Server Observer

Interesting Features

Icinga contains several interesting features that allow administrators to customize the network monitor to reflect their needs and system environment. For example, you can define distributed monitoring environments. If you need to monitor several hundred or thousand hosts, the Icinga server might conceivably run out of resources because every active check requires system resources. To take some of the load off the main server, Icinga can delegate individual tasks to auxiliary servers which, in turn, forward the results to a central server. Scheduling the checks can also help reduce this load. Instead of running all your active checks in parallel, you can let Icinga stagger them.

Another interesting feature is the ability to escalate notifications. Not every administrator can be available and ready for action 24/7. If the contact that Icinga notifies does not respond within a defined period, Icinga can attempt to establish contact on another channel (e.g., a cell phone instead of email). If this notification fails as well, the case can be escalated to someone higher up the chain of responsibility – the team leader, for example.

Conclusions

Icinga is complex tool that provides valuable services whenever an administrator needs to monitor computers on a network. But don't expect to be able to set up the network monitor in a couple of minutes of spare time; if all goes well, the installation and configuration will take at least a couple of hours. Once you have battled through the extensive configuration, you can reward yourself with an extended lunch break: If something happens that requires your attention, Icinga will tell you all about it.

The traditional web interface is clear cut and packed with information; when this article went to print, however, the new interface wasn't entirely convincing (Figure 5). The installation was tricky, the documentation required some imagination at times, and the final results were disappointing. The interface was buggy and very slow under my, admittedly, not very powerful Icinga test server (Via C3, 800MHz, 256MB RAM). As a default, you need a new username and password for Icinga Web. That said, however, the current status does reveal some potential; it makes sense to check how the new interface is developing from time to time.

Figure 5: Icinga Web beta was not entirely convincing. Version 1.0.3 is out now.

The Icinga kernel is well and comprehensively documented and leaves no questions unanswered. Icinga also offers a plethora of useful gadgets, such as the status map (Figure 6) or the alert histogram (Figure 7), making the job of monitoring hosts less boring – at least initially. The depth of information that Icinga provides is impressive and promises an escape route for avoiding calls from end users. In short, Icinga is a useful tool that makes the administrator's life more pleasant.

Figure 6: Network overview. If you need to monitor a large number of machines and have defined "parents," you can also visualize the intermediate nodes.

Figure 7: The alert histogram shows peak trouble times.