DBS-C01 Monitoring and Troubleshooting Practice Question
A company runs an Amazon Aurora MySQL DB cluster with one writer and two readers. They notice that one reader instance is consistently showing higher than expected lag. The other reader is fine. 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
✓
The reader instance is being used for heavy analytical queries
An imbalanced workload on that reader can cause it to lag. Option A is wrong because writer load affects all replicas. Option B is wrong because network issues would affect both readers. Option D is wrong because parameter group change would affect both readers if applied to cluster.
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 writer instance is experiencing high write activity
Why it's wrong here
Would affect all readers equally.
- ✗
There is a network connectivity issue between the writer and that reader
Why it's wrong here
A network issue would cause complete disconnection, not just higher lag.
- ✓
The reader instance is being used for heavy analytical queries
Why this is correct
Heavy read workload on a reader can cause replication lag.
- ✗
The reader instance has a different DB parameter group
Why it's wrong here
Parameter changes typically require reboot; otherwise they don't cause lag.
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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.