查找Linux中内存和CPU使用率最高的进程

需求：创建一个定时任务，每30分钟输出该时刻（年月日分秒）系统中内存占用最大的四个进程名及进程占用内存

打印当前系统时间（年月日分秒）

[root@localhost /]# date "+%Y-%m-%d %H:%M:%S"
2017-08-30 09:54:08

打印出系统消耗内存资源最高的四个进程

[root@localhost /]# ps aux | grep -v "USER" | sort -rn -k +4 | head -4 | awk -F ' ' '{print $11,$4}'
/usr/lib/vmware-vgauth/VGAuthService 0.9
/usr/sbin/vmtoolsd 0.7
/usr/lib/vmware-caf/pme/bin/ManagementAgentHost 0.5
sshd: 0.4

脚本如下：

#!/bin/bash

date=`date "+%Y-%m-%d %H:%M:%S"`
#打印消耗资源内存最高的进程名
first=`ps aux | grep -v "grep" | grep -v "USER" | sort -rn -k +4 | head -4 | awk -F ' ' '{print $11}' | sed -n 1p`
Second=`ps aux | grep -v "grep" | grep -v "USER" | sort -rn -k +4 | head -4 | awk -F ' ' '{print $11}' | sed -n 2p`
Third=`ps aux | grep -v "grep" | grep -v "USER" | sort -rn -k +4 | head -4 | awk -F ' ' '{print $11}' | sed -n 3p`
Fourth=`ps aux | grep -v "grep" | grep -v "USER" | sort -rn -k +4 | head -4 | awk -F ' ' '{print $11}' | sed -n 4p`
#打印消耗内存资源最高进程、内存使用率
one=`ps aux | grep -v "grep" | grep -v "USER" | grep "$first" | awk -F ' ' '{print $4}'`
two=`ps aux | grep -v "grep" | grep -v "USER" | grep "$Second" | awk -F ' ' '{print $4}'`
three=`ps aux | grep -v "grep" | grep -v "USER" | grep "$Third" | awk -F ' ' '{print $4}'`
four=`ps aux | grep -v "grep" | grep -v "USER" | grep "$Fourth" | awk -F ' ' '{print $4}'`

#使用echo打印结果
echo "$date $first $one"
echo "$date $Second $two"
echo "$date $Third $three"
echo "$date $Fourth $four"

每30分钟执行一次脚本

[root@localhost /]# crontab -e
crontab: installing new crontab
[root@localhost /]# crontab -l
*/30 * * * * /bin/bash /mem.sh >>/mem.log

执行mem.sh脚本输入结果如下：

[root@localhost /]# ./mem.sh
2017-08-30 10:27:30 /usr/lib/vmware-vgauth/VGAuthService 0.9
2017-08-30 10:27:30 /usr/sbin/vmtoolsd 0.7
2017-08-30 10:27:30 /usr/lib/vmware-caf/pme/bin/ManagementAgentHost 0.5
2017-08-30 10:27:30 sshd: 0.4