Question

A financial services company runs a critical transaction processing application in a single AWS Region on EC2 instances behind an Application Load Balancer, backed by an Amazon RDS for PostgreSQL database. The business requires a disaster recovery plan that can recover in a second Region within about 30 minutes (RTO) with minimal data loss (RPO of a few minutes), while keeping ongoing DR costs as low as possible. The company does not want to run a full-scale duplicate of the fleet during normal operations. Which disaster recovery strategy best meets these requirements?

Accepted Answer

Pilot light: continuously replicate the database to a minimal standby instance in the second Region and keep core infrastructure defined but scaled down, then scale up compute and promote the database during failover.

Answer

Backup-and-restore: take periodic EBS and RDS snapshots, copy them to the second Region, and provision all infrastructure from scratch only when a disaster occurs.

Answer

Warm standby: run a fully scaled, always-on duplicate of the production environment in the second Region receiving live traffic in an active-active configuration.

Answer

Multi-site active-active: distribute production traffic across both Regions simultaneously using Route 53 latency-based routing with identically sized fleets in each Region.