Why 'Is It Alive?' Is the Wrong Question for Monitoring Your Infrastructure

A home-lab operator running always-on machines and GPU-based AI workloads argues that standard process monitoring fails to catch the most damaging failures. A GPU node sat idle for 16 hours with all health checks showing green, because the only meaningful signal — rising output count — was never being tracked. The author proposes splitting monitoring into three distinct layers: liveness, connectivity, and progress, each revealing different failure modes. He also warns that stale metric values can appear normal on dashboards, masking real errors, and recommends a freshness gate so outdated readings cannot register as healthy. The core takeaway is that observability — confirming work is actually advancing — matters far more than simply confirming a process is running.