Nagios
- 1. NAGIOS A System and Network Monitoring Application
- 2. Agenda Introduction Objectives Features Requirements Architecture and Operation Operation Description Web Portal Plug-ins Plug-ins Description
- 3. What is Nagios? Nagios is an open source tool especially developed to monitor hosts and services and designed to inform the network incidents before end-users , clients do. It watches hosts and services which we specify and alerts when things go bad and when things get recovered. Initially developed for servers and application monitoring , it is now widely used to monitor networks availability.
- 4. Features Of Nagios Monitoring of network services (SMTP,POP3,HTTP,NNTP,PING etc) Monitoring of host resources (Disk Usage etc) Parallelized service checks Simple plug-in design that allows users to easily develop their own service checks. Contact Notifications when service or host problems occur and get resolved (via email , pager or user-defined method)
- 5. Features Continued.. Automatic Log Rotation Ability to define network host hierarchy using parent hosts. Support for implementing redundant monitoring hosts. Optional Web Interface for viewing current network status , notification and problem history , log file etc.
- 6. Requirements Things need to get Nagios working are: Nagios Plug-ins ( downloadable from nagios url) Graphics Libraries JPEG Libraries Database for storing log files
- 8. Architecture Nagios is built on a server/client architecture. Usually , on a network , a Nagios server is running on a host , and plugins are running on all the remote hosts that need to be monitored. These plugins send information to the server , which displays them in a GUI. Nagios is composed of three parts : A Scheduler : this is the server part of nagios. At regular interval , the scheduler checks the plugins , and according to their results, do some actions. A GUI : the interface of Nagios (with the configuration, the alerts ) . It is generated in web pages generated by CGI. The Plugins : They are configurable by the user. They check a service and return a result to the nagios server.
- 9. Architecture A Soft Alert is raised when a plug in returns a warning or an error. Then on the GUI ,a green button turns to red. When this soft alert is raised many times( the number is configurable) , a hard alert is raised , and the nagios server sends notifications : email , sms, etc.
- 11. Web Interface – Services Overview
- 12. Web Services – Services Details Overview
- 13. Configuration Files Nagios.cfg Main Configuration File Monitored elements configuration resource.cfg User defined elements configuration file cgi.cfg Display options for CGI host, hostgroup and hostextinfo Information concerning monitored equipments
- 14. Configuration Files service, servicextinfo Information concerning monitored services , service escalation host and service dependency Dependencies between hosts and between services host escalation, host group escalation Escalation Notification
- 15. Configuration Files contact Nagios users. To access Nagios interface, it is necessary to be registered in this contact file contactgroup User Groups. Notifications and display rights are settled in this file Timeperiod Use to configure period of time for elements monitoring and users notifications. command Set of commands used to control services, equipments, events management and notifications
- 16. Plugins A plugin is a small program that checks a service ( a daemon , some free space on a disk..). It must return a value and a small line of text. (Nagios will only grab the first line of text). Output should be in the format METRIC STATUS : information text/performance data . The allowed METRIC STATUS are 0(OK) , 1(WARNING) , 2(CRITICAL) or 3(UNKNOWN). The warning and critical thresholds are parameters , set by the user ,passed as arguments to the plugin. The plugins can be run : Locally on the Nagios server Remotely through a remote Nagios server , with ssh , with snmp , with NRPE (Nagios Remote Plugin Executor) , or with NSCA (Nagios Service Check Acceptor).
- 18. Thank You