The correct configuration is to create an ECS service with tasks distributed across multiple Availability Zones using a spread placement strategy. This approach explicitly instructs ECS Fargate to place tasks evenly across AZs using the 'availabilityZone' dimension, ensuring that if one AZ fails, the remaining tasks in other zones continue serving traffic without interruption. On the AWS Certified DevOps Engineer Professional DOP-C02 exam, this tests your understanding that Fargate services do not automatically distribute tasks across AZs; you must define the placement strategy to achieve Multi-AZ resilience. A common trap is assuming that simply selecting multiple subnets in different AZs is enough—without the spread strategy, tasks may still be placed in a single AZ. For a quick memory tip, think "spread for steadiness": the spread placement strategy spreads tasks like butter across AZs, keeping your application steady even when one zone goes down.
DOP-C02 Resilient Cloud Solutions Practice Question
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's application runs on Amazon ECS with Fargate launch type. The application must be resilient to an Availability Zone failure. Which configuration should be used?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Create an ECS service with tasks distributed across multiple Availability Zones using a spread placement strategy
Option A is correct because ECS services using the Fargate launch type can distribute tasks across multiple Availability Zones (AZs) by defining a spread placement strategy with the 'availabilityZone' dimension. This ensures that if one AZ fails, the tasks in the other AZs continue to serve traffic, providing resilience to an AZ failure. The spread strategy explicitly instructs ECS to place tasks evenly across AZs, which is essential for high availability.
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.
✓
Create an ECS service with tasks distributed across multiple Availability Zones using a spread placement strategy
Why this is correct
Spread strategy across AZs ensures resilience.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use an ECS cluster with a cluster placement strategy that prefers the same Availability Zone
Why it's wrong here
Preferred same AZ reduces resilience.
✗
Define multiple task definitions, one for each Availability Zone
Why it's wrong here
Unnecessary; service can spread tasks across AZs.
✗
Use an ECS service with a single task in one Availability Zone and rely on auto-scaling
Why it's wrong here
Single AZ is a single point of failure.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse 'spread placement strategy' with 'binpack' or 'random' strategies, or they assume that simply using multiple subnets automatically distributes tasks without explicitly setting the spread strategy.
Detailed technical explanation
How to think about this question
Under the hood, ECS with Fargate uses the AWS Nitro system to manage task placement, and the spread placement strategy with the 'availabilityZone' dimension ensures that tasks are placed in distinct AZs based on the VPC subnets specified in the service's network configuration. A subtle behavior is that you must define at least two subnets in different AZs in the service's network configuration for the spread strategy to work; otherwise, ECS will place all tasks in the single available AZ. In a real-world scenario, combining this with a multi-AZ Application Load Balancer target group ensures traffic is routed only to healthy tasks in surviving AZs.
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.
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: Create an ECS service with tasks distributed across multiple Availability Zones using a spread placement strategy — Option A is correct because ECS services using the Fargate launch type can distribute tasks across multiple Availability Zones (AZs) by defining a spread placement strategy with the 'availabilityZone' dimension. This ensures that if one AZ fails, the tasks in the other AZs continue to serve traffic, providing resilience to an AZ failure. The spread strategy explicitly instructs ECS to place tasks evenly across AZs, which is essential for high availability.
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.
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 →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company runs a microservices application on Amazon ECS with Fargate. The services need to be resilient to AZ failures. Which TWO actions should the company take? (Choose two.)
medium
✓ A.Configure the ECS service to spread tasks across multiple Availability Zones
✓ B.Enable Service Auto Scaling to maintain desired count across AZs
C.Use a Network Load Balancer in each AZ for the service
D.Use a placement group to ensure tasks are launched on the same underlying hardware
E.Place all tasks in a single Availability Zone to minimize cross-AZ latency
Why A: Spreading tasks across multiple AZs and using service auto scaling ensure resilience. Option A is wrong because a single AZ is not resilient. Option C is wrong because Fargate tasks are not attached to EC2 instances. Option E is wrong because a standalone ALB in one AZ is a single point of failure.
Variation 2. Which TWO strategies can be used to improve the resilience of an application running on Amazon ECS with Fargate? (Select TWO.)
medium
A.Use a single subnet for all tasks to simplify networking.
✓ B.Configure the ECS service to place tasks in multiple Availability Zones.
C.Increase the task memory reservation to handle peak load.
✓ D.Implement a circuit breaker pattern for downstream dependencies.
E.Use scheduled scaling to adjust task count based on historical patterns.
Why B: Option A (multi-AZ task placement) and Option D (circuit breaker pattern) are correct. Multi-AZ placement spreads tasks across Availability Zones to tolerate AZ failures. Circuit breaker pattern prevents cascading failures. Option B is wrong because increasing memory does not improve resilience. Option C is wrong because using the same subnet reduces resilience. Option E is wrong because scheduled scaling does not handle unexpected spikes.
Variation 3. A company uses Amazon ECS with Fargate for containerized applications. They need to ensure that if a task fails, it is automatically restarted and the application remains available. Which THREE actions should they take? (Choose THREE.)
hard
✓ A.Configure the ECS service to automatically restart failed tasks.
✓ B.Place tasks across multiple Availability Zones.
✓ C.Use an Application Load Balancer with health checks.
D.Set up a CloudWatch alarm to trigger AWS Lambda to restart tasks.
E.Configure an EC2 Auto Scaling group for the ECS cluster.
Why A: Options B, C, and E are correct. Service auto-restart ensures tasks are replaced. Deploying tasks across multiple AZs provides AZ resilience. Using an ALB with health checks ensures traffic is routed to healthy tasks. Option A is incorrect because ECS does not use EC2 Auto Scaling for Fargate. Option D is incorrect because CloudWatch alarms are not needed for automatic restart.
Variation 4. A company runs a critical microservices architecture on Amazon ECS with Fargate. They want to ensure that if a task fails, it is automatically restarted, and the service remains available across multiple Availability Zones. How should they configure the ECS service?
hard
A.Place all tasks in the same Availability Zone to reduce latency
B.Run a standalone Fargate task and use a CloudWatch alarm to restart it
C.Use an EC2 launch type with a single instance to reduce complexity
✓ D.Define an ECS service with a task definition, set desired count across multiple Availability Zones, and use Service Auto Scaling
Why D: Setting the number of tasks across multiple AZs and enabling Service Auto Scaling with task-level restart ensures resilience. The ECS service scheduler automatically restarts failed tasks. Option A is wrong because a single-AZ deployment is a single point of failure. Option B is wrong because placing all tasks in one AZ does not provide AZ resilience. Option D is wrong because a standalone task does not have automatic restart.
Variation 5. A company runs a microservices architecture on Amazon ECS with Fargate. Each service is deployed in its own ECS service. The company wants to ensure that if one Availability Zone (AZ) fails, the services can continue to operate with minimal impact. What is the MOST resilient task placement strategy?
hard
A.Use a task placement constraint to run tasks on distinct instances.
B.Use a task placement strategy that uses the random algorithm.
C.Use a task placement strategy that uses the binpack algorithm to maximize resource utilization.
✓ D.Use a task placement strategy that spreads tasks across Availability Zones.
Why D: Option A is correct because setting spread across AZ ensures tasks are distributed evenly across AZs, and binpack with a spread across AZ is not possible; spread is the correct strategy. Option B is wrong because binpack does not guarantee AZ distribution. Option C is wrong because random may not distribute evenly. Option D is wrong because distinct instance is for EC2, not Fargate.
Last reviewed: Jun 24, 2026
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.
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.
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.
Sign in to join the discussion.