- A
The Lambda function's execution role does not have permission to send messages to the DLQ.
Why wrong: If Lambda's DLQ is configured, the role needs permission; but if DLQ is not configured, permission is irrelevant.
- B
The SQS queue's redrive policy is not configured.
Why wrong: The SQS redrive policy moves messages to DLQ after a set number of receives, but Lambda deletes messages on success; on failure, Lambda does not delete, so the message becomes visible again. The redrive policy would eventually move it to DLQ if maxReceiveCount is exceeded. However, the question says 'occasionally fails' and 'not being sent to DLQ', so the likely issue is Lambda's DLQ is not set.
- C
The Lambda function's reserved concurrency is set to 0.
Why wrong: Reserved concurrency 0 would prevent invocation, not affect DLQ.
- D
The Lambda function does not have a dead-letter queue configured.
Lambda's DLQ must be explicitly configured to capture failed events.
Quick Answer
The answer is that the Lambda function does not have a dead-letter queue configured. When an SQS event source triggers Lambda, the function must explicitly define its own DLQ destination for failed invocations; without this, messages that exhaust the function’s retry attempts are simply discarded. This is a common trap on the AWS Certified Developer Associate DVA-C02 exam because candidates often confuse the SQS queue’s redrive policy with Lambda’s separate DLQ configuration—the SQS DLQ only catches messages that exceed the maxReceiveCount before Lambda ever processes them, not after Lambda fails. The exam tests your understanding that Lambda’s asynchronous invocation model requires a destination (like an SQS DLQ) to capture failures, and that reserved concurrency or the SQS source’s own DLQ does not fulfill this role. Memory tip: think of Lambda’s DLQ as a safety net for post-processing failures, while the SQS redrive policy is a pre-processing gate.
DVA-C02 Troubleshooting and Optimization Practice Question
This DVA-C02 practice question tests your understanding of troubleshooting and optimization. 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 developer is troubleshooting an AWS Lambda function that is triggered by an Amazon SQS queue. The function processes messages but occasionally fails. The failed messages are not being sent to the dead-letter queue (DLQ). What is the most likely reason?
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.
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
The Lambda function does not have a dead-letter queue configured.
For Lambda with SQS, a DLQ can be configured on the Lambda function or on the SQS source. If the Lambda function's DLQ is not configured, messages that fail after the maximum retries are discarded. The SQS queue's own DLQ (redrive policy) applies only if the message is not processed after the maxReceiveCount. But Lambda's DLQ is separate. Option A is wrong because the SQS queue's DLQ is for when messages are not deleted after processing; Lambda deletes messages on success. Option B is wrong because the Lambda function's failure handling does not automatically send to DLQ unless configured. Option C is wrong because the Lambda function's reserved concurrency does not affect DLQ. Option D is correct: the Lambda function's DLQ must be explicitly configured.
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.
- ✗
The Lambda function's execution role does not have permission to send messages to the DLQ.
Why it's wrong here
If Lambda's DLQ is configured, the role needs permission; but if DLQ is not configured, permission is irrelevant.
- ✗
The SQS queue's redrive policy is not configured.
Why it's wrong here
The SQS redrive policy moves messages to DLQ after a set number of receives, but Lambda deletes messages on success; on failure, Lambda does not delete, so the message becomes visible again. The redrive policy would eventually move it to DLQ if maxReceiveCount is exceeded. However, the question says 'occasionally fails' and 'not being sent to DLQ', so the likely issue is Lambda's DLQ is not set.
- ✗
The Lambda function's reserved concurrency is set to 0.
Why it's wrong here
Reserved concurrency 0 would prevent invocation, not affect DLQ.
- ✓
The Lambda function does not have a dead-letter queue configured.
Why this is correct
Lambda's DLQ must be explicitly configured to capture failed events.
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.
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.
What to study next
Got this wrong? Here's your next step.
Identify which DVA-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.
- →
Troubleshooting and Optimization — study guide chapter
Learn the concepts, then practise the questions
- →
Troubleshooting and Optimization practice questions
Targeted practice on this topic area only
- →
All DVA-C02 questions
1,616 questions across all exam domains
- →
AWS Certified Developer Associate DVA-C02 study guide
Full concept coverage aligned to exam objectives
- →
DVA-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related DVA-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Development with AWS Services practice questions
Practise DVA-C02 questions linked to Development with AWS Services.
Security practice questions
Practise DVA-C02 questions linked to Security.
Deployment practice questions
Practise DVA-C02 questions linked to Deployment.
Troubleshooting and Optimization practice questions
Practise DVA-C02 questions linked to Troubleshooting and Optimization.
DVA-C02 fundamentals practice questions
Practise DVA-C02 questions linked to DVA-C02 fundamentals.
DVA-C02 scenario practice questions
Practise DVA-C02 questions linked to DVA-C02 scenario.
DVA-C02 troubleshooting practice questions
Practise DVA-C02 questions linked to DVA-C02 troubleshooting.
Practice this exam
Start a free DVA-C02 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 DVA-C02 question test?
Troubleshooting and Optimization — This question tests Troubleshooting and Optimization — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The Lambda function does not have a dead-letter queue configured. — For Lambda with SQS, a DLQ can be configured on the Lambda function or on the SQS source. If the Lambda function's DLQ is not configured, messages that fail after the maximum retries are discarded. The SQS queue's own DLQ (redrive policy) applies only if the message is not processed after the maxReceiveCount. But Lambda's DLQ is separate. Option A is wrong because the SQS queue's DLQ is for when messages are not deleted after processing; Lambda deletes messages on success. Option B is wrong because the Lambda function's failure handling does not automatically send to DLQ unless configured. Option C is wrong because the Lambda function's reserved concurrency does not affect DLQ. Option D is correct: the Lambda function's DLQ must be explicitly configured.
What should I do if I get this DVA-C02 question wrong?
Identify which DVA-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.
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 →
Last reviewed: Jun 20, 2026
This DVA-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 DVA-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.