A company needs to build a disaster recovery (DR) solution for its ecommerce website. The web application is hosted on a fleet of t3.large Amazon EC2 instances and uses an Amazon RDS for MySQL DB instance. The EC2 instances are in an Auto Scaling group that extends across multiple Availability Zones. In the event of a disaster, the web application must fail over to the secondary environment with an RPO of 30 seconds and an RTO of 10 minutes. Which solution will meet these requirements MOST cost-effectively?
Select one answer.
Marked answer: B
Community Discussion
Written by other learners. Comments can disagree with the marked answer — check the official documentation when in doubt.
Chose B1
RPO 30s ⇒ Replication, not backups: Use RDS cross-Region read replica (cost-effective vs Aurora Global). RTO 10 min ⇒ Pilot-light/warm standby: Use AWS Elastic Disaster Recovery for EC2; launch & scale at failover time, not 24/7. Failover DNS: Route 53 failover routing (not geolocation/simple). → Therefore, B meets RPO/RTO at the lowest cost.
Chose B1
RPO seconds, RTO minutes => warm standby warm standby => always running but smaller always running but smaller => B. Run the EC2 instances at the minimum capacity in the DR Region
Chose B7
Bad question design. EC2 is in ASG, which means the application part is stateless, so no need to backup or replicate. Only database need replication.
