purpose of liveness_probe unclear

[smeijer]

Hi,

Given that the liveness_probe doesn't trigger restarts, I wonder what its purpose is. I'm using a ready_log_line to mark a process as "ready", and readiness_probes serves as a health check to restart processes in case of error, but the purpose of liveness_probes is unclear to me.

The summary of the kubernetes docs is clear:

• Startup Probe — Checks if the container has successfully started.
• Liveness Probe — Checks if the container is still running.
• Readiness Probe — Checks if the container is ready to accept traffic.

Should the liveness probe not invoke a restart when the restart policy is always?

Related issue: When using a ready_log_line to detect 'readiness,' I can't also use a readiness_proble to run health checks on interval. The logline is a much faster way to detect when a service is up, but given that the liveness_probe doesn't trigger restarts, those processes have no way of being restarted on failure.

In addition; when the liveness check fails, the process is still listed as "Running" as if all was fine.