Simple load test script with email alert

Today's simple Bash script is for those situations where you want to keep an eye on a Linux server's load statistic and have it email you if it exceeds a value you specify without setting up full-blown monitoring (Nagios, Zabbix, Zen, etc).

Here's an overview of the script and what it does (And as always, the most up-to-date version of the script will be in my Github repo):

#!/bin/bash # -------------------------- # Simple Load Test Utility # -------------------------- # Written by James Berger # Last updated: August 13th 2013 # Description: # ------------ # This grabs the five minute load average via the uptime command. # It compares it to the max_load variable and if the current load # average is higher than the max_load variable, it alerts and # sends you an email. # Setting our variables #---------------------- # (note that the max load variable is set to a very low value by #  default, 0.001. This is for testing purposes so you can verify #  if the script works or not. If you're actually using it, you #  should set it to a more reasonable value, like 1 or 0.75) max_load=0.001 email_destination=generic-email-address@somewhere.com # We call uptime, and then we use cut with space delimiters to grab # the five minute load average, then we use translate (tr) to strip # out any spaces and commas so we have a nice float value instead # of a string. current_load=$(uptime | cut -d' ' -f 15 | tr -d "," | tr -d " ") # Comparing the current load to the max load #-------------------------------------------- # Now we'll use an if statement to see if the current load exceeds # what was set for the max load. Bash doesn't like to evaluate # floating numbers, so we'll pipe it out to bc to do a simple # 'greater than?' check. If it passes the check, we email the # person specified in our email_destination variable and if not, # we simply exit. if [ $(echo "$current_load > $max_load"|bc) -eq 1 ] then echo -e "ALERT.\n This is a message from the Simple Load Test Utility. The current load of $current_load has exceeded the maximum defined load of $max_load on the server $(hostname).\n This alert was created on $(date) (local time on $(hostname))." | mail -s "High load alert on $(hostname)" $email_destination else   exit 0 fi exit 0