DEA-C01 Data Ingestion and Transformation Practice Question
A company ingests streaming data into Amazon Kinesis Data Streams. Producers write records using the PutRecords API with explicit partition keys based on customer ID. A data engineer observes that a few shards are consistently at 100 percent write throughput while others are underutilized, causing throttling. Which action should the engineer take to distribute the load more evenly?
⚠ Common exam trap
The trap here is assuming that adding shards or enabling enhanced fan-out will fix write throttling, when the actual cause is a skewed partition key that keeps sending traffic to the same shards.
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
✓
Change the partition key to include a random suffix or use a higher-cardinality key.
Hot shards occur when partition keys are skewed, causing the hash function to map most traffic to a few shards. Including a random suffix or using a higher-cardinality key distributes records more evenly across all shards. Adding shards or changing the write API does not alter the key-to-shard mapping, and enhanced fan-out only affects consumer reads, not producer write distribution.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Change the partition key to include a random suffix or use a higher-cardinality key.
Why this is correct
Kinesis Data Streams maps records to shards by hashing the partition key. If a small number of customer IDs generate most of the traffic, those keys hash to a few shards and create hot spots. Adding a random suffix or using a higher-cardinality key spreads records across more shards, balancing write throughput and eliminating throttling on the hot shards.
- ✗
Enable enhanced fan-out on the stream to give consumers dedicated throughput.
Why it's wrong here
Enhanced fan-out provides each consumer dedicated read throughput of up to 2 MB per second per shard, which addresses consumer-side contention. The reported problem is producer-side write throttling caused by skewed partition keys, not consumer read contention. Enhanced fan-out does not change how writes are distributed across shards, so it will not resolve the hot shard issue.
- ✗
Switch the producers to use the PutRecord API instead of PutRecords.
Why it's wrong here
PutRecord writes a single record per call, while PutRecords batches up to 500 records. Switching to PutRecord would reduce throughput efficiency and increase API call overhead, making throttling worse. The API choice does not affect shard placement because both use the partition key to determine the target shard, so the hot shard problem persists.
- ✗
Increase the number of shards in the stream to match the number of partition keys.
Why it's wrong here
Adding shards increases total stream capacity but does not change how records are mapped to shards. Partition keys are hashed to shards, so a few hot customer IDs will still map to the same shards and remain hot. Adding shards without changing the key strategy leaves the skew unresolved and may simply spread underutilized capacity across more shards.
Go deeper
Related to this question
About these practice questions
This DEA-C01 question is part of Courseiva's 1,321-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Amazon Web Services exam blueprint
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.