See [Amazon RDS Documentation for more information.](http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Overview.DBInstance.Modifying.html)
## Attributes Reference
The following attributes are exported:
*`id` - The RDS Cluster Identifier
*`cluster_identifier` - The RDS Cluster Identifier
*`cluster_members`–List of RDS Instances that are a part of this cluster
*`address` - The address of the RDS instance.
*`allocated_storage` - The amount of allocated storage
*`availability_zones` - The availability zone of the instance
*`backup_retention_period` - The backup retention period