Templates/Multi-region API Failover

Multi-region API Failover

InfrastructureStarterSingle team

Active-passive multi-region setup with DNS global load balancer, primary/replica PostgreSQL replication, and automated health-check-driven failover. Use for high-availability APIs with sub-minute RTO.

Recommended for: Mission-critical APIs

6 nodes6 connectionsBaseline architecture

Use Case

Mission-critical APIs, financial services, healthcare platforms, global SaaS with SLA requirements

Best Fit Scenarios

  • Mission-critical APIs
  • Financial services
  • Healthcare platforms

Stack Breakdown

DNS/GLBAPI (multi-region)PostgreSQLHealth Checker

Architecture Layers

1Global Load Balancing
2Regional API Clusters
3Database Replication
4Health Monitoring

Components by Category

infra

DNS / GLBHealth Checker

backend

API (US-East)API (EU-West)

database

DB PrimaryDB Replica

Why This Topology Works

DNS-based routing sends traffic to the nearest healthy region. Async replication keeps the secondary warm. Health checks trigger automatic failover, minimizing downtime to seconds.

Scaling Notes

Each region scales independently. DB replication lag is the RPO constraint. Consider CRDTs or conflict resolution for active-active setups.

Observability

Monitor replication lag, regional latency, health check success rate, and failover event frequency. Synthetic probes from each region.

Typical Bottlenecks

  • Deployment drift and regional resource saturation
  • Service latency and timeout behavior on critical routes
  • Write amplification and query contention on primary stores

Async Flow and Reliability

The flow is mostly synchronous. Add queue-backed workers for long-running or failure-prone operations to protect request latency.

Upgrade Path

Begin with a single deployable service and one datastore. Add background workers and dedicated observability as throughput grows.

Operating Envelope

Complexity is marked as Starter with an intended scope of Single team. Use this as a planning baseline before adapting the template to your reliability and team constraints.