AWS Certified Solutions Architect Professional SAP-C02 Practice Question

The pilot-light pattern keeps only core, data-bearing services running in the recovery Region, while other infrastructure is provisioned only when a disaster occurs. The correct option meets this definition by maintaining a cross-Region RDS read replica and replicating data to S3, which keeps data current and supports the ≤ 5-minute RPO. All compute capacity is kept at zero desired instances, with AMIs and launch templates ready for deployment. In a disaster, CloudFormation can quickly deploy the compute layer, the RDS replica can be promoted, and Route 53 can redirect traffic-achieving the ≤ 2-hour RTO with minimal steady-state cost.

The other options represent different DR strategies that do not meet all the requirements:

• One incorrect option describes backup and restore. With this method, no resources are active in the DR region, and the environment is built from snapshots. This typically results in an RTO that would exceed the 2-hour requirement.
• Another incorrect option describes warm standby. This involves running application servers at reduced capacity in the DR region. While providing a faster RTO than pilot light, it incurs higher costs than necessary, violating the cost-optimization requirement.
• The final incorrect option describes a multi-site active-active strategy. Deploying a fully scaled stack in both regions provides the lowest RTO but also the highest ongoing cost, which directly contradicts the requirement to keep DR costs as low as possible.