OpenNMS Horizon vs Thruk
A side-by-side comparison of two self-hosted monitoring & status options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | OpenNMS Horizon | Thruk |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 83 · Excellent | 74 · Good |
| Category | Monitoring & Status | Monitoring & Status |
| License | AGPL-3.0 | GPL-1.0 |
| Language | Java | Perl |
| Setup difficulty | Hard | Medium |
| Min. RAM | 4,096 MB | 512 MB |
| Deployment | docker, bare-metal | bare-metal, docker, source |
| GitHub stars | ★ 1,173 | ★ 442 |
| First released | 2000 | 2009 |
| Replaces | SolarWinds, PRTG | SolarWinds |
What are OpenNMS Horizon and Thruk?
OpenNMS Horizon
OpenNMS Horizon is an enterprise-grade network monitoring and management platform that handles fault, performance, and traffic monitoring at scale. It supports SNMP, flow analysis, and event correlation.
- Fault and performance monitoring
- Flow analysis
- Event correlation
- Scales to large networks
Thruk
Thruk is a multi-backend monitoring web interface compatible with Nagios, Icinga, Naemon, and Shinken. It provides a fast UI for managing many monitoring instances from one place.
- Multi-backend support
- Fast monitoring UI
- Reporting and SLA tools
- Business process modeling
OpenNMS Horizon vs Thruk: key differences
OpenNMS Horizon is written in Java, while Thruk is built with Perl. Licensing differs — AGPL-3.0 for OpenNMS Horizon versus GPL-1.0 for Thruk. Thruk is the lighter option, starting around 512 MB of RAM against 4,096 MB for OpenNMS Horizon. OpenNMS Horizon is the more established project (first released 2000), while Thruk arrived in 2009. OpenNMS Horizon has the considerably larger community, at 1,173 GitHub stars versus 442.
Why pick each one
Choose OpenNMS Horizon if…
- Released under the AGPL-3.0 license
- First-class Docker support for quick deployment
- Active community (1.2k GitHub stars)
- Written in Java
Choose Thruk if…
- Unifies many monitoring cores
- Mature and stable
Watch out for
- Requires a Nagios-family core
- Dated styling
Frequently asked questions
Is OpenNMS Horizon or Thruk better?
Neither is universally better. OpenNMS Horizon has the larger community, while Thruk is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are OpenNMS Horizon and Thruk free and open-source?
Yes. OpenNMS Horizon is licensed under AGPL-3.0 and Thruk under GPL-1.0. Both can be self-hosted at no software cost.
Can I run OpenNMS Horizon and Thruk with Docker?
OpenNMS Horizon: yes. Thruk: yes.
Which is lighter on resources, OpenNMS Horizon or Thruk?
Thruk has the smaller minimum footprint at 512 MB of RAM, compared to about 4,096 MB for OpenNMS Horizon. Real-world usage depends on library size, user count, and enabled features.