部署LVS高可用集群

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一、lvs+keepalived 高可用集群部署

案例需求

部署基于 LVS DR 模式的 web 高可用集群，实现：

• 实现数据服务器容错
• 实现分发器故障切换
• 任何机器宕机不中断 web 业务

实验环境

六台安装 CentOS8 的虚拟机一台测试机，两台 LVS 分发器，一台路由器，两台 web 服务器，关闭 selinux 关闭防火墙，停止 libvirtd.service 服务

实验拓扑图

实验步骤

a、配置客户端

ens33=192.168.1.200
[root@client ~]# route add default gw 192.168.1.1

b、设置路由

ens33=192.168.1.1
ens160=192.168.2.1

[root@route ~]# echo 1 > /proc/sys/net/ipv4/ip_forward

c、设置 RS 的 VIP、网关、内核参数

RS1
[root@rs1 ~]# route add default gw 192.168.2.1
[root@rs1 ~]# ifconfig lo:0 192.168.2.100 netmask 255.255.255.255 up
[root@rs1 ~]# echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore 
[root@rs1 ~]# echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce 

RS2
[root@rs2 ~]# route add default gw 192.168.2.1
[root@rs2 ~]# ifconfig lo:0 192.168.2.100 netmask 255.255.255.255 up
[root@rs2 ~]# echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore 
[root@rs2 ~]# echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce 

安装 web 服务，生成测试页面
RS1
[root@rs1 ~]# dnf install httpd -y
[root@rs1 ~]# echo "rs1" > /var/www/html/index.html
[root@rs1 ~]# systemctl start httpd.service
RS2
[root@rs2 ~]# dnf install httpd -y
[root@rs2 ~]# echo "rs2" > /var/www/html/index.html
[root@rs2 ~]# systemctl start httpd.service

d、设置 LVS

### LVS1 安装软件包，修改配置文件 
[root@lvs1 ~]# dnf install ipvsadm keepalived -y
[root@lvs1 ~]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {router_id lvs_1}
vrrp_instance apache {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {192.168.2.100/24
    }
}

virtual_server 192.168.2.100 80 {delay_loop 6
    lb_algo rr
    lb_kind DR
    nat_mask 255.255.255.0
#    persistence_timeout 50
    protocol TCP

    real_server 192.168.2.210 80 {weight 1
        TCP_CHECK {connect_timeout 3
              connect_port 80
            }
        }
    real_server 192.168.2.220 80 {weight 1
        TCP_CHECK {connect_timeout 3
              connect_port 80
            }
        }
}

### 重启 keepalived 服务 
[root@lvs1 ~]# systemctl start keepalived.service 

### 使用 ip add 命令查看所设置的 VIP 是否被设置 
[root@lvs1 ~]# ip add
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:6d:1c:b3 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.200/24 brd 192.168.2.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.2.100/24 scope global secondary ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::474:99dd:c899:455f/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever


### LVS2	安装软件包，修改配置文件 
[root@lvs2 ~]# dnf install ipvsadm keepalived -y
[root@lvs2 ~]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {router_id lvs_1}
vrrp_instance apache {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 10
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {192.168.2.100/24
    }
}

virtual_server 192.168.2.100 80 {delay_loop 6
    lb_algo rr
    lb_kind DR
    nat_mask 255.255.255.0
#    persistence_timeout 50
    protocol TCP

    real_server 192.168.2.210 80 {weight 1
        TCP_CHECK {connect_timeout 3
              connect_port 80
            }
        }
    real_server 192.168.2.220 80 {weight 1
        TCP_CHECK {connect_timeout 3
              connect_port 80
            }
        }
}

### 重启 keepalived 服务 
[root@lvs2 ~]# systemctl start keepalived.service

e、客户端测试

### 客户端验证分发 
[root@client ~]# elinks http://192.168.2.100 --dump
   rs1
[root@client ~]# elinks http://192.168.2.100 --dump
   rs2

### 停止 lvs1 的 keepalived 服务  验证分发器故障切换 
[root@lvs1 ~]# systemctl stop keepalived.service 

使用 ip add 命令查看 VIP 是否被释放
[root@lvs1 ~]# ip add
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:6d:1c:b3 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.200/24 brd 192.168.2.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::474:99dd:c899:455f/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever


切换到 lvs2 查看 VIP 是否被设置
[root@lvs2 ~]# ip add
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:5c:a0:66 brd ff:ff:ff:ff:ff:ff
    inet 192.168.2.150/24 brd 192.168.2.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.2.100/24 scope global secondary ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::5726:cbb9:c37b:d898/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever


切换到客户端测试
[root@client ~]# elinks http://192.168.2.100 --dump
   rs1
[root@client ~]# elinks http://192.168.2.100 --dump
   rs2


### 停止 RS1 数据服务器查看数据服务器容错 
[root@rs1 ~]#  systemctl stop httpd

切换到客户端测试: 用户只能访问到 RS1 的页面
[root@client ~]# elinks http://192.168.2.100 --dump
   rs1
[root@client ~]# elinks http://192.168.2.100 --dump
   rs1

提示：使用 tcpdump 命令可以看到 vrrp 的相关信息发送信息，深度理解 VRRP 协议

[root@lvs1 ~]# tcpdump -nn -vvv vrrp