The answer is to enable ALB access logging and parse the logs to filter by target group, then correlate with the ECS service name. This works because ALB access logs record the target group ARN for each request, including HTTP 5xx errors, but they do not directly include the ECS service name. By mapping the target group to the specific ECS service—often via tags or the AWS Management Console—you can track per-service error rates. On the DOP-C02 exam, this scenario tests your understanding that ALB logs are the source of truth for HTTP status codes, while Container Insights provides task-level metrics, not service-level aggregation. A common trap is assuming CloudWatch Logs Insights can query S3 logs directly; it cannot—you must stream them to CloudWatch Logs first. Memory tip: "Target group is the bridge between ALB errors and ECS services."
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 company runs a microservices application on Amazon ECS with Fargate launch type. The application uses an Application Load Balancer (ALB) to distribute traffic. The DevOps team wants to monitor the number of HTTP 5xx errors returned by each service. They configure the ALB to send access logs to an S3 bucket and enable CloudWatch Container Insights. However, the team cannot view 5xx errors per service. What should the team do to achieve this?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Enable ALB access logging and parse the logs to filter by target group, then correlate with the ECS service name.
Option B is correct. ALB access logs contain the target group, but not the service name. By using the target group, you can map to the service. Option A is incorrect because CloudWatch Logs Insights can query access logs, but the logs need to be in CloudWatch Logs, not S3. Option C is incorrect because Container Insights provides metrics per task, not per service. Option D is incorrect because adding a response header would not be visible in metrics.
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.
✗
Use CloudWatch Logs Insights to query the ALB access logs directly from S3.
Why it's wrong here
CloudWatch Logs Insights cannot query S3 directly; logs must be in CloudWatch Logs.
✗
Enable Container Insights and create a CloudWatch dashboard to view HTTP 5xx errors per ECS service.
Why it's wrong here
Container Insights does not provide ALB 5xx per service.
✓
Enable ALB access logging and parse the logs to filter by target group, then correlate with the ECS service name.
Why this is correct
Access logs include target group ARN which can be mapped to ECS service.
Related concept
Read the scenario before looking for a memorised answer.
✗
Configure the ALB to add a custom header with the service name and use CloudWatch metrics.
Why it's wrong here
Custom headers are not available as CloudWatch metrics.
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.
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.
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 ALB access logging and parse the logs to filter by target group, then correlate with the ECS service name. — Option B is correct. ALB access logs contain the target group, but not the service name. By using the target group, you can map to the service. Option A is incorrect because CloudWatch Logs Insights can query access logs, but the logs need to be in CloudWatch Logs, not S3. Option C is incorrect because Container Insights provides metrics per task, not per service. Option D is incorrect because adding a response header would not be visible in metrics.
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.
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 →
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.
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
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.