CV0-004 Deployment Practice Question
A cloud engineer is deploying a new version of an application to an Amazon ECS cluster using the rolling update deployment type. The engineer wants to ensure that the new version is deployed without downtime and that the old tasks are terminated only after the new tasks are healthy. Which parameter should the engineer configure?
⚠ Common exam trap
It's easy for candidates to confuse the deployment circuit breaker with the parameters that control the rolling update strategy; the circuit breaker only handles rollbacks on failure.
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
✓
Set the minimum healthy percent to 100 and the maximum percent to 200.
For a rolling update on Amazon ECS, the deployment configuration's minimum healthy percent and maximum percent control how many tasks must remain running and how many extra tasks can be launched. Setting minimum healthy percent to 100 and maximum percent to 200 ensures that the desired number of tasks is always running while allowing new tasks to start and become healthy before old tasks are terminated, thus achieving zero downtime.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Set the task placement strategy to spread across Availability Zones.
Why it's wrong here
Task placement strategies determine how tasks are distributed across instances or Availability Zones, but they do not control the order or timing of task replacement during a rolling update. The deployment configuration parameters (minimum healthy percent and maximum percent) are directly responsible for zero-downtime behavior. Placement strategies affect availability but not the update process itself.
- ✓
Set the minimum healthy percent to 100 and the maximum percent to 200.
Why this is correct
With a minimum healthy percent of 100, ECS ensures that the number of running tasks never drops below the desired count during deployment. The maximum percent of 200 allows ECS to launch additional tasks beyond the desired count, enabling new tasks to start and become healthy before old ones are stopped. This achieves zero-downtime deployment.
- ✗
Set the deployment circuit breaker to enabled with rollback.
Why it's wrong here
The deployment circuit breaker detects failed deployments and automatically rolls back, but it does not control the deployment strategy's task replacement behavior. It is a safety mechanism, not a method to ensure new tasks are healthy before old tasks are terminated. The engineer needs to adjust the deployment configuration percentages to achieve zero downtime.
- ✗
Set the minimum healthy percent to 50 and the maximum percent to 100.
Why it's wrong here
A minimum healthy percent of 50 means that ECS can stop up to half of the tasks before starting new ones, which can cause reduced capacity and potential downtime. The maximum percent of 100 prevents ECS from launching extra tasks, so new tasks cannot start until old tasks are stopped. This configuration does not guarantee zero downtime.
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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.