The answer is to increase the Lambda function reserved concurrency. This is correct because Lambda’s reserved concurrency sets a hard limit on the number of concurrent executions allocated to a function, and raising it allows more instances to process SQS messages in parallel, directly increasing throughput without any code changes. On the AWS Certified Solutions Architect Professional SAP-C02 exam, this scenario tests your understanding of Lambda scaling behavior with SQS as an event source, where the default unreserved concurrency pool may be insufficient during a backlog. A common trap is assuming that increasing the batch size or function timeout will help, but larger batches risk timeouts if message processing is already slow, and timeout adjustments don’t affect parallelism. Remember the memory tip: “Concurrency cures congestion” — when the queue backs up, think reserved concurrency, not code changes.
SAP-C02 Continuous Improvement for Existing Solutions Practice Question
This SAP-C02 practice question tests your understanding of continuous improvement for existing solutions. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 uses AWS Lambda functions to process events from Amazon SQS. The function's duration has increased, causing a backlog. The team wants to improve throughput without changing the function code. Which action should the team take?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Increase the Lambda function reserved concurrency.
Option B is correct because increasing the number of Lambda function instances will increase concurrency and process more messages in parallel. Option A is wrong because increasing batch size may cause timeouts. Option C is wrong because increasing function memory/timeout does not directly improve throughput. Option D is wrong because SQS visibility timeout does not affect Lambda concurrency.
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 SQS visibility timeout to allow more time per message.
Why it's wrong here
Does not increase processing rate.
✓
Increase the Lambda function reserved concurrency.
Why this is correct
More concurrent executions allow processing more messages simultaneously.
Related concept
Read the scenario before looking for a memorised answer.
✗
Increase the Lambda function memory and timeout settings.
Why it's wrong here
Improves performance per invocation but not concurrency.
✗
Increase the SQS batch size to the maximum of 100.
Why it's wrong here
Larger batch may cause function timeout and does not increase concurrency.
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 SAP-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.
Continuous Improvement for Existing Solutions — This question tests Continuous Improvement for Existing Solutions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Increase the Lambda function reserved concurrency. — Option B is correct because increasing the number of Lambda function instances will increase concurrency and process more messages in parallel. Option A is wrong because increasing batch size may cause timeouts. Option C is wrong because increasing function memory/timeout does not directly improve throughput. Option D is wrong because SQS visibility timeout does not affect Lambda concurrency.
What should I do if I get this SAP-C02 question wrong?
Identify which SAP-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 →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company uses AWS Lambda to process events from an Amazon SQS queue. The Lambda function is invoked with a batch size of 10. Recently, the function started failing with timeout errors when processing large batches. Which solution would improve the reliability of event processing without losing messages?
medium
A.Increase the SQS queue visibility timeout to match the function timeout.
B.Increase the Lambda function reserved concurrency to handle more invocations.
C.Increase the Lambda function timeout to the maximum 15 minutes.
✓ D.Reduce the batch size to a smaller value, such as 5.
Why D: Option C is correct because reducing the batch size decreases the processing time per invocation, reducing the chance of timeout. Option A is wrong because increasing the timeout may not help if the issue is total processing time. Option B is wrong because increasing reserved concurrency does not help with timeout. Option D is wrong because SQS queues do not send batches to Lambda as SQS batch size; the Lambda batch size is the relevant parameter.
Last reviewed: Jun 20, 2026
Question Discussion
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This SAP-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 SAP-C02 exam.
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