The main characteristic I adore is the open source character of it. You want to monitor a specific metric that nobody else has? You can do it even with the most basic of scripting skills, and you can always share it with the vast community of Nagios Exchange.
Like any monitoring tool, it gave me insight into multiple infrastructures I've been a part of, without any limitation (due to the open-source character that I referred to above).
It's more what I personally don't like, rather than what areas need improvement. For example, the PNP4Nagios plugin not working easily with XI is an issue for me, because some open source monitoring plugins do not work out of the box. But in the end, you learn to live with it.
I've been using Nagios since about 2005. I've seen the development path through the open-source version (and some other forks of it like Icinga and OMD) but for the last four years I've been entirely using the XI branch.
On older versions I had some minor issues. Currently, to be honest, it is as stable as I could hope for a monitoring tool.
Up to now, the infrastructures I've been a part of were not so large, up to 200 hosts and 1300 services. Even for XI which uses MySQL on the back end, a host with 8GB RAM and four vCPUs is adequate.
With the open source forks, the community is vast and so is the knowledge around the product. Because of this, even though I have a valid commercial support bundle, I have never had the need to use it.
No, I started with Nagios. I've used other apps also like Microsoft SCOM (which is not very good), Zabbix (which is very decent), Tivoli (which is also not very good), HP OpenView (which is vast and requires almost a duplicate infrastructure to run to its full extent), Icinga (a very good clone), Centreon (haven't used it much but it seems solid enough), but I've always ended up using Nagios.
For the latest versions, for me, it is pretty straightforward.
For the cost of the commercial product and support, and taking into account the open source characteristics of it, I believe it is difficult to a better value. Yes, it needs some time to configure and address its issues, but seriously, which monitoring solution does not?
Before going to Nagios XI (commercial, meaning with support), because of the relationship my company had with Microsoft, I evaluated also SCOM. As with Nagios, I went through the whole installation and configuration process. Because of my previous knowledge, I directly compared it with Nagios, and the latter won, hands down.
Be prepared to put some time into it and research it appropriately. If there is an option for consulting services through the support channel, don't be afraid to use it.
I spend about 3 weeks vetting through 20+ open source monitoring solutions and at the end of the process, the choices had boiled down to few major ones - OMD (best combination of open source plug-ins put together for Nagios), Zabbix, and Zenoss.
The main components of OMD are Check_MK, PNP4Nagios, Nagvis, and of course Nagios. Among these projects, Check_MK is the core of OMD that makes Nagios easy to configure, easy to scale, and mashed together all the other popular Nagios plug-ins into one unified user interface. Thus the following comparisons are done using Check_MK as the keyword, but I will also cover how other plug-ins makes OMD project stand out from the competitions.
A quick Google Trend search will tell you that Check_MK is up and rising. Together with the Nagios’s community size, you can certainly find custom monitoring plug-ins created by community members and save yourself time from reinventing the wheel.
Before you pick any open source tool for enterprise projects, you want to make sure that their code is not stale and the community is vibrant for the years to come. Active community and frequent code updates ensure your questions get answered and fast bug fixes. Free service from Ohloh will give you an overview of those aspects on open source projects. The following comparison charts are created from Ohloh.
Check_MK is a clear winner in this chart. It tells you that Check_MK is constantly making more improvement than the other 2 projects.
In this chart, Check_MK’s contributor is increasing and will soon surpass Zabbix. And don’t forget it is standing on giant’s shoulder, the largest monitoring community - Nagios.
Don’t just listen to me. Here is one of the blog post that talks about why moving away from Zabbix to Check_MK.
Moving From Zabbix to Check_MK
Administrators can really save time on not having to compile Nagios, or other plug-ins, trying to integrate and mess with configurations between plug-ins and Nagios. It really is a no-brainer to setup and start with.
Check_MK is an extension to the Nagios monitoring system that allows creating rule-based configuration using Python and offloading work from the Nagios core to make it scale better, allowing more systems to be monitored from a single Nagios server.
There are 2 significant modules that Check_MK uses to improve Nagios performance. One is called Livestatus and the other is called Livecheck.
status.dat. It becomes a bottleneck on CPU and IO for larger installation.status file status is not realtime, default is to update every 10 seconds.Before Nagios 4.0, Even a perfectly tuned system rarely manages to execute more then a few thousand checks per minute.
What make things worse: while your system is getting larger, the maximum check rate is even getting worse. The more hosts and services your system manages, the less checks per second it will be able to perform. Why?
Multisite is part of the Check_MK project as a better web UI alternative for Nagios.
A new and innovative GUI for viewing Nagios status information and controlling your monitoring system. It is based on MK Livestatus and aims at replacing the Nagios web GUI (also known as “the CGIs”). Multisite supports distributed monitoring in a very efficient way.
This is one of the most brilliant solutions from Check_MK project to tackle the notorious Nagios configuration disaster. Although Nagios is a flexible and powerful monitoring system, having to mess with its multi-level and confusing configuration files scares many people away. Now, there are many web interface plug-ins that try to take a stab at the issue, but WATO is by far the best that simplify the complexity of Nagios configuration while staying very flexible and more flexible by sitting on top of Check_MK.
WATO is a web based administration tool for Check_MK. It allows you to manage your hosts and services to be monitored and perfectly supports Check_MK’s mechanism of inventory to autodetect services to be checked on a host. WATO allows to move a substantial part of the daily workload from the monitoring administrator to his colleagues.
NagVis is a visualization addon for the well known network managment system Nagios. NagVis can be used to visualize Nagios Data, e.g. to display IT processes like a mail system or a network infrastructure.
Automation is build into Multisite. You can make web service request against Multisite to automate adding new host, enabling new service checks, or embed any of the host/service check web pages into any other websites.
This feature makes it very easy to integrate with Puppet or Chef for automatically adding new servers(hosts) and services to the monitoring system.
With Check_MK abstracting the original Nagio’s notification scheme, it has become possible to send notifications of any hosts or services to any number of people at any time.
You can even create custom script to send the notification in some creative ways like having the notification be ☎called via a VoIP server to your cell phone and read you the alert message or have the alert be sent to your ✐instant messenger.
http://mathias-kettner.de/checkmk_devel_multisite_icons.html
Distributed WATO allows you to manage several monitoring sites through a logically centralized WATO.
Available from version 1.2.3
Available from version 1.2.3
Before
<code>5 0 * * * root /usr/local/bin/backup >/dev/null</code>
After
<code>5 0 * * * root mk-job nightly-backup /usr/local/bin/backup >/dev/null</code>
Available from version 1.2.3
I will be sharing how I install OMD, optimized web interface (Multisite), utilized passive checks, implemented 24/7 on call plan, and integrated with automated business processes. I will add link here once they become available.
I agree!