高可用载均衡之LVS+Keepalived

高可用负载均衡之LVS+Keepalived

一、LVS+Keepalived介绍：

   LVS是Linux Virtual Server的简称，也就是Linux虚拟服务器,通过LVS提供的负载均衡技术和Linux操作系统实现一个高性能、高可用的服务器群集，它具有良好可靠性、可扩展性和可操作性。从而以低廉的成本实现最优的服务性能。

   Keepalived就是一个类似于3~5层交换机制的软件，具有3~5层交换功能，其主要作用是检测web服务器的健康状态，如果某台web服务器故障，Keepalived将检测到并将其从系统中剔除，当该web服务器工作正常后Keepalived自动将其加入到服务器群中，这些工作全部自动完成，而不需要人工干预，只需要人工修复故障的web服务器即可。

二、搭建LVS（DR模式）+ Keepalived高可用

  1. 服务器IP规划：

   Master DIP(192.168.126.1) VIP(192.168.126.5)

   Backup DIP(192.168.126.2) VIP(192.168.126.5)

   RIP (192.168.126.3) VIP(192.168.126.5)

   RIP (192.168.126.3) VIP(192.168.126.5)

 2.MASTER配置部分：

   编译安装LVS：Make && make install

   报错：make[1]: ***[libipvs.o] Error 1

                     make: ***[libs] Error 2

   解决：yum installlibnl*

   编译安装Keepalived

   ./configure�Cprefix=/usr/local/keepalived

   cp/usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/

   cp/usr/local/etc/sysconfig/keepalived /etc/sysconfig/

   cp/usr/local/keepalived/sbin/keepalived /usr/sbin/

    mkdir /etc/keepalived

    cp /usr/local/keepalived/etc/keepalived/keepalived.conf/etc/keepalived/

 配置在主负载均衡服务器上配置keepalived.conf
   #vi /etc/keepalived/keepalived.conf (master)
   ! Configuration File for keepalived
   global_defs {
   notification_email {
   root@localhost
  }
  notification_email_from keepalived@localhost
      smtp_server 127.0.0.1
      smtp_connect_timeout 30
      router_id LVS_DEVEL
}
   vrrp_instance VI_1 {
       state MASTER
       interface eth0
       virtual_router_id 51
       priority 101
       advert_int 1
       authentication {
           auth_type PASS
           auth_pass 1111
   }
       virtual_ipaddress {
           192.168.126.132/32 dev eth0 label eth0:0
   }
}

   virtual_server 192.168.126.132 80 {

       delay_loop 6    #(每隔6秒查询realserver状态)

       lb_algo rr      #(lvs 算法)

       lb_kind DR      #(Direct Route)

       nat_mask 255.255.255.0 #(同一IP的连接60秒内被分配到同一台realserver)

       protocol TCP    #(用TCP协议检查realserver状态)

   real_server 192.168.126.131 80 {

       weight 1        #(权重)

