The correct actions to improve availability are deploying EC2 instances across multiple Availability Zones and using an Auto Scaling group to replace unhealthy instances. Distributing instances across multiple Availability Zones eliminates a single point of failure by ensuring that if one zone goes down, the Application Load Balancer can route traffic to healthy instances in another zone. An Auto Scaling group automatically replaces failed or unhealthy instances, maintaining the desired capacity and further enhancing fault tolerance. On the AWS Certified SysOps Administrator Associate SOA-C02 exam, this question tests your understanding of high-availability architecture patterns, often with traps like choosing a single subnet or a larger instance type—both of which improve performance or simplicity, not availability. A common memory tip is to remember that availability comes from redundancy across zones and automated recovery, not from bigger or fewer resources. Think “spread and replace” to recall the two key actions.
SOA-C02 Networking and Content Delivery Practice Question
This SOA-C02 practice question tests your understanding of networking and content delivery. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
Which TWO actions can be taken to improve the availability of a web application hosted on EC2 instances behind an Application Load Balancer? (Select two.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Configure an Auto Scaling group with health checks to replace unhealthy instances.
Option A is correct because multi-AZ deployment distributes instances across Availability Zones for fault tolerance. Option B is correct because an Auto Scaling group can replace unhealthy instances automatically. Option C is wrong because a single subnet is a single point of failure. Option D is wrong because a larger instance type improves performance, not availability. Option E is wrong because a single region is more susceptible to regional failures.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Configure an Auto Scaling group with health checks to replace unhealthy instances.
Why this is correct
Auto Scaling automatically replaces unhealthy instances.
Single region does not provide regional fault tolerance.
✗
Place all EC2 instances in a single subnet.
Why it's wrong here
Single subnet is a single point of failure.
Common exam traps
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.
TExam Day Tips
→Write the block size before choosing the subnet.
→Check whether the question asks for hosts, subnets or a specific address range.
→Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
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.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related SOA-C02 subnetting questions on CIDR, address ranges, and subnet selection.
Networking and Content Delivery — This question tests Networking and Content Delivery — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Configure an Auto Scaling group with health checks to replace unhealthy instances. — Option A is correct because multi-AZ deployment distributes instances across Availability Zones for fault tolerance. Option B is correct because an Auto Scaling group can replace unhealthy instances automatically. Option C is wrong because a single subnet is a single point of failure. Option D is wrong because a larger instance type improves performance, not availability. Option E is wrong because a single region is more susceptible to regional failures.
What should I do if I get this SOA-C02 question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related SOA-C02 subnetting questions on CIDR, address ranges, and subnet selection.
What is the key concept behind this question?
CIDR notation defines the prefix length.
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. Which TWO actions can a SysOps administrator take to improve the availability of a web application using an Application Load Balancer (ALB) and EC2 instances? (Choose two.)
medium
A.Place all instances in a single subnet to reduce latency
✓ B.Configure health checks on the target group
✓ C.Deploy EC2 instances in multiple Availability Zones
D.Use larger instance types to handle more traffic
E.Increase the deregistration delay (connection draining) timeout
Why B: Options B and C are correct: Deploying EC2 instances in multiple Availability Zones provides high availability, and configuring health checks allows the ALB to route traffic only to healthy instances. Option A is wrong because using a larger instance type improves performance, not availability. Option D is wrong because a single subnet is a single point of failure. Option E is wrong because increasing the deregistration delay does not improve availability; it only affects connection draining.
Variation 2. Which TWO actions should a SysOps administrator take to improve the availability and reduce latency for a web application hosted on EC2 instances behind an Application Load Balancer?
medium
A.Use larger EC2 instance types to handle more traffic.
B.Configure the ALB health check to have a shorter interval.
C.Use an Amazon CloudFront distribution in front of the ALB to cache content at edge locations.
✓ D.Implement Auto Scaling to add instances based on CPU utilization.
✓ E.Deploy EC2 instances in multiple Availability Zones.
Why D: Deploying across multiple Availability Zones increases fault tolerance. Using Auto Scaling helps maintain performance during traffic spikes by adding or removing instances. Option C is incorrect because increasing instance size might help but does not provide the same resilience as distributing across AZs. Option D is incorrect because reducing health check interval increases load but not availability. Option E is incorrect because using a single EBS volume does not improve availability.
Last reviewed: Jun 20, 2026
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This SOA-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 SOA-C02 exam.
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