Book Image

Learning Nagios - Third Edition

By : Wojciech Kocjan, Piotr Beltowski
Book Image

Learning Nagios - Third Edition

By: Wojciech Kocjan, Piotr Beltowski

Overview of this book

Nagios, a powerful and widely used IT monitoring and management software for problem -solving. It detects problems related to your organizations infrastructure and helps in resolving the issue before it impacts the business. Following the success of the previous edition, this book will continue to help you monitor the status of network devices and also notify the system administrators of network problems. Starting with the fundamentals, the book will teach you how to install and configure Nagios for your environment. The book helps you learn how to end downtimes, adding comments and generating reports using the built-in Web interface of Nagios. Moving on, you will be introduced to the third-party web interfaces and applications for checking the status and report specific information. As you progress further in Learning Nagios, you will focus on the standard set of Nagios plugins and also focus on teach you how to efficiently manage large configurations and using templates. Once you are up to speed with this, you will get to know the concept and working of notifications and events in Nagios. The book will then uncover the concept of passive check and shows how to use NRDP (Nagios Remote Data Processor). The focus then shifts to how Nagios checks can be run on remote machines and SNMP (Simple Network Management Protocol) can be used from Nagios. Lastly, the book will demonstrate how to extend Nagios by creating custom check commands, custom ways of notifying users and showing how passive checks and NRDP can be used to integrate your solutions with Nagios. By the end of the book, you will be a competent system administrator who could monitor mid-size businesses or even large scale enterprises.
Table of Contents (19 chapters)
Learning Nagios - Third Edition
About the Authors
About the Reviewer

Monitoring resources

For servers or work stations to be responsive and to be kept from being overloaded, it is also worth monitoring system usage using various additional measures. Nagios offers several plugins to monitor resource usage and to report if the limits set for these checks are exceeded.

Checking system load

The first thing that should always be monitored is the system load, and it is calculated based on the count of the processes running or waiting to be running. This value reflects the number of processes and the amount of CPU capacity that they are utilizing. This means that if one process is using up to 50% of the CPU capacity, the value will be around 0.5; and if four processes try to utilize the maximum CPU capacity, the value will be around 4.0. The system load is measured in three values—the average loads in the last minute, last 5 minutes, and last 15 minutes. The syntax of the command and the description of the option is as follows:

check_load [-r] -w wload1,wload5,wload15...