Question 172 of 1,672
MLS-C01 Data Engineering Practice Question
A company is using Amazon DynamoDB to store sensor data. The data is exported to Amazon S3 using DynamoDB Streams and AWS Lambda for long-term archival. Recently, the Lambda function has been failing due to 'ProvisionedThroughputExceededException' on the DynamoDB stream. What is the most likely cause?
⚠ Common exam trap
A common misconception in AWS exams is that DynamoDB throttling errors are always related to table write capacity. However, the trap here is that the error is on the stream, not the table, and the root cause is the Lambda consumer's processing speed, not the table's provisioned throughput.
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 Lambda function is processing records too slowly, causing the stream to throttle.
A is correct because the 'ProvisionedThroughputExceededException' on a DynamoDB stream indicates that the stream's read throughput is being throttled. When a Lambda function processes records too slowly, it cannot keep up with the rate of new records being written to the stream, causing the stream shards to throttle the Lambda consumer. This is a common issue when the Lambda function's processing time per record is high or when the function is invoked with a large batch size that exceeds its 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.
- ✓
The Lambda function is processing records too slowly, causing the stream to throttle.
Why this is correct
Correct: Slow processing can lead to throttling; increasing batch size or concurrency can help.
- ✗
The DynamoDB stream is disabled.
Why it's wrong here
Incorrect: If disabled, the function would not receive events at all.
- ✗
The DynamoDB table's write capacity is too low.
Why it's wrong here
Incorrect: Write capacity affects writes, not stream reads.
- ✗
The Lambda function does not have enough memory allocated.
Why it's wrong here
Incorrect: Memory does not affect stream throughput.
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 |
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jul 4, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.