What is Nagios?

Nagios is a monitoring tool that allows you to monitor your servers, applications, and other IT assets. It can alert you when they go offline or have problems.

Nagios monitors all things, including hardware and software applications, network infrastructure like switches and routers, operating systems such as Windows or Linux servers and desktops, databases like MySQL or Oracle or PostgreSQL, and the list goes on. And if something goes wrong with any of those things? Nagios will let you know!

What does Nagios offer?

With Nagios, you can monitor;

• Server uptime and downtime
• DNS availability
• Network performance (bandwidth)
• CPU usage
• Disk space utilization
• Processes running on the system

Key features of Nagios

1. Nagios Core – This is the main program that performs most of the monitoring. It collects data from remote hosts via plug-ins and processes them to determine if they are working correctly or not.
2. Nagios Plugins – These are different programs that are used by Nagios Core to collect information about hosts or services. And plugins available for various purposes (such as HTTP, MySQL, etc.).
3. Nagios Web Interface – This provides a web interface for viewing status information from remote hosts and allows users to configure various parameters needed for monitoring these hosts (e.g., adding new hosts).

Benefits of Nagios

• Server Health Monitoring: This feature allows you to monitor several aspects of your server’s health to identify issues before they become critical. It includes CPU load, disk space usage, RAM usage, swap space usage, network activity, logged-in users and processes.
• Performance Data Collection: This feature allows you to collect performance data on host resources like CPU utilization, memory utilization and disk usage. You can also configure alerts based on thresholds set for each metric.
• Service/Application Monitoring: Service/Application monitoring is used to monitor services or applications running on your hosts like web servers or databases, etc.

It can monitor the status of your servers, applications and networks by checking their availability, performance and health. The main features of Nagios are:

• The ability to monitor multiple hosts on a single machine through an agent that runs on each host
• The ability to send alerts when something goes wrong with your servers, applications or networks
• A web interface where you can see the status of your servers, applications or networks at any time
• A distributed architecture that can scale up.

Nagios vs Zabbix

Nagios and Zabbix are both monitoring tools. They monitor your servers and the status of your applications, and they alert you when something goes wrong.

But what’s the difference between these two tools?

Nagios is written in PHP and uses a client/server architecture, while Zabbix is written in C++, with a multi-threaded architecture.

Zabbix offers more flexibility in scheduling checks than Nagios does—you can use cron jobs or command line scripts to schedule checks. But with Nagios, you have to set up scheduled checks manually in the web interface.

Nagios has more integration options than Zabbix does—it can integrate with almost any other tool that sends an email message or SMS text message, for example. But Zabbix allows for more customized alerts than Nagios does—you can create alert rules that include multiple hosts or services monitored by Zabbix and evaluate them based on host states or service states.

Nagios Core

Nagios Core is a free version of Nagios that offers limited features and functionality. It is intended for small businesses or home users who don’t require advanced features like alerting or host/service checks. However, it is an essential tool for any system administrator because it allows you to keep track of your environment in real-time!

Nagios Core can monitor almost any server or application: web servers, databases, etc. It can also monitor SNMP devices and Linux processes running on Unix-like systems.

Nagios XI

Nagios XI is a monitoring solution for servers and networks. It is designed to be easy to install, configure, and maintain. The installation procedure is fairly simple, but we will discuss that in more detail later on.

Nagios XI provides a web-based interface where you can view the status of all the monitored devices on your network. You can also configure alerts that notify you when something goes wrong with one of these devices.

The benefits of using Nagios XI include;

• Easy installation and configuration
• Customizable alerting capabilities with email notifications
• An intuitive user interface

Here is a tutorial on getting started with Nagios