Intelligent failover using AWS Lambda@Edge and Amazon DynamoDB

This article describes a serverless solution using AWS Lambda@Edge and Amazon DynamoDB to intelligently route user traffic across multiple AWS regions with session affinity and automatic failover capabilities.

• Lambda@Edge runs custom routing logic at 13 Regional Edge Cache locations to dynamically assign users to specific regions based on session IDs
• DynamoDB stores endpoint configurations and user-session mappings, with Global Tables enabling multi-region replication for resilience
• Solution handles regional outages gracefully by evacuating users from impaired regions and redistributing them to healthy endpoints
• Operates on the data plane after setup, avoiding control plane bottlenecks and enabling millisecond-level failover decisions
• Ideal for applications requiring session affinity, A/B testing, cell-based architectures, and high availability in e-commerce, finance, and healthcare
• Open-source implementation available via AWS CDK for easy deployment

This architecture provides a cost-effective, scalable foundation for mission-critical applications requiring resilient multi-region traffic management with minimal operational complexity.