DEA-C01 Data Operations and Support Practice Question
A data engineer manages an Amazon Kinesis Data Stream with multiple shards. The stream is experiencing high throughput, and the engineer notices that some shards are throttling while others are underutilized. The engineer needs to redistribute the data evenly across shards to avoid throttling. Which action should the engineer take?
⚠ Common exam trap
The trap here is thinking that adding more shards or enabling enhanced fan-out will fix throttling, when the real issue is data distribution due to partition key skew.
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
✓
Modify the partition key strategy in the producer to ensure even distribution across shards.
Uneven shard utilization with throttling on some shards is typically caused by a partition key that does not distribute records uniformly. Changing the partition key strategy—for example, by incorporating a random value or using a composite key—ensures records are spread evenly across all shards. This addresses the root cause without altering shard count or read capacity.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use the MergeShards API to combine underutilized shards and reduce the total number of shards.
Why it's wrong here
Merging shards reduces capacity and can worsen throttling if the overall throughput is high. It also does not address the uneven distribution; it simply consolidates shards. This action is typically used to scale down when throughput decreases, not to fix hot shards.
- ✓
Modify the partition key strategy in the producer to ensure even distribution across shards.
Why this is correct
Throttling on specific shards while others are underutilized indicates a skewed partition key. By changing the partition key strategy—such as adding a random suffix or using a more uniform key—the producer can distribute records more evenly across all shards, resolving the throttling without changing shard count.
- ✗
Increase the number of shards using the UpdateShardCount API to add more capacity.
Why it's wrong here
Increasing the number of shards adds capacity but does not automatically redistribute existing data or fix uneven partitioning. If the partition key is skewed, adding shards may not help because data will still be routed to the same hot shards. The root cause is uneven distribution due to partition key logic, not total capacity.
- ✗
Enable enhanced fan-out for the stream to provide dedicated throughput for consumers.
Why it's wrong here
Enhanced fan-out improves read throughput for consumers by providing dedicated bandwidth, but it does not affect write distribution or shard-level throttling. The issue is on the write side, where records are unevenly distributed. Enhanced fan-out would not resolve the hot shard problem.
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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.