DBS-C01 Monitoring and Troubleshooting Practice Question
A company notices that its Aurora MySQL cluster has a high number of locks and deadlocks. The application uses read replicas for read scaling. What is the MOST likely cause?
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
✓
Long-running transactions on the writer instance
Long-running transactions on the writer instance hold locks for extended periods, increasing the probability of lock contention and deadlocks. Option A is incorrect because Performance Insights is a monitoring tool and does not cause locks or deadlocks. Option B is incorrect because mismatched instance sizes may affect performance but do not directly cause locks or deadlocks. Option D is incorrect because Aurora read replicas are read-only and cannot perform write 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.
- ✗
Performance Insights is enabled
Why it's wrong here
Performance Insights is a monitoring tool, not a cause of deadlocks.
- ✗
The writer and reader instances are of different sizes
Why it's wrong here
Instance size difference affects performance but not lock contention.
- ✓
Long-running transactions on the writer instance
Why this is correct
Long transactions hold locks, increasing contention and deadlock probability.
- ✗
Read replicas are performing write operations
Why it's wrong here
Aurora read replicas are read-only.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DBS-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 DBS-C01 exam.