How to Get a Email when System Load Average is High ? (Crontab)

In this post and this, we know we can use several methods to check the system load average for Linux OS. We also know that, similar to this post (get a email when VPS is rebooted), we can setup a crontab job that runs at the given interval.

So, we can get a email to alert us that the system load average is high (exceeded a threshold).

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 */2 * * * * /var/www/checkload.sh > /dev/null 2>&1

 */2 * * * * /var/www/checkload.sh > /dev/null 2>&1

The above runs every 2 minutes, so we need to create this checkload.sh using your favorite text editor.

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#!/bin/bash
 
load=`echo $(cat /proc/loadavg | awk '{print $1}') \> 3 | bc -l`
if [ "$load" -ne 0 ]; then
        echo "Your Server Load Alert Needs Attention! " | mail -s "System Load Alert $load" mail@helloacm.com
        echo "Alert email sent to [email protected]"
fi
 
echo "System Load $(cat /proc/loadavg)"

#!/bin/bash

load=`echo $(cat /proc/loadavg | awk '{print $1}') \> 3 | bc -l`
if [ "$load" -ne 0 ]; then
        echo "Your Server Load Alert Needs Attention! " | mail -s "System Load Alert $load" [email protected]
        echo "Alert email sent to [email protected]"
fi

echo "System Load $(cat /proc/loadavg)"

We use awk to extract the first number (similar as the split function) and pipe in the calculator bc if it is larger than 3 (changed this accordingly). If the load average is more than 3, then the result will be 1 (-ne 0). Then we send a email.

The VPS I am using is from QuickHOSTUK, which has 4 cores, setting the load average threshold to 3 should be reasonable for now.

PS: You can use api/cat-proc/?file=loadavg API from this page to run the command cat /proc/loadavg to see the load average of the VPS current blog is on.

This online utility helps configuration of the crontab.

We can integrate this script with showing the last requests so that we can get a rough understanding of what are causing the trouble to the server: How to Get the Last Requests to Apache2 Server?

–EOF (The Ultimate Computing & Technology Blog) —