SOA-C02 Monitoring, Logging, and Remediation Practice Question

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

  Increasing the InnoDB buffer pool size is a direct fix for high ReadIOPS because the buffer pool caches frequently accessed table and index pages in memory. When the pool is too small, pages are repeatedly evicted and must be fetched from disk, driving up read I/O. Enlarging the pool, typically to 75% of DB instance memory, raises the cache hit ratio and reduces disk reads for the working set.

• ✓

  Enable query caching in MySQL to avoid repeated reads of the same data.

  Why this is correct

  Enabling the MySQL query cache stores the result set of identical SELECT statements so that subsequent executions return the cached output without scanning tables or reading indexes from disk. This directly lowers the number of physical read operations for repetitive read-only queries, but note the query cache is globally invalidated on writes and is best suited to read-heavy, low-write workloads. It complements buffer pool caching by eliminating the need to execute the query at all.

• ✓

  Add read replicas to offload read queries from the primary instance.

  Why this is correct

  Adding RDS read replicas offloads read traffic from the primary DB instance by directing SELECT queries to replica endpoints via application connection logic. Read replicas use asynchronous replication, and since they serve reads independently, they absorb a portion of the read IOPS that would otherwise hit the primary. However, replicas are not used for writes, so this is a horizontal scaling approach for read-heavy scenarios rather than a tuning of the primary instance.

• ✗

  Change the storage type to Provisioned IOPS for better performance.

  Why it's wrong here

  Provisioned IOPS provides a guaranteed IOPS baseline and lower latency, but it does not reduce the number of read operations the database must perform. If the bottleneck is excessive disk reads caused by a small buffer pool or inefficient queries, simply increasing IOPS capacity does not address the underlying cause and may only mask latency while incurring higher cost. It improves the speed of each I/O, not the count of I/Os required.

• ✗

  Enable Multi-AZ deployment for high availability.

  Why it's wrong here

  Enabling Multi-AZ deploys a synchronous standby replica in a different Availability Zone for automatic failover, which provides high availability but no performance benefit. The standby is not used for reads or writes during normal operation; it only takes over upon failover. Therefore, Multi-AZ does not reduce ReadIOPS, improve query latency, or increase throughput, making it an incorrect answer for a performance issue.

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