SOA-C02 Cost and Performance Optimization Practice Question
A company wants to reduce costs for a production Amazon RDS for MySQL DB instance that is running 24/7 but only heavily used during business hours (9 AM to 5 PM). Which TWO actions would be MOST effective in optimizing costs without significantly impacting performance during peak hours?
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
✓
Purchase Reserved Instances for the DB instance.
(Multi-AZ) increases cost and is not needed for cost optimization. Option B (reserved instances) provides a discount for consistent usage. Option C (Migrate to gp3 storage) can be more cost-effective than provisioned IOPS for many workloads, but it is not the most effective action because the instance is only heavily used during business hours. Option D (scheduled scaling) can reduce instance size during off-peak hours, saving cost. Option E (Auto Scaling) is not applicable to standard RDS without additional services like Aurora Auto Scaling. Correct answers: B and D.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Enable Multi-AZ deployment for high availability.
Why it's wrong here
Enable Multi-AZ increases cost and does not directly optimize cost.
- ✓
Purchase Reserved Instances for the DB instance.
Why this is correct
Reserved Instances provide a discount for consistent usage, reducing cost.
- ✗
Migrate from Provisioned IOPS (io1) storage to General Purpose (gp3) storage.
Why it's wrong here
(migrate to gp3) can be more cost-effective than provisioned IOPS for many workloads.
- ✓
Use AWS Application Auto Scaling to schedule scale-down of the instance size outside business hours.
Why this is correct
Scheduled scaling reduces instance size during off-peak hours, saving cost.
- ✗
Enable Auto Scaling for the DB instance.
Why it's wrong here
(auto scaling) is not applicable to RDS without additional services like Aurora Auto Scaling.
Go deeper
Related to this question
About these practice questions
One of 247 original SOA-C02 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
2 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 wants to reduce costs for their Amazon RDS for PostgreSQL database. Which TWO actions would help achieve this?
easy- A.Enable Multi-AZ deployment for high availability.
- ✓ B.Stop the database instance during non-business hours.
- C.Enable deletion protection to prevent accidental deletion.
- D.Increase the backup retention period to 35 days.
- ✓ E.Purchase a Reserved Instance for the database instance.
Why B: Options B and E are correct because stopping the database instance during non-business hours reduces compute costs by eliminating charges when the instance is not used, and purchasing a Reserved Instance for a predictable workload provides a significant discount compared to On-Demand pricing. Option A is incorrect because Multi-AZ deployment increases costs due to standby instance charges. Option C is incorrect because deletion protection does not reduce costs. Option D is incorrect because increasing backup retention to 35 days increases storage costs.
Variation 2. A company is using Amazon RDS for MySQL with Multi-AZ deployment. They want to optimize costs while maintaining high availability. Which TWO actions should the SysOps administrator take?
medium- ✓ A.Purchase Reserved Instances for the database instance.
- B.Remove Multi-AZ to reduce costs.
- C.Enable auto scaling for the RDS instance to handle variable load.
- ✓ D.Review the instance size and downsize if it is over-provisioned.
- E.Move to a single-AZ deployment and take snapshots for recovery.
Why A: Purchasing Reserved Instances for a Multi-AZ RDS instance provides significant discounts over On-Demand pricing, reducing costs while maintaining high availability. Option D is correct because reviewing and downsizing the instance size if it is over-provisioned directly reduces costs without impacting availability. Option B is incorrect because removing Multi-AZ would eliminate high availability. Option C is incorrect because RDS does not support auto scaling for compute capacity; you can use read replicas or adjust instance size manually. Option E is incorrect because moving to a single-AZ deployment sacrifices high availability, which conflicts with the requirement.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.