Shell script to measure the java heap memory usage over the execution of the JVM

gistfile1.txt

#!/bin/sh
 
#
# Description:
#	This program shall display the statistics about the usage of the heap
#	by the JVM during the execution of this program
#

## Functions ##

function show_help
{
	echo "Usage:"
	echo "	sh heap_usage.sh <vmid> [interval] [count]"
	echo "		vmid - Virtual Machine Identifier, string that indicates the target JVM"
	echo "		interval - Sampling interval in seconds"
	echo "		count - Number of samples to display"
	exit 1;
}

function update_result
{
	#Update max value
	if [[ $1 -ge $max ]]
	then
		max=$1
	fi

	#Update min value
	if (( ($min == 0) || ($1 < $min) ))
	then
		min=$1
	fi
}

## Main ##

if [[ $# -le 0 ]] 
then
	show_help
fi

# variable
jvmid=$1
interval=0.3
count=100
i=0
min=0
max=0


if [ -n "$2" ]
then
	interval=$2
fi

if [ -n "$3" ]
then
	count=$3
fi

while [[ $i -le $count ]]
do
	dummy=`jps | grep $jvmid | head -1 | cut -d' ' -f1`
	if [[ $dummy -eq "" ]]
	then
		echo "Exiting..."
		break
	fi
	result=`jmap -heap $jvmid | grep "^\s*used" | awk -F' ' '{ sum += $3 } END { print sum }'`
	echo $result
	update_result $result
	sleep $interval
	((i++))
done

echo "Results Summary"
#max=max/1024/1024
max=`expr $max / 1024`
max=`expr $max / 1024`
min=`expr $min / 1024`
min=`expr $min / 1024`
echo "		Max Heap Usage: $max MB"
echo "		Min Heap Usage: $min MB"