AWS Certified Solutions Architect – Associate (SAA-C03)Design Resilient ArchitecturesMedium
A global e-commerce company hosts its primary application in the `us-east-1` region. Due to regulatory compliance and business continuity requirements, they need to implement a disaster recovery strategy that can restore their application in a different AWS region with a Recovery Time Objective (RTO) of less than 4 hours and a Recovery Point Objective (RPO) of less than 1 hour. The solution must minimize continuous operational costs while providing a functional, though scaled-down, environment ready for quick failover. Which disaster recovery strategy should they implement?
- AMulti-site Active/Active
- BWarm Standby
- CPilot Light
- DBackup and Restore
Show answer & explanationAnswer & explanation
Correct answer: B. Warm Standby
Warm Standby is the most suitable strategy for the given RTO/RPO requirements while balancing cost. It maintains a scaled-down but functional copy of the application in the DR region, allowing for faster recovery than Pilot Light or Backup and Restore, and is less costly than Multi-site Active/Active.
Why the other options are wrong
- A. Multi-site Active/Active provides the lowest RTO/RPO but incurs the highest operational costs, which goes against the requirement to minimize continuous operational costs.
- C. Pilot Light maintains only core services, requiring more time to fully provision and scale up, which might exceed the 4-hour RTO.
- D. Backup and Restore typically has the highest RTO and RPO, which would not meet the specified requirements.
Warm Standby DR
A disaster recovery strategy where a scaled-down but functional version of the application is continuously running in a secondary region, ready to handle traffic upon failover.
- Achieves RTO in minutes to hours and RPO in minutes.
- Higher cost than Pilot Light but lower than Multi-site Active/Active.
- Pre-provisioned infrastructure in the DR region.
Memory trick: DR strategies: B.P.W.A. - Big Problems With AWS