How we solved cache invalidation in Kubernetes with a headless service

This article details a practical solution for cache invalidation in a Kubernetes cluster using headless services. The author describes a real-world scenario where a Node.js microservice serving lab test booking data faced performance issues due to database load. By implementing in-memory caching with @nestjs/cache-manager, they reduced latency but encountered cache inconsistency across multiple dynamic pods. The innovative solution leverages Kubernetes headless services (clusterIP: None) to discover all active pod IPs via DNS, enabling a targeted HTTP broadcast for cache invalidation. The article covers the problem, architecture, and step-by-step implementation, making it highly relevant for IT/TECHNOLOGY professionals working with distributed systems, Kubernetes, and caching strategies.