Design for region failure. Active/passive and active/active, data replication, and failover testing.

On this page

Multi-Region Resilience: Failover, Data, and DNS

Single-region risk is high. Multi-region design improves availability and disaster recovery.

Patterns #

Active/passive: One primary region; failover to secondary on failure. RTO/RPO depend on replication and DNS.
Active/active: Traffic in multiple regions; better latency and availability, harder data consistency.

Replication: Async for RPO tolerance; sync for strong consistency (with latency tradeoff).
Conflict resolution: Last-write-wins or application-defined; test conflict scenarios.

Route53 / global load balancers: Health checks and failover or weighted routing.
TTL: Lower TTL before failover to reduce propagation delay; balance with DNS load.

Multi-region adds cost and complexity; start with critical paths and expand.