A business service requires an RPO of five minutes and an RTO of 30 minutes, but keeping all application EC2 instances running in the recovery Region is too expensive.
Database and other core resources are replicated; during a disaster the application tier can be started and DNS can be switched.
Which disaster recovery strategy is the best fit?
Use a pilot light strategy: replicate core data and infrastructure, then start the application tier and switch DNS during recovery.
Detailed explanation
A scaled-down but functional application environment runs continuously. It can meet the targets but costs more than the stated plan to stop the application tier.
A scaled-down but functional application environment runs continuously. It can meet the targets but costs more than the stated plan to stop the application tier.
Keep core data and minimal infrastructure available in the recovery Region and start the remaining application tier during a disaster. This generally costs less than warm standby while meeting a moderate RTO.
Keep core data and minimal infrastructure available in the recovery Region and start the remaining application tier during a disaster. This generally costs less than warm standby while meeting a moderate RTO.
The infrastructure and data would be created or restored during recovery, so a 30-minute RTO cannot be relied on consistently.
The infrastructure and data would be created or restored during recovery, so a 30-minute RTO cannot be relied on consistently.
Multiple Regions process traffic continuously. It can target faster failover but is excessive for the cost constraint and stated recovery model.
Multiple Regions process traffic continuously. It can target faster failover but is excessive for the cost constraint and stated recovery model.
Check official documentation
Compare the following points with the official documentation.
AWS Well-Architected disaster recovery optionsのPilot Light、Warm Standby、RPO、RTOの説明を確認する。
Official references
What to confirm
バックアップと復元、パイロットライト、ウォームスタンバイ、アクティブ／アクティブの常時稼働範囲を比較できる。
Key points
- Pilot light
- RPO
- RTO
- Warm standby
Notes
- Environment: AWS公式SOA-C03試験ガイドとAWS公式ドキュメントの確認
- Confirm current behavior in the official SOA-C03 guide and AWS service documentation.
Foundation review
Recovery readiness
More continuously running components generally reduce recovery time but increase cost.
Objective matching
The selected strategy must satisfy both data-loss and service-restoration limits, not just one of them.