       HTTP_GET {

       url {

       path /

       status_code 200

   }

       connect_timeout 3

       nb_get_retry 3

       delay_before_retry 3

   }

}

   real_server 192.168.126.149 80 {

       weight 1

       HTTP_GET {

       url {

       path /

       status_code 200

}

       connect_timeout 3

       nb_get_retry 3

       delay_before_retry 3

       }

   }

}

   ipvsadm�CC 清除所有规则

   ipvsadm-A -t 192.168.126.1132:80 -s wlc

   ipvsadm-a -t 192.168.126.132:80 -r 192.168.126.131 -g -w 2

   ipvsadm-a -t 192.168.126.132:80 -r 192.168.126.149 -g -w 1

   ipvsadm-L �Cn 查看规则

   ipvsadm�CS 保存规则

  3.BACKUP配置部分：

   编译安装LVS：Make && make install

   报错：make[1]: ***[libipvs.o] Error 1

                     make: ***[libs] Error 2

   解决：yum installlibnl*

   编译安装Keepalived

   ./configure�Cprefix=/usr/local/keepalived

   cp/usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/

   cp/usr/local/etc/sysconfig/keepalived /etc/sysconfig/

   cp/usr/local/keepalived/sbin/keepalived /usr/sbin/

    mkdir /etc/keepalived

    cp /usr/local/keepalived/etc/keepalived/keepalived.conf/etc/keepalived/

  配置在主负载均衡服务器上配置keepalived.conf
   #vi /etc/keepalived/keepalived.conf (备调度器Backup)
   ! Configuration File for keepalived
   global_defs {
   notification_email {
   root@localhost
      }
  notification_email_from keepalived@localhost
  smtp_server 127.0.0.1
  smtp_connect_timeout 30
  router_id LVS_DEVEL
}
   vrrp_instance VI_1 {
   state BACKUP
   interface eth0
   virtual_router_id 51
   priority 100
   advert_int 1
   authentication {
       auth_type PASS
       auth_pass 1111
   }
   virtual_ipaddress {
       192.168.2.170/32 eth0 label eth0:0
   }
}

   virtual_server 192.168.126.13280 {

       delay_loop 6

       lb_algo rr

       lb_kind DR

       nat_mask 255.255.255.0

       protocol TCP

   real_server 192.168.126.131 80 {

       weight 1

       HTTP_GET {

       url {

       path /

       status_code 200

   }

       connect_timeout 3

       nb_get_retry 3

       delay_before_retry 3

   }

}

   real_server 192.168.126.149 80 {

       weight 1

       HTTP_GET {

       url {

       path /

       status_code 200

   }

       connect_timeout 3

       nb_get_retry 3

       delay_before_retry 3

       }

   }

}

   ipvsadm�CC 清除所有规则

   ipvsadm -A -t 192.168.126.1132:80 -s wlc

   ipvsadm -a -t 192.168.126.132:80 -r 192.168.126.131 -g -w 2

   ipvsadm -a -t 192.168.126.132:80 -r 192.168.126.149 -g -w 1

   ipvsadm -L �Cn 查看规则

   ipvsadm�CS 保存规则

4.Real-Server1配置部分：

       Echo 1 > /proc/sys/net/ipv4/conf/eth0/arp_ignore

       Echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore

       Echo 2 > /proc/sys/net/ipv4/conf/eth0/arp_arp_announce

       Echo 2 > /proc/sys/net/ipv4/conf/all/arp_arp_announce

   限定linux主机对arp广播请求的响应级别，以及向外通告自己的IP地址的，通告级别！

   配置虚拟IP:

ifconfiglo:0 192.168.100.1(VIP) netmask 255.255.255.255 broadcast 192.168.1.255(广播地址) up

   Routeadd �Chost ip(vip) dev eth0:0

       RS上要做路由，要是不做路由响应客户端时会用eth0响应，而不是VIP

       Service httpd  restart

       Echo “this isreal-server1” > /var/www/html/index.html

   开启路由转发

   5.Real-Server2配置部分:

   Echo 1 >/proc/sys/net/ipv4/conf/eth0/arp_ignore

   Echo 1 >/proc/sys/net/ipv4/conf/all/arp_ignore

   Echo 2 > /proc/sys/net/ipv4/conf/eth0/arp_arp_announce

   Echo 2 > /proc/sys/net/ipv4/conf/all/arp_arp_announce

   限定linux主机对arp广播请求的响应级别，以及向外通告自己的IP地址的，通告级别！

   配置虚拟IP:

ifconfiglo:0 192.168.100.1(VIP) netmask 255.255.255.255 broadcast 192.168.1.255(广播地址) up

   Routeadd �Chost ip(vip) dev eth0:0

   RS上要做路由，要是不做路由响应客户端时会用eth0响应，而不是VIP

       Service httpdrestart

       Echo “this isreal-server1” > /var/www/html/index.html

   开启路由转发

  注意：Rlear-Server限定linux主机对arp广播请求的响应级别后在配置VIP

  Keepalived.conf配置文件定要copy到/etc/目录下