【Python】一次性查看所有集群节点信息：节点内核数、物理内存使用率、CPU使用率、负载。

1. 源码文件

为了方便自己的使用，我完成了该代码，由两部分构成:

源码文件：CPU_usage.py

执行文件：CPU_usage.sh

（1）CPU_usage.py代码

# -*- coding:utf-8 -*-
from multiprocessing import cpu_count
#!/usr/bin/env python


import os, time

last_worktime=0
last_idletime=0

def get_cpu():
        global last_worktime, last_idletime
        f=open("/proc/stat","r")
        line=""
        while not "cpu " in line: line=f.readline()
        f.close()
        spl=line.split(" ")
        worktime=int(spl[2])+int(spl[3])+int(spl[4])
        idletime=int(spl[5])
        dworktime=(worktime-last_worktime)
        didletime=(idletime-last_idletime)
        rate=float(dworktime)/(didletime+dworktime)
        last_worktime=worktime
        last_idletime=idletime
        if(last_worktime==0): return 0
        return rate

def get_mem_usage_percent():
    try:
        f = open('/proc/meminfo', 'r')
        for line in f:
            if line.startswith('MemTotal:'):
                mem_total = int(line.split()[1])
            elif line.startswith('MemFree:'):
                mem_free = int(line.split()[1])
            elif line.startswith('Buffers:'):
                mem_buffer = int(line.split()[1])
            elif line.startswith('Cached:'):
                mem_cache = int(line.split()[1])
            elif line.startswith('SwapTotal:'):
                vmem_total = int(line.split()[1])
            elif line.startswith('SwapFree:'):
                vmem_free = int(line.split()[1])
            else:
                continue
        f.close()
    except:
        return None
    physical_percent = usage_percent(mem_total - (mem_free + mem_buffer + mem_cache), mem_total)
    virtual_percent = 0
    if vmem_total > 0:
        virtual_percent = usage_percent((vmem_total - vmem_free), vmem_total)
    return physical_percent, virtual_percent

def usage_percent(use, total):
    try:
        ret = (float(use) / total) * 100
    except ZeroDivisionError:
        raise Exception("ERROR - zero division error")
    return ret


if __name__ == "__main__":
    cpucount = "内核数： %s" % cpu_count() + "  "
    # statvfs = os.statvfs('/')
    # total_disk_space = statvfs.f_frsize * statvfs.f_blocks
    # free_disk_space = statvfs.f_frsize * statvfs.f_bfree
    # disk_usage = (total_disk_space - free_disk_space) * 100.0 / total_disk_space
    # disk_usage = int(disk_usage)
    # disk_tip = "硬盘空间使用率：" + str(disk_usage) + "%  "

    mem_usage = get_mem_usage_percent()
    mem_usage = int(mem_usage[0])
    mem_tip = "物理内存使用率：" + str(mem_usage) + "%  "

    cpu_usage = int(get_cpu() * 100)
    cpu_tip = "CPU使用率：" + str(cpu_usage) + "%  "

    load_average = os.getloadavg()
    load_tip = "系统负载" + str(load_average)

    print(cpucount + mem_tip + cpu_tip + load_tip)

说明：参考了网上资源（资源链接）

（2）CPU_usage.sh代码：

for k in $(seq 2 96)
do
	ssh cluster@AiLab${k} "hostname && cd ~ $$ sh CPU_usage.sh"
done

说明：我的集群节点是2到92，把编号改为你自己的集群节点编号。

2. 使用命令

最开始我是用原始的“sh CPU_usage.sh”来执行命令，实在是不方便。

于是研究了一下怎么把命令改为自定义命令。

后来找到~/.bashrc，在里面添加了alias命令自定义名字，偶然看到网上另一个教程（资源链接），改变了注意。

资源里说：

“bashrc 中有一句话
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
就是说可以另外新建一个文件用于专门存放自己的alias信息”

于是，可以这样来做：

$ cd ~
$ vi .bash_aliases

在文件中输入自己想设置的命令：

alias usageinfo='cd ~ && sh CPU_info.sh'  

然后:wq保存退出，用下面命令激活：

$ source .bashrc

接下来，在任何目录下输入”usageinfo“，都可以方便地查看集群节点信息了。

by CS青雀

2018年7月26日