查看JAVA占用CPU高的线程日志

Posted 2020-11-30 chenzechao

 

# 1. 查看主进程占用cpu高
top
#    1647 java

# 2. 按照线程占用cpu由高到低进行排查：
ps -mp 1647 -o THREAD,tid,time | sort -rn |head -6

# USER     %CPU PRI SCNT WCHAN  USER SYSTEM   TID     TIME
# root      1.6   -    - -         -      -     - 00:02:07
# root      0.1  19    - futex_    -      -  1767 00:00:11
# root      0.1  19    - futex_    -      -  1766 00:00:11
# root      0.1  19    - futex_    -      -  1765 00:00:10
# root      0.0  19    - skb_re    -      -  5048 00:00:00

# 3. 将线程号转化为16进制：
printf "%x
" 1767
6e7

# 4. 通过主进程搜索所有的线程执行的内容
#    注意点:
#        项目运行的用户
#        使用的jdk版本下的jstack去查看
flag="0x"
sudo -u root /opt/jdk1.8.0_191/bin/jstack 1647 |grep ${flag}6e7 -A 30

### 将整个流程写成脚本，查找tomcat占用CPU高的线程日志
pid=$(ps -ef|grep tomcat|grep -v grep|awk ‘{print $2}‘|head -1)
flag="0x"
jstack="/opt/jdk1.8.0_191/bin/jstack"
for tpid in `ps -mp ${pid} -o THREAD,tid,time | sort -rn |head -6|awk ‘$8 ~ /[0-9]+/ {print $8}‘`
do
    tpid_16hex=$(printf "%x
" ${tpid})
    echo "------------------------------------- tpid:[ ${tpid} ] -----------------------------------------------------"
    sudo -u root ${jstack} ${pid} |grep ${flag}${tpid_16hex} -A 40
done