LVS基于NAT模式搭建负载均衡群集

2021-09-21 22:06:18

LVS的基本架构图

负载均衡群集中，包括三个层次的组件：

1、第一层，负载调度器（BL）

前段至少有一个负载调度器（Load Balancer 或称为Director）负责响应并分发来自客户端的访问请求。

这是访问整个集群系统的唯一入口，对外使用所有服务器共有的VIP（Virtual IP，虚拟IP）地址，也称为群集IP地址，通常会配置主、备两台调度器实现热备份，当主机调度器失效以后平滑替换至备用调度器，确保高可用性。

2、第二层，服务器池(Real Server)

后端由大量真实服务器（Real Server）构成服务器池（Server Pool），提供实际的应用服务，整个群集的伸缩性通过增加、删除服务器节点来完成，而这些过程对客户机是透明的。

群集所提供的应用服务（如HTTP、FTP）由服务器池承担，其中的每个节点具有独立的RIP（Real IP，真实IP）地址，只处理调度器分发过来的客户机请求。当某个节点暂时失效时，负载调度器的容错机制会将其隔离，等待错误排除以后再重新纳入服务器池。

3、第三层，共享储存（NFS）

为了保持服务的一致性，所有节点使用共享储存设备。

为了服务器池中的所有节点提供稳定、一致的文件存取服务，确保整个集群的统一性。在Linux/UNIX环境中，共享储存可以使用NAS设备，或者提供NFS（Network File System，网络文件系统）共享服务的专用服务器。

实验环境：

LVS调度器（BL）作为Web1、Web2两台Web服务器池的网关

BL两块网卡，分别连接内外网（本次实验是单节点调度的，若要高可用请添加多台备用调度器+keepalive实现，本次实验只是做负载均衡）

BL主机（负载调度器）：

外网地址：192.168.10.20/24，同时也作为整个群集的VIP

内网地址：192.168.1.11/24

Web1主机：192.168.1.22/24

Web2主机：192.168.1.33/24

NFS主机：192.168.1.44/24

使用轮询（rr）调度算法

主机名称	内网IP地址	外网IP地址	部署软件
LVS-master（BL主机）	192.168.1.11	192.168.10.20	ipvsadm
NFS	192.168.1.22	无	nfs、rpcbind
WEB1	192.168.1.33	无	httpd、nfs-utils
WEB2	192.168.1.44	无	httpd、nfs-utils

LVS的NAT负载均衡模式原理：

1、PC机直接访问BL服务器的VIP：192.168.10.20

2、BL服务器接收到请求后，通过自身调度算法选择一台下面的WEB服务器，并将目标地址为某一WEB服务器的IP，源地址不变。

3、WEB服务器接受到请求后，将数据包解封并返回数据给BL，返回的数据包中，源IP为WEB自身IP，目标IP为PC机IP。

4、BL服务器接收到WEB响应的数据包后，将数据包的源IP改为自身IP，目标IP不变，发给PC机

整个过程PC机并不知道WEB服务器的存在。

开始搭建

1、配置NAS（nfs）共享储存服务器

 [root@nfs ~]# yum -y install nfs-utils rpcbind    #下载NFS rpcbind

 [root@nfs ~]# mkdir /opt/www

 [root@nfs ~]# vim /etc/exports                    #设置共享目录，将/opt/www作为共享目录，要求192.168.2.0/24网段只读权限访问网页数据（若增加读写速度和安全性，可结合raid5+LVM）

 /opt/www        192.168.1.0/(ro,sync,no_root_squash)

 [root@nfs ~]# /etc/init.d/rpcbind start

 正在启动 rpcbind：                                         [确定]

 [root@nfs ~]# /etc/init.d/nfs start

 启动 NFS 服务：                                            [确定]

 启动 NFS mountd：                                          [确定]

 启动 NFS 守护进程：                                        [确定]

 正在启动 RPC idmapd：                                      [确定]

 [root@nfs ~]# showmount -e 192.168.1.22            #查看nfs挂载情况

 Export list for 192.168.1.22:

 /opt/www 192.168.1.0/

 [root@nfs ~]# chkconfig rpcbind on   #设置开机启动

 [root@nfs ~]# chkconfig nfs on       #设置开机启动

 [root@nfs ~]# echo "<h1>it works</h1>">/opt/www/index.html   #编辑共享文件内容

2、配置WEB1、WEB2（操作相同）

 [root@WEB1 ~]#yum -y install httpd nfs-utils                   #下载Apache、nfs服务

 [root@WEB1 ~]#sed -i '/#S/ s/#//' /etc/httpd/conf/httpd.conf   #启用apache的域名服务

 [root@WEB1 ~]#sed -n '/com:80/p' /etc/httpd/conf/httpd.conf

 ServerName www.example.com:

