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Building a Nagios 4 / Nagios XI Prototype Box

So after an awesome set of presentations at the Nagios World Conference 2012, one of the hot topics for discussion was clearly the upcoming Nagios Core 4 release. Andreas Ericsson has been hard at work overhauling the Core engine to optimize performance and reduce Disk and CPU usage for Nagios, and initial tests are showing his work has paid off in a substantial way. For this experiment, we’re going to use a system with the following specs:

  • Virtual Machine running under Vmware Workstation 8
  • 2GB of RAM
  • 1 CPU, 4 Cores
  • 80GB Hard Disk
  • Nagios XI Installed
  • Nagios binaries replace with Nagios 4 monitoring engine
  • ndoutils binaries replaced with with the latest SVN code for ndoutils: nagios/ndoutils/branches/ndoutils-2-0
  • No initial performance tweaks other than Nagios 4 and ndoutils 2

I’ll post setup instructions below for users who also want to play around with this setup. Note: This setup is not intended for production installs, use this in test environments only!

Start with Nagios XI installed, either through the pre-installed VM or with a manual installation. I chose a manual installation for this demo so I could set up the hardware to my liking and give it sufficient hard drive space to test a LOT of hosts. My first attempt at the prototype only had 10GB on the box, and filled up quite quickly because of performance data. .I ran the following commands after initial Nagios XI installation and setup was completed.

From the command-line:

You can verify the upgrade succeeded by reviewing the /usr/local/nagios/var/nagios.log file. There should be some new warnings about obsolete definitions like “failure_prediction_enabled”, which we won’t worry about for now. For now I’d like to see what kind of performance impact I can expect for a large number of checks being run on this machine, so I need to quickly create a large number of checks.  I’ll achieve this by running a tools script that we include with every installation of Nagios XI.

I chose to use static configs instead of the CCM for this benchmark for ease of setup time, and also easy removal later on. This also creates a list of checks with 25% of the services showing up as critica, which is useful in testing a system stressed with alerts and notifications. However, I’m also going to turn off notifications and event handlers during this setup phase just to make sure I don’t bottleneck somewhere and tank the entire box. Now lets restart Nagios to start using the new configs.

After adding 1000 hosts and 4000 services all at a 5mn interval the CPU load is running at a nominal level, averaging anywhere from .30 – .70, which is pretty impressive for a 4 core system! There is still some Disk IO because performance data processing is happening for each service, and this will likely be one of the noticeable bottlenecks as we add more checks to this system. After the system levels out and all of the checks are settled into a hard state, I turn on notifications and event handlers and begin watching the system and testing for bottlenecks. I’ll post back with some results soon! If there are any XI users out there who want to give this a shot in their test environments and post back with their results we’d love to hear what you find!




Nagios V-Shell 1.9 Released

Nagios V-Shell 1.9 includes major performance updates, and a re-implementation of PHP caching that should decrease V-Shell page load times anywhere from 40-75%.  I ran some benchmarking tests on a test system(Dual core desktop with 4GB of RAM) with 1800 hosts, and 7200 services.  This system runs with an average CPU load of 2.0-6.0 throughout the day, so the hardware is being pushed pretty hard already from the check load. V-Shell 1.8 created page load times anywhere from 18-28 seconds throughout the interface without APC caching enabled.  Needless to say, this is problematic for many users with larger environments.  The Core cgi’s were able to load anywhere from 2-11 seconds, with the service status page taking around 9-11 seconds to load all of the data.  My goal for 1.9 was to minimize any unnecessary processing, and optimize any functions that were inefficient or using slower PHP built-in functions.  The differences in 1.9 are substantial.  Without any caching enabled at all, I was able to decrease the average page load time to 9-14 seconds, which is 40-50% faster by itself.  Once I had the code optimized, I reworked the APC caching functionality.  If a user has PHP’s APC caching packages installed and enabled on their web server, V-Shell will cached the objects.cache file until it detects any changes in the file, while the data in the status.dat file will be cached based on a TTL (time to live) config option which now exists in 1.9.  Once the data is cached in APC, the page load times throughout the interface averaged between 4-5 seconds for all pages, which is a 75% decrease in load time on average.

My goal for the next version of V-Shell is to add support for mklivestatus and ndoutils for backend data, which will eliminate the need to parse the objects.cache file and status.dat files for systems with those backends.  This should further improve performance for larger installations.

Download Nagios V-Shell 1.9



Vote For Nagios As Your Favorite Monitoring App

The 2011 Member’s Choice Awards voting is going on now and Nagios is a candidate for the best Network Monitoring Application. Show your love for Nagios by voting in the poll. The poll closes this Thursday (February 9th), so don’t delay.

NOTE: If you haven’t participated on the LQ forum, before you’ll have to create an account and post a new message before you can vote.

Nagios V-Shell 1.8 Release

Over the past few years, there’s been a strong outpouring of requests for an updated interface for Nagios.  We released Nagios V-Shell just about a year ago now, and we’re happy to see that it currently stands as the most popular item on the Nagios Exchange, with over 100,000 views!  I don’t usually post to labs every time I make an update to V-Shell, but I thought this time around would be worth mentioning.  I’ve spent the last few weeks doing a major overhaul of the permissions in order to mirror the same permissions scheme that people are used to in Nagios Core.  Initially V-Shell has limited user-level control in regards to permissions, but as of v1.8 I’m pleased to say I’ve finally got that major TODO crossed off my list.  V-Shell now supports user-level access, as well as read-only access to match the permissions scheme of Nagios Core.  Feel free to check out V-Shell 1.8 on the Nagios Exchange.