Cloud Architecture: Scenario-Based Questions

A multi-region architecture enhances availability, disaster recovery, and latency performance by deploying across geographically separate data centers. Automatic failover ensures continuity in the event of a regional outage.

🌐 Key Design Goals

• Minimize downtime during regional failures.
• Ensure data consistency and synchronization.
• Balance traffic based on latency, availability, or compliance.

🏗️ Architectural Components

• Global DNS: Use Route 53, Cloud DNS, or Azure Traffic Manager for geo-based routing with health checks.
• Compute: Deploy replicas in multiple regions using EC2, GKE, or ECS.
• Database: Use active-active DBs (e.g., CockroachDB, Spanner) or active-passive with replication (e.g., RDS read replicas).
• Storage: Use global object stores (e.g., S3 with replication or GCS multi-region).

🧪 Failover Strategy

• Health-check both infrastructure and app endpoints at the global level.
• Trigger DNS or load balancer switch when primary region fails.
• Replicate critical data and configuration (e.g., secrets, app settings).
• Use infrastructure-as-code to keep environments in sync.

✅ Best Practices

• Perform chaos testing regularly (e.g., simulate regional failover).
• Document RTO (Recovery Time Objective) and RPO (Recovery Point Objective).
• Isolate deployment pipelines per region to avoid cascading failures.
• Use feature flags to enable/disable region-specific behavior quickly.

🚫 Pitfalls to Avoid

• Assuming data is instantly consistent across regions.
• Single-region config store or secrets manager dependency.
• Improperly tested failover plans or outdated runbooks.

📌 Real-World Insight

Multi-region deployments are critical for disaster resilience in global applications. Tech leaders invest in tooling, simulations, and observability to ensure seamless region failover under stress.