zoukankan      html  css  js  c++  java
  • 系统维护常用脚本

    在linux系统维护过程中,经常需要解决各种各样的需求,最简单的方式还是用linux系统本身的shell,最简单有效

    这个网站很好推荐给大家点这里

    1.释放内存:

    cat monitor_mem.sh
    #!/bin/bash
    
    used=`free -m | awk 'NR==2' | awk '{print $3}'`
    free=`free -m | awk 'NR==2' | awk '{print $4}'`
    
    echo " date:`date +%Y%m%d%H%M` ===========================" > /var/log/mem.log
    date >> /var/log/mem.log
    echo "Memory usage | [Use:${used}MB][Free:${free}MB]" >> /var/log/mem.log
    
    if [ $free -le 4000 ] ; then
    
            sync && echo 1 > /proc/sys/vm/drop_caches
            sync && echo 2 > /proc/sys/vm/drop_caches
            sync && echo 3 > /proc/sys/vm/drop_caches
            echo "OK" >> /var/log/mem.log
            mail -s "`hostname` mem monitor info" 15001027302@139.com < /var/log/mem.log
    else
            echo "Not required" >> /var/log/mem.log
    fi
    exit
    

    2,列数据转为行

    cat test.txt
    
    192.168.5.44
    192.168.5.45
    192.168.5.46
    192.168.5.47
    192.168.5.51
    192.168.5.52
    192.168.5.54
    192.168.5.55
    
    
    sed ':a;$!N;s/
    /,/;ta' test.txt 
    192.168.5.44,192.168.5.45,192.168.5.46,192.168.5.47,192.168.5.51,192.168.5.52,192.168.5.54,192.168.5.55
    

    3,获取进程运行的时间

    cat ./get_process_time.sh
    #!/bin/bash
    function show_elapsed_time()
    {
        user_hz=$(getconf CLK_TCK) #mostly it's 100 on x86/x86_64
        pid=$1
        jiffies=$(cat /proc/$pid/stat | cut -d" " -f22)
        sys_uptime=$(cat /proc/uptime | cut -d" " -f1)
        last_time=$(( ${sys_uptime%.*} - $jiffies/$user_hz ))
        echo "the process $pid lasts for $last_time seconds."
    }
    
    if [ $# -ge 1 ];then
        for pid in $@
        do
            show_elapsed_time $pid
        done
    fi
    
    while read pid
    do
        show_elapsed_time $pid
    done
    
    执行示例:
    
    ./get_process_time.sh 4260
    

    4,获取进程运行的时间并杀死过期进程,以免占用内存及swap空间

    cat ./get_process_time.sh
    #!/bin/bash
    
    #set -x
    function show_elapsed_time()
    {
        user_hz=$(getconf CLK_TCK) #mostly it's 100 on x86/x86_64
        pid=$1
        oneday=86400
        jiffies=$(cat /proc/$pid/stat | cut -d" " -f22)
        sys_uptime=$(cat /proc/uptime | cut -d" " -f1)
        last_time=$(( ${sys_uptime%.*} - $jiffies/$user_hz ))
        if [ $last_time -gt $oneday ];then
            echo "the process $pid lasts for $last_time seconds."
        kill -9 $pid
        else
        echo "no exits gt $oneday process"
        fi
    }
    
    if [ $# -ge 1 ];then
        for pid in $@
        do
            show_elapsed_time $pid
        done
    fi
    
    执行示例:
    ./get_process_time.sh `ps aux | grep java| grep -v grep |awk '{print $2}'|sed ':a;$!N;s/
    / /;ta'`
    
  • 相关阅读:
    sql: table,view,function, procedure created MS_Description in sql server
    sql: sq_helptext
    sql:Oracle11g 表,视图,存储过程结构查询
    sql:MySQL 6.7 表,视图,存储过程结构查询
    csharp: MongoDB
    10个出色的NoSQL数据库
    算法习题---3.01猜数字游戏提示(UVa340)
    03--STL算法(常用算法)
    STL函数适配器
    02--STL算法(函数对象和谓词)
  • 原文地址:https://www.cnblogs.com/shantu/p/4598893.html
Copyright © 2011-2022 走看看