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RDS Cluster

Amazon Relational Database Service (RDS) Clusters provide a managed, highly-available relational database running on multiple Availability Zones. An RDS Cluster contains one or more database instances that share storage, backups, and endpoints, and can be configured for automatic fail-over and read-scaling. Aurora MySQL and Aurora PostgreSQL engines run exclusively within clusters, while other engines (e.g. MySQL, PostgreSQL) can participate in global database topologies through cluster links.
Official documentation: https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/CHAP_AuroraOverview.html

Terrafrom Mappings:

  • aws_rds_cluster.cluster_identifier

Supported Methods​

  • GET: Get a cluster by identifier
  • LIST: List all RDS clusters
  • SEARCH: Search for a cluster by ARN

rds-db-subnet-group​

Each RDS Cluster is associated with a DB subnet group that defines the set of subnets (and therefore Availability Zones) in which its instances can run.

dns​

The cluster exposes an endpoint such as mycluster.cluster-123456789012.eu-west-2.rds.amazonaws.com; this hostname is represented as a DNS record linked to the cluster.

rds-db-cluster​

Clusters can reference other clusters as replication sources or targets (e.g. in an Aurora global database), creating a dependency link between the participating RDS clusters.

ec2-security-group​

Traffic to and from the cluster’s instances is controlled by one or more EC2 security groups attached to the cluster.

route53-hosted-zone​

Organisations often create Route 53 records (A/AAAA or CNAME) in their hosted zones to provide friendly names for the cluster endpoint, linking the hosted zone to the RDS Cluster.

kms-key​

If storage encryption is enabled, the cluster uses a customer-managed or AWS-managed KMS key; compromising or deleting the key will render the data inaccessible.

rds-option-group​

Certain engines allow additional features to be enabled via option groups (e.g. Oracle options); a cluster may reference an option group to configure those extensions.

iam-role​

An RDS Cluster can assume IAM roles for tasks such as exporting snapshots to S3, publishing logs to CloudWatch, or accessing AWS services like Kinesis; these roles are linked resources.