We have just released:
send_nrdp.sh Bash NRDP Client
send_nrdp.py Python NRDP Client

You no longer need to install PHP or Perl on your client machines to run passive checks with NRDP.  Both of these implementations can accept result piped from STDIN and you can change the delimiters to whatever you like.

STDIN results should be in the following order, for HOST checks:

HOSTNAME    STATE    OUTPUT

for SERVICE checks

HOSTNAME    SERVICENAME    STATE    OUTPUT

Additionally, the bash version can take an XML file of check results formatted like so:

<?xml version='1.0'?>
<checkresults>
<checkresult type="host" checktype="1">
  <hostname>YOUR_HOSTNAME</hostname>
  <state>0</state>
  <output>OK|perfdata=1.00;5;10;0</output>
</checkresult>
<checkresult type="service" checktype="1">
  <hostname>YOUR_HOSTNAME</hostname>
  <servicename>YOUR_SERVICENAME</servicename>
  <state>0</state>
  <output>OK|perfdata=1.00;5;10;0</output>
</checkresult>
</checkresults>

You can download the new version from the Nagios Library – Nagios XI Customer Downloads section.

• Asia Pacific (Singapore)
• Asia Pacific (Tokyo)

The Nagios XI cloud images are an excellent opportunity to try Nagios XI without having the upfront expense of dedicated hardware and can be upgraded with virtually zero downtime.

• US East (Virginia)
• US West (N. California)
• EU West (Ireland)

Additionally, the new version will automatically install the latest Nagios XI when if is first booted. This will eliminate the need to change AMI ID’s when new version come out.  While it is convenient to not have to lookup the AMI ID, please be aware when you first start your instance the current version of Nagios XI is installed and compiled at boot. This will take at least 15 minutes before the instance will become available. The amount of time will depend on the instance size you create.

Another change was made to meet Amazon security guidelines and now all instances have an ec2-user account to be used for ssh access.  This user has full sudo access and will login with a key pair as usual.

Additional documentation on using the Amazon cloud images for your Nagios XI deployment may be found on the Exchange.

Using Nagios XI In Amazon EC2 Cloud

If you are using Nagios to monitor a windows environment, you can use FTP as a component to deploying NSClient++. We just posted a document on the Nagios Library, which explains how to configure FTP for Nagios. You can review it here.

Additional information on deploying NSClient++ via FTP in Nagios will be available soon.

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.

Enjoy!

Lets look at some of the key files that create disk activity on a Nagios install.  The examples below match a typical source install of Nagios Core, and any vanilla Nagios XI install.

/usr/local/nagios/var/status.dat – This is the bread and butter file of all of the “live” information on the monitoring environment.  This file gets updated every  10-20 seconds (as specified in nagios.cfg) with all current status information.

/usr/local/nagios/var/objects.cache – This file stores all of the object configuration data for Nagios.  This file only gets updated upon a restart of the Nagios process.

/usr/local/nagios/var/host-perfdata && service-perfdata – These files may be in a different location for  Core install, but this file functions as an intermediary file for PNP’s NPCD daemon that processes performance data results.  This file gets updated about every 10-15 seconds.

/usr/local/nagios/var/spool – This directory tree acts as a dropbox for all incoming check results.  The disk activity in this directory is almost constant, since both Nagios and NPCD are continually creating result files, and then reaping the results every X number of seconds.

/usr/local/nagios/var/*.log – I thought the log files were worth mentioning.  Logging takes both CPU and disk activity, so minimize all unnecessary logging if you need to scale.

Test Case: My old desktop workstation as an XI Server.  This machine is not especially powerful, but one of my side projects is seeing how much I can load it up purely with configuration changes:

Nagios XI Server .

