Linux-利用keepalived实现lvs的高可用性

单主模型ipvs示例

配置keepalive

高可用的ipvs集群示例：修改keepalived配置文件

修改主机：192.168.234.27的keepalived配置文件

  1 [root@234c27 ~]# vim /etc/keepalived/keepalived.conf
  2 ! configuration file for keepalived
  3 
  4 global_defs {
  5 notification_email {
  6 root@localhost  //接受邮件地址
  7 }
  8 notification_email_from keepalived@localhost  //发送邮件地址
  9 smtp_server 127.0.0.1  //发送邮件服务器ip
 10 smtp_connect_timeout 30  //邮件连接超时时长
 11 router_id kptwo  //路由id
 12 vrrp _mcast_group4 234.10.10.10  //指定vrrp协议的多播地址
 13 }
 14 
 15 vrrp_instance vi_1 {  //vrrp协议的
 16 state master  //lvs的master服务器
 17 interface ens37  //
 18 virtual_router_id 50  //虚拟路由
 19 priority 100  //权重为100.越大越先
 20 advert_int 1  //发送组博包的间隔
 21 authentication {  //验证
 22 auth_type pass  //方式为pass( 明文)
 23 auth_pass 1111  //密码
 24 }
 25 virtual_ipaddress { //keepalived虚拟ip
 26 10.0.0.100/24
 27 }
 28 }
 29 virtual_server 10.0.0.100 80 {
 30     delay_loop 6  //检查后端服务器的时间间隔
 31     lb_algo wrr  //定义调度方法
 32     lb_kind dr  //集群的类型
 33     #persistence_timeout 50  //持久连接时长
 34     protocol tcp  //服务协议，仅支持tcp
 35     real_server 192.168.234.47 80 {  //后端real_server服务器地址
 36         weight 1 //权重
 37         http_get {  //应用层检测
 38             url {
 39               path /  //定义要监控的url
 40               status_code 200  //判断上述检测机制为健康状态的响应码
 41             }
 42             connect_timeout 3  //连接请求的超时时长
 43             nb_get_retry 3  //重试次数
 44             delay_before_retry 3  //重试之前的延迟时长
 45         }
 46     }
 47     real_server 192.168.234.57 80 {
 48         weight 2
 49         http_get {
 50             url {
 51                 path /
 52                 status_code 200
 53             }
 54             connect_timeout 3
 55             nb_get_retry 3
 56             delay_before_retry 3
 57         }
 58     }
 59 }

修改主机：192.168.234.37的keepalived配置文件

[root@234c37 ~]# vim /etc/keepalived/keepalived.conf

! 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 kptwo
   vrrp _mcast_group4 234.10.10.10
}

vrrp_instance vi_1 {
    state backup
    interface ens37
    virtual_router_id 50
    priority 80
    advert_int 1
    authentication {
        auth_type pass
        auth_pass 1111
    }
    virtual_ipaddress {
       10.0.0.100/24
    }
}
virtual_server 10.0.0.100 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind dr
    #persistence_timeout 50
    protocol tcp
    sorry_server 127.0.0.1:80
    real_server 192.168.234.47 80 {
        weight 1
        http_get {
            url {
              path /
              status_code 200
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
    real_server 192.168.234.57 80 {
        weight 2
        http_get {
            url {
              path /
                status_code 200
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

查看keepalived

[root@234c37 ~]# systemctl status keepalived
● keepalived.service - lvs and vrrp high availability monitor
   loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
   active: inactive (dead)
…………
[root@234c37 ~]# ipvsadm -ln
ip virtual server version 1.2.1 (size=4096)
prot localaddress:port scheduler flags
  -> remoteaddress:port           forward weight activeconn inactconn
//暂无ipvsadm

启动服务

[root@234c27 keepalived]# systemctl start keepalived.service
[root@234c27 keepalived]# systemctl status keepalived.service
● keepalived.service - lvs and vrrp high availability monitor
   loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
   active: active (running) since fri 2018-08-31 20:30:02 cst; 12s ago
  process: 9657 execstart=/usr/sbin/keepalived $keepalived_options (code=exited, status=0/success)
 main pid: 9658 (keepalived)
………………
[root@234c27 keepalived]# ipvsadm -ln
ip virtual server version 1.2.1 (size=4096)
prot localaddress:port scheduler flags
  -> remoteaddress:port           forward weight activeconn inactconn
tcp  10.0.0.100:80 wrr
  -> 192.168.234.47:80            route   1      0          0
  -> 192.168.234.57:80            route   2      0          0
//启动服务lvs vs已配置好

