MLS-C01 Practice Question: Machine Learning Implementation and Operations
A company wants to use Amazon SageMaker to train a model using data that is updated daily. The training data is stored in an S3 bucket, and the team wants to automate the training process whenever new data arrives. Which AWS service should be used to trigger the SageMaker training job?
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
✓
AWS Lambda triggered by S3 event notifications
AWS Lambda can be triggered by S3 event notifications (e.g., object creation). The Lambda function can then start the SageMaker training job using the AWS SDK, automating the process when new data arrives. Option B (Amazon CloudWatch Events) is incorrect because CloudWatch Events can schedule events based on time or AWS API calls but cannot directly react to S3 object creation without additional services. Option C (Amazon SQS) is incorrect because SQS is a message queue service; it does not natively trigger from S3 events without an intermediary like Lambda, which would still be the trigger. Option D (AWS Step Functions with a scheduled trigger) is incorrect because a scheduled trigger is time-based, not event-driven; Step Functions would need an S3 event to start, and that event would typically come via Lambda.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
AWS Lambda triggered by S3 event notifications
Why this is correct
Lambda can be triggered by S3 events to start the training job.
- ✗
Amazon CloudWatch Events
Why it's wrong here
CloudWatch Events can schedule but not directly react to S3 object creation.
- ✗
Amazon Simple Queue Service (SQS)
Why it's wrong here
SQS alone does not trigger Lambda; a Lambda function would need to poll the queue.
- ✗
AWS Step Functions with a scheduled trigger
Why it's wrong here
Step Functions needs a trigger; S3 events can start a Step Function via Lambda.
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 |
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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