DBS-C01 Deployment and Migration Practice Question
A company is deploying a new web application that uses Amazon RDS for MySQL. The application has unpredictable read traffic spikes. The company wants to minimize read latency and automatically scale read capacity. What is the MOST cost-effective solution?
⚠ Common exam trap
Watch out — candidates often confuse Multi-AZ (which provides high availability but no read scaling) with read replicas (which provide read scaling but not automatic failover), leading them to select Multi-AZ as a solution for read performance.
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
✓
Create an Amazon RDS read replica and configure the application to use it for read traffic
Amazon RDS read replicas allow you to offload read traffic from the primary DB instance to one or more replicas, which can be scaled horizontally by adding more replicas as needed. This is the most cost-effective solution among the options for handling unpredictable read spikes because it directly addresses read capacity scaling without the cost of a full caching layer. Multi-AZ provides only high availability, not read scaling; ElastiCache adds cost and complexity; RDS Proxy manages connections but does not scale read 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.
- ✗
Use Amazon ElastiCache as a caching layer
Why it's wrong here
ElastiCache requires application changes and may be less cost-efficient than read replicas for this scenario.
- ✗
Use Amazon RDS Proxy to manage connections
Why it's wrong here
RDS Proxy manages connections but does not scale read capacity.
- ✗
Deploy the RDS instance in a Multi-AZ configuration
Why it's wrong here
Multi-AZ provides failover, not read scaling.
- ✓
Create an Amazon RDS read replica and configure the application to use it for read traffic
Why this is correct
Read replicas offload read traffic and can be scaled manually; they are cost-effective.
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 →
Same concept, more angles
2 more ways this is tested on DBS-C01
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company is deploying a new web application on AWS. The application uses Amazon RDS for MySQL with a Multi-AZ deployment. The application team wants to reduce latency for read-heavy workloads. Which action should be taken?
hard- A.Enable Multi-AZ on the existing RDS instance
- B.Increase the instance size of the primary RDS instance
- ✓ C.Add a read replica in the same Region
- D.Switch from RDS to Amazon DynamoDB with DAX
Why C: Adding a read replica in the same Region offloads read-heavy workloads from the primary RDS instance, reducing latency for read queries because replicas serve read traffic directly. Amazon RDS for MySQL read replicas use asynchronous replication and can be promoted to a primary instance if needed, making this the most effective and cost-efficient solution for read scaling.
Variation 2. A company is deploying a new web application using Amazon RDS for PostgreSQL. The application requires read-heavy workloads and automatic failover. Which configuration should be used?
hard- A.Multi-AZ deployment without Read Replicas
- B.Single-AZ with a Read Replica in the same region
- C.Multiple Read Replicas in different regions
- ✓ D.Multi-AZ deployment with one or more Read Replicas
Why D: A Multi-AZ deployment provides automatic failover to a standby instance in a different Availability Zone, ensuring high availability. Adding one or more Read Replicas offloads read-heavy workloads from the primary instance, improving performance. This combination meets both the read-heavy and automatic failover requirements for the application.
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.