How to Monitor Cron Jobs with Retry and Alerts

The problem with cron jobs

When a cron job silently fails, you might not notice until it's too late. A script error, a crash, or a network issue can cause a job to stop working — and there's no built-in alert system.

What we’ll configure

• Monitoring for cron job success
• Retry logic on failure
• Alerting if all retries fail

1. Wrap your cron job in a shell script

This wrapper will retry the job up to 3 times if it fails:

#!/bin/bash

MAX_RETRIES=3
RETRY_DELAY=10
COUNT=0
SUCCESS=0

while [ $COUNT -lt $MAX_RETRIES ]; do
  echo "Attempt $((COUNT+1))..."
  /usr/bin/python3 /scripts/my_task.py && SUCCESS=1 && break
  COUNT=$((COUNT+1))
  sleep $RETRY_DELAY
done

if [ $SUCCESS -eq 1 ]; then
  curl -fsS https://ev.okchecker.com/p/<api-key>/backup-db > /dev/null
else
  curl -fsS https://ev.okchecker.com/p/<api-key>/backup-db?status=fail > /dev/null
fi

2. Add it to your crontab

Open crontab -e and add:

*/15 * * * * /scripts/task_wrapper.sh

This runs every 15 minutes. On success, it sends a ping. On failure, it sends a different signal that can trigger an alert.

3. Configure alerts

In your Monitoring SaaS dashboard, set this as a "cron monitor" and define the expected interval. If no ping arrives or a failure ping is received — you'll get notified.

4. Security tips

• Store secrets in environment variables, not hardcoded
• Log failures to troubleshoot issues

5. Alternative: systemd with restart

If you use systemd instead of cron, you can use Restart=on-failure in your service file. Add a curl ping to ExecStartPost to integrate with monitoring.

Conclusion

Adding monitoring and retry logic to your cron jobs helps prevent data loss and ensures task reliability. Better safe than sorry!