Dead Man’s Switch
Missed pings
How missed Dead Man’s Switch check-ins are marked and how alerts fire.
What missed means
When DMS is enabled and CronFox starts an execution, it expects a ping within the grace period. If no valid ping arrives in time, the run is treated as missed.
That is different from an HTTP failed status:
| Signal | Meaning |
|---|---|
| HTTP failed | CronFox could not complete the request successfully |
| DMS missed | The request may have started, but your process never checked in |
What you see
On the task’s execution history:
- A run is created when the job is scheduled or run manually.
- While waiting, DMS is pending.
- After a successful ping, DMS is recorded as OK (
dms_status=ok) with a last-pinged timestamp. - After the grace period with no ping, the run is missed and can trigger alerts.
Exact labels in the UI follow the product; use the execution detail panel when debugging.
Enable alerts
- Enable DMS on the task (setup).
- Open Settings → Notifications.
- Turn on DMS Missed Ping.
- Ensure at least one integration is enabled (and email/in-app masters as needed).
When a ping is missed, CronFox notifies through those channels.
Troubleshoot
- Confirm DMS is enabled on the task and the grace period is long enough.
- Copy the current ping URL from the edit form — an old token will not work.
- Ping manually with curl after a Run now to isolate app vs CronFox issues.
- Check network egress from your worker (firewalls, missing HTTPS).
- Check notification preferences if the miss appears in history but no message arrived.
Still stuck? File a ticket from Help with the task ID and approximate run time.