下文给大家带来基于直接路由模式（DR）的负载均衡群集的概述及其构建，希望能够给大家在实际运用中带来一定的帮助，负载均衡涉及的东西比较多，理论也不多，网上有很多书籍，今天我们就用在行业内累计的经验来做一个解答。

一、开始配置DR模式LVS

准备工作：
Centos 7操作系统四台；
Centos01模拟Web1云服务器：IP地址/192.168.100.10
Centos02模拟Web2服务器：IP地址/192.168.100.20
Centos03模拟NFS服务器：  IP地址/192.168.100.30
Centos05模拟LVS服务器：  IP地址/192.168.100.50
Windows 客户端一台；

1、配置负载调度器

1）配置虚拟IP地址（VIP）

[root@centos05 ~]# cp /etc/sysconfig/network-scripts/ifcfg-ens32 
/etc/sysconfig/network-scripts/ifcfg-ens32:0   
[root@centos05 ~]# vim /etc/sysconfig/network-scripts/ifcfg-ens32:0   
                                    
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
NAME=ens32:0   
DEVICE=ens32:0   
ONBOOT=yes
IPADDR=192.168.100.253    
NATEMASK=255.255.255.0
[root@centos05 ~]# systemctl restart network   
[root@centos05 ~]# ifconfig      
ens32: flags=4163  mtu 1500
        inet 192.168.100.50  netmask 255.255.255.0  broadcast 192.168.100.255
        inet6 fe80::20c:29ff:fe16:c54b  prefixlen 64  scopeid 0x20
        ether 00:0c:29:16:c5:4b  txqueuelen 1000  (Ethernet)
        RX packets 2795  bytes 1095013 (1.0 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1371  bytes 182001 (177.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens32:0: flags=4163  mtu 1500
        inet 192.168.100.253  netmask 255.255.255.0  broadcast 192.168.100.255
        ether 00:0c:29:16:c5:4b  txqueuelen 1000  (Ethernet)

2）调整/proc相应参数

[root@centos05 ~]# vim /etc/sysctl.conf    
                  
net.ipv4.ip_forward = 1
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.conf.ens32.send_redirects = 0

[root@centos05 ~]# sysctl -p   

3）配置负载分配策略

[root@centos05 ~]# modprobe ip_vs        
[root@centos05 ~]# yum -y install ipvsadm   
[root@centos05 ~]# ipvsadm -C       
[root@centos05 ~]# ipvsadm -A -t 192.168.100.253:80 -s rr    
[root@centos05 ~]# ipvsadm -a -t 192.168.100.253:80 -r 192.168.100.10:80 -g -w 1   
                                                   
[root@centos05 ~]# ipvsadm -a -t 192.168.100.253:80 -r 192.168.100.20:80 -g -w 1  
                                                      
[root@centos05 ~]# ipvsadm-save > /etc/sysconfig/ipvsadm        
[root@centos04 ~]# ipvsadm -ln     
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.100.253:80 rr
  -> 192.168.100.10:80            Route   1      0          0         
  -> 192.168.100.20:80            Route   1      0          0         

2、配置web节点1服务器

[root@centos01 ~]# yum -y install httpd            
[root@centos01 ~]# echo "www.benet.com" > /var/www/html/index.html          
             
[root@centos01 ~]# systemctl start httpd               
[root@centos01 ~]# systemctl enable httpd           
[root@centos01 ~]# cp /etc/sysconfig/network-scripts/ifcfg-lo 
/etc/sysconfig/network-scripts/ifcfg-lo:0     
[root@centos01 ~]# vim /etc/sysconfig/network-scripts/ifcfg-lo:0  
                                      
DEVICE=lo:0
IPADDR=192.168.100.253
NETMASK=255.255.255.255
ONBOOT=yes
[root@centos01 ~]# systemctl restart network  
[root@centos01 ~]# ifconfig    
lo:0: flags=73  mtu 65536
        inet 192.168.100.253  netmask 255.255.255.255
        loop  txqueuelen 1  (Local Loopback)
[root@centos01 ~]# vim /etc/sysctl.conf    
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.default.arp_ignore = 1
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
[root@centos01 ~]# sysctl -p     

3、配置web节点2服务器

[root@centos02 ~]# yum -y install httpd            
[root@centos02 ~]# echo "www.accp.com" > /var/www/html/index.html          
             
[root@centos02 ~]# systemctl start httpd               
[root@centos02 ~]# systemctl enable httpd           
[root@centos01 ~]# scp /etc/sysctl.conf root@192.168.100.20:/etc/  
 
The authenticity of host '192.168.100.30 (192.168.100.20)' can't be established.
ECDSA key fingerprint is SHA256:PUueT9fU9QbsyNB5NC5hbSXzaWxxQavBxXmfoknXl4I.
ECDSA key fingerprint is MD5:6d:f7:95:0e:51:1a:d8:9e:7b:b6:3f:58:51:51:4b:3b.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.100.20' (ECDSA) to the list of known hosts.
root@192.168.100.20's password: 
sysctl.conf   
[root@centos01 ~]# scp /etc/sysconfig/network-scripts/ifcfg-lo:0  
                            root@192.168.100.20:/etc/sysconfig/network-scripts/
root@192.168.100.20's password: 
ifcfg-lo:0                                                          100%   70   177.3KB/s   00:00
[root@centos02 ~]# sysctl -p   
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.default.arp_ignore = 1
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
[root@centos02 ~]# systemctl restart network  

4、客户端访问

客户端配置和服务器同网段IP地址，浏览器访问http://192.168.100.253

关闭浏览器删除缓存，重新访问就会得到一个新的页面，实现了负载均衡

二、安装NFS共享存储

1、配置NFS

[root@centos03 ~]# yum -y install rpcbind nfs-utils   
[root@centos03 ~]# mkdir /web   
[root@centos03 ~]# echo "www.nfs.com" > /web/index.html  
[root@centos03 ~]# vim /etc/exports      
/web    192.168.100.10(ro) 192.168.100.20(rw)
[root@centos03 ~]# systemctl start rpcbind  
[root@centos03 ~]# systemctl start nfs   
[root@centos03 ~]# systemctl enable rpcbind  
[root@centos03 ~]# systemctl enable nfs   
[root@centos03 ~]# showmount -e 192.168.100.30   
Export list for 192.168.100.30:
/web 192.168.100.20,192.168.100.10

2、Web节点1服务器挂载共享目录

[root@centos01 ~]# mount 192.168.100.30:/web /var/www/html/
                             
[root@centos01 ~]# cat /var/www/html/index.html  
www.nfs.com
[root@centos01 ~]# systemctl restart httpd 

3、Web节点2服务器挂载共享目录

[root@centos02 ~]# mount 192.168.100.30:/web /var/www/html/ 
                                            
[root@centos02 ~]# cat /var/www/html/index.html  
www.nfs.com
[root@centos02 ~]# systemctl restart httpd 

4、客户端访问

使用tail -f /var/log/httpd/access.log查看访问成功日志，一定要想监听再去访问才可以看到效果

5、配置自动挂载NFS

1）web节点1服务器

[root@centos01 ~]# vim /etc/fstab
192.168.100.30:/web /var/www/html/                                nsf     defaults        0 0

2）web节点2服务器

[root@centos02 ~]# vim /etc/fstab
192.168.100.30:/web /var/www/html/                                nsf     defaults        0 0

看了以上关于基于直接路由模式（DR）的负载均衡群集的概述及其构建，如果大家还有什么地方需要了解的可以在行业资讯里查找自己感兴趣的或者找我们的专业技术工程师解答的，技术工程师在行业内拥有十几年的经验了。