*`availability_zones` - (Optional) A list of EC2 Availability Zones that
instances in the DB cluster can be created in
*`backup_retention_period` - (Optional) The days to retain backups for. Default
1
*`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
*`backup_window` - The backup window
*`endpoint` - The primary, writeable connection endpoint
*`engine` - The database engine
*`engine_version` - The database engine version
*`maintenance_window` - The instance maintenance window
*`database_name` - The database name
*`port` - The database port
*`status` - The RDS instance status
*`username` - The master username for the database
*`storage_encrypted` - Specifies whether the DB instance is encrypted