DEA-C01 Data Operations and Support Practice Question
A company runs a data processing pipeline on Amazon EMR. The pipeline reads data from S3, processes it with Spark, and writes results back to S3. The engineer notices that the cluster is underutilized and wants to reduce costs. Which TWO actions should the engineer take? (Choose TWO.)
⚠ Common exam trap
Watch out — candidates often confuse cost optimization features like Spot instances and auto-termination with performance improvements or data consistency settings, leading them to select options that increase resources or enable features unrelated to cost reduction.
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
✓
Use Spot instances for task nodes.
Using Spot instances for task nodes in Amazon EMR can significantly reduce costs, as Spot instances are spare EC2 capacity offered at up to 90% discount compared to On-Demand instances. Since task nodes are stateless and can be added or removed without affecting cluster stability, they are ideal candidates for Spot instances, allowing the engineer to lower expenses while maintaining processing 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 Spot instances for task nodes.
Why this is correct
Spot instances are cheaper than On-Demand.
- ✓
Configure the cluster to terminate after the job completes.
Why this is correct
Auto-termination avoids paying for idle resources.
- ✗
Change the master node to a larger instance type.
Why it's wrong here
Larger master node increases cost.
- ✗
Enable EMRFS consistent view.
Why it's wrong here
Consistent view ensures data consistency but does not reduce cost.
- ✗
Increase the number of core nodes to improve parallelism.
Why it's wrong here
More nodes increase cost, not reduce.
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
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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.