SDN_POX_负载均衡 – 技术分享

诀赛：基于SDN的校园网应用服务器负载均衡

shell.sh
定时获取主机的cpu负载情况。
这里应当选取合适的计算公式，当时时间紧迫便只以cpu的负载情况来判断服务器状况。应当将各种因素都考虑进去。

#/bin/bash
num=`cat /proc/cpuinfo |grep "processor"|wc -l`
IP=`ifconfig|awk 'NR==2{split($2,a,":");print a[2]}'` 
co=`uptime|awk -F, '{print ('$num'-$4)*100}'`
temp=`cat /home/try/pox/data/Weight.db|grep -c $IP `
if [ $temp -eq 0 ]
then
  echo $IP:$co >> /home/try/pox/data/Weight.db
fi
while true
do 
  co=`uptime|awk -F, '{print ('$num'-$4)*100}'`
  sed -i "s/^.*$IP.*$/$IP:$co/" /home/try/pox/data/Weight.db
  sleep 10 
done

#/bin/bash

num=`cat /proc/cpuinfo |grep "processor"|wc -l`

IP=`ifconfig|awk 'NR==2{split($2,a,":");print a[2]}'`

co=`uptime|awk -F, '{print ('$num'-$4)*100}'`

temp=`cat /home/try/pox/data/Weight.db|grep -c $IP `

if [ $temp -eq 0 ]

then

echo $IP:$co >> /home/try/pox/data/Weight.db

while true

co=`uptime|awk -F, '{print ('$num'-$4)*100}'`

sed -i "s/^.*$IP.*$/$IP:$co/" /home/try/pox/data/Weight.db

sleep 10

done

topo-3sw-6host.py
拓扑文件代码:定义了三台交换机、6台服务器

#!/usr/bin/python

"""
Script created by VND - Visual Network Description (SDN version)
"""
from mininet.net import Mininet
from mininet.node import Controller, RemoteController, OVSKernelSwitch, UserSwitch
from mininet.cli import CLI
from mininet.log import setLogLevel
from mininet.link import Link, TCLink

def topology():
    "Create a network."
    net = Mininet( controller=RemoteController, link=TCLink, switch=OVSKernelSwitch )

    print "------Creating nodes------"
    h1 = net.addHost( 'h1', mac='00:00:00:00:00:01', ip='10.0.0.1/8' )
    h2 = net.addHost( 'h2', mac='00:00:00:00:00:02', ip='10.0.0.2/8' )
    h3 = net.addHost( 'h3', mac='00:00:00:00:00:03', ip='10.0.0.3/8' )
    h4 = net.addHost( 'h4', mac='00:00:00:00:00:04', ip='10.0.0.4/8' )
    h5 = net.addHost( 'h5', mac='00:00:00:00:00:05', ip='10.0.0.5/8' )
    h6 = net.addHost( 'h6', mac='00:00:00:00:00:06', ip='10.0.0.6/8' )
    c1 = net.addController( 'c1', controller=RemoteController, ip='127.0.0.1', port=6633 )
    c2 = net.addController( 'c2', controller=RemoteController, ip='127.0.0.1', port=6644 )
    s1 = net.addSwitch( 's1', listenPort=6634, mac='00:00:00:00:00:08' )
    s2 = net.addSwitch( 's2', listenPort=6635, mac='00:00:00:00:00:09' )
    s3 = net.addSwitch( 's3', listenPort=6636, mac='00:00:00:00:00:10' )

    print "------Creating links------"
    net.addLink(h6, s1, 0, 1)
    net.addLink(h5, s3, 0, 3)
    net.addLink(h4, s3, 0, 2)
    net.addLink(h3, s2, 0, 4)
    net.addLink(h2, s2, 0, 3)
    net.addLink(h1, s2, 0, 2)
    net.addLink(s1, s2, 2, 1)
    net.addLink(s3, s1, 1, 3)
    print "*** Starting network"
    net.start()
    s1.start( [c1] )
    s2.start( [c2] )
    s3.start( [c2] )
    c1.start()
    c2.start()

    print "*** Running CLI"
    CLI( net )

    print "*** Stopping network"
    net.stop()

if __name__ == '__main__':
    setLogLevel( 'info' )
    topology()

#!/usr/bin/python

"""

Script created by VND - Visual Network Description (SDN version)

"""

from mininet.net import Mininet

from mininet.node import Controller, RemoteController, OVSKernelSwitch, UserSwitch

from mininet.cli import CLI

from mininet.log import setLogLevel

from mininet.link import Link, TCLink

def topology():

"Create a network."

