Apress - Pro Nagios 2.0

Introduction

You are an IT manager in charge of numerous systems spread across multiple countries. It’s 4:00 a.m. and you are in bed asleep. Your cell phone rings. It’s the Help Desk calling to tell you that users in Indonesia can’t access their email. You get up, dial into work, and start to diagnose the problem. After an hour of work you identify that the issue is disk space on the mail server in the Indonesian office. You clear some free space, confirm the users can access their mail, and go back to sleep.

This is a common scenario in the IT industry. IT staff are geographically and temporally separated from the systems and applications they manage. All troubleshooting, monitoring, and management of systems and applications occurs remotely. The systems and applications being managed are complex and hugely configurable. They are also made up of multiple components— hardware, software, networking devices, networks, and supporting infrastructure like environmental and electrical systems. In the event of a problem, many of these components need to be checked in order to eliminate them as a cause.

All this has resulted in monitoring, management, and troubleshooting becoming increasingly complicated and time consuming. No longer do IT professionals have time to individually review every log, every setting, and every variable on all the systems and applications they are responsible for. They need tools to automatically monitor the characteristics of the assets they are responsible for managing . . . tools that will detect anomalies, failures, or performance issues and alert IT staff via email, a pager, or an SMS message . . . tools that can automatically perform actions, such as restarting a service, in response to events they have detected. These types of tools perform functions generally known as enterprise management.

So what advantages does an enterprise management solution offer? Well, let’s say that as an IT manager you have deployed an enterprise management solution. With this solution in place, let’s revisit our troubleshooting scenario again. Instead of a call from the Help Desk, this time your cell phone beeps to indicate it has received an SMS message. You read the message: 4/21/05 04:54AM C:\ drive on server INDOEXCH01 has 1% of free space remaining.

You get up, dial into work, connect to the INDOEXCH01 server, clear some free space, confirm the server is functional, and then go back to sleep. Total elapsed time? Ten minutes. Now instead of your having to diagnose the problem, eliminate all the possible variables, review log files, and test multiple components, the actual root cause of the issue is presented directly to you.

In this book I am going to introduce the popular open source enterprise management tool Nagios. At the time of this writing, version 2.0 has just been released as the stable production version. This book takes advantage of this release to provide an introduction to Nagios and how you can use it streamline, manage, and monitor your IT assets.