Monitoring Cron Jobs

The Pattern

The simplest and most reliable way to monitor a cron job is to append a curl call after the main command. The ping only fires on success because && requires the previous command to exit with code 0.

# ✅ Only pings if backup.sh succeeds
0 3 * * * /usr/bin/backup.sh && curl -fsS https://ping.cronping.com/<token>

The -fsS flags make curl fail silently on HTTP errors (-f), suppress progress output (-s), but still show errors if something goes wrong (-S).

Suppressing output

Cron sends an email for any command that produces output. To suppress that, redirect both stdout and stderr:

0 3 * * * /usr/bin/backup.sh >> /var/log/backup.log 2>&1 && curl -fsS https://ping.cronping.com/<token> > /dev/null

Wrapping a command with `&&`

If your job is a chain of commands and only the last one produces exit code 0, wrap everything in a subshell:

5 4 * * * ( /usr/bin/step1.sh && /usr/bin/step2.sh ) && curl -fsS https://ping.cronping.com/<token>

Full example crontab

# Daily database backup at 3:00 AM
0 3 * * * /usr/local/bin/backup-db.sh && curl -fsS https://ping.cronping.com/TOKEN1

# Hourly queue worker health check
0 * * * * /usr/local/bin/check-queue.sh && curl -fsS https://ping.cronping.com/TOKEN2

# Weekly report generation — Mondays at 8 AM
0 8 * * 1 /usr/local/bin/generate-report.sh && curl -fsS https://ping.cronping.com/TOKEN3

Cron syntax reference

┌───────────────── minute (0–59)
│ ┌─────────────── hour (0–23)
│ │ ┌───────────── day of month (1–31)
│ │ │ ┌─────────── month (1–12)
│ │ │ │ ┌───────── day of week (0–7, 0 and 7 = Sunday)
│ │ │ │ │
* * * * *

Expression	Meaning
`* * * * *`	Every minute
`0 * * * *`	Every hour (at :00)
`0 3 * * *`	Every day at 3:00 AM
`0 9 * * 1-5`	Weekdays at 9:00 AM
`0 8 * * 1`	Every Monday at 8:00 AM
`/15 * * *`	Every 15 minutes
`0 0 1 * *`	First day of every month at midnight
`0 0 1 1 *`	January 1st at midnight (yearly)

Windows Task Scheduler

On Windows, use PowerShell to make the ping request:

# Run your script, then ping Cronping on success
your-script.ps1
if ($LASTEXITCODE -eq 0) {
    Invoke-RestMethod -Uri "https://ping.cronping.com/<token>" -Method Get
}

Or create a wrapper .bat file:

REM Run job script
call C:\Scripts\backup.bat

REM Check exit code and ping Cronping on success
IF %ERRORLEVEL% EQU 0 (
    curl -fsS https://ping.cronping.com/<token>
)

Reliability tips

Use && (not ;) — && only pings on success. ; would ping even if the job failed.
Set a timeout on curl — prevents curl from hanging indefinitely: curl -fsS --max-time 10 https://...
Choose a generous grace time — if your job normally takes 2 minutes but occasionally 8, set grace time to at least 10 minutes.
Match the timezone — when using cron expressions, always set the timezone to match your server's local time to avoid issues with DST.
Test it — after adding the ping, manually run the command and verify the heartbeat transitions to Up in the dashboard.