Apache MaxClients/MaxRequestWorkers Calculation

In order to set optimal values to MaxClients or MaxRequestWorkers we have to know how much memory apache consumes for each process. The script below give you Maximum memory usage of a single process and average memory usage of each process. But the values change under server load. So, stress test your server to fill up the memory to set correct values. This won’t give you the exact/absolute value but does most of the job.Setting values between average and max should save you.

Download Script

# This script is intended to determine apache memory footprint.
# This footprint can be used to set MaxClients/MaxRequestWorkers values
# Set a value between average and max values for best results.
# Values are subject to change under load. Run under different loads.
# comments to http://www.cirgan.net
# Usage : sh yourscriptname.sh yourapacheprocessname

httpdname=$(netstat -tunalp | grep :80| grep “/” | awk ‘{print $7’} | cut -d “/” -f2 | tail -n 1)
totmem=$(free -m | grep -i mem | awk ‘{print $2}’)

finkfink() {

httpdmemtot=$(ps -aylC $1 |grep “$1” |awk ‘{print $8’} |sort -n | awk ‘{ SUM += $1} END { print SUM }’)
httpdmemmax=$(ps -aylC $1 |grep “$1” |awk ‘{print $8’} |sort -n |tail -n 1)
avghttp=$(expr $httpdmemtot / $httpdcount)
n=$(expr $avghttp / $div)
m=$(expr $httpdmemmax / $div)

if [ “$1” = “$httpdname” ] ; then

max=$(expr $totmem / $n)
max1=$(expr $totmem / $m)
echo “Total System Memory = $totmem MB”
echo “$httpdcount $httpdname processes running”
echo “$httpdname average memory allocation= $n MB”
echo “Max memory allocated $httpdname process= $m MB”
echo “Average Memory MaxClients/MaxRequestWorkers = $max”
echo “Max Memory MaxClients/MaxRequestWorkers = $max1”

#End of Finkfink

if [ $# -eq 0 ]; then
echo “Insufficient parametres. Usage: sh $0 $httpdname”
exit 1

if [ “$1” != “$httpdname” ] ; then

echo “I couldn’t find $1.Please type apache process name correctly. Usage: sh $0 $httpdname”
exit 1

httpdcount=$(ps -aylC $1 |grep “$1” |awk ‘{print $8’} |sort -n | wc -l)

if [ “$httpdcount” -gt 0 ] ; then

finkfink $*


echo “Something went wrong.Is your web server running?”

exit 1

exit 0

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