线上Java应用,在业务高峰期的时候经常出现CPU跑高,需要查看实时的线程占用cpu情况,下面是一个很好用的脚本,可以快速导出每个线程的占用CPU情况,结合jstack日志,排查到具体的线程类名。
一、首先获得jvm的进程ID:
ps -ef|grep java tomcat 374 372 1 11:45 ? 00:02:30 jsvc.exec -java-home /usr/java/latest -user tomcat -pidfile /usr/local/tomcat7/logs/tomcat7.pid -outfile /usr/local/tomcat7/logs/catalina-daemon.out -errfile &1 -classpath /usr/local/tomcat7/bin/bootstrap.jar:/usr/local/tomcat7/bin/commons-daemon.jar:/usr/local/tomcat7/bin/tomcat-juli.jar -Djava.util.logging.config.file=/usr/local/tomcat7/conf/logging.properties -Djava.awt.headless=true -Xmx10240m -XX:MaxPermSize=2096m -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.endorsed.dirs=/usr/local/tomcat7/endorsed -Dcatalina.base=/usr/local/tomcat7 -Dcatalina.home=/usr/local/tomcat7 -Djava.io.tmpdir=/usr/local/tomcat7/temp org.apache.catalina.startup.Bootstrap
#!/bin/shexport LANG="zh_CN.UTF-8"; export LC_ALL="zh_CN.UTF-8";
LOG_FILE="/tmp/jkiller.log"; JSTACK_FILE="/tmp/jstack.log";
PID="$1"; shift; i=0; j="$1"; if [ -z "${j}" ]; then j=5; fi
ps -mp ${PID} -o THREAD,tid,time | sort -rn > ${LOG_FILE}; jstack ${PID} > ${JSTACK_FILE};
for LINE in `cat ${LOG_FILE}|gawk -F '-' '{print $4}'|gawk -F ' ' '{print $1}'` do i=$(($i+1)); if (($i>$j)); then break; fi; XPID=`printf "%x\n" ${LINE}`; echo -ne "\033[32m"; echo ${XPID}; echo -e "\033[34m"; grep -A 10 "0x${XPID}" ${JSTACK_FILE}; echo -e "\e[0m"; done;
执行该脚本:
./jkiller.sh 374