Monitoring using Nagios

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• Monitoring using Nagios

Shyam Mani fox2mike_at_gentoo.org
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What we'll cover

• Features
• Configuration
• Anatomy of Checks
• Notifications
• NRPE/NSCA
• Web Features
• Negatives

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Features

• Network, services, hosts other metrics
• Intelligent checks/problem views
• Network Mapping
• Notification
• Web-Interface (optional)
• Scaling
• Object Inheritance (configuration)
• Setup and forget

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Configuration Overview
nagios.cfg
cgi.cfg
hostgroups hosts timeperiods services servicegroup
s misccommands chkcommands contacts contactgroups
Apache
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Configuration Files

• /etc/nagios/nagioscgi.cfg
• Everything else defined from there
• KISS Separate files
• Pre-flight check Extremely good idea
• And so...combining everything..

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Anatomy of a Service check
Dominica (Nagios Server)
check_sshd
Timeout
Grenada
SSH OK - OpenSSH_3.9p1 (protocol 2.0) 
check_smtp
check_http
Fiji
Aruba
HTTP OK HTTP/1.0 200 OK - 1340 bytes in 9.001
seconds
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Ok, there's an issue...now what?

• Various forms of notification. Email, SMS, IRC
• Completely configurable
• Number of filters
• Acknowledge issues

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Nagios Remote Plugin Execution

• Why?
• How?
• Security - SSL
• Standalone/xinetd
• No overhead of SNMP
• No overhead of key-based ssh
• TCP Wrapper support

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Other features (Web)

• Performance Stats
• External commands
• Viewing Logs
• Status Maps
• Notes/Ticketing
• Reports on the fly
• Demo

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Possible Negatives

• False notifications?
• Fail proof systems for production use?
• Minor security issues

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For more info...

• http//www.nagios.org/
• This work is licensed under the Creative Commons
  Attribution-NonCommercial-ShareAlike License. To
  view a copy of this license, please visit
• http//creativecommons.org/licenses/by-nc-sa/2.5/
• Slides at http//dev.gentoo.org/fox2mike/talks/