← DOP-C02·Amazon Web Services

Question 729 of 1,750

Monitoring and Logging →mediumMultiple ChoiceObjective-mapped

DOP-C02 Monitoring and Logging Practice Question

This DOP-C02 practice question tests your understanding of monitoring and logging. 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 DevOps engineer is troubleshooting an application that runs on Amazon EC2 instances behind an Application Load Balancer. Users report intermittent 503 errors. CloudWatch metrics for the ALB show an increase in 'HTTPCode_ELB_5XX_Count' but the backend 'HealthyHostCount' remains stable. Which action should the engineer take to identify the root cause?

A
Increase the size of the EC2 instances to handle more requests.
Why wrong: Increasing instance size addresses capacity, but the issue is intermittent 503s with stable healthy host count, suggesting a timeout or configuration problem.
B
Enable detailed CloudWatch metrics on the EC2 instances to monitor CPU and memory.
Why wrong: EC2 instance metrics monitor resource utilization, but the ALB is returning 503s even though backend hosts are healthy, so the problem is likely at the load balancer level.
C
Enable and review the ALB access logs stored in Amazon S3 to analyze the HTTP response codes and request patterns.
ALB access logs provide detailed information about each request, including response codes, timestamps, and request paths, enabling identification of the specific requests that are failing.
D
Increase the idle timeout setting on the ALB.
Why wrong: Increasing the idle timeout might help if requests are timing out, but the 503 errors could be due to other reasons like connection limits or application errors.

Full breakdown with real-world context →

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

✓

Enable and review the ALB access logs stored in Amazon S3 to analyze the HTTP response codes and request patterns.

Option C is correct because ALB access logs capture detailed information about each request, including HTTP status codes, request processing times, and target response times. By analyzing these logs in Amazon S3, the engineer can identify which specific requests are resulting in 503 errors, examine if there are patterns such as high latency or target unavailability, and determine the root cause. Option A is incorrect because increasing instance size does not address the intermittent 503 errors; if the instances are healthy (HealthyHostCount stable), the issue is likely not capacity but something else like configuration or request handling. Option B is incorrect because detailed CloudWatch metrics on instances, while useful for performance, would not directly reveal why the ALB is returning 503 errors; the backend might be healthy but returning errors or timing out. Option D is incorrect because increasing the idle timeout would only help if requests are being dropped due to idle connections, but 503 errors typically indicate that the targets are not responding or are returning errors, not idle timeouts.

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.

✗
Increase the size of the EC2 instances to handle more requests.
Why it's wrong here
Increasing instance size addresses capacity, but the issue is intermittent 503s with stable healthy host count, suggesting a timeout or configuration problem.
✗
Enable detailed CloudWatch metrics on the EC2 instances to monitor CPU and memory.
Why it's wrong here
EC2 instance metrics monitor resource utilization, but the ALB is returning 503s even though backend hosts are healthy, so the problem is likely at the load balancer level.
✓
Enable and review the ALB access logs stored in Amazon S3 to analyze the HTTP response codes and request patterns.
Why this is correct
ALB access logs provide detailed information about each request, including response codes, timestamps, and request paths, enabling identification of the specific requests that are failing.
Related concept
Read the scenario before looking for a memorised answer.
✗
Increase the idle timeout setting on the ALB.
Why it's wrong here
Increasing the idle timeout might help if requests are timing out, but the 503 errors could be due to other reasons like connection limits or application errors.

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

A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.

Quick reference

AWS S3 Storage Class Comparison

Storage Class	Min Duration	Retrieval	Use Case
S3 Standard	None	Immediate	Frequently accessed data
S3 Standard-IA	30 days	Immediate	Infrequent access, rapid retrieval
S3 One Zone-IA	30 days	Immediate	Non-critical infrequent data
S3 Intelligent-Tiering	None	Immediate–hours	Unknown or changing access patterns
S3 Glacier Instant	90 days	Milliseconds	Archive with instant retrieval
S3 Glacier Flexible	90 days	Minutes–hours	Archive, flexible retrieval
S3 Glacier Deep Archive	180 days	Hours	Long-term compliance archive

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.

Related DOP-C02 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Configuration Management and IaC practice questions

Practise DOP-C02 questions linked to Configuration Management and IaC.

Resilient Cloud Solutions practice questions

Practise DOP-C02 questions linked to Resilient Cloud Solutions.

Monitoring and Logging practice questions

Practise DOP-C02 questions linked to Monitoring and Logging.

Incident and Event Response practice questions

Practise DOP-C02 questions linked to Incident and Event Response.

Security and Compliance practice questions

Practise DOP-C02 questions linked to Security and Compliance.

SDLC Automation practice questions

Practise DOP-C02 questions linked to SDLC Automation.

DOP-C02 fundamentals practice questions

Practise DOP-C02 questions linked to DOP-C02 fundamentals.

DOP-C02 scenario practice questions

Practise DOP-C02 questions linked to DOP-C02 scenario.

DOP-C02 troubleshooting practice questions

Practise DOP-C02 questions linked to DOP-C02 troubleshooting.

Practice this exam

Start a free DOP-C02 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions 20 questions 30 questions 50 questions Timed 30

DOP-C02 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this DOP-C02 question test?

Monitoring and Logging — This question tests Monitoring and Logging — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Enable and review the ALB access logs stored in Amazon S3 to analyze the HTTP response codes and request patterns. — Option C is correct because ALB access logs capture detailed information about each request, including HTTP status codes, request processing times, and target response times. By analyzing these logs in Amazon S3, the engineer can identify which specific requests are resulting in 503 errors, examine if there are patterns such as high latency or target unavailability, and determine the root cause. Option A is incorrect because increasing instance size does not address the intermittent 503 errors; if the instances are healthy (HealthyHostCount stable), the issue is likely not capacity but something else like configuration or request handling. Option B is incorrect because detailed CloudWatch metrics on instances, while useful for performance, would not directly reveal why the ALB is returning 503 errors; the backend might be healthy but returning errors or timing out. Option D is incorrect because increasing the idle timeout would only help if requests are being dropped due to idle connections, but 503 errors typically indicate that the targets are not responding or are returning errors, not idle timeouts.

What should I do if I get this DOP-C02 question wrong?

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 →

How Courseiva writes practice questions · Editorial policy

Keep practising

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.

Loading comments…

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.