This guide on Best Practices is about monitoring the Nagios XI server itself and what services you could deploy.
Monitoring the Nagios XI "localhost"
Do you know how your XI server is performing?
Services you should ideally be monitoring
crond, httpd, mysqld, ndo2db, npcd, ntpd, postgresql
postgresql is not used on fresh installations of XI 5.x onwards. If you upgraded to XI 5 from a previous version postgres is still used.
snmptrapd and snmptt are not present until you follow the XI SNMP Trap procedure
The plugin called check_init_service that is part of the linux-nrpe-agent.tar.gz package can be used to monitor these services
Requires the following line in /etc/sudoers
nagios ALL=NOPASSWD: /usr/local/nagios/libexec/check_init_service
sudo $USER1$/check_init_service $ARG1$
File counts - check these folders to make sure the temp files are being processed
NPCD Perfdata spool directory
xidpe spool directory
Check results folder
snmptt spool folderNOTE: These locations can vary if a RAM Disk has been implemented
Use the Folder Watch wizard to create services to monitor these folders
Has the nagios user account expired?
In some customer installations, it’s possible that the nagios user account expires. This isn’t always that obvious to troubleshoot, so checking that it hasn’t expired is a good precautionary measure.
check_pass_expire.plis the plugin you can use
File permission changes required:
setfacl -m u:nagios:r-- /etc/shadow
Plugin also needs line 23 changed
use lib ".";
use lib "/usr/local/nagios/libexec";
root mailbox size
If you’re not a Linux person then you probably don’t know about the system mailbox. This is a local mail system on the linux server where messages are sometimes sent.
Certain components used in Nagios XI such as MRTG will send messages to this mailbox when it has a problem. An incorrect MRTG configuration can cause a message to be sent every five minutes as this is when MRTG runs. That’s about 288 messages a day. Over time the root mailbox can grow to GB in size causing issues. I wrote a plugin which can monitor this and let you know when it gets too big.
box293_check_mbox.plis the plugin you can use
File permission changes required:
setfacl -m u:nagios:r-- /var/spool/mail/root
MySQL / MariaDB Databases
If the tables are crashed and go undetected, this can have a severe impact on the system and you may not be storing important data and it may cause strange problems.
box293_check_mysql_table_status is the plugin you can use to check this:
Another problem can occur if the database engine runs on a different timezone to the local system.
box293_check_mysql_date is the plugin you can use to check this:
Monitor Max_used_connections and Threads_connected
check_mysql_query is the plugin you can use to check this, here is a guide that explains it all:
check_load is the plugin included with Nagios XI (5)
Memory Free – Physical
Make sure your XI server doesn't run out of memory
check_memory.sh is the plugin you can use
If the system runs out of physical memory and starts swapping to disk, the system performance will be greatly impacted.
This service is included by default in Nagios XI
check_swap is the plugin included with Nagios XI (5)
Disk free space is very important.
This service is included by default in Nagios XI however it only monitors /
If you have different volumes mounted then you should be monitoring each one of these.
check_disk is the plugin included with Nagios XI (5)
For any support related questions please visit the Nagios Support Forums at:
Article ID: 502
Created On: Mon, May 2, 2016 at 10:04 PM
Last Updated On: Thu, Jun 2, 2016 at 2:47 AM
Authored by: tlea
Online URL: https://support.nagios.com/kb/article/nagios-xi-monitoring-the-nagios-xi-localhost-502.html