Monitoring CPU Load Averages with Shell Script

After little R & D on Google/Internet found few suitable solutions. I had chosen 'uptime' command running with remote SSH connection in a loop. Adding more value to this sending a mail on the event of crossing the threshold value. This threshold will be vary depending upon the application and CPU power. Trial and error make you to identify what could be the threshold. Once script started working he was amazed and appreciated as well.

This script can be run forever with a specified time interval. You can use 'at' command or 'crontab' also for this task. I prepared a 'bash' script that could work for Solaris and also on Linux.

Before to this script we need to establish the password less connection to all the remote machines with 'key-gen' command. Public key authentication, which is the good choice password less connecting remote UNIX machines. Here, you can use any choice for encryption algorithms such as RSA, DSA etc.,

Customization/Cosmotics to this script

When you run this script at your prompt you can see the high load average server details in red colour which makes sense to act up on that quicker. All server list I had kept in a plan text file and accessed it line by line as array for looping.

#!/bin/bash

#======================================================

# This script will check CPU Load, network ping status

# and also checks diskspace on every machine

#======================================================

RECIPIENTS="xyz@gmail.com"

LOG=./load.log

check_load()

{

        loadnow=`echo $msg| cut -d, -f4 | cut -d: -f2 | cut -d. -f1`

        d=`echo $msg |awk '{print $((NF-1))}'`

        SD=`date "+%Y-%h-%d@%H:%M:%S"`

        echo $SD '****'

        if [ $loadnow -gt 14 ]; then

                echo -e ' \033[31m' $server ' ' $loadnow '\033[m'>>$LOG

                echo $SD $server ' ' $loadnow |mailx -s LOAD_WARN $RECPIENTS

        elif [ $loadnow -gt 19 ]; then

                echo -e ' \033[31m' $server ' ' $loadnow '\033[m'>>$LOG

                echo $SD $server ' ' $loadnow |mailx -s LOAD_CRITICAL $RECPIENTS

        else

                echo -e $server '\t' $loadnow '\t' $p '\t'$d >>$LOG

        fi

}

#==============================================================

#                 M A I N  S C R I P T

#==============================================================

if [ -f $LOG ]

then

        rm $LOG

fi

serlist=`cat prodServers.txt`

echo -e "========================================================">>$LOG

echo -e "  HOSTNAME  CPU Load     Network status       Disk Space">>$LOG

echo -e "========================================================">>$LOG

for server in $serlist

do

        echo 'connecitng to ' $server

        msg=`ssh $server "uptime; df -k |grep /WASLogs |awk '{print \$5}'"`

        p=`ping $server 56 2 |grep loss | awk -F',' '{ print $3 }'`

        check_load

done

cat load.log

Please make sure that you must have prodServers.txt file in the same script path. Sample prodServers.txt file as follows:

myprod.server1.com

myprod.server2.com

...

myprod.server20.com