MLS-C01 Data Engineering Practice Question
A data engineer needs to move 10 TB of historical data from an on-premises Hadoop cluster to Amazon S3 for ML training. The data is currently stored in HDFS and is compressible. The network bandwidth between the on-premises data center and AWS is 1 Gbps. The team needs to minimize the time to transfer and also wants to avoid any downtime for the on-premises system. Which solution meets these requirements?
⚠ Common exam trap
The trap here is that candidates often overlook the compression capability of DataSync and assume that faster network options like Direct Connect or Transfer Acceleration alone are sufficient, ignoring that compression is critical to minimize transfer time over a fixed bandwidth.
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
✓
Install the AWS DataSync agent on-premises, configure a task to transfer data to S3 with compression enabled.
AWS DataSync is designed for large-scale data transfers from on-premises storage to AWS, and it can compress data in transit to reduce transfer time over a 1 Gbps link. It also operates as an agent-based solution that does not require downtime for the on-premises Hadoop cluster, as it reads data from HDFS without disrupting ongoing operations.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Set up an AWS Direct Connect connection and use rsync to copy data to S3.
Why it's wrong here
Direct Connect improves network stability but rsync lacks optimization for large transfers.
- ✗
Enable S3 Transfer Acceleration on the bucket and use the AWS CLI to copy data.
Why it's wrong here
Transfer Acceleration helps with latency but not as efficient as DataSync for large datasets.
- ✓
Install the AWS DataSync agent on-premises, configure a task to transfer data to S3 with compression enabled.
Why this is correct
DataSync is optimized for large data transfers with compression and parallelization.
- ✗
Use AWS Snowball Edge devices to export the data and ship them to AWS.
Why it's wrong here
Snowball Edge involves shipping time and is not necessary for 10 TB over 1 Gbps.
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
Related to this question
About these practice questions
One of 1,672 original MLS-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 →
Same concept, more angles
1 more way this is tested on MLS-C01
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A data engineering team needs to move 10 TB of historical data from an on-premises Hadoop cluster to Amazon S3. The data is currently stored in HDFS. Which service should they use for an efficient transfer?
medium- ✓ A.AWS DataSync
- B.S3 Transfer Acceleration
- C.Amazon Kinesis Data Streams
- D.AWS Snowball Edge
Why A: AWS DataSync is the correct choice because it is designed to efficiently transfer large volumes of data from on-premises storage systems, including HDFS, to AWS services like Amazon S3. It uses a purpose-built network protocol and parallel multi-threading to optimize transfer speed over the internet or AWS Direct Connect, and it can handle the 10 TB volume without requiring physical appliances or complex streaming setups.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This MLS-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 MLS-C01 exam.