MirrorProxy
Production-grade traffic shadowing and replay system for Node.js applications that duplicates requests to shadow services and compares responses to detect behavioral differences before deployments
Features
- HTTP proxy middleware that forwards requests to primary upstream service
- Asynchronous shadow dispatch with strict timeouts to prevent impact on production
- Response comparison engine analyzing status codes, normalized bodies, and latency
- Rules engine with route-based filtering, method filtering, and percentage-based sampling
- Global kill switch for immediate disabling of all shadow traffic
- Control plane API for CRUD operations on shadow targets and rules management
- MongoDB persistence for storing comparison results and system state
- Observability with structured logging, metrics, and OpenTelemetry distributed tracing
Stack
Node.js Express.js MongoDB Mongoose TypeScript Pino OpenTelemetry Prometheus Docker Kubernetes