The answer is that S3 bucket PUT request throttling is the most likely cause of the Kinesis Firehose delivery delay beyond the 5-minute buffer interval. With 1 GB per minute of 1 KB records, the 64 MB buffer fills in under 4 seconds, far faster than the 300-second interval, so the buffer itself is not the bottleneck. Instead, when Firehose attempts to deliver data to S3, the bucket’s default PUT request limit (around 3,500 requests per second) can be exceeded by the high throughput of roughly 16,000 PUT requests per minute, forcing retries and causing delivery to stretch beyond 10 minutes. On the AWS Certified Data Engineer Associate DEA-C01 exam, this scenario tests your understanding that Firehose delays are often due to downstream throttling, not buffer settings—a common trap where candidates blame the buffer size or interval. Remember the memory tip: “Buffer fills fast, but S3 caps the blast.”
DEA-C01 Data Ingestion and Transformation Practice Question
This DEA-C01 practice question tests your understanding of data ingestion and transformation. 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 Amazon Kinesis Data Firehose to deliver data to Amazon S3. The Firehose delivery stream has a buffer size of 64 MB and a buffer interval of 300 seconds. The data volume is 1 GB per minute, and the average record size is 1 KB. The data must be delivered to S3 within 5 minutes of ingestion. The engineer notices that some files are being delivered after 10 minutes. What is the most likely cause?
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 the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The S3 bucket is throttling PUT requests due to high throughput
Option A is correct because with 1 KB records and 64 MB buffer, it takes ~64,000 records to fill the buffer. At 1 GB/min (~1,000,000 records/min), the buffer fills in ~3.84 seconds, so the 300-second interval is not the bottleneck. However, if the S3 bucket has a PUT request rate limit, Firehose may retry and cause delays. Option B is incorrect because 64 MB is default, not too small. Option C is incorrect because 300 seconds is actually long, but data volume is high enough to trigger delivery sooner. Option D is incorrect because compression would reduce size, not cause delays.
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 buffer size of 64 MB is too small for the data volume
Why it's wrong here
64 MB is the default; with high volume, buffer fills quickly, so size is not the issue.
✗
The data is not compressed, causing larger file sizes
Why it's wrong here
Compression is not enabled by default but would only reduce size, not cause delays.
✗
The buffer interval of 300 seconds is too long
Why it's wrong here
Buffer interval is 5 minutes; data volume ensures buffer fills faster, so interval is not the cause.
✓
The S3 bucket is throttling PUT requests due to high throughput
Why this is correct
High PUT request rates can cause throttling, leading to retries and increased delivery time.
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 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: The S3 bucket is throttling PUT requests due to high throughput — Option A is correct because with 1 KB records and 64 MB buffer, it takes ~64,000 records to fill the buffer. At 1 GB/min (~1,000,000 records/min), the buffer fills in ~3.84 seconds, so the 300-second interval is not the bottleneck. However, if the S3 bucket has a PUT request rate limit, Firehose may retry and cause delays. Option B is incorrect because 64 MB is default, not too small. Option C is incorrect because 300 seconds is actually long, but data volume is high enough to trigger delivery sooner. Option D is incorrect because compression would reduce size, not cause delays.
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.
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 →
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.
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
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.