I am need of a bit of a history lesson

Long-story-short, I am new to Icinga. I am trying to understand the differences between Nagios 3 and Nagios 4. I figured the Icinga 2.0.0 would be a good place to start looking. However, the 2.0.0 release notes are pretty sparse as far as enhancements. Am I missing something? How does Icinga do numbering?

I can only put two links in a post as a new member, so I just stripped the github links.

2.0.0 (2014-06-16)


First official release


  • [#1600]: Prepare 2.0.0 release
  • [#1575] (Cluster): Cluster: global zone for all nodes
  • [#1348]: move vagrant box into dedicated demo project
  • [#1341]: Revamp migration script
  • [#1322]: Update website for release

Long-story-short, I am new to Icinga.

Welcome :slight_smile:

I am trying to understand the differences between Nagios 3 and Nagios 4.

Er, this seems like an odd place to ask about a different project. You’d be
better off asking the Nagios people :slight_smile:

I figured the Icinga 2.0.0 would be a good place to start looking.

If you mean “it would be better to look at Icinga2 rather than Icinga 1”, then
you’re right, but Icinga is now a quite separate project from nagios.

However, the 2.0.0 release notes are pretty sparse as far as enhancements.
Am I missing something? How does Icinga do numbering?

I don’t understand that last question. Numbering of what?



1 Like

Apologies for the confusion. Icinga was forked from Nagios 3, so that code base would be a direct comparison. However, since then, Nagios 4 and Icinga 2 have both come out. I did, in fact, ask Nagios about the differences between Icinga and Nagios, and I got nothing from them. Well, I mean, I got a nice email from them, but nothing useful to the question at hand.

The release for 2.0.0 in the changelog does not look like a big release, so I am wondering if the 2 is not meant to signify a major version.

We currently support Nagios (and Zabbix, and Prometheus). We are trying to make a determination as to if we can add Icinga to the list of supported applications. Our timeframe is, sadly, rather short.


and welcome. :slight_smile:

Icinga started as a fork, this resulted in Icinga 1.x. You can still find the code on GitHub. Icinga 1.x is official EOL since 31.12.2018.

Icinga 2.x is a complete new application written from scratch. The goal was to create a modern monitoring application with a modern architecture. Icinga 2.x uses a complete new configuration language but also provides compatibility to run existing check plugins. Another feature set of Icinga 2.x is the Integration with other tools like Graphite, InfluxDB and Elasticsearch.

So Icinga 1.x and Icinga 2.x are two different applications.

To answer the numbering question: Icinga 2.x started with version 2.0.0, previous versions would referee to Icinga 1.x.

Best regards


Thanks. To add, the tech preview versions of Icinga 2 followed the v0.0.x schema. We then discussed for weeks if we should release

Icinga 2 v1.0.0


Icinga 2 v2.0.0

The changelog is sparse, but not really the source of thruth. Release blog posts are what you are looking for.

Since its first release on 16.6.2014, Icinga 2 got numerous enhancements … you have a lot of things to learn and follow.

Especially since Icinga 2 only is the core, the Icinga Web framework opens up a whole new ecosystem with modules, integrations, etc.

Since you’ve mentioned Nagios, the open source stack from Icinga provides more flexibility and features these days than their paid enterprise version. Core v4 may have improved with regard of faster check exeuction, but does it have secured distributed monitoring built-in?

Anyhow, since we stopped comparison charts to Nagios (they btw didn’t, their PDFs still compare their enterprise version with Icinga 1.x), you may just follow along with either trying e.g. the Vagrant boxes or a self-installed demo. Or you’ll follow along with the documentation.




Not that it really matters, but they didn’t send me the Icinga PDF, so someone over there knows it is an out of date comparison.

Unclear when any decisions will be made, but if we decide to move forward, I am likely to have additional questions. This thread is probably done and dusted. I think @dnsmichi answered the question I needed answered!

Hmm, I’m wondering why nobody mentioned distributed monitoring which is in my opinion one of the most valuable feature of Icinga 2.


Highly likely. Our relationship is not the best, since they tried everything to fight against forks and thus against the community. 6 years ago this exploded with lying about the monitoring plugins project. That included some illegal actions and public shaming of community members. Nothing I’d like to dig up again, still, the Internet doesn’t forget, and neither do well known community members.

Luckily the majority of our users shares a long and friendly history with us, and we are all thriving for making Icinga better, no matter if it is called 1.x or 2.x, or just without. We are not a fork anymore.

@rsx The whole distributed monitoring and cluster thing is always forgotten, thanks. And there’s even more, ranging from packages (no more compiling) to more convenient documentation to specific modules with business processes, certificate monitoring, etc. - https://icinga.com/products/

Besides, from the core parts, the DSL is “monitoring as code”. Ranging from the simplicity to create a ping service for all hosts …

apply Service "ping4" {
  check_command = "ping4"

  assign where host.address != ""

to advanced methods with conditionally creating notifications and generating objects from nested hashes. You can even do runtime calculations.

Besides, Icinga 2 has a real REST API, not only status but also object creation, actions, etc. Safe and secure, in contrast to the command pipe permission foo.

All in all, after thinking about this, there’s so many details added with the lovely feedback from our community making this a strong monitoring ecosystem.

And it does not end there - IcingaConf is coming soon, with more enhancements on the backend side (IcingaDB), reporting in all its glory (free, no enterprise model) and event pipelines. You’ll also learn more about technology (containers, cloud, incident handling, observability, etc.).