net = Mininet( controller=RemoteController, link=TCLink, switch=OVSKernelSwitch )

print "------Creating nodes------"

h1 = net.addHost( 'h1', mac='00:00:00:00:00:01', ip='10.0.0.1/8' )

h2 = net.addHost( 'h2', mac='00:00:00:00:00:02', ip='10.0.0.2/8' )

h3 = net.addHost( 'h3', mac='00:00:00:00:00:03', ip='10.0.0.3/8' )

h4 = net.addHost( 'h4', mac='00:00:00:00:00:04', ip='10.0.0.4/8' )

h5 = net.addHost( 'h5', mac='00:00:00:00:00:05', ip='10.0.0.5/8' )

h6 = net.addHost( 'h6', mac='00:00:00:00:00:06', ip='10.0.0.6/8' )

c1 = net.addController( 'c1', controller=RemoteController, ip='127.0.0.1', port=6633 )

c2 = net.addController( 'c2', controller=RemoteController, ip='127.0.0.1', port=6644 )

s1 = net.addSwitch( 's1', listenPort=6634, mac='00:00:00:00:00:08' )

s2 = net.addSwitch( 's2', listenPort=6635, mac='00:00:00:00:00:09' )

s3 = net.addSwitch( 's3', listenPort=6636, mac='00:00:00:00:00:10' )

print "------Creating links------"

net.addLink(h6, s1, 0, 1)

net.addLink(h5, s3, 0, 3)

net.addLink(h4, s3, 0, 2)

net.addLink(h3, s2, 0, 4)

net.addLink(h2, s2, 0, 3)

net.addLink(h1, s2, 0, 2)

net.addLink(s1, s2, 2, 1)

net.addLink(s3, s1, 1, 3)

print "*** Starting network"

net.start()

s1.start( [c1] )

s2.start( [c2] )

s3.start( [c2] )

c1.start()

c2.start()

print "*** Running CLI"

CLI( net )

print "*** Stopping network"

net.stop()

if __name__ == '__main__':

setLogLevel( 'info' )

topology()

webservice.py
这里因为涉及的数据较少，只是进行简单的文件读写，建议应该用数据库，且NoSql首选。
定义REST API接口共前端可视化调用

#---------------------get weight----------------------------
  def _exec_get_Weight(self):
    ser=open('/home/try/pox/data/Weight.db')
    t=ser.read()
    return {'result':t}
#-----------------------end----------------------------------
#---------------------get Account----------------------------
  def _exec_get_Account(self):
    ser=open('/home/try/pox/data/Account.db')
    t=ser.read()
    return {'result':t}
#------------------------end---------------------------------
#---------------------get Priority----------------------------
  def _exec_get_Priority(self):
    ser=open('/home/try/pox/data/Priority.db')
    t=ser.read()
    return {'result':t}
#------------------------end---------------------------------

#---------------------get weight----------------------------

def _exec_get_Weight(self):

ser=open('/home/try/pox/data/Weight.db')

t=ser.read()

return {'result':t}

#-----------------------end----------------------------------

#---------------------get Account----------------------------

def _exec_get_Account(self):

ser=open('/home/try/pox/data/Account.db')

t=ser.read()

return {'result':t}

#------------------------end---------------------------------

#---------------------get Priority----------------------------

def _exec_get_Priority(self):

ser=open('/home/try/pox/data/Priority.db')

t=ser.read()

return {'result':t}

#------------------------end---------------------------------

ip_loadbalancer.py
负载均衡代码，选用的算法为最小连接算法。这里是贴了关于负载均衡算法和主备用服务器切换的代码，关于服务器优先级的定义及部分预处理这里就不贴了。

  def _pick_server (self, key, inport):
    global cw
    global n
    global m
    global b
    temp4=[]
    temp5=[]
    temp6=[]
    temp7=[]
    temp8=[]
    temp9=[]
    temp10=[]
    temp11=[]
    temp12=[]
    global serIP 
    global serCPU
    global Weight
    global Weight_main
    global Weight_bak
    global using_servers
    global live_main_servers
    #global Weight
    #global Account

