SDN大作業 ODL-負載均衡-example-2

代碼位置
Github

實驗概述

使用兩個互為備份的中心交換機
連接兩兩互為備份的共計四個交換機
下接四組各連有兩台主機的交換機
作為數據中心類型網絡拓撲的一個小型實現
上、中、下層均可以擴展來實現對更多網絡主機的支持
實現在網絡中心區域防止單個設備故障所引發的網絡中斷

實驗拓撲

實驗環境部署

建立流程如下
1.開ODL
./karaf
ODL需求組件（沒有請順序安裝）

install odl-restconf
install odl-l2switch-switch-ui
install odl-openflowplugin-all
install odl-mdsal-apidocs
install odl-dlux-core
install odl-dlux-node
install odl-dlux-yangui

2.運行mininet建立拓撲結構
sudo mn --custom datacenter.py --topo mytopo --controller=remote,ip=127.0.0.1,port=6633 --switch ovsk,protocols=OpenFlow13

mininet的拓撲結構的Python代碼如下：

datacenter.py

#!/usr/bin/python
#創建網絡拓撲
"""Custom topology example
Adding the 'topos' dict with a key/value pair to generate our newly defined
topology enables one to pass in '--topo=mytopo' from the command line.
"""
 
from mininet.topo import Topo
from mininet.net import Mininet
from mininet.node import RemoteController,CPULimitedHost
from mininet.link import TCLink
from mininet.util import dumpNodeConnections
 
class MyTopo( Topo ):
    "Simple topology example."
 
    def __init__( self ):
        "Create custom topo."
 
        # Initialize topology
        Topo.__init__( self )
        L1 = 2
        L2 = L1 * 2 
        L3 = L2
        c = []
        a = []
        e = []
          
        # add core ovs  
        for i in range( L1 ):
                sw = self.addSwitch( 'c{}'.format( i + 1 ) )
                c.append( sw )
    
        # add aggregation ovs
        for i in range( L2 ):
                sw = self.addSwitch( 'a{}'.format( L1 + i + 1 ) )
                a.append( sw )
    
        # add edge ovs
        for i in range( L3 ):
                sw = self.addSwitch( 'e{}'.format( L1 + L2 + i + 1 ) )
                e.append( sw )
 
        # add links between core and aggregation ovs
        for i in range( L1 ):
                sw1 = c[i]
                for sw2 in a[i/2::L1/2]:
                # self.addLink(sw2, sw1, bw=10, delay='5ms', loss=10, max_queue_size=1000, use_htb=True)
			            self.addLink( sw2, sw1 )
 
        # add links between aggregation and edge ovs
        for i in range( 0, L2, 2 ):
                for sw1 in a[i:i+2]:
	                for sw2 in e[i:i+2]:
			            self.addLink( sw2, sw1 )
 
        #add hosts and its links with edge ovs
        count = 1
        for sw1 in e:
                for i in range(2):
                	host = self.addHost( 'h{}'.format( count ) )
                	self.addLink( sw1, host )
                	count += 1
topos = { 'mytopo': ( lambda: MyTopo() ) }

3.打開http://127.0.0.1:8181/index.html#/topology來查看拓撲

也可查看節點相關信息

下發初始流表連接鏈路

備注：在此之前已經給本文件夾所有文件賦予權限
在下圖路徑中

sudo chmod -R 777 example-2
1.清空所有流表項
./delflows.sh

delflows.sh

sudo ovs-ofctl -O Openflow13 del-flows c1
sudo ovs-ofctl -O Openflow13 del-flows c2
sudo ovs-ofctl -O Openflow13 del-flows a3
sudo ovs-ofctl -O Openflow13 del-flows a4
sudo ovs-ofctl -O Openflow13 del-flows a5
sudo ovs-ofctl -O Openflow13 del-flows a6
sudo ovs-ofctl -O Openflow13 del-flows e7
sudo ovs-ofctl -O Openflow13 del-flows e8
sudo ovs-ofctl -O Openflow13 del-flows e9
sudo ovs-ofctl -O Openflow13 del-flows e10

2.下發流表（上中下層合在一起下發）
./add.sh

add.sh

#下層
#e7
sudo ovs-ofctl -O OpenFlow13 add-flow e7 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e7 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e7 priority=2,in_port=3,actions=output:1,output:2,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e7 priority=2,in_port=4,actions=output:1,output:2,output:3
#e8
sudo ovs-ofctl -O OpenFlow13 add-flow e8 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e8 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e8 priority=2,in_port=3,actions=output:1,output:2,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e8 priority=2,in_port=4,actions=output:1,output:2,output:3
#e9
sudo ovs-ofctl -O OpenFlow13 add-flow e9 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e9 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e9 priority=2,in_port=3,actions=output:1,output:2,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e9 priority=2,in_port=4,actions=output:1,output:2,output:3
#e10
sudo ovs-ofctl -O OpenFlow13 add-flow e10 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e10 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e10 priority=2,in_port=3,actions=output:1,output:2,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow e10 priority=2,in_port=4,actions=output:1,output:2,output:3

