Healthchecks — Cron Job Monitoring with Smart Alerts

Introduction

Healthchecks is a cron job monitoring service that listens for HTTP pings from your scheduled tasks and alerts you when pings are overdue. Each check gets a unique URL that your cron jobs hit upon completion. If a ping does not arrive within the expected interval, Healthchecks sends alerts through email, Slack, PagerDuty, or 25+ other integrations.

What Healthchecks Does

• Monitors cron jobs and scheduled tasks by tracking periodic HTTP or email pings
• Sends alerts via email, Slack, Telegram, PagerDuty, Opsgenie, and 25+ channels
• Supports cron expression schedules with grace periods for flexible timing
• Provides a dashboard showing check status with uptime history and response times
• Measures job execution duration when start and success pings are both sent

Architecture Overview

Healthchecks is a Django application with a PostgreSQL or MySQL database backend. A background worker process monitors check deadlines and dispatches alert notifications. The ping endpoint is optimized for high throughput with minimal overhead. The web dashboard uses server-side rendering with progressive JavaScript enhancements for real-time status updates.

Self-Hosting & Configuration

• Deploy via Docker with environment variables for SECRET_KEY and database connection
• Configure SMTP settings for email alerts and add integration webhooks in the UI
• Set ALLOWED_HOSTS and SITE_ROOT for proper URL generation behind a reverse proxy
• Use PostgreSQL for production or SQLite for small deployments
• Enable Prometheus metrics endpoint for monitoring Healthchecks itself

Key Features

• 25+ notification channels including Slack, Telegram, Discord, PagerDuty, and webhooks
• Cron expression and interval-based scheduling with configurable grace periods
• Job duration measurement by tracking start and completion pings
• Badge API for embedding status indicators in README files and dashboards
• Team management with projects and read-only access for stakeholders

Comparison with Similar Tools

• Uptime Kuma — Monitors service availability; Healthchecks monitors job execution schedules
• Cronitor — Commercial SaaS; Healthchecks is fully open source and self-hostable
• Dead Man's Snitch — SaaS cron monitor; Healthchecks offers the same model for free self-hosted
• Grafana Alerting — Metric-based alerts; Healthchecks uses a simpler ping-based dead man's switch
• Gatus — HTTP endpoint monitoring; Healthchecks focuses on periodic job completion tracking

FAQ

Q: How do I integrate with an existing cron job? A: Append a curl command to your cron entry: && curl -fsS http://hc-host/ping/uuid. The check turns red if the ping stops arriving.

Q: Can it monitor jobs that run on different servers? A: Yes. Each check has a unique ping URL accessible from anywhere. Jobs on any server can ping the same Healthchecks instance.

Q: Does it support measuring how long a job takes? A: Yes. Send a start ping before the job and a success ping after. Healthchecks calculates and displays the duration.

Q: What happens during Healthchecks downtime? A: Missed pings are not recorded. When Healthchecks comes back, overdue checks will trigger alerts based on their last known ping time.

Sources

• https://github.com/healthchecks/healthchecks
• https://healthchecks.io/docs/