DOP-C02 Resilient Cloud Solutions Practice Question
A company runs a critical e-commerce application on Amazon EC2 instances behind an Application Load Balancer (ALB) with Auto Scaling. The application must be resilient to an Availability Zone (AZ) failure. What is the MOST resilient configuration?
⚠ Common exam trap
Many candidates confuse high availability with fault tolerance, mistakenly thinking that a single large instance or a single AZ with a larger instance type provides resilience, when in fact distributing workloads across multiple AZs is the only way to survive an AZ failure without manual intervention.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Configure the Auto Scaling group to span at least three AZs and set the ALB to route traffic to all AZs.
Spanning the Auto Scaling group across at least three Availability Zones (AZs) and routing traffic from the ALB to all AZs ensures that if one AZ fails, the remaining AZs can handle the load without interruption. This configuration leverages the ALB's native cross-zone load balancing and Auto Scaling's ability to maintain desired capacity across multiple AZs, providing fault isolation and high availability for the critical e-commerce application.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Configure the Auto Scaling group to launch instances in a single AZ with a larger instance type.
Why it's wrong here
Single AZ is not resilient to AZ failure.
- ✗
Deploy a single large EC2 instance in one AZ and use an Elastic IP for failover.
Why it's wrong here
Single instance is a single point of failure.
- ✗
Use a Network Load Balancer instead of an ALB and deploy instances in two AZs.
Why it's wrong here
Two AZs provide less resilience than three, and NLB does not add resilience by itself.
- ✓
Configure the Auto Scaling group to span at least three AZs and set the ALB to route traffic to all AZs.
Why this is correct
Multi-AZ deployment ensures resilience.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DOP-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DOP-C02 exam.