项目实战03：Keepalived 实现高可用

目录

• 实验一：实现keepalived主从方式高可用基于LVS-DR模式的应用实战：
  • 1、环境准备：
  • 2、在lvs-server-master 主上
  • 3、在lvs-server-backup 从上
  • 4、在real server 上
  • 5、测试
• 实验二：实现keepalived双主方式高可用基于LVS-DR模式的应用实战：
  • 1、实验环境，基本同上
  • 2、在lvs-server1 上，基本同上，就是加了一个实例段
  • 3、在lvs-server2 上，基本同1，就是把实例的主从调换一下
  • 4、在real server 上
  • 5、测试
• 实验三：实现keepalived主从方式高可用基于LVS-NAT模式的应用实战：
  • 1、环境准备
  • 2、在lvs-server-master 主上
  • 4、在real server 上
  • 5、测试
• 实验四：实现keeaplived 故障通知机制
  • 1、编写好脚本
  • 2、在keepalived 的配置文件调用脚本
• 实验五：实现keepaplived自定义脚本检测功能
  • 方案一：检测是否存在down文件，来实现主从的调整
  • 方案二：检测nginx服务是否开启，来实现调整主从

① 全局段，故障通知邮件配置
global_defs {
   notification_email {
        root@localhost
   }
   notification_email_from root@along.com
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id keepalived_lvs
}

② 配置虚拟路由器的实例段，VI_1是自定义的实例名称，可以有多个实例段
vrrp_instance VI_1 {    　#VI_1是自定义的实例名称
    state MASTER   　　 　 #初始状态，MASTER|BACKUP
    interface eth1 　　 　 #通告选举所用端口
    virtual_router_id 51  #虚拟路由的ID号（一般不可大于255）
    priority 100  　　　　　#优先级信息 #备节点必须更低
    advert_int 1  　　　　　#VRRP通告间隔，秒
    authentication {
        auth_type PASS    #认证机制
        auth_pass along   #密码（尽量使用随机）
    } 
    virtual_ipaddress {
        172.17.100.100   　#vip
    }
}

③ 设置一个virtual server段
virtual_server 172.17.100.100 80 {   #设置一个virtual server:
    delay_loop 6   # service polling的delay时间，即服务轮询的时间间隔
    lb_algo wrr　　　 #LVS调度算法：rr|wrr|lc|wlc|lblc|sh|dh
    lb_kind DR　　　　#LVS集群模式：NAT|DR|TUN
    nat_mask 255.255.255.255  
    persistence_timeout 600  #会话保持时间（持久连接，秒），即以用户在600秒内被分配到同一个后端realserver
    protocol TCP   　#健康检查用的是TCP还是UDP

④ real server设置段
    real_server 172.17.1.7 80 { #后端真实节点主机的权重等设置
        weight 1  #给每台的权重，rr无效
        HTTP_GET {  #http服务
            url {
              path /
            }
            connect_timeout 3    #连接超时时间
            nb_get_retry 3　　    #重连次数
            delay_before_retry 3 #重连间隔
        }
    }
    real_server 172.17.22.22 80 {
        weight 2
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth1
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass along
    }

net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2

vrrp_instance VI_1 {
    state MASTER
    interface eth1
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass along
    }
    virtual_ipaddress {
        172.17.100.100
    }
}

virtual_server 172.17.100.100 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    nat_mask 255.255.255.255
    persistence_timeout 600
    protocol TCP

    real_server 172.17.1.7 80 {
        weight 1
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
    real_server 172.17.22.22 80 {
        weight 1
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

vrrp_instance VI_2 {
    state BACKUP
    interface eth1
    virtual_router_id 52
    priority 98
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass along
    }
    virtual_ipaddress {
        172.17.100.101
    }
}

virtual_server 172.17.100.101 443 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    nat_mask 255.255.255.255
    persistence_timeout 600
    protocol TCP

    real_server 172.17.1.7 443 {
        weight 1
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
    real_server 172.17.22.22 443 {
        weight 1
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

① vrrp_instance VI_1 {
    state BACKUP
    interface eth1
    virtual_router_id 51
    priority 98
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass along
    }
    virtual_ipaddress {
        172.17.100.100
    }
}
② vrrp_instance VI_2 {
    state MASTER
    interface eth1
    virtual_router_id 52
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass along
    }
    virtual_ipaddress {
        172.17.100.101
    }
}

global_defs {
   notification_email {
        root@localhost
   }
   notification_email_from root@along.com
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id keepalived_lvs
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass along
    }
    virtual_ipaddress {
       172.17.100.100
192.168.30.100
    }
}

virtual_server 172.17.100.100 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind NAT
    nat_mask 255.255.255.255
    persistence_timeout 100
    protocol TCP

    real_server 192.168.30.107 80 {
        weight 1
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }

    real_server 192.168.30.7 80 {
        weight 2
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth1
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass along
    }

#!/bin/bash
# Author: www.magedu.com
contact=‘root@localhost‘
notify() {
        mailsubject="$(hostname) to be $1: vip floating"
        mailbody="$(date +‘%F %H:%M:%S‘): vrrp transition, $(hostname) changed to be $1"
        echo $mailbody | mail -s "$mailsubject" $contact
}
case $1 in
master) 
        notify master
        exit 0
;;
backup)
        notify backup
        exit 0
;;
fault)
        notify fault
        exit 0
;;
*)
        echo "Usage: $(basename $0) {master|backup|fault}"
        exit 1
;;
esac

notify_backup "/etc/keepalived/notify.sh backup"
notify_master "/etc/keepalived/notify.sh master"
notify_fault "/etc/keepalived/notify.sh fault"

vrrp_script chk_down {    #定义一个脚本，脚本名称为chk_down
 　　script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"   #检查这个down文件，若存在返回值为1，keepalived会停止；不存在返回值为0，服务正常运行；这里的exit和bash脚本里的return很相似
 interval 2   #每2秒检查一次
}

track_script {
    chk_down
}

vrrp_script chk_nginx {
     script "killall -0 nginx" #killall -0 检测这个进程是否还活着，不存在就减权重
     interval 2 #每2秒检查一次
     fall 2 #失败2次就打上ko的标记
     rise 2 #成功2次就打上ok的标记
     weight -4 #权重，优先级-4，若为ko
}

track_script {
    chk_nginx
}