The correct answer is to use Amazon S3 event notifications to invoke an AWS Lambda function that starts the Glue job automatically. This solution works because S3 event notifications fire immediately when new objects are written to the bucket, allowing a Lambda function to trigger the Glue ETL job in near-real-time—well within the required 30-minute window. On the AWS Certified Machine Learning Specialty MLS-C01 exam, this scenario tests your understanding of event-driven architectures for reducing ETL latency, a common pattern for streaming log processing. A frequent trap is confusing S3 event notifications with scheduled triggers or assuming that increasing crawler frequency will speed up transformations; remember, crawlers only update the Data Catalog, not run ETL jobs. Another distractor is Redshift Spectrum, which queries data directly in S3 but does not perform transformations. For the exam, keep this memory tip: “S3 event + Lambda = instant Glue trigger,” contrasting with “cron or crawler = delayed data.”
MLS-C01 Data Engineering Practice Question
This MLS-C01 practice question tests your understanding of data engineering. 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 is designing a data pipeline to process log files from multiple sources. The logs are written to Amazon S3 every hour. The data is then transformed using AWS Glue ETL jobs and loaded into Amazon Redshift for analysis. The company needs to ensure that the data is available for analysis within 30 minutes of being written to S3. Currently, the Glue job is triggered hourly, but the company wants to reduce the latency. Which solution should the company implement?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use Amazon S3 event notifications to invoke an AWS Lambda function that starts the Glue job automatically
Option C is correct because configuring an S3 event notification to invoke AWS Lambda, which starts the Glue job, allows near-real-time processing within minutes. Option A is wrong because hourly triggers do not reduce latency. Option B is wrong because increasing the crawler frequency does not trigger ETL jobs. Option D is wrong because Redshift Spectrum does not transform data.
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 frequency of the Glue crawler to run every 5 minutes
Why it's wrong here
Crawlers update the Data Catalog, but do not trigger ETL jobs.
✗
Use Amazon Redshift Spectrum to query the data directly from S3 without transformation
Why it's wrong here
Spectrum queries data in place but does not perform transformations required by the pipeline.
✓
Use Amazon S3 event notifications to invoke an AWS Lambda function that starts the Glue job automatically
Why this is correct
S3 events trigger Lambda immediately, which starts the Glue job with low latency.
Related concept
Read the scenario before looking for a memorised answer.
✗
Reduce the Glue job trigger frequency to every 15 minutes
Why it's wrong here
This still introduces up to 15 minutes of delay, not meeting the 30-minute requirement easily.
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 MLS-C01 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.
Data Engineering — This question tests Data Engineering — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use Amazon S3 event notifications to invoke an AWS Lambda function that starts the Glue job automatically — Option C is correct because configuring an S3 event notification to invoke AWS Lambda, which starts the Glue job, allows near-real-time processing within minutes. Option A is wrong because hourly triggers do not reduce latency. Option B is wrong because increasing the crawler frequency does not trigger ETL jobs. Option D is wrong because Redshift Spectrum does not transform data.
What should I do if I get this MLS-C01 question wrong?
Identify which MLS-C01 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.
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This MLS-C01 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 MLS-C01 exam.
Question Discussion
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