watcher.script.show-busy-java-threads.sh Maven / Gradle / Ivy

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#!/bin/bash
# @Function
# Find out the highest cpu consumed threads of java, and print the stack of these threads.
#
# @Usage
#   $ ./show-busy-java-threads.sh
#
# @author Jerry Lee

PROG=`basename $0`

usage() {
    cat < /dev/null; then
    [ -z "$JAVA_HOME" ] && {
        redEcho "Error: jstack not found on PATH!"
        exit 1
    }
    ! [ -f "$JAVA_HOME/bin/jstack" ] && {
        redEcho "Error: jstack not found on PATH and $JAVA_HOME/bin/jstack file does NOT exists!"
        exit 1
    }
    ! [ -x "$JAVA_HOME/bin/jstack" ] && {
        redEcho "Error: jstack not found on PATH and $JAVA_HOME/bin/jstack is NOT executalbe!"
        exit 1
    }
    export PATH="$JAVA_HOME/bin:$PATH"
fi

uuid=`date +%s`_${RANDOM}_$$

cleanupWhenExit() {
    rm /tmp/${uuid}_* &> /dev/null
}
trap "cleanupWhenExit" EXIT

printStackOfThread() {
    while read threadLine ; do
        pid=`echo ${threadLine} | awk '{print $1}'`
        threadId=`echo ${threadLine} | awk '{print $2}'`
        threadId0x=`printf %x ${threadId}`
        user=`echo ${threadLine} | awk '{print $3}'`
        pcpu=`echo ${threadLine} | awk '{print $5}'`
        
        jstackFile=/tmp/${uuid}_${pid}
        
        [ ! -f "${jstackFile}" ] && {
            jstack ${pid} > ${jstackFile} || {
                redEcho "Fail to jstack java process ${pid}!"
                rm ${jstackFile}
                continue
            }
        }

        redEcho "Busy(${pcpu}%) thread(${threadId}/0x${threadId0x}) stack of java process(${pid}) under user(${user}):"
        sed "/nid=0x${threadId0x} /,/^$/p" -n ${jstackFile}
    done
}

ps -Leo pid,lwp,user,comm,pcpu --no-headers | {
    [ -z "${pid}" ] &&
    awk '$4=="java"{print $0}' ||
    awk -v "pid=${pid}" '$1==pid,$4=="java"{print $0}'
} | sort -k5 -r -n | head --lines "${count}" | printStackOfThread