DEA-C01 Data Operations and Support Practice Question
A data engineer is using Amazon EMR to process large datasets. The cluster uses a mix of Spot Instances and On-Demand Instances. The engineer wants to reduce costs while ensuring the job can complete even if Spot Instances are reclaimed. Which TWO actions should the engineer take? (Choose two.)
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
✓
Enable Instance Fleets to use multiple instance types for Spot Instances.
Enabling Instance Fleets allows EMR to use multiple instance types for Spot Instances, reducing the risk of interruption by diversifying across instance pools. Option E is correct because using a task instance group with Spot Instances for non-critical tasks ensures that if Spot Instances are reclaimed, only those non-critical tasks are affected, while core and master nodes running on On-Demand continue processing. Option B is incorrect because using only On-Demand increases costs. Option C is incorrect because using Spot Instances for core nodes risks data loss or job failure if they are reclaimed, as HDFS data is stored on core nodes. Option D is incorrect because termination protection prevents accidental termination, but does not address Spot Instance interruptions.
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 Instance Fleets to use multiple instance types for Spot Instances.
Why this is correct
Instance Fleets reduce the impact of Spot interruptions by diversifying instance types.
- ✗
Use only On-Demand Instances for all nodes.
Why it's wrong here
This increases cost, not reduces.
- ✗
Use Spot Instances for core nodes to reduce cost.
Why it's wrong here
Core nodes hold HDFS data; Spot interruptions can cause data loss.
- ✗
Enable termination protection for the cluster.
Why it's wrong here
Termination protection prevents accidental termination, not Spot interruptions.
- ✓
Use a task instance group with Spot Instances for non-critical processing tasks.
Why this is correct
Task nodes are ephemeral and do not store data; they are ideal for Spot.
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Variation 1. A company uses Amazon EMR to run Spark jobs on a transient cluster. The jobs process data from S3 and write results back to S3. The team wants to reduce costs by optimizing the cluster. Which action should the team take?
easy- ✓ A.Use Spot Instances for the task nodes.
- B.Increase the number of core nodes and use larger instance types.
- C.Enable EMRFS consistent view.
- D.Terminate the cluster after each job and manually restart it for the next job.
Why A: Using Spot Instances for task nodes in a transient EMR cluster significantly reduces compute costs because Spot Instances are spare AWS EC2 capacity offered at up to 90% discount compared to On-Demand. Since transient clusters are terminated after job completion, the risk of Spot Instance interruptions is mitigated—the job can simply be retried on a new cluster if needed. This directly addresses the cost optimization goal without sacrificing job functionality.
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.