We have various scripts on a server that process files that are uploaded to a specific directory so we needed a way to monitor these directories and verify that all files are being processed. Once they are processed on our server they are moved to different directory so the file count should never get over a certain amount of files. The below script assumes that you have NRPE installed on the server so you can reference the bash script locally. Follow the directions below with some monitor modifications and you can monitor directories for the number of files with Nagios very easily.
Nagios is an awesome open source application that provides a way to monitor pretty much anything that you can think of on your network. There are tons of plugins written for Nagios that will monitor anything from PostgreSQL database size to the number of users logged into a server. Today I needed to start monitoring the size of a Ruby process that has been growing out of hand so the below is what I came up with being the best solution. Follow the directions below to deploy a Perl script that will use SNMP to retrieve Linux server process size.