NRPE

NRPE - Monitoring Tool

Introduction:- 

NRPE is stand for Nagios Remote Plugin Executor, is used for the remote system monitoring by executing scripts on remote systems. NRPE is used to monitor "local" resources on remote systems (Linux/Unix). NRPE allows monitoring of Disk Usage, system's load or number of users currently logged in and much more.

                           Basically, NRPE can only monitor public services such as HTTP, FTP, etc., but it also work on client - server basis, you need install a daemon on the server machine ( machine on which you want to monitor), then setup your Nagios server to connect to the remote daemon to collect information about the remote machines. 

NOTE:-

           Using NSClient++ instead of NRPE on the remote host you can execute checks on Windows machines as well.

Figure :- NRPE

DESIGN OVERVIEW:

NRPE addon works in two different stages:

• The check_nrpe plugin, which works on the local machine.
• The NRPE daemon, which works on the remote LINUX/UNIX machine.

When Nagios needs to monitor resources of a remote machine:

• Nagios will execute the check_nrpe plugin and tell it what service needs to be checked.
• The check_nrpe plugin contact the NRPE daemon using a SSL-protected connection.
• The NRPE daemon run the Nagios plugin to check the service or resource.
• NRPE daemon transfer the result of the service check back to the check_nrpe plugin, which further transfer the check result to the Nagios process.