= Linux/Bash/CpuLoadAvg =

== cron job to capture load average ==
 * script to call from cron
   * cron {{{
* * * * *  /home/<user>/cron-log-cpu.sh /home/<user>/cpu_usage.log

}}
   * bash script cron-log-cpu.sh {{{
#!/usr/bin/bash
log_file="${1:-${HOME}/cpu_usage.log}"    

if [[ $( awk '{ print ($1 > 2.0) }' /proc/loadavg ) -eq 1 ]];
then 
    ( echo; date -Is; top -b -n1 -c -w | head -n 12 | grep -v "^$" ) >> ${log_file}
else
     # Check if last update as Low loadave in last hour, should start with date
     if [[ -f ${log_file} ]] && tail -n 1 ${log_file} | grep -q "^$( date -Is | cut -c1-13)" > /dev/null; then
         :
     else
	 echo
         echo "$( date -Is ) Low loadavg 1,5,15min $( cat /proc/loadavg )" >> ${log_file}
     fi	 
fi

}}}

 * Log top 5 process by cpu if loadavg > 3, every minute.
   * Can remove echo after "||" to not log low load avg.
 * crontab -e {{{

* * * * *  [[ $( echo "$(awk '{ print $1 }' /proc/loadavg) > 3" |bc ) -eq 1 ]] && ( echo; date -Is; top -b -n1 -c -w | head -n 12 ) >> ~/cpu_usage.log || echo "$( date -Is ) Low loadavg 1,5,15min $( cat /proc/loadavg )" >> ~/cpu_usage.log

}}}

 * 2nd version using if else {{{
* * * * *  if (( $( awk '{ print ($1 > 3.0) }' /proc/loadavg ) )); then ( echo; date -Is; top -b -n1 -c -w | head -n 12 ) >> ~/cpu_usage.log; else echo "$( date -Is ) Low loadavg 1,5,15min $( cat /proc/loadavg )" >> ~/cpu_usage.log; fi

}}}
 * view with {{{
tail -f ~/cpu_usage.log
}}}