DVA-C02 Development with AWS Services Practice Question
A company runs a Node.js application on AWS Elastic Beanstalk. The application experiences high latency during peak hours. The developer suspects that the environment's EC2 instances are under-provisioned. Which configuration change would MOST effectively address the latency issue with minimal cost increase?
⚠ Common exam trap
Candidates often confuse adding a load balancer (Option A) with solving capacity issues, but a load balancer only distributes traffic and does not increase compute resources, so latency remains if instances are saturated.
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
✓
Enable Auto Scaling and configure scaling triggers based on CPU utilization.
Enabling Auto Scaling with CPU utilization triggers dynamically adds EC2 instances during peak hours, distributing the load and reducing latency without over-provisioning during off-peak times. This matches the symptom of under-provisioned instances and minimizes cost by scaling only when needed, unlike static solutions that waste resources.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Place the environment behind an Application Load Balancer.
Why it's wrong here
Placing the environment behind an Application Load Balancer (ALB) is a best practice for distributing incoming HTTP/HTTPS traffic and enabling high availability. However, an ALB primarily functions to route requests across *existing* healthy instances; it does not automatically provision or de-provision EC2 instances to increase or decrease the total capacity of the application. Therefore, while crucial for traffic management, it does not directly address the need to scale out the number of instances in response to increased load.
- ✓
Enable Auto Scaling and configure scaling triggers based on CPU utilization.
Why this is correct
Enabling Auto Scaling and configuring scaling triggers based on CPU utilization is the most effective and elastic solution for handling variable loads in a Node.js application. When the average CPU utilization across the Auto Scaling group exceeds a predefined threshold, new EC2 instances are automatically launched to distribute the workload, improving responsiveness and preventing performance degradation. Conversely, instances are terminated during periods of low utilization, optimizing operational costs.
- ✗
Change the instance type to a larger size in the environment configuration.
Why it's wrong here
Changing the instance type to a larger size (scaling up) provides more resources like CPU and memory to a single instance, which might offer a temporary performance boost. However, this approach is less flexible and often more expensive than scaling out, as it does not dynamically adapt to fluctuating demand. A single larger instance also represents a single point of failure and cannot match the fault tolerance and cost-efficiency of multiple smaller instances managed by an Auto Scaling group.
- ✗
Decrease the minimum number of instances in the Auto Scaling group.
Why it's wrong here
Decreasing the minimum number of instances in the Auto Scaling group would reduce the baseline capacity available to the application, making it less resilient to traffic spikes. This action would directly worsen application performance and increase latency during periods of high demand, as fewer instances would be available to process requests. It fundamentally contradicts the objective of improving application responsiveness under load.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DVA-C02 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 DVA-C02 exam.