We use Icinga 2 at work which serves our needs well enough. The configuration was a bit of an initial hurdle when coming from icinga 1 / nagios - the config sy

We use Icinga 2 at work which serves our needs well enough. The configuration was a bit of an initial hurdle when coming from icinga 1 / nagios - the config syntax is essentially an EDSL for programming your monitoring requirements - but the flexibility is worth it. Adding new hosts and services is pretty cheap (programmer-time-wise), and I can use whatever programming constructs and conditions I want to decide what services to apply to which hosts in which measure. That said, it's still in a bit of a young state and some parts are very rough around the edges - for example, icinga 2's dependency model is a bit naive. You can configure email notifications to ignore notifications for services that depend on a different failed host/service, but this only applies if icinga already knows about the dependency having failed. So when a parent service dies, an extra e-mail notification could be generated for each of its children before icinga realizes the parent has also died and stops sending notifications for them. tl;dr I had fun setting it up and it works well for us, but expect some quirks