SAP-C02 Continuous Improvement for Existing Solutions Practice Question
A company runs a monolithic application on a single EC2 instance. The application is critical and must be highly available. The company wants to migrate to a containerized architecture on Amazon ECS with minimal downtime. Which approach should the company take?
⚠ Common exam trap
SAP-C02 often tests the misconception that Route 53 weighted routing or simple task definition updates provide blue/green deployments; candidates must recognize that CodeDeploy with ALB and ECS is the AWS-recommended approach for minimal-downtime container deployments.
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 Application Load Balancer with blue/green deployment using AWS CodeDeploy and ECS.
Using an Application Load Balancer (ALB) with blue/green deployment via AWS CodeDeploy and ECS allows you to shift traffic gradually from the old (blue) environment to the new (green) environment with minimal downtime. CodeDeploy orchestrates the deployment, and the ALB routes traffic to the appropriate target group. This approach provides high availability and rollback capability.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Launch a new ECS cluster with the containerized application and use Route 53 weighted routing to shift traffic.
Why it's wrong here
Route 53 weighted routing balances DNS responses between the EC2 instance and ECS, but DNS caching and TTL mean traffic shifts gradually and the monolith remains a single point of failure. It is tempting because weighted records suit gradual cutovers, but the correct option uses an ALB with two target groups.
- ✗
Deploy the monolith as a single task in ECS and update the task definition with new container versions.
Why it's wrong here
Updating a single ECS task definition replaces the only running task, causing an outage because no second task serves traffic during the deployment. It is tempting because task definition revisions are the standard ECS update mechanism, but the correct option runs multiple tasks behind a load balancer with rolling deployment.
- ✗
Use AWS CodeStar to automatically deploy the application to ECS with blue/green deployments.
Why it's wrong here
CodeStar provisions CI/CD scaffolding and pipelines, not blue/green cutover orchestration for an existing monolith; it cannot itself perform traffic shifting between ECS task sets. It is tempting because CodeStar templates do generate deployment pipelines, and would suit greenfield projects wanting managed toolchain setup rather than a minimal-downtime migration.
- ✓
Use an Application Load Balancer with blue/green deployment using AWS CodeDeploy and ECS.
Why this is correct
An Application Load Balancer with blue/green deployment via CodeDeploy shifts traffic between two ECS task sets, satisfying the minimal-downtime constraint. New tasks reach healthy status before the ALB reroutes production traffic, and instant rollback is possible if verification fails. This avoids the outage inherent in stopping the monolith before starting containers.
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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 SAP-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 SAP-C02 exam.