The correct answer is to increase the health check interval and increase the unhealthy threshold. This configuration directly addresses ALB health check tuning for transient errors by making the load balancer less sensitive to brief spikes in latency or temporary 503 responses, allowing the application time to recover before an instance is marked unhealthy. On the AWS Certified DevOps Engineer Professional DOP-C02 exam, this scenario tests your understanding of how health check parameters like interval and threshold interact with application resilience under load—a common trap is to assume that faster checks catch errors sooner, but that actually worsens the problem by triggering premature instance replacements. The key insight is that transient errors are short-lived, so you want to dampen the health check’s reaction time, not accelerate it. Remember the mnemonic “Slow and Steady Wins the Race” for transient errors: increase the interval and threshold to let the application breathe.
DOP-C02 Resilient Cloud Solutions Practice Question
This DOP-C02 practice question tests your understanding of resilient cloud solutions. 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 company runs a critical web application on EC2 instances in an Auto Scaling group. The application uses an Application Load Balancer (ALB) with health checks pointing to /health. Recently, the application experienced intermittent failures where the ALB would mark instances as unhealthy and route traffic away, causing a reduction in capacity. The development team noticed that the /health endpoint occasionally returns HTTP 503 when the application is under heavy load, but the application can recover quickly. The team wants to avoid unnecessary instance replacements while ensuring availability. Which solution should the DevOps engineer implement?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Increase the health check interval and increase the unhealthy threshold
Option B is correct because increasing the health check interval and unhealthy threshold reduces sensitivity to transient errors, avoiding unnecessary instance replacements. Option A is wrong because decreasing the interval makes the health check more sensitive, worsening the issue. Option C is wrong because reducing the unhealthy threshold makes it easier to mark instances unhealthy. Option D is wrong because custom actions are not necessary; the health check configuration can be tuned.
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.
✗
Implement a custom health check using Lambda that ignores 503 responses
Why it's wrong here
Not needed; ALB health check tuning is sufficient.
✗
Decrease the unhealthy threshold to mark instances unhealthy faster
Why it's wrong here
Increases replacements.
✓
Increase the health check interval and increase the unhealthy threshold
Why this is correct
Less sensitive to transient errors.
Related concept
Read the scenario before looking for a memorised answer.
✗
Decrease the health check interval and decrease the healthy threshold
Why it's wrong here
More sensitive, more replacements.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
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.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→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 DOP-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Resilient Cloud Solutions — This question tests Resilient Cloud Solutions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Increase the health check interval and increase the unhealthy threshold — Option B is correct because increasing the health check interval and unhealthy threshold reduces sensitivity to transient errors, avoiding unnecessary instance replacements. Option A is wrong because decreasing the interval makes the health check more sensitive, worsening the issue. Option C is wrong because reducing the unhealthy threshold makes it easier to mark instances unhealthy. Option D is wrong because custom actions are not necessary; the health check configuration can be tuned.
What should I do if I get this DOP-C02 question wrong?
Identify which DOP-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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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.
Question Discussion
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