- A
Place the instances in a single subnet and increase the instance size.
Why wrong: This does not add automatic recovery or remove unhealthy instances from service.
- B
Use an Application Load Balancer with an Auto Scaling group and configure health checks.
An Application Load Balancer distributes traffic across healthy targets, and an Auto Scaling group can replace instances that fail health checks. Together, they provide automatic recovery from instance failure and keep the application available across multiple Availability Zones. This is the standard resilient design for stateless EC2 web tiers.
- C
Use a network ACL to detect failed instances and restart them.
Why wrong: Network ACLs filter traffic, but they do not monitor instance health or restart servers.
- D
Store the web servers on EBS volumes so the data survives failures.
Why wrong: Persistent storage alone does not automatically recover failed compute instances or shift traffic.
Quick Answer
The answer is to use an Application Load Balancer with an Auto Scaling group and configure health checks. This solution is correct because the ALB performs HTTP/HTTPS health checks against each EC2 instance, and when an instance fails, the Auto Scaling group automatically terminates the unhealthy instance and launches a replacement to maintain the desired capacity, ensuring automatic instance replacement without manual action. On the SAA-C03 exam, this scenario tests your understanding of how ALB health checks integrate with Auto Scaling to provide self-healing infrastructure across multiple Availability Zones—a common trap is thinking a standalone ALB or a simple CloudWatch alarm can replace instances, but only the Auto Scaling group has the lifecycle management to launch new instances. Remember the memory tip: “ALB checks, ASG replaces”—the load balancer detects the problem, but the Auto Scaling group is the one that actually swaps out the unhealthy instance.
SAA-C03 Design Secure Architectures Practice Question
This SAA-C03 practice question tests your understanding of design secure architectures. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. 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 stateless web application runs on Amazon EC2 instances across two Availability Zones. The team wants unhealthy instances to be removed automatically and replaced without manual action. What is the best solution?
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
Use an Application Load Balancer with an Auto Scaling group and configure health checks.
Option B is correct because an Application Load Balancer (ALB) with an Auto Scaling group provides automated health checks and instance replacement. The ALB performs HTTP/HTTPS health checks against the instances, and when an instance fails the health check, the Auto Scaling group automatically terminates the unhealthy instance and launches a new one to maintain the desired capacity. This ensures the stateless web application remains available across both Availability Zones without manual intervention.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Place the instances in a single subnet and increase the instance size.
Why it's wrong here
This does not add automatic recovery or remove unhealthy instances from service.
- ✓
Use an Application Load Balancer with an Auto Scaling group and configure health checks.
Why this is correct
An Application Load Balancer distributes traffic across healthy targets, and an Auto Scaling group can replace instances that fail health checks. Together, they provide automatic recovery from instance failure and keep the application available across multiple Availability Zones. This is the standard resilient design for stateless EC2 web tiers.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Use a network ACL to detect failed instances and restart them.
Why it's wrong here
Network ACLs filter traffic, but they do not monitor instance health or restart servers.
- ✗
Store the web servers on EBS volumes so the data survives failures.
Why it's wrong here
Persistent storage alone does not automatically recover failed compute instances or shift traffic.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse network ACLs (stateless packet filters) with health check mechanisms, or assume that persistent storage (EBS) alone provides high availability without an orchestration layer like Auto Scaling.
Detailed technical explanation
How to think about this question
Under the hood, the ALB health check pings the configured endpoint (e.g., /health) at a specified interval (default 30 seconds) with a configurable threshold (e.g., 2 consecutive failures marks unhealthy). The Auto Scaling group uses Amazon EC2 Auto Scaling lifecycle hooks and the EC2 instance status checks to coordinate termination and launch, ensuring the replacement instance is registered with the ALB only after passing its initial health check. In a real-world scenario, if the health check path is misconfigured (e.g., returns a 404), the ALB will mark all instances as unhealthy, triggering a full replacement cycle that could cause an outage.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
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
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Design Secure Architectures — study guide chapter
Learn the concepts, then practise the questions
- →
Design Secure Architectures practice questions
Targeted practice on this topic area only
- →
All SAA-C03 questions
1,040 questions across all exam domains
- →
SAA-C03 study guide
Full concept coverage aligned to exam objectives
- →
SAA-C03 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related SAA-C03 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Design Secure Architectures practice questions
Practise SAA-C03 questions linked to Design Secure Architectures.
Design Resilient Architectures practice questions
Practise SAA-C03 questions linked to Design Resilient Architectures.
Design High-Performing Architectures practice questions
Practise SAA-C03 questions linked to Design High-Performing Architectures.
Design Cost-Optimized Architectures practice questions
Practise SAA-C03 questions linked to Design Cost-Optimized Architectures.
SAA-C03 VPC practice questions
Practise SAA-C03 questions linked to SAA-C03 VPC.
SAA-C03 S3 lifecycle policy questions
Practise SAA-C03 questions linked to SAA-C03 S3 lifecycle policy questions.
SAA-C03 RDS Multi-AZ questions
Practise SAA-C03 questions linked to SAA-C03 RDS Multi-AZ questions.
SAA-C03 IAM policy practice questions
Practise SAA-C03 questions linked to SAA-C03 IAM policy.
SAA-C03 Route 53 failover questions
Practise SAA-C03 questions linked to SAA-C03 Route 53 failover questions.
SAA-C03 CloudFront practice questions
Practise SAA-C03 questions linked to SAA-C03 CloudFront.
SAA-C03 NAT gateway questions
Practise SAA-C03 questions linked to SAA-C03 NAT gateway questions.
SAA-C03 VPC endpoint questions
Practise SAA-C03 questions linked to SAA-C03 VPC endpoint questions.
Practice this exam
Start a free SAA-C03 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 SAA-C03 question test?
Design Secure Architectures — This question tests Design Secure Architectures — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use an Application Load Balancer with an Auto Scaling group and configure health checks. — Option B is correct because an Application Load Balancer (ALB) with an Auto Scaling group provides automated health checks and instance replacement. The ALB performs HTTP/HTTPS health checks against the instances, and when an instance fails the health check, the Auto Scaling group automatically terminates the unhealthy instance and launches a new one to maintain the desired capacity. This ensures the stateless web application remains available across both Availability Zones without manual intervention.
What should I do if I get this SAA-C03 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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?
Read the scenario before looking for a memorised answer.
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 →
Last reviewed: Jun 11, 2026
This SAA-C03 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 SAA-C03 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.