- A
Elasticity
Why wrong: Elasticity refers to the ability to automatically provision and de-provision resources to match current demand. The scenario does not describe scaling based on load changes; it describes adding a redundant instance for fault tolerance.
- B
High availability
Correct. High availability is the ability to keep applications running with minimal downtime by eliminating single points of failure. Placing instances in multiple Availability Zones behind a load balancer ensures that the application remains accessible even if one instance fails.
- C
Scalability
Why wrong: Scalability is the ability of a system to handle growing demand by adding resources. The scenario does not involve increasing capacity to handle more users; it focuses on maintaining uptime during failures.
- D
Fault tolerance
Why wrong: Fault tolerance implies that the system continues to operate without any interruption (zero downtime) even when a component fails. The scenario mentions 'minimal downtime' during failure, which aligns more with high availability than with strict fault tolerance. Achieving true fault tolerance typically requires more complex architecture, such as active-active deployment with real-time replication.
CLF-C02 Cloud Concepts Practice Question
This CLF-C02 practice question tests your understanding of cloud concepts. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. A key principle to apply: high availability ensures applications remain operational despite component failures.. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company runs a customer-facing web application on a single Amazon EC2 instance. To ensure the application remains accessible if the instance fails, the company launches a second EC2 instance in a different Availability Zone and configures an Application Load Balancer to distribute traffic. The application continues to serve users with minimal downtime during the failure of any single instance. This scenario best demonstrates which cloud computing concept?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"best"Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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
High availability is the correct concept because the architecture uses redundant EC2 instances in separate Availability Zones behind an Application Load Balancer to eliminate a single point of failure. If one instance fails, the load balancer automatically routes traffic to the healthy instance, ensuring the application remains accessible with minimal downtime. This design specifically addresses fault tolerance and uptime, not the ability to handle variable load or scale resources.
Key principle: High availability ensures applications remain operational despite component failures.
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 refers to the ability to automatically provision and de-provision resources to match current demand. The scenario does not describe scaling based on load changes; it describes adding a redundant instance for fault tolerance.
- ✓
High availability
Why this is correct
Correct. High availability is the ability to keep applications running with minimal downtime by eliminating single points of failure. Placing instances in multiple Availability Zones behind a load balancer ensures that the application remains accessible even if one instance fails.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
High availability ensures applications remain operational despite component failures.
- ✗
Scalability
Why it's wrong here
Scalability is the ability of a system to handle growing demand by adding resources. The scenario does not involve increasing capacity to handle more users; it focuses on maintaining uptime during failures.
- ✗
Fault tolerance
Why it's wrong here
Fault tolerance implies that the system continues to operate without any interruption (zero downtime) even when a component fails. The scenario mentions 'minimal downtime' during failure, which aligns more with high availability than with strict fault tolerance. Achieving true fault tolerance typically requires more complex architecture, such as active-active deployment with real-time replication.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse high availability with elasticity or scalability because all three involve multiple instances, but high availability is specifically about redundancy and fault tolerance to minimize downtime, not about adjusting capacity to meet demand.
Trap categories for this question
Scenario analysis trap
Elasticity refers to the ability to automatically provision and de-provision resources to match current demand. The scenario does not describe scaling based on load changes; it describes adding a redundant instance for fault tolerance.
Detailed technical explanation
How to think about this question
Under the hood, the Application Load Balancer performs health checks on each target (EC2 instance) using HTTP/HTTPS pings to a configured endpoint (e.g., /health). If a health check fails consecutively (default threshold is 2-10 failures), the load balancer marks the instance as unhealthy and stops sending traffic to it, while DNS-based routing (via the load balancer's static endpoint) ensures client connections are unaffected. In a real-world scenario, if the primary instance's underlying hardware fails, the load balancer's cross-zone load balancing and health check mechanism can failover traffic to the secondary instance in under 30 seconds, achieving high availability without manual intervention.
KKey Concepts to Remember
- High availability ensures applications remain operational despite component failures.
- Achieved by eliminating single points of failure, often using redundancy.
- Utilizes multiple Availability Zones to protect against data center-wide outages.
- Application Load Balancers distribute traffic and perform health checks to support high availability.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
High availability ensures applications remain operational despite component failures.
Real-world example
How this comes up in practice
A company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
What to study next
Got this wrong? Here's your next step.
Review high availability ensures applications remain operational despite component failures., then practise related CLF-C02 questions on the same topic to reinforce the concept.
- →
Cloud Concepts — study guide chapter
Learn the concepts, then practise the questions
- →
Cloud Concepts practice questions
Targeted practice on this topic area only
- →
All CLF-C02 questions
1,024 questions across all exam domains
- →
AWS Certified Cloud Practitioner CLF-C02 study guide
Full concept coverage aligned to exam objectives
- →
CLF-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related CLF-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Cloud Concepts practice questions
Practise CLF-C02 questions linked to Cloud Concepts.
Security and Compliance practice questions
Practise CLF-C02 questions linked to Security and Compliance.
Cloud Technology and Services practice questions
Practise CLF-C02 questions linked to Cloud Technology and Services.
Billing, Pricing, and Support practice questions
Practise CLF-C02 questions linked to Billing, Pricing, and Support.
AWS shared responsibility model practice questions
Practise CLF-C02 questions linked to AWS shared responsibility model.
AWS IAM practice questions
Practise CLF-C02 questions linked to AWS IAM.
AWS pricing practice questions
Practise CLF-C02 questions linked to AWS pricing.
AWS support plans practice questions
Practise CLF-C02 questions linked to AWS support plans.
AWS S3 practice questions
Practise CLF-C02 questions linked to AWS S3.
AWS EC2 practice questions
Practise CLF-C02 questions linked to AWS EC2.
Practice this exam
Start a free CLF-C02 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this CLF-C02 question test?
Cloud Concepts — This question tests Cloud Concepts — High availability ensures applications remain operational despite component failures..
What is the correct answer to this question?
The correct answer is: High availability — High availability is the correct concept because the architecture uses redundant EC2 instances in separate Availability Zones behind an Application Load Balancer to eliminate a single point of failure. If one instance fails, the load balancer automatically routes traffic to the healthy instance, ensuring the application remains accessible with minimal downtime. This design specifically addresses fault tolerance and uptime, not the ability to handle variable load or scale resources.
What should I do if I get this CLF-C02 question wrong?
Review high availability ensures applications remain operational despite component failures., then practise related CLF-C02 questions on the same topic to reinforce the concept.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
High availability ensures applications remain operational despite component failures.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Keep practising
More CLF-C02 practice questions
- A company publishes a message each time a new product is added to its catalogue. Three services need to receive this mes…
- A media company stores frequently accessed video thumbnails in Amazon S3. The thumbnails are read multiple times every d…
- A company needs a service to translate domain names (like www.example.com) into IP addresses, check the health of their…
- A startup runs an application on AWS and receives a monthly bill that charges exactly for the number of compute hours us…
- A financial institution runs its core banking application on-premises due to regulatory requirements. It has connected i…
- A company wants to run a MySQL database in AWS without managing database software installation, applying patches, settin…
Last reviewed: Jun 11, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.