 [root@WEB1 ~]# /etc/init.d/httpd start

 正在启动 httpd：                                           [确定]

 [root@WEB1 ~]# vim /etc/fstab           #编辑fstab文件，写入nfs服务器的挂载目录，使其永久生效。

 ……

 192.168.1.22:/opt/www/   /var/www/html/          nfs     defaults,_netdev

 #挂载点IP：挂载点目录       #挂载到的目录            

 [root@WEB1 ~]# mount -a    #挂载所以可挂载点

 [root@WEB1 ~]# df -hT      #查看挂载情况

 Filesystem                 Type   Size  Used Avail Use% Mounted on

 /dev/mapper/vg_www-lv_root ext4    37G  .3G   34G   % /

 /dev/sda1                  ext4   485M   33M  427M   % /boot

 tmpfs                      tmpfs  242M       242M   % /dev/shm

 192.168.1.22:/opt/www/      nfs     37G  1.3G   34G   4% /var/www/html

3、PC机访问WEB服务器测试

aaarticlea/png;base64,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" alt="" />

4、配置LVS服务器（BL）

 （）加载ip_vs模块，安装ipvsadm工具

 [root@bl ~]# modprobe ip_vs

 [root@bl ~]# cat /proc/net/ip_vs

 IP Virtual Server version 1.2. (size=)

 Prot LocalAddress:Port Scheduler Flags

   -> RemoteAddress:Port Forward Weight ActiveConn InActConn

 [root@bl ~]# yum -y install ipvsadm

 （）配置负载调度器SNAT转发规则

 [root@bl ~]# /etc/init.d/ipvsadm stop

 ipvsadm: Clearing the current IPVS table:                  [确定]

 ipvsadm: Unloading modules:                                [确定]

 [root@bl ~]# ipvsadm -A -t 192.168.10.20: -s rr

 [root@bl ~]# ipvsadm -a -t 192.168.10.20: -r 192.168.1.33: -m -w

 [root@bl ~]# ipvsadm -a -t 192.168.10.20: -r 192.168.1.44: -m -w

 [root@bl ~]# ipvsadm -L -n

 IP Virtual Server version 1.2. (size=)

 Prot LocalAddress:Port Scheduler Flags

   -> RemoteAddress:Port           Forward Weight ActiveConn InActConn

 TCP  192.168.10.20: rr

   -> 192.168.1.33:               Masq

   -> 192.168.1.44:               Masq

 [root@bl ~]#ipvsadm -S >> /etc/sysconfig/ipvsadm

 ipvsadm: Saving IPVS table to /etc/sysconfig/ipvsadm:      [确定]

 [root@bl ~]# chkconfig ipvsadm on

 （）开启路由转发功能

 [root@bl ~]#echo "net.ipv4.ip_forward=1

 net.ipv4.conf.all.rp_filter=

 net.ipv4.conf.default.rp_filter= " > /etc/sysctl.conf  

 [root@bl ~]# sysctl -p

 net.ipv4.ip_forward =

 net.ipv4.conf.all.rp_filter =

 net.ipv4.conf.default.rp_filter =

5、PC机访问VIP测试

（若不成功，检查各个服务器的防火墙与selinux机制是否关闭）多刷新几次

多次CTRL+f5刷新后查看

  [root@bl ~]#ipvsadm -L -n -c

  IPVS connection entries

  pro expire state       source               virtual            destination

  TCP :  TIME_WAIT   192.168.10.10: 192.168.10.20:    192.168.1.33:

  TCP :  TIME_WAIT   192.168.10.10: 192.168.10.20:    192.168.1.33:

  TCP :  TIME_WAIT   192.168.10.10: 192.168.10.20:    192.168.1.44:

  TCP :  TIME_WAIT   192.168.10.10: 192.168.10.20:    192.168.1.44:

  TCP :  TIME_WAIT   192.168.10.10: 192.168.10.20:    192.168.1.44:

  TCP :  TIME_WAIT   192.168.10.10: 192.168.10.20:    192.168.1.33:

  TCP :  TIME_WAIT   192.168.10.10: 192.168.10.20:    192.168.1.33:

  TCP :  TIME_WAIT   192.168.10.10: 192.168.10.20:    192.168.1.33:

之所以看到的结果并不是轮询的一次是192.168.1.33下一次是192.168.1.44，是因为负载调度器要判断一次完整TCP连接结束后才会进行轮询，也就是完成完整的三次握手与四次断开，因此若在网页上下载电影时及时刷新了网页，也不会轮询到下一台服务器导致传输中断。

Have fun!!!

码农公寓

相关文章