#中層
#a3
sudo ovs-ofctl -O OpenFlow13 add-flow a3 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a3 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a3 priority=2,in_port=3,actions=output:1,output:2,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a3 priority=2,in_port=4,actions=output:1,output:2,output:3
#a4
sudo ovs-ofctl -O OpenFlow13 add-flow a4 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a4 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a4 priority=2,in_port=3,actions=output:1,output:2,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a4 priority=2,in_port=4,actions=output:1,output:2,output:3
#a5
sudo ovs-ofctl -O OpenFlow13 add-flow a5 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a5 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a5 priority=2,in_port=3,actions=output:1,output:2,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a5 priority=2,in_port=4,actions=output:1,output:2,output:3
#a6
sudo ovs-ofctl -O OpenFlow13 add-flow a6 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a6 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a6 priority=2,in_port=3,actions=output:1,output:2,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a6 priority=2,in_port=4,actions=output:1,output:2,output:3

#底層
#c1
sudo ovs-ofctl -O OpenFlow13 add-flow c1 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow c1 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow c1 priority=2,in_port=3,actions=output:1,output:2
sudo ovs-ofctl -O OpenFlow13 add-flow c1 priority=2,in_port=4,actions=output:1,output:2
#c2
sudo ovs-ofctl -O OpenFlow13 add-flow c2 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow c2 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow c2 priority=2,in_port=3,actions=output:1,output:2
sudo ovs-ofctl -O OpenFlow13 add-flow c2 priority=2,in_port=4,actions=output:1,output:2

測試鏈路可用性

1.在mininet中運行pingall命令

說明鏈路已經連接成功
2.測試帶寬
h1-h2

h1-h3

h1-h7

不難得出結論：隨着跨交換機網絡的轉發，性能隨着跨交換機網絡而減弱
為了數據在跨多交換機傳輸時能獲得更高的可用帶寬，我們利用基於時間段給交換機分片（組）的方式來實現負載均衡（提高可用帶寬）

負載均衡實現

通過將某段時間流表設置成c1,a3,a5一組和c2,a4,a6一組來達到交換機的負載均衡，以提高性能。
將分組代碼整合在一起並運行
./auto.py

auto.py

import os
import time
def runteam1():
	os.system("./addt1.sh")
	time.sleep(1)
	os.system("./delt2.sh")
	return 1;
def runteam2():
	os.system("./addt2.sh")
	time.sleep(1)
	os.system("./delt1.sh")
	return 1;
os.system("./delflows.sh")
os.system("./inite.sh")
while(True):
	runteam1()
	runteam2()

其中addt1.sh和delt1.sh如下（addt2.sh和delt2.sh類似）

addt1.sh

#c1
sudo ovs-ofctl -O OpenFlow13 add-flow c1 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow c1 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow c1 priority=2,in_port=3,actions=output:1,output:2
sudo ovs-ofctl -O OpenFlow13 add-flow c1 priority=2,in_port=4,actions=output:1,output:2
#a3
sudo ovs-ofctl -O OpenFlow13 add-flow a3 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a3 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a3 priority=2,in_port=3,actions=output:1,output:2,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a3 priority=2,in_port=4,actions=output:1,output:2,output:3
#a5
sudo ovs-ofctl -O OpenFlow13 add-flow a5 priority=2,in_port=1,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a5 priority=2,in_port=2,actions=output:3,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a5 priority=2,in_port=3,actions=output:1,output:2,output:4
sudo ovs-ofctl -O OpenFlow13 add-flow a5 priority=2,in_port=4,actions=output:1,output:2,output:3

delt1.sh

sudo ovs-ofctl -O Openflow13 del-flows c1
sudo ovs-ofctl -O Openflow13 del-flows a3
sudo ovs-ofctl -O Openflow13 del-flows a5

負載均衡后再次執行鏈路性能測試(測試結果取同一時段的三次均值，因為網絡會有波動）
h1-h2因為沒有鏈路變化所以帶寬基本不變
負載均衡前
負載均衡后
h1-h3帶寬略有增加，但是變化不明顯
負載均衡前
負載均衡后
h1-h7帶寬提升很多，變換明顯
負載均衡前
負載均衡后