← DOP-C02·Amazon Web Services

Question 1,615 of 1,750

Monitoring and Logging →hardMultiple 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 AWS Lambda function that processes messages from an Amazon SQS queue. The function is configured with a reserved concurrency of 5 and a batch size of 10. The SQS queue has a visibility timeout of 30 seconds, and the Lambda function typically completes processing each batch in 10 seconds. Recently, the engineer noticed that messages are repeatedly processed, causing duplicates. The CloudWatch Logs show that the function is experiencing throttling errors. What is the MOST likely cause of the duplicate processing?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.

A
Lambda is throttling the function, and the visibility timeout expires before the function can process the messages.
Throttling prevents processing, and visibility timeout expires, making messages visible again.
B
The SQS queue's dead-letter queue (DLQ) is not configured, causing messages to be reprocessed.
Why wrong: DLQ does not cause duplicate processing; it stores failed messages.
C
The function's batch size is too large, causing timeouts.
Why wrong: Batch size of 10 is within limit and function completes in 10 seconds.
D
The function's reserved concurrency is too high, causing overloading.
Why wrong: Reserved concurrency limits the function; it does not cause overload.

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

✓

Lambda is throttling the function, and the visibility timeout expires before the function can process the messages.

The correct answer is A. When Lambda throttles due to reserved concurrency of 5, it cannot process all incoming messages. SQS does not delete messages after sending them to Lambda; Lambda must explicitly delete them after processing. If throttling occurs frequently, messages remain in the queue while Lambda retries, but if the visibility timeout of 30 seconds expires before a successful invocation processes the batch, the messages become visible to other consumers or the same consumer, leading to duplicate processing. The typical completion time of 10 seconds per batch is much shorter than the visibility timeout, but throttling delays processing beyond 30 seconds, causing the visibility timeout to expire. Option B is incorrect because a dead-letter queue stores messages that fail repeatedly, but it does not cause duplicates. Option C is incorrect because the batch size of 10 is within the maximum allowed, and the function completes in 10 seconds, so timeout is not the issue. Option D is incorrect because a higher reserved concurrency would reduce throttling, not cause duplicates.

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.

✓
Lambda is throttling the function, and the visibility timeout expires before the function can process the messages.
Why this is correct
Throttling prevents processing, and visibility timeout expires, making messages visible again.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The SQS queue's dead-letter queue (DLQ) is not configured, causing messages to be reprocessed.
Why it's wrong here
DLQ does not cause duplicate processing; it stores failed messages.
✗
The function's batch size is too large, causing timeouts.
Why it's wrong here
Batch size of 10 is within limit and function completes in 10 seconds.
✗
The function's reserved concurrency is too high, causing overloading.
Why it's wrong here
Reserved concurrency limits the function; it does not cause overload.

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 startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.

Quick reference

Cloud Service Model Comparison

Model	You Manage	Provider Manages	Examples
IaaS	OS, runtime, apps, data	Hardware, hypervisor, networking	EC2, Azure VMs, GCP Compute Engine
PaaS	Apps and data	OS, runtime, middleware, hardware	Elastic Beanstalk, Azure App Service
SaaS	Data and settings only	Everything else	Microsoft 365, Salesforce, Workday
FaaS / Serverless	Function code only	Infra, scaling, runtime	Lambda, Azure Functions, Cloud Run
CaaS	Containers and apps	Kubernetes, OS, hardware	EKS, AKS, GKE

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: Lambda is throttling the function, and the visibility timeout expires before the function can process the messages. — The correct answer is A. When Lambda throttles due to reserved concurrency of 5, it cannot process all incoming messages. SQS does not delete messages after sending them to Lambda; Lambda must explicitly delete them after processing. If throttling occurs frequently, messages remain in the queue while Lambda retries, but if the visibility timeout of 30 seconds expires before a successful invocation processes the batch, the messages become visible to other consumers or the same consumer, leading to duplicate processing. The typical completion time of 10 seconds per batch is much shorter than the visibility timeout, but throttling delays processing beyond 30 seconds, causing the visibility timeout to expire. Option B is incorrect because a dead-letter queue stores messages that fail repeatedly, but it does not cause duplicates. Option C is incorrect because the batch size of 10 is within the maximum allowed, and the function completes in 10 seconds, so timeout is not the issue. Option D is incorrect because a higher reserved concurrency would reduce throttling, not cause duplicates.

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

Are there clue words in this question I should notice?

Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.

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.