Health check endpoints for liveness, readiness, dependency monitoring. Use for Kubernetes, load balancers, auto-scaling, or encountering probe failures, startup delays, dependency checks, timeout configuration errors.

Health Check Endpoints Implement health checks for monitoring service availability and readiness. Probe Types Probe Purpose Failure Action Liveness Is process alive? Restart container Readiness Can handle traffic? Remove from LB Startup Has app started? Delay other probes Deep All deps healthy? Trigger alerts Implementation (Express) Kubernetes Configuration Best Practices Keep liveness checks minimal (no external deps) Check only critical systems in readiness Return 200 for healthy, 503 for unhealthy Set reasonable timeouts to prevent cascading failures Include response time metrics Additional Implementations See [references/implementations.md](references/implementations.md) for: Python Flask complete health checker Java Spring Boot Actuator Full Kubernetes deployment config Never Do Make liveness depend on external services Return 200 when dependencies are down Skip dependency checks in readiness

health-check-endpoints