Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A company runs a web application on Amazon EC2 instances behind an Application Load Balancer (ALB). The application reads data from an Amazon RDS for MySQL database. During peak hours, the database CPU utilization is consistently high, and the application experiences increased latency. The SysOps administrator observes that 90% of database queries are read-only. Which combination of actions will both improve performance and optimize costs?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
Enable Multi-AZ for the RDS instance and scale up the instance size
Multi-AZ provides high availability, not read scaling. The standby is not used for reads. Scaling up increases cost without addressing the root cause (read-heavy workload) and may provide limited improvement.
B
Best answer
Implement a read replica for the RDS instance and modify the application to route read queries to the read replica
Read replicas can handle read traffic, reducing load on the primary instance. This improves performance and, by avoiding unnecessary scale-up, can be more cost-effective. Only the primary instance needs to be sized for writes.
C
Distractor review
Enable Amazon RDS Performance Insights and increase the storage allocation
Performance Insights helps identify performance bottlenecks but does not directly reduce CPU load. Increasing storage may improve I/O performance if bottlenecks are I/O-related, but it does not address high CPU from read queries and increases cost.
D
Distractor review
Implement Amazon ElastiCache for Memcached in front of the database and migrate read-heavy queries to cache
ElastiCache can improve performance by caching frequent reads, but it adds additional cost and operational overhead. For a workload where 90% of queries are reads, read replicas are a simpler and often more cost-effective solution, especially if the data is not highly cacheable or frequently updated.
Common exam trap
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.
Technical deep dive
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.
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.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A company uses Amazon CloudFront to deliver content to a global audience. The origin is an Application Load Balancer in us-east-1. The SysOps administrator wants to reduce costs by minimizing the number of requests that reach the origin server. Which action should the administrator take?
Question 2
A company runs a batch processing application on Amazon EC2 that runs for 2 hours every night. The workload can tolerate interruptions. Which EC2 purchasing option provides the lowest cost for this use case?
Question 3
A SysOps administrator needs to monitor the CPU utilization of an Amazon RDS DB instance and receive an alarm when CPU utilization exceeds 80% for 5 consecutive minutes. Which AWS service should be used to create this alarm?
Question 4
A company runs a critical web application on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer (ALB). The application uses session stickiness (sticky sessions) to maintain user sessions. The SysOps administrator notices that when instances are replaced during a scale-in or failure event, users lose their session data. The administrator needs to preserve session data across instance failures without losing stickiness benefits. What should the administrator do?
Question 5
A company runs a production web application on a single Amazon EC2 instance. The application experiences a predictable and steady workload 24/7. The SysOps administrator wants to minimize compute costs for this instance while ensuring it remains available during the expected workload. Which EC2 purchasing option should the administrator use?
Question 6
A company has a VPC with public and private subnets. The private subnets host application servers that need to make outbound HTTPS connections to the internet. The SysOps administrator must implement a solution that provides outbound internet connectivity while preventing inbound connections from the internet. Additionally, the solution must allow the company to control which domains the application servers can access. Which solution should the administrator implement?
FAQ
Questions learners often ask
What does this SOA-C02 question test?
Static NAT maps one inside address to one outside address.
What is the correct answer to this question?
The correct answer is: Implement a read replica for the RDS instance and modify the application to route read queries to the read replica — Implementing an RDS read replica offloads read queries from the primary database instance. By modifying the application to direct read queries to the read replica, the primary instance's CPU utilization decreases, reducing latency. This can also delay or eliminate the need to scale up the instance size, thus optimizing costs as read replicas are charged separately but can be of a smaller instance type.
What should I do if I get this SOA-C02 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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