What happens when a server locks up and FrontierStack can't reach it?

It depends on what is still running. If the server's Host Monitor is alive, Lockup reboot in its Service Watchdog panel lets the server reboot itself when SSH stops answering; the monitor waits for sshd's greeting, not just an open port; or when it can no longer reach its gateway, after the minutes you choose (10 by default). It reboots at most once per interval, only after the check has worked once, and only with Allow actions and Allow reboot on. From monitor 1.24.0 a root reboot sentinel backs this up through the kernel, so it still works when the server can't start new processes; the case where ports accept connections but sshd and Screen Sharing never answer. Meanwhile the server's pane shows what FrontierStack last saw: addresses, services and any scheduled reboot. A kernel hang stops everything on the box, so pair this with Restart if it freezes on Macs and a smart plug or recovery observer for power-level recovery. The forced reboot skips a graceful shutdown, so databases run crash recovery afterwards. See the manual.

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