后端real_server准备

增加ip在网卡上 修改限制arp通告及应答级别 rs1 rs2都做，网关并指向路由

ip a a 10.0.0.100/32 dev ens37

echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce

route add default gw 192.168.234.17

安装httpd服务 写好网页文件

启动服务

多主模型ipvs示例

配置keepalive

高可用的ipvs集群示例：修改keepalived配置文件

修改主机：192.168.234.27的keepalived配置文件

[root@234c27 keepalived]# vim /etc/keepalived/keepalived.conf
global_defs {
   notification_email {
     root@localhost
   }
   notification_email_from keepalived@localhost
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id kpone
   vrrp _mcast_group4 234.10.10.10
}

vrrp_instance vi_1 {
    state master
    interface ens37
    virtual_router_id 50
    priority 100
    advert_int 1
    authentication {
        auth_type pass
        auth_pass 1111
    }
    virtual_ipaddress {
       10.0.0.100/24
    }
}
vrrp_instance vi_2 {
    state backup
    interface ens37
    virtual_router_id 51
    priority 80
    advert_int 1
    authentication {
        auth_type pass
        auth_pass 2222
    }
    virtual_ipaddress {
        10.0.0.200/24
    }
}
virtual_server 10.0.0.100 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind dr
    #persistence_timeout 50
    protocol tcp
    #sorry_server 127.0.0.1:80
    real_server 192.168.234.47 80 {
        weight 1
        http_get {
            url {
              path /
              status_code 200
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}
virtual_server 10.0.0.200 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind dr
    #persistence_timeout 50
    protocol tcp
    #sorry_server 127.0.0.1:80
    real_server 192.168.234.57 80 {
        weight 1
        http_get {
            url {
              path /
              status_code 200
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

修改主机：192.168.234.37的keepalived配置文件

[root@234c37 ~]# vim /etc/keepalived/keepalived.conf
! 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 kptwo
   vrrp _mcast_group4 234.10.10.10
}

vrrp_instance vi_1 {
    state backup
    interface ens37
    virtual_router_id 50
    priority 80
    advert_int 1
    authentication {
        auth_type pass
        auth_pass 1111
    }
    virtual_ipaddress {
       10.0.0.100/24
    }
}
vrrp_instance vi_2 {
    state master
    interface ens37
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type pass
        auth_pass 2222
    }
    virtual_ipaddress {
        10.0.0.200/24
    }
}
virtual_server 10.0.0.100 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind dr
    #persistence_timeout 50
    protocol tcp
    #sorry_server 127.0.0.1:80
    real_server 192.168.234.47 80 {
        weight 1
        http_get {
            url {
              path /
              status_code 200
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}
virtual_server 10.0.0.200 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind dr
    #persistence_timeout 50
    protocol tcp
    #sorry_server 127.0.0.1:80
    real_server 192.168.234.57 80 {
        weight 1
        http_get {
            url {
              path /
              status_code 200
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

让10.0.0.100的ip优先分配至192.168.234.47 192.168.234.57备用

让10.0.0.200的ip优先分配至192.168.234.57 192.168.234.47备用

后端real_server准备

修改192.168.234.57的vip为10.0.0.200/32

  1 [root@234c27 keepalived]# ipvsadm -ln
  2 ip virtual server version 1.2.1 (size=4096)
  3 prot localaddress:port scheduler flags
  4   -> remoteaddress:port           forward weight activeconn inactconn
  5 tcp  10.0.0.100:80 wrr
  6   -> 192.168.234.47:80            route   1      0          0
  7 tcp  10.0.0.200:80 wrr
  8   -> 192.168.234.57:80            route   1      0          0

现在宕掉一个lvs

  1 [root@234c27 keepalived]# systemctl stop keepalived.service
  2 [root@234c27 keepalived]# ipvsadm -ln
  3 ip virtual server version 1.2.1 (size=4096)
  4 prot localaddress:port scheduler flags
  5   -> remoteaddress:port           forward weight activeconn inactconn
  6 

依然提供服务

  1 [root@234c37 ~]# ipvsadm -ln
  2 ip virtual server version 1.2.1 (size=4096)
  3 prot localaddress:port scheduler flags
  4   -> remoteaddress:port           forward weight activeconn inactconn
  5 tcp  10.0.0.100:80 wrr
  6   -> 192.168.234.47:80            route   1      0          21
  7 tcp  10.0.0.200:80 wrr
  8   -> 192.168.234.57:80            route   1      0          39

后一个实现基于前一个的基础上修改来的

假设要实现sorry_server

1.把rs服务都停掉。然后在lvs上安装apache或者nginx服务

2.将keepalived配置文件中的

  1 virtual_server 10.0.0.200 80 {
  2     delay_loop 6
  3     lb_algo wrr
  4     lb_kind dr
  5     #persistence_timeout 50
  6     protocol tcp
  7     #sorry_server 127.0.0.1:80  //这一行来修改 写出服务出错之后的页面
  8     real_server 192.168.234.57 80 {
  9         weight 1
 10         http_get {
 11             url {
 12               path /
 13               status_code 200
 14             }
 15             connect_timeout 3
 16             nb_get_retry 3
 17             delay_before_retry 3
 18         }
 19     }
 20 }