The answer is scheduled scaling, as it is the most cost-effective solution for predictable traffic spikes. This approach works by proactively adding EC2 instances before the anticipated 2 PM spike and removing them afterward, ensuring performance during high demand while avoiding unnecessary costs during off-peak hours. On the AWS Certified SysOps Administrator Associate SOA-C02 exam, this question tests your understanding of scaling strategies for variable but predictable workloads—a common scenario where dynamic scaling would introduce a lag as it reacts to real-time metrics, and manual scaling lacks automation. A frequent trap is choosing dynamic scaling because it sounds automated, but for known patterns, scheduled scaling eliminates the performance lag and optimizes cost by running only needed instances. Remember the mnemonic: "Predict the peak, schedule the fleet" to distinguish proactive scheduled scaling from reactive dynamic scaling.
SOA-C02 Cost and Performance Optimization Practice Question
This SOA-C02 practice question tests your understanding of cost and performance optimization. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 running a web application on a fleet of EC2 instances behind an Application Load Balancer. The application experiences variable traffic patterns with predictable spikes every day at 2 PM. The company wants to optimize costs while maintaining performance. Which solution is MOST cost-effective?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use scheduled scaling to add instances before the spike and remove them after.
Scheduled scaling allows you to add capacity in advance of the predictable spike, ensuring performance during the spike and reducing costs by running only needed instances at other times. Dynamic scaling reacts to real-time metrics, which may cause a temporary performance lag. Manual scaling is not automated. Reserved Instances provide a discount but do not adjust capacity automatically.
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.
✗
Use manual scaling by adjusting the desired capacity each day at 2 PM.
Why it's wrong here
Manual scaling is not automated and may not be timely.
✗
Purchase Reserved Instances for the entire fleet to reduce costs.
Why it's wrong here
Reserved Instances provide a discount but do not adjust capacity automatically.
✓
Use scheduled scaling to add instances before the spike and remove them after.
Why this is correct
Scheduled scaling adds capacity before the predictable spike and removes it after, optimizing cost and performance.
Related concept
Static NAT maps one inside address to one outside address.
✗
Use dynamic scaling policies based on CPU utilization.
Why it's wrong here
Dynamic scaling reacts to real-time metrics, which may cause a temporary performance lag.
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 — 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: Use scheduled scaling to add instances before the spike and remove them after. — Scheduled scaling allows you to add capacity in advance of the predictable spike, ensuring performance during the spike and reducing costs by running only needed instances at other times. Dynamic scaling reacts to real-time metrics, which may cause a temporary performance lag. Manual scaling is not automated. Reserved Instances provide a discount but do not adjust capacity automatically.
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 →
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 is running a production web application on EC2 instances behind an ALB. The application experiences predictable traffic spikes during business hours. Which cost optimization strategy would be MOST effective?
medium
✓ A.Configure Scheduled Scaling to add instances before the spike and remove after.
B.Use Spot Instances for the entire workload.
C.Use larger instance types to handle the spikes without scaling.
D.Use On-Demand instances exclusively to handle the spikes.
Why A: Option B is correct because using Scheduled Scaling for predictable patterns reduces costs by running only needed capacity. Option A is wrong because On-Demand is flexible but not cost-optimized for predictable spikes. Option C is wrong because increasing instance size doesn't dynamically adjust to spikes. Option D is wrong because Spot Instances are not suitable for production workloads that require 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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