What is Health Check?
An endpoint or mechanism that reports whether an application is running correctly and ready to handle requests.
Health checks enable load balancers and orchestrators to detect unhealthy instances. Liveness probes check if the application is running (restart if not). Readiness probes check if it can handle traffic (remove from load balancer if not).
A health endpoint (/health or /healthz) typically checks database connectivity, disk space, memory usage, and dependent service availability. Kubernetes supports HTTP, TCP, and command-based health checks with configurable intervals and thresholds.