Webpage to Monitor CPU usage on a linux box.

calendar May 5, 2011 · 2 min read · linux  ·
Share on: linkedin copy

This cgi script allows you to post a webpage on your multi-processor Linux server which shows the current CPU usage. Useful if you want to quickly and easily check the load on the system and see if multi-processor applications are spreading themselves across the available cores.

This code has been tested on a 48-core server running Centos 5. The usual disclaimers apply.

Prerequisites

For this script to work you will need a Linux system with a cgi-capable webserver installed and running. My system has apache on it, but whatever flavour you like is probably fine. The server will also need the sh shell installed and the mpstat command. The latter is part of the sysstat package so can be installed on Centos/Fedora/RedHat systems with the command.

1yum install sysstat

Installation

Using your favourite editor open a new text file called cpu.cgi in the cgi-bin folder on your server, for example:

1vi /var/www/cgi-bin/cpu.cgi

And copy and paste in the following code. Be aware the line starting mpstat is quite long so be careful it isn’t chopped up by cutting and pasting. The next line of code starts with the echo.

 1#!/bin/sh
 2#CGI script for displaying CPU usage on a web page
 3
 4#Output the header
 5echo Content-type: text/html
 6echo
 7
 8#Output the top of the html page
 9echo "<html><head><title>CPU Usage</title></head>"
10echo "<body>"
11
12#Stick anything to go above the table on the webpage here
13
14#output the table with the CPU usage
15echo "<table border=1>"
16echo "<tr><td>CPU</td><td colspan=2>% Usage</td></tr>"
17mpstat -P ALL 1 1 | sed /^$/d | sed /^Linux/d | sed -n '/CPU/,/CPU/p' | sed /CPU/d | awk ' { print "<tr><td>",$2,"</td><td>",100-$10,"</td><td><div style=\"width:",(100-$10)*2,"px;background:green;border: 1px solid black;\">&nbsp;</div></td></tr>" }'
18echo "</table>"
19
20#Put anything to go below the table on the webpage here
21
22#Finish off the HTML output.
23echo "</body></html>"

All that’s left to do is make the script executable:

1chmod +x /var/www/cgi-bin/cpu.cgi

And now just point your web browser at the following URL to view the results. http://myserver/cgi-bin/cpu.cgi