Basic Information
| Field | Details |
|---|---|
| English name | High Availability & Fault Tolerance |
| Full name | High Availability & Fault Tolerance |
| Chinese description | 高可用与容错 |
| Japanese description | 高可用性とフォールトトレランス |
| Exam frequency | ⭐⭐⭐⭐⭐ |
| Often confused with | Redundancy / DR / Elasticity |
In one sentence
High availability reduces downtime through redundancy and recovery, while fault tolerance continues operation with minimal interruption.
Key points
- Deploy across multiple Availability Zones to avoid a single-AZ dependency.
- Load balancers, health checks, Auto Scaling, and replicated data layers remove single points of failure.
- High availability may allow brief recovery; fault-tolerant designs require more redundancy and cost.
Exam takeaway
Define failure domains, RTO, RPO, state handling, and recovery tests instead of relying on service labels alone.