SAA-C03 Design Resilient Architectures Practice Question
A startup runs a single Amazon EC2 instance hosting both a web application and its MySQL database. The founders want the application to survive the failure of the underlying hardware without changing the database engine, and they want the smallest possible operational change. What should the architect recommend?
⚠ Common exam trap
The trap here is believing that monitoring, snapshots, or backups constitute high availability, when they only improve detection or recovery time rather than preventing downtime.
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
✓
Move the database to an Amazon RDS for MySQL Multi-AZ DB instance and place the web application on an EC2 instance in an Auto Scaling group spanning two Availability Zones.
The goal is automatic recovery for both tiers without changing the database engine. RDS for MySQL Multi-AZ provides a managed standby that fails over automatically, and an Auto Scaling group across two Availability Zones can replace a failed web server. Together they remove the single point of failure with far less operational burden than self-managing replication or restoring snapshots.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Move the database to an Amazon RDS for MySQL Multi-AZ DB instance and place the web application on an EC2 instance in an Auto Scaling group spanning two Availability Zones.
Why this is correct
RDS Multi-AZ maintains a synchronous standby replica in a different Availability Zone and fails over automatically if the primary fails, while an Auto Scaling group across two zones can replace a failed web instance. The engine stays MySQL, matching the no-engine-change constraint, and both tiers gain automatic recovery with minimal ongoing operational effort from the founders.
- ✗
Keep both tiers on one EC2 instance but enable detailed monitoring and create an Amazon CloudWatch alarm that emails the founders when CPU is high.
Why it's wrong here
Monitoring and alerting only notify humans; they do not restore service when hardware fails. The single instance remains a single point of failure, so the application still goes down and waits for manual recovery. This option adds observability without addressing the core resilience requirement of surviving a hardware failure.
- ✗
Create an Amazon EBS snapshot schedule for the instance's volume and restore the snapshot to a new instance if the hardware fails.
Why it's wrong here
Snapshots provide a recovery point, not automatic recovery. Restoring a snapshot is a manual, time-consuming process that also loses all data written since the last snapshot, so the application is unavailable for an extended period. The scenario asks for survival of hardware failure with minimal operational change, and a manual restore workflow does not meet that bar.
- ✗
Migrate the database to Amazon DynamoDB and rewrite the application to use the DynamoDB API.
Why it's wrong here
DynamoDB is a fully managed NoSQL service, so moving to it requires rewriting the application and abandoning the MySQL relational model. The scenario explicitly rules out changing the database engine and asks for the smallest operational change, making a full rewrite the most disruptive possible answer. It solves availability at the cost of the stated constraints.
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Amazon Web Services exam blueprint
This SAA-C03 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 SAA-C03 exam.