- A
Switch to a target tracking scaling policy based on request count per target.
Why wrong: Target tracking improves responsiveness but does not inherently reduce cost; instances remain On-Demand.
- B
Implement scheduled scaling to add capacity during known peak hours.
Why wrong: Scheduled scaling works for predictable patterns, but the traffic is variable and unpredictable.
- C
Configure the Auto Scaling group to use a mixed instances policy with Spot Instances for a portion of the capacity and On-Demand for the remainder.
Spot Instances can reduce costs significantly while maintaining availability through On-Demand fallback.
- D
Purchase Reserved Instances for the minimum expected capacity to get a discount.
Why wrong: Reserved Instances reduce cost for baseline capacity, but do not address spike handling cost-effectively.
Quick Answer
The answer is to configure the Auto Scaling group with a mixed instances policy that combines Spot Instances for a portion of the capacity with On-Demand Instances for the remainder. This approach directly reduces cost because Spot Instances leverage unused AWS capacity at steep discounts—often 60-90% off On-Demand pricing—while the On-Demand portion ensures baseline availability during spikes or when Spot capacity is reclaimed. On the AWS Certified SysOps Administrator Associate SOA-C02 exam, this scenario tests your understanding of balancing cost and reliability for variable, unpredictable traffic; a common trap is choosing Reserved Instances, which lock in cost for steady-state usage but offer no flexibility for spikes, or selecting target tracking scaling, which improves responsiveness but does not lower instance costs. Remember the key trade-off: Spot for savings, On-Demand for stability. A useful memory tip is “Spot the savings, keep the On-Demand anchor”—the mixed policy lets you ride the cost wave without crashing on availability.
SOA-C02 Cost and Performance Optimization Practice Question
This SOA-C02 practice question tests your understanding of cost and performance optimization. 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.
A company hosts a web application on EC2 instances behind an Application Load Balancer (ALB). The application experiences variable traffic patterns with occasional spikes. The current setup uses On-Demand instances in an Auto Scaling group with a simple scaling policy based on average CPU utilization. The team wants to optimize cost while ensuring that the application can handle spikes in traffic. What should the team do to reduce cost?
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
Configure the Auto Scaling group to use a mixed instances policy with Spot Instances for a portion of the capacity and On-Demand for the remainder.
Option B is correct because Spot Instances are cost-effective and can be used alongside On-Demand for variable workloads; the Auto Scaling group can use a mixed instances policy to maintain availability while reducing cost. Option A (reserved instances) locks in cost for steady usage but does not help with spikes. Option C (scheduled scaling) is not suitable for unpredictable traffic. Option D (target tracking) improves scaling but does not directly reduce cost; it uses On-Demand instances which are more expensive.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Switch to a target tracking scaling policy based on request count per target.
Why it's wrong here
Target tracking improves responsiveness but does not inherently reduce cost; instances remain On-Demand.
- ✗
Implement scheduled scaling to add capacity during known peak hours.
Why it's wrong here
Scheduled scaling works for predictable patterns, but the traffic is variable and unpredictable.
- ✓
Configure the Auto Scaling group to use a mixed instances policy with Spot Instances for a portion of the capacity and On-Demand for the remainder.
Why this is correct
Spot Instances can reduce costs significantly while maintaining availability through On-Demand fallback.
Related concept
Static NAT maps one inside address to one outside address.
- ✗
Purchase Reserved Instances for the minimum expected capacity to get a discount.
Why it's wrong here
Reserved Instances reduce cost for baseline capacity, but do not address spike handling cost-effectively.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
- Static NAT maps one inside address to one outside address.
- PAT allows many inside hosts to share one public address using ports.
- Inside local and inside global describe the private and translated addresses.
- NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
- Identify inside and outside interfaces first.
- Check whether the scenario needs static NAT, dynamic NAT or PAT.
- Do not confuse NAT matching ACLs with normal packet-filtering intent.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
How this comes up in practice
A startup's cloud architect reviews their monthly bill and notices costs are higher than expected for a long-running batch job. Switching from on-demand instances to Reserved Instances — or using Spot/Preemptible VMs — can reduce compute costs by up to 72 %. Questions like this test whether you understand the tradeoffs between commitment, flexibility, and cost across cloud pricing models.
What to study next
Got this wrong? Here's your next step.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related SOA-C02 NAT questions on configuration and troubleshooting.
- →
Cost and Performance Optimization — study guide chapter
Learn the concepts, then practise the questions
- →
Cost and Performance Optimization practice questions
Targeted practice on this topic area only
- →
All SOA-C02 questions
1,546 questions across all exam domains
- →
AWS Certified SysOps Administrator Associate SOA-C02 study guide
Full concept coverage aligned to exam objectives
- →
SOA-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related SOA-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Monitoring, Logging, and Remediation practice questions
Practise SOA-C02 questions linked to Monitoring, Logging, and Remediation.
Reliability and Business Continuity practice questions
Practise SOA-C02 questions linked to Reliability and Business Continuity.
Deployment, Provisioning, and Automation practice questions
Practise SOA-C02 questions linked to Deployment, Provisioning, and Automation.
Security and Compliance practice questions
Practise SOA-C02 questions linked to Security and Compliance.
Networking and Content Delivery practice questions
Practise SOA-C02 questions linked to Networking and Content Delivery.
Cost and Performance Optimization practice questions
Practise SOA-C02 questions linked to Cost and Performance Optimization.
SOA-C02 fundamentals practice questions
Practise SOA-C02 questions linked to SOA-C02 fundamentals.
SOA-C02 scenario practice questions
Practise SOA-C02 questions linked to SOA-C02 scenario.
SOA-C02 troubleshooting practice questions
Practise SOA-C02 questions linked to SOA-C02 troubleshooting.
Practice this exam
Start a free SOA-C02 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this SOA-C02 question test?
Cost and Performance Optimization — This question tests Cost and Performance Optimization — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: Configure the Auto Scaling group to use a mixed instances policy with Spot Instances for a portion of the capacity and On-Demand for the remainder. — Option B is correct because Spot Instances are cost-effective and can be used alongside On-Demand for variable workloads; the Auto Scaling group can use a mixed instances policy to maintain availability while reducing cost. Option A (reserved instances) locks in cost for steady usage but does not help with spikes. Option C (scheduled scaling) is not suitable for unpredictable traffic. Option D (target tracking) improves scaling but does not directly reduce cost; it uses On-Demand instances which are more expensive.
What should I do if I get this SOA-C02 question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related SOA-C02 NAT questions on configuration and troubleshooting.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
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 →
Same concept, more angles
1 more ways this is tested on SOA-C02
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 critical web application on EC2 instances behind an ALB. The application experiences unpredictable traffic spikes. The SysOps administrator wants to ensure that the application can handle spikes without performance degradation while minimizing costs. Which TWO actions should the administrator take?
hard- ✓ A.Use a mix of On-Demand and Spot Instances in the Auto Scaling group.
- B.Use Amazon DynamoDB auto scaling to handle the spikes.
- C.Use scheduled scaling to add instances during expected peak hours.
- ✓ D.Use a target tracking scaling policy based on CPU utilization.
- E.Use larger EC2 instance types to handle spikes.
Why A: Option A is correct because Spot Instances can reduce costs if the application can handle interruptions. Option D is correct because target tracking scaling adjusts capacity based on load. Option B is wrong because DynamoDB auto scaling is not relevant for EC2. Option C is wrong because scheduled scaling cannot handle unpredictable spikes. Option E is wrong because increasing instance size may not be as cost-effective as scaling out.
Last reviewed: Jun 20, 2026
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.
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.