Q1 — Multi-AZ vs Read Replica

A company's RDS MySQL database is being overwhelmed by read traffic from a reporting application. The team wants to reduce load on the primary database without affecting write availability. What should they implement?

• A. Enable RDS Multi-AZ
• B. Create a Read Replica and direct reporting queries to it
• C. Enable automated backups with a 35-day retention window
• D. Upgrade the RDS instance to a larger instance class
• Correct answer:

Q2 — Multi-AZ failover behavior

A company runs a production RDS instance with Multi-AZ enabled. The primary database instance fails. What happens?

• A. An administrator must manually promote the standby to primary
• B. AWS creates a new primary in the same AZ within 10 minutes
• C. Failover is automatic; the DNS endpoint is updated to point to the standby; no application connection string change is required
• D. All in-flight transactions are replayed on the standby upon promotion
• Correct answer:

Q3 — Read Replica consistency

A developer queries an RDS Read Replica immediately after a write to the primary. The query returns data from before the write. Why?

• A. Multi-AZ replication failed
• B. Read Replicas use asynchronous replication, so there can be a slight lag