keepalived高可用简介及部署

1. keepalived简介

Keepalived软件起初是专门为LVS负载均衡软件设计的用来管理并监控LVS集群系统中各个服务节点的状态，后来又加入了可以实现高可用的VRRP功能。因此，Keepalived除了能够管理LVS软件外，还可以作为其他服务的高可用解决方案软件。

Keepalived软件主要是通过VRRP协议实现高可用功能的,VRRP是Virtual Router Redundancy Protocol（虚拟路由器冗余协议）的缩写.VRRP出现的目的就是为了解决静态路由单点故障问题的。

Keepalived高可用故障切换转移原理

Keepalived高可用故障切换，是通过VRRP虚拟路由器冗余协议来实现的。

在Keepalived服务正常工作时，主Master节点会不断地向备节点发送（多播的方式）心跳消息，用以告诉备Backup节点自己还活着，当主Master节点发生故障时，就无法发送心跳消息，备节点无法检测到来自主Master节点心跳了，于是调用自身的接管程序，接管主Master节点的IP资源及服务。而当主Master节点恢复时，备Backup节点又会释放主节点故障时自身接管的IP资源及服务，恢复到原来的备用角色。

keepalived 有三个重要的功能，分别是：

• 管理LVS负载均衡软件
• 实现LVS集群节点的健康检查
• 作为系统网络服务的高可用性（failover）

keepalived高可用架构图

keepalived工作原理描述

Keepalived高可用对之间是通过VRRP通信的，因此，我们从 VRRP开始了解起：

1. VRRP,全称 Virtual Router Redundancy Protocol,中文名为虚拟路由冗余协议，VRRP的出现是为了解决静态路由的单点故障。
2. VRRP是通过一种竟选协议机制来将路由任务交给某台 VRRP路由器的。
3. VRRP用 IP多播的方式（默认多播地址（224.0_0.18))实现高可用对之间通信。
4. 工作时主节点发包，备节点接包，当备节点接收不到主节点发的数据包的时候，就启动接管程序接管主节点的开源。备节点可以有多个，通过优先级竞选，但一般 Keepalived系统运维工作中都是一对。
5. VRRP使用了加密协议加密数据，但Keepalived官方目前还是推荐用明文的方式配置认证类型和密码。

Keepalived服务的工作原理：

Keepalived高可用是通过 VRRP 进行通信的， VRRP是通过竞选机制来确定主备的，主的优先级高于备，因此，工作时主会优先获得所有的资源，备节点处于等待状态，当主挂了的时候，备节点就会接管主节点的资源，然后顶替主节点对外提供服务。

在 Keepalived 服务之间，只有作为主的服务器会一直发送 VRRP 广播包,告诉备它还活着，此时备不会枪占主，当主不可用时，即备监听不到主发送的广播包时，就会启动相关服务接管资源，保证业务的连续性.接管速度最快可以小于1秒。

2. keepalived配置文件讲解

keepalived默认配置文件

keepalived 的主配置文件是 /etc/keepalived/keepalived.conf。其内容如下：

[root@wyt1 ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {       //全局配置
   notification_email {     //定义报警收件人邮件地址
     [email protected]
     [email protected]
     [email protected]
   }
   notification_email_from [email protected]    //定义报警发件人邮箱
   smtp_server 192.168.200.1    //邮箱服务器地址
   smtp_connect_timeout 30      //定义邮箱超时时间
   router_id LVS_DEVEL          //定义路由标识信息，同局域网内唯一
   vrrp_skip_check_adv_addr
   vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_instance VI_1 {        //定义实例
    state MASTER            //指定keepalived节点的初始状态，可选值为MASTER|BACKUP
    interface eth0          //VRRP实例绑定的网卡接口，用户发送VRRP包
    virtual_router_id 51    //虚拟路由的ID，同一集群要一致
    priority 100            //定义优先级，按优先级来决定主备角色，优先级越大越优先
    nopreempt               //设置不抢占
    advert_int 1            //主备通讯时间间隔
    authentication {        //配置认证
        auth_type PASS      //认证方式，此处为密码
        auth_pass 1111      //同一集群中的keepalived配置里的此处必须一致，推荐使用8位随机数
    }
    virtual_ipaddress {     //配置要使用的VIP地址
        192.168.200.16
    }
}

virtual_server 192.168.200.16 1358 {    //配置虚拟服务器
    delay_loop 6        //健康检查的时间间隔
    lb_algo rr          //lvs调度算法
    lb_kind NAT         //lvs模式
    persistence_timeout 50      //持久化超时时间，单位是秒
    protocol TCP        //4层协议

