Nagios Core Administration Cookbook Second Edition

Nagios Core Administration Cookbook Second Edition - Second Edition

By : Tom Ryder

Buy this Book

Nagios Core Administration Cookbook Second Edition - Second Edition

By: Tom Ryder

Buy this Book

Overview of this book

Nagios Core is an open source monitoring framework suitable for any network that ensures both internal and customer-facing services are running correctly and manages notification and reporting behavior to diagnose and fix outages promptly. It allows very fine configuration of exactly when, where, what, and how to check network services to meet both the uptime goals of your network and systems team and the needs of your users. This book shows system and network administrators how to use Nagios Core to its fullest as a monitoring framework for checks on any kind of network services, from the smallest home network to much larger production multi-site services. You will discover that Nagios Core is capable of doing much more than pinging a host or to see whether websites respond. The recipes in this book will demonstrate how to leverage Nagios Core's advanced configuration, scripting hooks, reports, data retrieval, and extensibility to integrate it with your existing systems, and to make it the rock-solid center of your network monitoring world.

Nagios Core Administration Cookbook Second Edition

Credits

About the Author

About the Reviewer

www.PacktPub.com

Preface

Free Chapter

Understanding Hosts, Services, and Contacts

Introduction

Creating a new network host

Creating a new HTTP service

Creating a new e-mail contact

Verifying configuration

Creating a new hostgroup

Creating a new servicegroup

Creating a new contactgroup

Creating a new time period

Running a service on all hosts on a group

Working with Commands and Plugins

Creating a new command

Customizing an existing command

Using an alternative check command for hosts

Writing a new plugin from scratch

Implementing threshold checks in a plugin

Using macros as environment variables in a plugin

Working with Checks and States

Introduction

Specifying how frequently to check a host or service

Changing thresholds for PING RTT and packet loss

Changing thresholds for disk usage

Scheduling downtime for a host or service

Managing brief outages with flapping

Adjusting flapping percentage thresholds for a service

Configuring Notifications

Introduction

Configuring notification periods

Configuring notifications for groups

Choosing states for notification

Specifying the number of failed checks before notification

Automating contact rotation

Defining an escalation for repeated notifications

Defining a custom notification method

Filtering notifications based on a host or service value

Monitoring Methods

Introduction

Monitoring PING for any host

Monitoring SSH for any host

Checking an alternative SSH port

Monitoring mail services

Monitoring web services

Checking that a website returns a given string

Monitoring database services

Monitoring the output of an SNMP query

Monitoring a RAID or other hardware device

Creating an SNMP OID for monitoring

Enabling Remote Execution

Introduction

Monitoring local services on a remote machine with NRPE

Setting the listening address for NRPE

Setting allowed client hosts for NRPE

Creating new NRPE command definitions securely

Giving limited sudo(8) privileges to NRPE

Using check_by_ssh with key authentication instead of NRPE

Using check_mk instead of NRPE

Using the Web Interface

Introduction

Using the Tactical Overview

Viewing and interpreting availability reports

Viewing and interpreting trends

Viewing and interpreting notification history

Adding comments on hosts or services in the web interface

Viewing configuration in the web interface

Scheduling checks from the web interface

Acknowledging a problem via the web interface

Managing Network Layout

Introduction

Creating a network host hierarchy

Using the network map

Choosing icons for hosts

Establishing a host dependency

Establishing a service dependency

Monitoring individual nodes in a cluster

Using the network map as an overlay

Managing Configuration

Introduction

Grouping configuration files in directories

Keeping a configuration under version control

Configuring host roles using groups

Building groups using regular expressions

Using inheritance to simplify configuration

Defining macros in a resource file

Using another object's directives in a host or service check

Using custom directives

Dynamically building host definitions

Security and Performance

Introduction

Using authentication for the Nagios Core web interface

Using authenticated contacts

Writing debugging information to the Nagios log file

Monitoring Nagios performance with nagiostats

Setting up a redundant monitoring host

Automating and Extending Nagios Core

Introduction

Allowing and submitting passive checks

Submitting passive checks from a remote host with NSCA

Submitting passive checks in response to SNMP traps

Setting up an event handler script

Tracking host and service states with Nagiosgraph

Reading status in a MySQL database with NDOUtils

Reading status from a Unix socket with MK Livestatus

Writing customized Nagios Core reports

Getting extra visualizations with NagVis

Writing custom Nagios Core management scripts

Index

Customer Reviews

5 star

4 star

3 star

2 star

1 star

Specifying the number of failed checks before notification

In this recipe, we'll learn how to arrange Nagios Core configuration to send notifications about problems with a host or service only after a check has been repeated a certain number of times and failed each time.

This can be an ideal arrangement for non-critical hosts that occasionally have "blips" or short outages and only become problematic if they remain down after repeated checks. It prevents sending notifications on the first check, only sending them if the problem turns out to be consistent.

Getting ready

You should have a Nagios Core 4.0 or newer server, with at least one host configured already. We'll use the example of sparta.example.net, a host defined in its own file. We'll arrange for it to send us notifications only after a total of five failed host checks.

How to do it...

We can configure the number of failed checks to be tolerated before sending a notification as follows:

Change to the objects configuration directory for...

Nagios Core Administration Cookbook Second Edition - Second Edition

By : Tom Ryder

Nagios Core Administration Cookbook Second Edition - Second Edition

By: Tom Ryder

Overview of this book

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Current Title:

Nagios Core Administration Cookbook Second Edition - Second Edition

Specifying the number of failed checks before notification

Getting ready

How to do it...