DEA-C01 Data Operations and Support Practice Question
A data engineer is troubleshooting a Kinesis Data Analytics application that processes streaming data. The application is falling behind, and the metric 'MillisBehindLatest' is consistently above 60000. The source Kinesis stream has 10 shards, and the application uses a Flink application with default parallelism. What is the MOST likely cause of the lag?
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
✓
The Flink application parallelism is set to 1.
In Kinesis Data Analytics with Flink, the default parallelism is 1. With 10 shards in the source Kinesis stream, a single parallel task must read from all shards, creating a bottleneck and causing the 'MillisBehindLatest' metric to be consistently high (above 60000). Option A is wrong because while a throttling sink can cause backpressure, the question specifically states the application is falling behind and the metric is high, which is more directly explained by insufficient parallelism. Option C is wrong because 10 shards is typically sufficient; the issue is how they are consumed. Option D is wrong because the retention period does not affect the lag metric; it only controls how long data is stored.
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 sink (destination) is throttling writes.
Why it's wrong here
The lag is measured at the source, not the sink.
- ✓
The Flink application parallelism is set to 1.
Why this is correct
Default parallelism of 1 causes a single consumer to process all shards.
- ✗
The Kinesis stream has too few shards.
Why it's wrong here
10 shards is reasonable; the issue is parallelism.
- ✗
The retention period of the Kinesis stream is too short.
Why it's wrong here
Retention period does not cause lag.
Go deeper
Related to this question
About these practice questions
One of 1,711 original DEA-C01 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.