Liveness Probe
ELI5 — The Vibe Check
A liveness probe is Kubernetes repeatedly poking your app and asking 'are you still alive?' If the app stops responding, Kubernetes kills it and starts a fresh one. It catches deadlocks, infinite loops, and zombie processes. It's the 'have you tried turning it off and on again' automation.
Real Talk
A liveness probe is a Kubernetes health check that determines if a container is still running correctly. If the probe fails consecutively (configurable threshold), Kubernetes restarts the container. It detects situations where an application is running but unable to make progress, such as deadlocks or corrupted state. Supports HTTP, TCP, and exec checks.
When You'll Hear This
"The liveness probe detected the deadlock and restarted the pod automatically." / "Don't put database checks in liveness probes — a DB outage shouldn't restart your entire app."
Related Terms
Health Endpoint
A health endpoint is a simple URL (usually /health or /healthz) that returns 'I'm alive and everything's fine' or 'something's broken.
Kubernetes
Kubernetes is a robot manager for your containers.
Readiness Probe
A readiness probe tells Kubernetes 'I'm ready to receive traffic.
Startup Probe
A startup probe gives slow-starting apps time to boot without Kubernetes killing them. Some apps need 60 seconds to load ML models or warm caches.