DEA-C01 Data Ingestion and Transformation Practice Question

A data pipeline uses Kinesis Data Firehose to deliver streaming data to an S3 bucket. The data volume spikes occasionally, causing the Firehose buffer to fill up and leading to increased delivery latency. The latency must remain under 60 seconds. What should be done to minimize latency?

⚠ Common exam trap

AWS often tests the misconception that increasing buffer size or enabling compression reduces latency, when in fact these options increase latency by allowing more data to accumulate before delivery.

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

✓

Reduce the buffer interval to 60 seconds.

Reducing the buffer interval to 60 seconds ensures that Firehose delivers data to S3 at most every 60 seconds, directly capping latency even if the buffer size is not full. This aligns with the requirement to keep latency under 60 seconds, as Firehose delivers data when either the buffer interval or buffer size threshold is met first.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
Enable GZIP compression on the Firehose delivery stream.
Why it's wrong here
Compression adds CPU overhead and may increase latency.
✗
Increase the buffer size to 128 MB to accommodate larger batches.
Why it's wrong here
Larger buffer size increases latency as it waits to fill.
✗
Switch to Kinesis Data Streams with a Lambda consumer.
Why it's wrong here
This changes architecture but does not directly reduce Firehose latency.
✓
Reduce the buffer interval to 60 seconds.
Why this is correct
This forces delivery every 60 seconds, meeting the latency requirement.

Quick reference

AWS S3 Storage Class Comparison

Storage Class	Min Duration	Retrieval	Use Case
S3 Standard	None	Immediate	Frequently accessed data
S3 Standard-IA	30 days	Immediate	Infrequent access, rapid retrieval
S3 One Zone-IA	30 days	Immediate	Non-critical infrequent data
S3 Intelligent-Tiering	None	Immediate–hours	Unknown or changing access patterns
S3 Glacier Instant	90 days	Milliseconds	Archive with instant retrieval
S3 Glacier Flexible	90 days	Minutes–hours	Archive, flexible retrieval
S3 Glacier Deep Archive	180 days	Hours	Long-term compliance archive

Go deeper

DEA-C01 Data Ingestion and Transformation Practice Question

Why each option matters

Option-by-option breakdown

AWS S3 Storage Class Comparison

Related to this question