DVA-C02 Deployment Practice Question
A developer is using AWS CodeDeploy to deploy an application to a fleet of EC2 instances in an Auto Scaling group. The application must remain available during the deployment. The developer wants to update one instance at a time, ensuring that only one instance is taken offline at any moment. Which deployment configuration should the developer choose?
⚠ Common exam trap
Test-takers frequently confuse 'one at a time' with 'half at a time' or 'all at once' due to misreading the requirement for minimal disruption, or they may incorrectly apply a Lambda-specific configuration to an EC2 deployment.
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
✓
CodeDeployDefault.OneAtATime
CodeDeployDefault.OneAtATime is the correct deployment configuration because it deploys the application to only one instance at a time, ensuring that the remaining instances continue to serve traffic. This matches the requirement to take only one instance offline at any moment, preserving high availability throughout the deployment.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
CodeDeployDefault.OneAtATime
Why this is correct
The CodeDeployDefault.OneAtATime configuration deploys application revisions to exactly one EC2 instance at a time within the target fleet. This strategy ensures maximum application availability during deployments, as only a single instance is ever out of service or being updated at any given moment. While slower, it significantly minimizes the risk of widespread service disruption and is ideal for critical applications requiring continuous uptime.
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CodeDeployDefault.HalfAtATime
Why it's wrong here
The CodeDeployDefault.HalfAtATime configuration deploys the application to half of the EC2 instances in the target fleet simultaneously. This approach can lead to a substantial reduction in available capacity (up to 50%) during the deployment window, potentially causing performance degradation or service outages if the remaining instances cannot handle the full production load. It offers a faster deployment than OneAtATime but at a higher risk to availability.
- ✗
CodeDeployDefault.AllAtOnce
Why it's wrong here
The CodeDeployDefault.AllAtOnce configuration deploys the application revision to all EC2 instances in the target fleet concurrently. This method results in the fastest deployment time but carries the highest risk, as all instances are updated simultaneously, leading to a complete service interruption during the deployment process. It is generally suitable only for non-production environments or applications that can tolerate full downtime, often requiring careful management with a load balancer.
- ✗
CodeDeployDefault.LambdaCanary10Percent5Minutes
Why it's wrong here
The CodeDeployDefault.LambdaCanary10Percent5Minutes configuration is specifically designed for AWS Lambda compute platform deployments, not for EC2 instances. This strategy gradually shifts 10% of traffic to the new Lambda function version over a 5-minute interval, allowing for canary testing and automated rollbacks based on alarms. It is entirely incompatible with EC2/On-Premises deployment groups, which require different deployment configurations.
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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.