Question 10
Domain 1: Cloud ConceptsA company is using EC2 Instances to run their e-commerce site on the AWS platform. If the site becomes unavailable, the company will lose a significant amount of money for each minute the site is unavailable. Which design principle should the company use to minimize the risk of an outage?
Correct answer: C
Explanation
Fault tolerance reduces outage risk by designing the system to keep operating when a component fails. AWS supports this with high availability patterns like launching EC2 instances in separate Availability Zones, since "each subnet must reside entirely within one Availability Zone" and HA comes from spreading instances across zones.
Why each option is right or wrong
A. Least Privilege.
B. Pilot Light.
C. Fault Tolerance.
AWS design guidance for minimizing outage impact is to build for failure so the application continues operating when an EC2 host or even an entire Availability Zone is impaired; a subnet is confined to a single AZ, so resilience requires placing instances in separate AZs rather than relying on one subnet or one zone. In this scenario, every minute of downtime has direct revenue loss, so the relevant principle is the one that keeps service available despite component failure, not a cost-optimization or scaling choice.
D. Multi-threading.