DOP-C02 SDLC Automation Practice Question
A DevOps engineer wants to use AWS CodeDeploy to deploy an application to an Auto Scaling group. The deployment must ensure that only a certain percentage of instances are taken out of service at a time. Which deployment configuration supports this requirement?
⚠ Common exam trap
Many exam-takers confuse deployment configurations designed for Lambda functions (like Canary and Linear) with those for EC2/On-Premises, or they mistakenly think AllAtOnce limits the percentage of instances taken out of service, when in fact it takes all instances out at once.
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 ensures that only one instance in the Auto Scaling group is taken out of service at a time, which directly satisfies the requirement of limiting the percentage of instances removed during deployment. This configuration is designed for EC2/On-Premises deployments and uses a fixed number of instances (one) rather than a percentage, making it ideal for gradual, safe rollouts.
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
This is the right choice for minimizing risk during deployment to an EC2/ASG. It shifts traffic to one instance at a time, waiting for a successful deployment health check on that instance before proceeding to the next, so if something fails, only that instance is affected and deployment can be stopped before impacting the rest of the fleet. This is akin to a rolling update with a batch size of one, preserving overall availability.
- ✗
CodeDeployDefault.LambdaCanary10Percent5Minutes
Why it's wrong here
This is a Lambda deployment configuration, not for EC2/ASG. For Lambda, it shifts 10% of traffic to the new function version initially, waits 5 minutes for validation, then shifts the remaining 90%. It cannot be used with EC2/On-Premises deployment groups because those use instance-level in-place or blue/green deployments, not traffic shifting.
- ✗
CodeDeployDefault.AllAtOnce
Why it's wrong here
This deploys to all instances simultaneously, taking the entire fleet out of service at once (or updating them all at once). While it's the fastest, it causes downtime or a full simultaneous cutover, so any deployment failure affects all users immediately. It does not provide a rolling or staged process, increasing risk compared to OneAtATime.
- ✗
CodeDeployDefault.LambdaLinear10PercentEvery1Minute
Why it's wrong here
Another Lambda-only configuration where traffic is shifted linearly in 10% increments every minute, completing in 10 minutes. Like the canary option, it's intended for serverless Lambda functions and is invalid for EC2/ASG deployment groups that require an instance-based deployment configuration such as AllAtOnce, OneAtATime, or a custom configuration.
Go deeper
Related to this question
About these practice questions
Courseiva writes every DOP-C02 question from scratch — 1,298 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DOP-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 DOP-C02 exam.