DBS-C01 Workload-Specific Database Design Practice Question
Network Topology
Refer to the exhibit. A developer reports that the RDS MySQL instance 'mydb' is experiencing high write latency. The storage is gp2 with 100 GB. What is the MOST likely cause of the write latency?
⚠ Common exam trap
The trap here is that candidates may overlook the gp2 IOPS-to-size ratio and assume any gp2 volume can burst indefinitely, or they may confuse storage performance issues with instance class or replication factors.
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 gp2 volume size is too small, resulting in insufficient baseline IOPS
The gp2 volume's baseline IOPS are determined by the volume size at a ratio of 3 IOPS per GB, up to 16,000 IOPS. With a 100 GB gp2 volume, the baseline IOPS is only 300 (100 × 3). This is insufficient for write-heavy workloads, causing write latency as the volume exhausts its IOPS credit balance and enters a throttled state. Burst credits can temporarily boost performance, but sustained high write throughput will deplete credits and lead to latency.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
There is a read replica causing replication lag
Why it's wrong here
No read replicas are configured.
- ✓
The gp2 volume size is too small, resulting in insufficient baseline IOPS
Why this is correct
gp2 baseline IOPS is 3 per GB, so 100 GB gives only 300 IOPS.
- ✗
The instance class db.r5.large does not provide enough memory
Why it's wrong here
Memory affects caching, not directly write latency.
- ✗
Multi-AZ is not enabled, causing synchronous replication overhead
Why it's wrong here
Multi-AZ is not enabled, so there is no replication overhead.
Go deeper
Related to this question
About these practice questions
One of 1,663 original DBS-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 →
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.