CLF-C02 Cloud Concepts Practice Question
A company runs a web application on a single Amazon EC2 instance. To improve the application's ability to remain operational even if an entire data center becomes unavailable, the company deploys identical application instances across three AWS Availability Zones and places them behind an Application Load Balancer. Which characteristic of cloud computing does this architecture best demonstrate?
⚠ Common exam trap
It's easy for candidates to confuse high availability with elasticity or scalability, but high availability specifically focuses on fault tolerance and uptime through redundancy across isolated failure domains, not on dynamic resource adjustment or load handling.
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
✓
High availability
Deploying identical application instances across three Availability Zones and placing them behind an Application Load Balancer ensures that if an entire data center (AZ) becomes unavailable, traffic is automatically rerouted to healthy instances in the remaining AZs. This architecture directly demonstrates high availability, which is the ability of a system to remain operational despite component failures, by eliminating a single point of failure at the data center level.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Elasticity
Why it's wrong here
Elasticity describes the ability to automatically scale compute resources up or down in response to changing demand, such as adding instances during peak traffic and removing them during off-peak times. The problem in this scenario is not fluctuating load but rather a single instance that, if it fails, takes the entire application offline. Adding elasticity alone does not eliminate the existing single point of failure, because the system still depends on that one instance; therefore, elasticity is not the correct cloud characteristic.
When this WOULD be correct
A question describing an application that automatically adds or removes EC2 instances based on CPU utilization or traffic spikes would make elasticity the correct answer, as it demonstrates dynamic resource adjustment.
- ✓
High availability
Why this is correct
High availability is the cloud characteristic that keeps a workload operational during component or infrastructure failures by removing single points of failure. In this scenario, a single EC2 instance is a sole point of failure; deploying the web application across multiple Availability Zones and placing it behind a load balancer ensures that if one instance or an entire AZ fails, traffic is redirected to healthy instances. This directly meets the requirement for continuous availability, so it is the correct answer.
- ✗
Scalability
Why it's wrong here
Scalability is the capacity to handle increased workloads by adding CPU, memory, or additional instances (horizontal scaling), but it does not inherently protect against availability failures. If a single EC2 instance fails, even a highly scalable system can be unavailable because the instance is the only compute resource. While horizontal scaling combined with a load balancer can improve availability, the scenario's primary goal is redundancy across Availability Zones, not accommodating workload growth, so scalability is incorrect.
When this WOULD be correct
A question describing a web application that experiences unpredictable traffic spikes and automatically adds or removes EC2 instances based on demand using Auto Scaling groups would make scalability the correct answer.
- ✗
Agility
Why it's wrong here
Agility is the cloud property that enables rapid provisioning of new resources, fast development cycles, and quick response to changing business requirements. The described change—moving from one instance to multiple instances with a load balancer—is about designing for fault tolerance and uptime, not about accelerating deployment or reducing time-to-market. Thus, agility does not capture the architectural intent of this solution, making it a wrong answer.
When this WOULD be correct
A question asking which cloud characteristic allows a company to quickly deploy a new application environment in response to a sudden market opportunity, with minimal manual intervention and rapid provisioning of compute and storage resources.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The CLF-C02 exam frequently reuses these exact scenarios with slightly different constraints.
✓High availabilityCorrect answer▾
Why this is correct
High availability is the cloud characteristic that keeps a workload operational during component or infrastructure failures by removing single points of failure. In this scenario, a single EC2 instance is a sole point of failure; deploying the web application across multiple Availability Zones and placing it behind a load balancer ensures that if one instance or an entire AZ fails, traffic is redirected to healthy instances. This directly meets the requirement for continuous availability, so it is the correct answer.
✗ElasticityWrong answer — click to see why▾
Why this is wrong here
Elasticity refers to automatically scaling resources up or down based on demand, not distributing workloads across Availability Zones for fault tolerance. The described architecture focuses on redundancy across zones, not dynamic scaling.
★ When this WOULD be the correct answer
A question describing an application that automatically adds or removes EC2 instances based on CPU utilization or traffic spikes would make elasticity the correct answer, as it demonstrates dynamic resource adjustment.
Why candidates choose this
Candidates may confuse high availability with elasticity because both involve multiple instances, but elasticity emphasizes scaling to meet demand, not surviving zone failures.
✗ScalabilityWrong answer — click to see why▾
Why this is wrong here
Scalability refers to the ability to automatically adjust resources to handle varying load, not to surviving data center failures. The scenario describes distributing instances across Availability Zones for fault tolerance, which is high availability, not scalability.
★ When this WOULD be the correct answer
A question describing a web application that experiences unpredictable traffic spikes and automatically adds or removes EC2 instances based on demand using Auto Scaling groups would make scalability the correct answer.
Why candidates choose this
Candidates may confuse distributing resources across zones with scaling out, but the primary goal here is resilience, not capacity adjustment.
✗AgilityWrong answer — click to see why▾
Why this is wrong here
Agility refers to the ability to rapidly provision and deprovision resources, not to maintaining operation during data center failures. The scenario describes distributing instances across Availability Zones to ensure uptime, which is high availability.
★ When this WOULD be the correct answer
A question asking which cloud characteristic allows a company to quickly deploy a new application environment in response to a sudden market opportunity, with minimal manual intervention and rapid provisioning of compute and storage resources.
Why candidates choose this
Candidates may confuse agility with high availability because both involve quick responses, but agility is about speed of resource provisioning, not fault tolerance.
Analysis generated from the official CLF-C02blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CLF-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 CLF-C02 exam.