Find HighCpu Threads on Weblogic Linux

FIND HIGH CPU ON LINUX with JDK

Lot of times on the WLS PROD Environment we see high CPU on the java process , We just end up restarting the server , Its very hard to find the root cause


Here is small utility script that will display the Top 10 cpu consuming threads of the java process we just need to pass the <Java PID> to the script.


cpuhigh.sh

 Just copy the script to  a sh file

./cpuhigh.sh <javaPID>

#!/bin/bash

# put your JAVA_HOME here,
JAVA_HOME=/JDK/jdk160_31

PID=$1
IFS=''
top_number=10
if [ $# -gt 1 ] ; then
top_number=$2
fi

top_number=$((top_number+1))

java_stack=`$JAVA_HOME/bin/jstack -l $PID`

top=`top -s -b -H -p $PID -n 1 | grep -vE '^top|^Tasks|^Cpu|^Mem|^Swap|^$' | awk 'NR==1; NR > 1 {print $0 | "sort -nrk 9"}' | head -$top_number`
echo $top

echo $top | while read psline; do
if [ `echo $psline|grep -c PID` -gt 0 ] ;
then continue
fi
lwp_id=`echo $psline | awk '{print $1}'`
nid=`printf '%x\n' $lwp_id `
echo "========> Java LWP: $lwp_id - Native Thread ID=$nid"
echo $java_stack | sed -n "/$nid/,/^$/ p" ;
done

Sample Output