#!/bin/bash
# @Function
# Find out the highest cpu consumed threads of java processes, and print the stack of these threads.
# @github https://github.com/cjunn/script_tool/
# @author cjunn
# @date Sun Jan 12 2020 21:08:58 GMT+0800
#
pid='';
count=5;
function usage(){
readonly PROG="`basename $0`"
cat <<EOF
Usage: ${PROG} [OPTION]
Find out the highest cpu consumed threads of java processes,
and print the stack of these threads.
Example:
${PROG} -p <pid> -c 5 # show top 5 busy java threads info
Output control:
-p, --pid <java pid> find out the highest cpu consumed threads from
the specified java process.
default from all java process.
-c, --count <num> set the thread count to show, default is 5.
Miscellaneous:
-h, --help display this help and exit.
EOF
}
#1.Collect script parameters
#2.Check whether PID exists
if [ $# -gt 0 ];
then
while true; do
case "$1" in
-c|--count)
count="$2"
shift 2
;;
-p|--pid)
pid="$2"
shift 2
;;
-h|--help)
usage
exit 0;
;;
--)
shift
break
;;
*)
shift
if [ -z "$1" ] ; then
break
fi
;;
esac
done
fi
if [ ! -n "$pid" ] ;then
echo "error: -p is empty"
exit 1;
fi
function worker(){
#1.Query all threads according to PID.
#2.Delete header and first line information.
#3.According to the second column of CPU to sort, reverse display.
#4.Delete the count + 1 to last column based on the count value.
#5.Get CPU utilization, TID value, thread used time, and assign them to CPU, TID, time respectively.
#6.Perform hex conversion on TID.
#7.Use JDK to monitor all threads of jstack output PID.
#8.Use awk to regularly query the thread information of tid_hex required.
#9.Display the stack information of count before thread busy.
local whilec=0;
ps -mp $pid -o THREAD,tid,time | sed '1,2d' | sort -k 2 -n -r |sed $[$count+1]',$d' | awk '{print $2,$8,$9}' | while read cpu tid time
do
tid_hex=$(printf "%x" $tid);
echo "====================== tid:${tid} tid_hex:${tid_hex} cpu:${cpu} time:${time} ======================";
jstack $pid | awk 'BEGIN {RS = "\n\n+";ORS = "\n\n"} /'${tid_hex}'/ {print $0}'
echo "";
whilec=$[$whilec+1];
done
if [ $whilec -eq 0 ] ; then
echo "error : thread not found, make sure pid exists.";
fi