← DOP-C02·Amazon Web Services

Question 11 of 1,750

Resilient Cloud Solutions →mediumMultiple ChoiceObjective-mapped

ECS Fargate High Availability with AZ Spreading

This DOP-C02 practice question tests your understanding of resilient cloud solutions. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.

A company is deploying a critical microservice on Amazon ECS with Fargate. They need to ensure that the service can tolerate an Availability Zone failure. What is the BEST approach?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.

A
Use a cluster placement constraint to spread tasks across instances
Why wrong: Fargate does not use placement constraints.
B
Use EC2 launch type and spread tasks across instance types
Why wrong: Not applicable to Fargate.
C
Define the service to spread tasks across multiple Availability Zones
ECS Fargate services can spread across AZs.
D
Configure service auto scaling to add tasks when CPU is high
Why wrong: Does not directly handle AZ failure.

Full breakdown with real-world context →

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

✓

Define the service to spread tasks across multiple Availability Zones

Option C is correct because Amazon ECS with Fargate allows you to define a service with a 'spread across Availability Zones' strategy. By setting the service's placement strategy to spread tasks across multiple Availability Zones, the service automatically distributes tasks evenly across the specified AZs. If one AZ fails, the remaining tasks in other AZs continue to serve traffic, ensuring high availability. This is the most direct and effective method for tolerating an AZ failure in a Fargate-based deployment.

Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
Use a cluster placement constraint to spread tasks across instances
Why it's wrong here
Fargate does not use placement constraints.
✗
Use EC2 launch type and spread tasks across instance types
Why it's wrong here
Not applicable to Fargate.
✓
Define the service to spread tasks across multiple Availability Zones
Why this is correct
ECS Fargate services can spread across AZs.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Configure service auto scaling to add tasks when CPU is high
Why it's wrong here
Does not directly handle AZ failure.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates often confuse 'spreading tasks across instances' (Option A) or 'across instance types' (Option B) with the correct concept of spreading across Availability Zones, or they mistakenly think auto scaling (Option D) alone provides AZ failure tolerance, when in fact it only scales based on load and does not guarantee multi-AZ distribution.

Detailed technical explanation

How to think about this question

Under the hood, when you define an ECS service with Fargate and set the 'spread across Availability Zones' strategy, the ECS service scheduler uses the Availability Zone information from the VPC subnets you specify. It ensures that tasks are placed in different AZs by using a 'spread' placement strategy with a field of 'attribute:ecs.availability-zone'. This is similar to how Amazon ECS with EC2 launch type uses 'spread' strategies, but Fargate abstracts the underlying instances. In a real-world scenario, if you have a service with a desired count of 3 tasks and 3 AZs, ECS will place one task per AZ; if one AZ fails, the remaining two tasks continue to handle traffic, and ECS will automatically replace the failed task in a healthy AZ if you have configured the service for automatic recovery.

KKey Concepts to Remember

Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.

TExam Day Tips

Watch for words such as best, first, most likely and least administrative effort.
Review why wrong options are wrong, not only why the correct option is correct.

Key takeaway

Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Real-world example

How this comes up in practice

An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.

What to study next

Got this wrong? Here's your next step.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

Related DOP-C02 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Configuration Management and IaC practice questions

Practise DOP-C02 questions linked to Configuration Management and IaC.

Resilient Cloud Solutions practice questions

Practise DOP-C02 questions linked to Resilient Cloud Solutions.

Monitoring and Logging practice questions

Practise DOP-C02 questions linked to Monitoring and Logging.

Incident and Event Response practice questions

Practise DOP-C02 questions linked to Incident and Event Response.

Security and Compliance practice questions

Practise DOP-C02 questions linked to Security and Compliance.

SDLC Automation practice questions

Practise DOP-C02 questions linked to SDLC Automation.

DOP-C02 fundamentals practice questions

Practise DOP-C02 questions linked to DOP-C02 fundamentals.

DOP-C02 scenario practice questions

Practise DOP-C02 questions linked to DOP-C02 scenario.

DOP-C02 troubleshooting practice questions

Practise DOP-C02 questions linked to DOP-C02 troubleshooting.

Practice this exam

Start a free DOP-C02 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions 20 questions 30 questions 50 questions Timed 30

DOP-C02 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this DOP-C02 question test?

Resilient Cloud Solutions — This question tests Resilient Cloud Solutions — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Define the service to spread tasks across multiple Availability Zones — Option C is correct because Amazon ECS with Fargate allows you to define a service with a 'spread across Availability Zones' strategy. By setting the service's placement strategy to spread tasks across multiple Availability Zones, the service automatically distributes tasks evenly across the specified AZs. If one AZ fails, the remaining tasks in other AZs continue to serve traffic, ensuring high availability. This is the most direct and effective method for tolerating an AZ failure in a Fargate-based deployment.

What should I do if I get this DOP-C02 question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

Are there clue words in this question I should notice?

Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

About these practice questions

Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

Keep practising

Question Discussion

Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.

Loading comments…

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.