A web application runs in one AWS Region.
The design must avoid a single facility failure taking down the whole service.
Choose TWO appropriate high-availability practices.
Distribute the execution layer across Availability Zones and route traffic to healthy targets so a single AZ failure does not remove every target.
Detailed explanation
Separate AZ failure boundaries reduce the chance that one facility failure affects every application target.
Separate AZ failure boundaries reduce the chance that one facility failure affects every application target.
Concentrating targets in one failure boundary leaves a single point of failure.
Concentrating targets in one failure boundary leaves a single point of failure.
AZ distribution improves availability but does not replace data protection or recovery planning.
AZ distribution improves availability but does not replace data protection or recovery planning.
Health checks and routing help avoid sending new requests to failed targets.
Health checks and routing help avoid sending new requests to failed targets.
Check official documentation
Compare the following points with the official documentation.
AWS CLF-C02 Domain 3.2とElastic Load Balancingの複数AZ・ヘルスチェックの説明を確認する。
What to confirm
複数AZへの分散と正常ターゲットへの振り分けを高可用性の対策として説明できる。
Key points
- Multiple Availability Zones
- High availability
- Health check
Notes
- Environment: AWS公式Global Infrastructure・Elastic Load Balancingドキュメントの確認
- Confirm current AWS service behavior and pricing conditions in the official documentation.
Foundation review
Failure isolation
Multiple AZs reduce dependence on one facility.
Layered availability
Placement and health-based routing solve different parts of the availability problem.