A global app must accept writes in two regions simultaneously, survive a full regional outage with near-zero RPO, and resolve write conflicts. Which data-layer combination supports true active-active?
A.RDS Multi-AZ plus read replicas in a second region
Multi-AZ ≠ multi-region; cross-region replicas require promotion before accepting writes — not active-active.
B.DynamoDB global tables (or Aurora Global Database with write forwarding)
Correct. Global tables are the canonical multi-writer, conflict-resolved, near-zero-RPO answer.
C.S3 cross-region replication for the primary datastore
S3 is object storage, not a transactional datastore — and replication is async, one-directional per bucket pair.
D.A single-region Aurora cluster with automated backups
Single-region can't accept writes during a regional outage — RPO/RTO fail.
Why this answer
Active-active needs multi-writer replication: DynamoDB global tables replicate writes across regions with last-writer-wins conflict resolution. Aurora Global Database is single-writer (write forwarding proxies to the writer) — acceptable for many active-active reads but not symmetric multi-region writes.
Correct answer: B · Last reviewed 2026-10-26
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