The answer is to increase the InnoDB buffer pool size, as this directly reduces high ReadIOPS on RDS MySQL by allowing more data and indexes to reside in memory, thereby minimizing costly disk reads. When the buffer pool is too small, frequently accessed pages must be fetched from storage, spiking the ReadIOPS metric. On the AWS Certified SysOps Administrator Associate SOA-C02 exam, this scenario tests your understanding of RDS performance tuning and the distinction between scaling vertically (adjusting instance size or parameters) versus horizontally (adding read replicas). A common trap is immediately choosing read replicas for any read bottleneck, but replicas primarily offload query processing, not reduce per-instance I/O pressure—the buffer pool fix addresses the root cause of high disk reads. Remember the mnemonic “BIG for I/O”: Buffer pool Increase = Good for Input/Output.
SOA-C02 Monitoring, Logging, and Remediation Practice Question
This SOA-C02 practice question tests your understanding of monitoring, logging, and remediation. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 SysOps administrator is investigating a performance issue where an Amazon RDS for MySQL instance's ReadIOPS metric is consistently high. The database is used by a web application. Which THREE actions should the administrator take to improve performance?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Increase the InnoDB buffer pool size to cache more data in memory.
Increasing the InnoDB buffer pool size allows more data and indexes to be cached in memory, reducing the need for disk reads and thus lowering ReadIOPS. This is a direct and effective tuning action for MySQL on RDS when read I/O is the bottleneck.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Increase the InnoDB buffer pool size to cache more data in memory.
Why this is correct
A larger buffer pool reduces the need to read from disk, lowering ReadIOPS.
Related concept
Read the scenario before looking for a memorised answer.
✓
Enable query caching in MySQL to avoid repeated reads of the same data.
Why this is correct
Query caching stores results, reducing disk reads for repeated queries.
Related concept
Read the scenario before looking for a memorised answer.
✓
Add read replicas to offload read queries from the primary instance.
Why this is correct
Read replicas handle SELECT queries, reducing read IOPS on the primary.
Related concept
Read the scenario before looking for a memorised answer.
✗
Change the storage type to Provisioned IOPS for better performance.
Why it's wrong here
Provisioned IOPS improves throughput but does not reduce the number of read operations.
✗
Enable Multi-AZ deployment for high availability.
Why it's wrong here
Multi-AZ is for failover, not performance improvement.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse Provisioned IOPS with reducing I/O demand, when it only improves I/O performance, and Multi-AZ with read scaling, when it is solely for failover and availability.
Detailed technical explanation
How to think about this question
The InnoDB buffer pool is a memory area that caches table and index data; when it is too small, frequently accessed data must be read from disk repeatedly, causing high ReadIOPS. The MySQL query cache (option B) is deprecated in MySQL 8.0 and can cause contention on write-heavy workloads, but in read-heavy scenarios it can reduce repeated reads of identical result sets. Read replicas (option C) offload SELECT queries from the primary instance, distributing read load and reducing primary ReadIOPS.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Monitoring, Logging, and Remediation — This question tests Monitoring, Logging, and Remediation — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Increase the InnoDB buffer pool size to cache more data in memory. — Increasing the InnoDB buffer pool size allows more data and indexes to be cached in memory, reducing the need for disk reads and thus lowering ReadIOPS. This is a direct and effective tuning action for MySQL on RDS when read I/O is the bottleneck.
What should I do if I get this SOA-C02 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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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.
Question Discussion
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