#------------------------------save Account > Account.db--------------------------------
    out=open('data/Account.db','w')
    for k in Account:
      out.write(str(k))
      out.write(":")
      out.write(str(Account[k])+'\n')
    out.close()
#-------------------------------end--------------------------------------------------
#------------------------------get cpu usage < Weight--------------------------------
    ser=open('data/Weight.db')
    t=ser.read()
    t=t.replace(":","\n")
    li=t.split("\n")
    for k in range(0,len(li)-1,2):
      k=li[k:k+2]
      serIP.append(k[0])
      serCPU.append(int(k[1]))
    serIP=[IPAddr(x) for x in serIP]
    Weight=dict(zip(serIP,serCPU))
    for k in Weight:
      if Weight[k]Weight_main Weight_bak-------------
    c=Priority.values()
    c.sort()
    bak_pri=c[0]
    Weight_main=Weight.copy()
    for k in Priority: 
      if Priority[k]==bak_pri:
        Weight_main.pop(k)
        temp8.append(k)
        temp9.append(Weight[k])
    Weight_bak=dict(zip(temp8,temp9))
#--------------------------------------end-------------------------------------------
#---------------------------------set using servers---------------------------------
    for k in self.live_servers:
      if Weight[k]>60:
        temp4.append(k)
        temp5.append(Weight[k]) 
        using_servers=dict(zip(temp4,temp5))
    if len(using_servers)>(len(Weight_bak)+1):
      for k in Priority: 
        if Priority[k]==bak_pri:
          if k in using_servers:
            using_servers.pop(k)
    a=using_servers.keys()
#--------------------------------------end--------------------------------------------
#-------------------------get using servers'account-----------------------------------
    for k in using_servers:
        temp10.append(k)
        temp11.append(Account[k]) # C(Si)       
        temp12.append(Weight[k])  # W(Si)
    using_Account=dict(zip(temp10,temp11))
    print temp11
    print temp12
#--------------------------------------end--------------------------------------------
    print "**************************Account  list*******************************"
    for k in Account:
      print k,":",Account[k]
    print "***************************************************************************"
    print "**************************using srvers list*******************************"
    for k in using_servers:
	  print k,":",using_servers[k]
    print "***************************************************************************"
   
    print "**************************live srvers list*******************************"
    for k in self.live_servers:
	  print k,":",self.live_servers[k]
    print "***************************************************************************"

    print "**************************main  srvers list********************************"
    for k in Weight_main:
	  print k,":",Weight_main[k]
    print "***************************************************************************"

    print "**************************bak  srvers list********************************"
    for k in Weight_bak:
	  print k,":",Weight_bak[k]
    print "***************************************************************************"
#-----------------------------------------get W(Si)-------------------------------

#--------------------------------WLC code-----------------------------------------
    while (1):
      print temp11
      print temp12
      
      for m in range(len(temp11)):
        if(temp12[m]>0):
          i=m+1
          for i in range(m,len(temp11)):
            if temp11[m]*temp12[i]>temp11[i]*temp12[m]:
              m=i
          b=a[m]
          Account[b]+=1
          print "--------------------Account---------------------"
          for k in Account:   
            print k,":",Account[k]
          return b
      return NULL
#---------------------------------end-------------------------------------------

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def _pick_server (self, key, inport):

global cw

global n

global m

global b

temp4=[]

temp5=[]

temp6=[]

temp7=[]

temp8=[]

temp9=[]

temp10=[]

temp11=[]

temp12=[]

global serIP

global serCPU

global Weight

global Weight_main

global Weight_bak

global using_servers

global live_main_servers

#global Weight

#global Account

#------------------------------save Account > Account.db--------------------------------

out=open('data/Account.db','w')

for k in Account:

out.write(str(k))

out.write(":")

out.write(str(Account[k])+'\n')

out.close()

#-------------------------------end--------------------------------------------------

#------------------------------get cpu usage < Weight--------------------------------

ser=open('data/Weight.db')

t=ser.read()

t=t.replace(":","\n")

li=t.split("\n")

for k in range(0,len(li)-1,2):

k=li[k:k+2]

serIP.append(k[0])

serCPU.append(int(k[1]))

serIP=[IPAddr(x) for x in serIP]

Weight=dict(zip(serIP,serCPU))

for k in Weight:

if Weight[k]Weight_main Weight_bak-------------

c=Priority.values()

c.sort()

bak_pri=c[0]

Weight_main=Weight.copy()

for k in Priority:

if Priority[k]==bak_pri:

Weight_main.pop(k)

temp8.append(k)

temp9.append(Weight[k])

Weight_bak=dict(zip(temp8,temp9))

#--------------------------------------end-------------------------------------------

#---------------------------------set using servers---------------------------------

for k in self.live_servers:

if Weight[k]>60:

temp4.append(k)

temp5.append(Weight[k])

using_servers=dict(zip(temp4,temp5))

if len(using_servers)>(len(Weight_bak)+1):

for k in Priority:

if Priority[k]==bak_pri:

if k in using_servers:

using_servers.pop(k)

a=using_servers.keys()

#--------------------------------------end--------------------------------------------

#-------------------------get using servers'account-----------------------------------

for k in using_servers:

temp10.append(k)

temp11.append(Account[k]) # C(Si)

temp12.append(Weight[k]) # W(Si)

using_Account=dict(zip(temp10,temp11))

print temp11

print temp12

#--------------------------------------end--------------------------------------------

print "**************************Account list*******************************"

for k in Account:

print k,":",Account[k]