A production RDS instance must survive an Availability Zone outage with minimal downtime and no manual failover steps. What configuration provides this?
A.A read replica in another AZ
Read replicas replicate asynchronously and require manual promotion.
B.Multi-AZ deployment with synchronous standby and automatic failover
Correct. Sync standby + automatic failover = built for AZ loss.
C.Daily snapshots to S3
Snapshots are for recovery, not availability — restore takes much longer.
D.A larger instance in the same AZ
Instance size doesn't protect against AZ failure.
Why this answer
Multi-AZ RDS keeps a synchronous standby in another AZ and fails over automatically (typically ~60-120s) — surviving AZ loss with no admin action. Read replicas are for scale-out/DR, not automatic AZ-failure protection.
Correct answer: B · Last reviewed 2026-10-26
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