AWS Certified Cloud Practitioner / Question #1281 of 719

Question #1281

A company is designing a fault-tolerant application architecture within a single AWS Region using multiple Availability Zones. What is the primary objective of this design approach?

A

Increased network bandwidth for inter-application communication

B

Fault tolerance and continuous availability during infrastructure failures

C

Lower operational costs through resource consolidation

D

Streamlined compliance with international data residency laws

Explanation

The correct answer is B. When designing a fault-tolerant architecture, the primary purpose of using multiple Availability Zones (AZs) is to ensure fault tolerance and continuous availability during infrastructure failures. AZs are physically separate, isolated data centers within an AWS Region, each with independent power, cooling, and networking. Deploying resources across AZs ensures redundancy, so if one AZ experiences an outage, the application can continue operating from another AZ.

Why other options are incorrect:
- A: While AZs are connected via high-speed links, the primary goal is not increased bandwidth but redundancy.
- C: Multi-AZ deployments typically increase costs due to resource duplication, not lower them.
- D: Data residency compliance depends on the AWS Region selected, not the use of multiple AZs within a Region.

Key Points:
- AZs provide isolation and redundancy within a Region.
- Fault tolerance requires distributing resources across AZs to mitigate failures.
- High availability is achieved by redundancy, not bandwidth or cost optimization.

Answer

The correct answer is: B