• Intel Dual Core CPU 3gz
• 2gb of RAM
• 140gb SATA HD, probably 7200 RPM
• Offloaded MySQL to a VM with 1gb of RAM, and a single CPU
• 1823 Hosts, 7379 Services.  All active checks running on a 5mn check interval.
• 9202 checks in 5mn
• Around 40 checks per second
• All active checks are being executed from the XI server, mostly running PING, HTTP, DNS To IP, and DNS Resolution

Pre-Existing Tweaks:

• Offloaded MySQL to a 2nd machine
• RAM Disk for status.dat and object.cache
• rrdcached in use
• Minimal Logging
• Minimized Notifications – Don’t send more notifications than you need to. This holds up the main Nagios execution loop and uses more CPU.

The Problem:

• In this experiment I started with around 5000 checks, and tried increasing to around 8000.  I found that the CPU load was will fine (around 2.0), but my host and service latencies were continually growing with time, and Nagios couldn’t maintain the check schedule.  This wasn’t an overtaxing of the CPU, but Nagios simply couldn’t write information to the disk fast enough to keep up with the check schedule.  It was essentially constantly waiting in line to access the disk.

The Solution:

• Although this won’t work for every environment, I basically moved every file with constant disk activity to the RAM disk.  The danger of this is that if the server experienced a hard power-down, then all of those check results and performance data results would get lost.  However, if your monitoring server has a hard shutdown, you’ve probably got bigger problems than just a few lost check results.
• All performance data and check results in the spool directory are now written to the RAM disk, as well as the intermediary perfdata files.

ll /var/ramdisk

total 19264
-rw-rw-r-- 1 nagios users     16646 Jan 30 11:35 host-perfdata
-rw-r--r-- 1 nagios nagios  7070305 Jan 19 15:56 objects.cache
-rw-rw-r-- 1 nagios users    106435 Jan 30 11:35 service-perfdata
drwxrwxrwx 4 nagios nagios     4096 Jan 19 15:11 spool
-rw-rw-r-- 1 nagios users  12487278 Jan 30 11:35 status.dat
ll /var/ramdisk/spool
total 100
drwxrwxrwx 2 root root 86016 Jan 30 11:36 checkresults
drwxrwxrwx 2 root root 12288 Jan 30 11:36 perfdata
In order to set this up properly, I had to modify my main nagios.cfg file, as well as some of my command definitions.

/usr/local/nagios/etc/nagios.cfg Modifications:

host_perfdata_file=/var/ramdisk/host-perfdata
host_perfdata_file=/var/ramdisk/host-perfdata

object_cache_file=/var/ramdisk/objects.cache

check_result_path=/var/ramdisk/spool/checkresults

status_file=/var/ramdisk/status.dat

/usr/local/nagios/etc/pnp/npcd.cfg Modifications:

perfdata_spool_dir = /var/ramdisk/spool/perfdata/

Modified Nagios XI Command Definitions:

define command {
       command_name                          process-host-perfdata-file-bulk
       command_line                          /bin/mv /var/ramdisk/host-perfdata /var/ramdisk/spool/perfdata/$TIMET$.perfdata.host
}    
define command {
       command_name                          process-host-perfdata-file-pnp-bulk
       command_line                          /bin/mv /var/ramdisk/host-perfdata /var/ramdisk/spool/perfdata/host-perfdata.$TIMET$
}    
define command {
       command_name                          process-service-perfdata-file-bulk
       command_line                          /bin/mv /var/ramdisk/service-perfdata /var/ramdisk/spool/perfdata/$TIMET$.perfdata.service
}    
define command {
       command_name                          process-service-perfdata-file-pnp-bulk
       command_line                          /bin/mv /var/ramdisk/service-perfdata /var/ramdisk/spool/perfdata/service-perfdata.$TIMET$
}

For some long time Core users, this may not be new information.  But what I’ve found in researching this topic is that a lot of people have done modifications to their system like this, but there is very little public documentation on how people actually did it.  I’m hoping this information will be useful to some users and maybe even save somebody some money on hardware. : )

Download Nagios XI Operations Center Component

Enjoy!