Cron Monitoring

Monitor cron jobs, scheduled tasks, and heartbeats. Know when jobs fail, run late, or disappear. Dead man's switch included.

How Cron Monitoring Works

Unsparing uses ping URLs for cron monitoring. Your cron job pings Unsparing when it starts (or finishes). If Unsparing doesn't receive a ping within the expected window, it triggers an alert.

This is the dead man's switch pattern: silence is the signal.

Adding a Cron Task

Navigate to Cron → Tasks and click Add Task
Configure the task:

Field	Description
Name	A human-readable name (e.g., "Backup Database")
Schedule	Cron expression or human-readable schedule
Grace Period	How long to wait after the expected time before alerting
Timezone	The timezone for the schedule

Unsparing generates a unique ping URL: https://api.unsparing.dev/api/v1/ping/{task_id}
Add the ping to your cron job

Integration Patterns

Crontab

# Ping before the job
0 2 * * * curl -s https://api.unsparing.dev/api/v1/ping/YOUR_PING_ID >> /dev/null 2>&1 && /usr/local/bin/backup.sh

Systemd Timer

[Service]
ExecStart=/usr/local/bin/backup.sh
ExecPostStart=/usr/bin/curl -s https://api.unsparing.dev/api/v1/ping/YOUR_PING_ID

Any Script

#!/bin/bash
# At the start of your job
curl -s https://api.unsparing.dev/api/v1/ping/YOUR_PING_ID

# Your job logic here
/usr/local/bin/your-script.sh

# Optional: ping again to mark completion
curl -s https://api.unsparing.dev/api/v1/ping/YOUR_PING_ID/finish

Kubernetes CronJob

apiVersion: batch/v1
kind: CronJob
metadata:
  name: backup
spec:
  schedule: "0 2 * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: backup
            image: backup:latest
            command: ["/bin/sh", "-c"]
            args:
            - |
              curl -s https://api.unsparing.dev/api/v1/ping/YOUR_PING_ID
              /usr/local/bin/backup.sh

Alert Types

Alert	Trigger
Job didn't run	No ping received within schedule + grace period
Job ran late	Ping received after the expected window
Job ran outside schedule	Ping received outside the cron schedule
Job completed	Ping with `/finish` endpoint received

Grace Periods

Grace periods prevent false alerts. If your job usually takes 5 minutes, set a grace period of 10 minutes. Unsparing will only alert if no ping is received after the grace period expires.

Recommended grace periods:

Job Type	Grace Period
Quick tasks (< 1 min)	5 minutes
Medium tasks (1-10 min)	15 minutes
Long tasks (10-60 min)	30 minutes
Batch jobs (1+ hour)	2x the expected runtime

API Endpoints

List Cron Tasks

curl -H "Authorization: Bearer YOUR_API_KEY" \
  https://api.unsparing.dev/api/v1/cron/tasks

Create a Cron Task

curl -X POST -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name": "Backup Database", "schedule": "0 2 * * *", "grace_period": 300}' \
  https://api.unsparing.dev/api/v1/cron/tasks

Ping a Cron Task

curl https://api.unsparing.dev/api/v1/ping/YOUR_PING_ID

Plan Limits

Plan	Cron Tasks
Free	3
Homelabber	Unlimited
Teams	Unlimited
Agency	Unlimited

→ Alerts & Notifications · API Reference

On this page