Freeze Detection

Freeze Detection

Coming. The learning half already runs; the judging half is being built. This page describes what exists today and what the section will do.

A frozen device is the failure nothing else catches: the device stops reporting but its entities keep showing the last healthy value. The temperature reads 21 degrees forever. Everything looks fine, and nothing is.

What already runs

Device Sentinel has been learning every device's reporting rhythm since installation: how often it normally speaks, tracked per device, with any entity's activity counting. This is what the soak period and the Devices Learned count are about. The full mechanics are on How Device Sentinel Learns.

What is coming

Each device gets its own freeze window: its learned rhythm plus a margin. A device that reports every 30 seconds is judged on a scale of minutes; a device that reports twice a day is judged on a scale of days. No fixed timeout exists anywhere, because no fixed timeout can be right for both of those devices.

When a device goes silent past its own window, it is flagged. Devices with no natural heartbeat, like buttons and remotes that only speak when pressed, are never judged frozen at all.

The section's configuration screen will hold the sensitivity levers and a freeze-only exclude list, in the same shape as Low Battery.

What you can do today

Nothing is required. Learning is automatic. If you want stronger freeze detection when it arrives, press Scan and Enable Signal and Last-Seen Entities on the device page: last-seen entities are protocol truth, the most reliable clock a device can offer, and some integrations ship them turned off.