A reporting feature adds heavy read traffic to an RDS MySQL database, slowing the primary writer. Most reads are tolerant of slight staleness. What is the standard way to scale reads?
A.Convert the DB to a larger instance class
Bigger instances help vertically but do not isolate reporting load from the writer.
B.Add RDS read replicas and direct reporting queries to them
Correct. Read replicas scale reads horizontally and keep the writer responsive.
C.Enable Multi-AZ and point reads at the standby
The Multi-AZ standby does not accept connections — it only takes over on failover.
D.Move the database to a single DynamoDB table without changes
DynamoDB is a different data model; a transparent migration is not possible without re-architecting.
Why this answer
RDS read replicas asynchronously replicate data and serve read traffic, offloading the writer. Multi-AZ standbys exist purely for failover and cannot serve reads, and switching engines mid-flight is a redesign, not a scaling step.
Correct answer: B · Last reviewed 2026-10-25
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