linuxgyanibaba-linux,server administrator

All about Nagios Monitoring Tools

What is Nagios?

it is open-source software for constant monitoring of the system, network, and infrastructure. It runs plugins that are stored on a server and are connected with a host or server on your network or the internet. In case of failure, it alerts bout the issue so the technical team performs the recovery process.

Nagios Features:

It reduces downtime

The free version is Nagios xi

Nagios works on client-server architecture. it uses port number 5666,5667,5668 to monitor its client. allow you to monitor and troubleshoot server performance issues. automatically fix problem

Active monitoring of entire infrastructure. good log and database. informative and attractive web interface. analyze data and report finding

Monitor network services like HTTP,SMTP,FTP,ssh,SNMP,pop,DNS ,LDAP

Architecture of Nagios

Nagios works on client-server architecture

Mention all details in the configuration file like port numbers all details of services.

Daemon is a service in Nagios it collects information from configuration files through plugin NRPE(NAGIOS REMOTE PLUGIN EXECUTOR)

NRPE collects information from CHECK BY SSH in the client machine. Basically, it is called NRP Eagent it communicates to the client.

NRPE gives all information to the daemon and it stores all information in the local database, and it flashes all details of the client in Nagios dashboard.

Pre-requisite

you must have httpd server enable

PHP for dashboard

gcc & gd it is a compiler to convert code into binary numbers

make file -> it is used to build server

Its main configuration file is /user/local/nagios/etc/nagios.cfg

Installation of nagios in rhel,centos

# sudo su

# yum install httpd* php -y

# yum install gcc glib glibc-common

# yum install gd gd devel

create account information

# useradd -m nagios

# password nagios

# groupadd nagioscmd

# usermod -a -G nagioscmd nagios

# usermod -a -G nagioscmd apache

Download Nagios core and plugins create a directory for storing download

# mkdir /download

# cd /download

# wget https://assets.nagios.com/downloads/nagioscore/releases/nagios-4.4.5.tar.gz

# wget https://nagios-plugins.org/download/nagios-plugins-2.2.1.tar.gz

# tar zxvf nagios-4.4.5.tar.gz

# cd nagios-4.4.5.tar.gz

# ./configure --with-command-group=nagioscmd

# make all

# make install

# make install-init

# make install-config

# make install-commandmode

# make install-webconf

# htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

# service httpd restart

# cd ~/downloads

# tar zxvf nagios-plugins-2.2.1.tar.gz

# cd nagios-plugins-2.2.1

# ./configure --with-nagios-user=nagios --with-nagios-group=nagios

# make

# make install

# chkconfig --add nagios

# chkconfig nagios on

# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

# service nagios start

# service httpd restart

Nagios commands

Nagios commands comprise service check, service notification, service event handlers,host check, and host event handlers

So you define-command by

define command{

command_name command_name

command__line command_line

}

define command{

command_name check_ssh

command_line /usr/lib/nagios/plugins/check_ssh ‘$HOSTADDRESS$’

}

This command is used for host check is below:

define host {

host_name server.example.com

address 192.168.50.13

check_command check_ssh

}

Conclusion:

Nagios is powerful tools. It performs checks for defamation assurance, Nagios configure event handlers the number of notifications is drastically decreased. Nagios helps client's website uptime to 98 percent.

That's all Thank you