The correct answer is to decrease the buffer interval to 120 seconds. This works because Kinesis Data Firehose delivers data to S3 based on whichever condition is met first: the buffer interval or the buffer size. With a current buffer interval of 300 seconds and a data arrival rate of 2 MB per second, the 5 MB buffer size fills in about 2.5 seconds, yet Firehose waits the full 300-second interval before delivering, causing the observed 10-minute delays. By lowering the buffer interval to 120 seconds, you force more frequent deliveries, ensuring data lands in S3 well within the 5-minute SLA without altering the buffer size. On the AWS Certified Data Engineer Associate DEA-C01 exam, this scenario tests your understanding of the buffer interval as the primary lever for reducing delivery delay when buffer size is fixed. A common trap is confusing buffer size with interval—remember that interval controls time, size controls volume. Memory tip: “Time to trim the timer” to reduce delay.
DEA-C01 Data Ingestion and Transformation Practice Question
This DEA-C01 practice question tests your understanding of data ingestion and transformation. 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 media company uses Amazon Kinesis Data Firehose to ingest log data from web servers into Amazon S3. The data is then processed by AWS Glue jobs. The company wants to ensure that data is delivered to S3 within 5 minutes of ingestion. Currently, the Firehose delivery stream is configured with a buffer interval of 300 seconds and a buffer size of 5 MB. The log data arrives at a rate of 2 MB per second. The data engineer notices that some log files are delayed by up to 10 minutes. The company cannot change the buffer size due to downstream requirements. What should the data engineer do to meet the 5-minute delivery requirement?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Decrease the buffer interval to 120 seconds.
Option A is correct. Decreasing the buffer interval to 120 seconds will cause Firehose to deliver data more frequently, meeting the 5-minute SLA. Option B is wrong because increasing buffer interval would increase delay. Option C is wrong because increasing buffer size would also increase delay. Option D is wrong because compressing data does not reduce buffer interval.
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 buffer interval to 600 seconds to reduce the number of delivery attempts.
Why it's wrong here
Increasing interval would increase delay, not reduce it.
✗
Increase the buffer size to 10 MB to ensure data is delivered in larger chunks.
Why it's wrong here
Larger buffer size may increase delay because it waits for more data.
✗
Enable GZIP compression on the Firehose stream to reduce data size.
Why it's wrong here
Compression does not affect buffer interval or delivery frequency.
✓
Decrease the buffer interval to 120 seconds.
Why this is correct
Lower interval triggers delivery more often, reducing latency.
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 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 DEA-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 Ingestion and Transformation — This question tests Data Ingestion and Transformation — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Decrease the buffer interval to 120 seconds. — Option A is correct. Decreasing the buffer interval to 120 seconds will cause Firehose to deliver data more frequently, meeting the 5-minute SLA. Option B is wrong because increasing buffer interval would increase delay. Option C is wrong because increasing buffer size would also increase delay. Option D is wrong because compressing data does not reduce buffer interval.
What should I do if I get this DEA-C01 question wrong?
Identify which DEA-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 DEA-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 DEA-C01 exam.
Question Discussion
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