What is Continuous Monitoring ?

Continuous monitoring is a process to detect, report, respond to all the attacks which occur in its infrastructure. Once the application is deployed into the server, the role of continuous monitoring comes in to play. The entire process is all about taking care of the company's infrastructure and responding appropriately.


What is Nagios ?

Nagios is a free to use open source software tool for continuous monitoring. It helps you to monitor systems, network, and infrastructure. It is used for continuous monitoring of systems, applications, service and business processes in a DevOps culture.

Nagios runs plugins stored on the same server. It plugin's connects with a host or another server on your network or the Internet. Therefore, in the case of failure Nagios core can alert the technical staff about the issues. So that, your technical team performs the recovery process before the outage in the business processes.


Why Do We Need Nagios?

Here, are Important reasons to use Nagios monitoring tool are:

Detects all types of network or server issues

Helps you to find the root cause of the problem which allows you to get the permanent solution to the problem

Active monitoring of your entire infrastructure and business processes

Allows you to monitors and troubleshoot server performance issues

Helps you to plan for infrastructure upgrades before outdated systems create failures

You can maintain the security and availability of the service

Automatically fix problems in a panic situation


History of Nagios

1996-Ethan Galstad uses the ideas and architecture of his earlier work to begin building a new application which runs under Linux OS

1999-The plugins that were which were originally distributed as a part of the NetSaint distribution are soon as a separate Nagios Plugins project

2002- Ethan renames the project to "Nagios" because of trademark issues with the name "NetSaint."

2005- Nagios becomes SourceForge.net Project of the Month in June

2009-Nagios Enterprises releases its first commercial version, Nagios XI

2012-Nagios again renamed as Nagios Core

2016-Nagios core surpasses 7,500,000 downloads directly from SourceForge.net website


Features of Nagios

Following are the important features of Nagios:

Relatively scalable, Manageable, and Secure

Good log and database system

Informative and attractive web interfaces

Automatically send alerts if condition changes

If the services are running fine, then there is no need to do check that host is an alive

Helps you to detect network errors or server crashes

You can troubleshoot the performance issues of the server.

The issues, if any, can be fixed automatically as they are identified during the monitoring process

You can monitor the entire business process and IT infrastructure with a single pass

The product's architecture is easy writing new plugins in the language of your choice

Nagios allows you to read its configuration from an entire directory which helps you to decide how to define individual files

Utilizes topology to determine dependencies

Monitor network services like HTTP, SMTP, HTTP, SNMP, FTP, SSH, POP, etc.


Helps you to define network host hierarchy using parent hosts

Ability to define event handlers which runs during service or host events for proactive problem resolution

Support for implementing redundant monitoring hosts


Nagios Architecture ?

Nagios is a client-server architecture. Usually, on a network, a Nagios server is running on a host, and plugins are running on all the remote hosts which should be monitored.

The scheduler is a component of the server part of Nagios. It sends a signal to execute the plugins at the remote host.

The plugin gets the status from the remote host

The plugin sends the data to the process scheduler

The process scheduler updates the GUI and notifications are sent to admins.