CV0-004 Deployment Practice Question
A cloud engineer is deploying a multi-tier web application on AWS. The web tier must be able to scale out during traffic spikes, but the database tier should remain on a fixed set of instances. The engineer wants to define the infrastructure as code using AWS CloudFormation. Which CloudFormation feature should be used to automatically adjust the number of web tier instances based on CPU utilization?
⚠ Common exam trap
It's easy for candidates to confuse update policies or change sets with actual scaling mechanisms; only a scaling policy tied to a metric enables dynamic capacity adjustments.
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
✓
Use an Auto Scaling group with a scaling policy based on the CPUUtilization metric.
The correct approach is to define an Auto Scaling group with a scaling policy that uses the CPUUtilization metric. This allows CloudFormation to manage the group and its scaling behavior declaratively, automatically increasing or decreasing instances as needed. Other options either handle updates, protect resources, or preview changes, but none provide dynamic scaling based on metrics.
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 a CloudFormation stack policy to allow scaling actions.
Why it's wrong here
A stack policy is used to prevent accidental updates or deletions of specific resources during stack operations. It does not trigger scaling actions or monitor metrics. While it can protect resources, it has no role in dynamically adjusting instance count based on CPU utilization, so it is irrelevant to the scaling requirement.
- ✗
Use a CloudFormation change set to modify the desired capacity.
Why it's wrong here
A change set previews how a stack update will impact resources but does not automatically apply changes or respond to runtime metrics. It requires manual execution and is intended for planned modifications, not for automatic scaling during traffic spikes. It cannot adjust capacity based on CPU utilization in real time.
- ✓
Use an Auto Scaling group with a scaling policy based on the CPUUtilization metric.
Why this is correct
An Auto Scaling group with a scaling policy that references the Amazon CloudWatch CPUUtilization metric automatically adjusts the desired capacity of the web tier instances when average CPU crosses defined thresholds. This is the standard, declarative way to implement dynamic scaling in CloudFormation, ensuring the application can handle traffic spikes without manual intervention.
- ✗
Use a CloudFormation update policy with AutoScalingRollingUpdate.
Why it's wrong here
AutoScalingRollingUpdate is an update policy that controls how instances are replaced during a stack update, not how the group scales in response to load. It does not monitor metrics or adjust capacity; it only manages the rolling replacement of instances when the launch configuration or template changes, so it cannot provide dynamic scaling for traffic spikes.
About these practice questions
This CV0-004 question is part of Courseiva's 834-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This CV0-004 practice question is part of Courseiva's free CompTIA 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 CV0-004 exam.