    sorry_server 192.168.200.200 1358   //定义备用服务器，当所有RS都故障时用sorry_server来响应客户端

    real_server 192.168.200.2 1358 {    //定义真实处理请求的服务器
        weight 1    //给服务器指定权重，默认为1
        HTTP_GET {
            url {
              path /testurl/test.jsp    //指定要检查的URL路径
              digest 640205b7b0fc66c1ea91c463fac6334d   //摘要信息
            }
            url {
              path /testurl2/test.jsp
              digest 640205b7b0fc66c1ea91c463fac6334d
            }
            url {
              path /testurl3/test.jsp
              digest 640205b7b0fc66c1ea91c463fac6334d
            }
            connect_timeout 3       //连接超时时间
            nb_get_retry 3          //get尝试次数
            delay_before_retry 3    //在尝试之前延迟多长时间
        }
    }

    real_server 192.168.200.3 1358 {
        weight 1
        HTTP_GET {
            url {
              path /testurl/test.jsp
              digest 640205b7b0fc66c1ea91c463fac6334c
            }
            url {
              path /testurl2/test.jsp
              digest 640205b7b0fc66c1ea91c463fac6334c
            }
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

定制主配置文件

vrrp_instance段配置

nopreempt   //设置为不抢占。默认是抢占的，当高优先级的机器恢复后，会抢占低优先 \
级的机器成为MASTER，而不抢占，则允许低优先级的机器继续成为MASTER，即使高优先级 \
的机器已经上线。如果要使用这个功能，则初始化状态必须为BACKUP。

preempt_delay   //设置抢占延迟。单位是秒，范围是0---1000，默认是0.发现低优先 \
级的MASTER后多少秒开始抢占。

vrrp_script段配置

//作用：添加一个周期性执行的脚本。脚本的退出状态码会被调用它的所有的VRRP Instance记录。
//注意：至少有一个VRRP实例调用它并且优先级不能为0.优先级范围是1-254.
vrrp_script <SCRIPT_NAME> {
          ...
    }

//选项说明：
script "/path/to/somewhere"      //指定要执行的脚本的路径。
interval <INTEGER>              //指定脚本执行的间隔。单位是秒。默认为1s。
timeout <INTEGER>               //指定在多少秒后，脚本被认为执行失败。
weight <-254 --- 254>           //调整优先级。默认为2.
rise <INTEGER>                  //执行成功多少次才认为是成功。
fall <INTEGER>                  //执行失败多少次才认为失败。
user <USERNAME> [GROUPNAME]     //运行脚本的用户和组。
init_fail                       //假设脚本初始状态是失败状态。

//weight说明： 
1. 如果脚本执行成功(退出状态码为0)，weight大于0，则priority增加。
2. 如果脚本执行失败(退出状态码为非0)，weight小于0，则priority减少。
3. 其他情况下，priority不变。

real_server段配置

weight <INT>            //给服务器指定权重。默认是1
inhibit_on_failure      //当服务器健康检查失败时，将其weight设置为0， \
                        //而不是从Virtual Server中移除
notify_up <STRING>      //当服务器健康检查成功时，执行的脚本
notify_down <STRING>    //当服务器健康检查失败时，执行的脚本
uthreshold <INT>        //到这台服务器的最大连接数
lthreshold <INT>        //到这台服务器的最小连接数

tcp_check段配置

connect_ip <IP ADDRESS>     //连接的IP地址。默认是real server的ip地址
connect_port <PORT>         //连接的端口。默认是real server的端口
bindto <IP ADDRESS>         //发起连接的接口的地址。
bind_port <PORT>            //发起连接的源端口。
connect_timeout <INT>       //连接超时时间。默认是5s。
fwmark <INTEGER>            //使用fwmark对所有出去的检查数据包进行标记。
warmup <INT>    //指定一个随机延迟，最大为N秒。可防止网络阻塞。如果为0，则关闭该功能。
retry <INIT>                //重试次数。默认是1次。
delay_before_retry <INT>    //默认是1秒。在重试之前延迟多少秒。

实例

global_defs {
    router_id LVS_Server
}
vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 150
    nopreempt
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass wangqing
    }
    virtual_ipaddress {  
        192.168.179.200 dev ens33
    }
}
virtual_server 192.168.179.200 80 {
    delay_loop 3
    lvs_sched rr
    lvs_method DR
    protocol TCP
    real_server 192.168.179.128. 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
    real_server 192.168.179.129. 8080 {
        weight 1
        TCP_CHECK {
            connect_port 8080
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

3.keepalived实现nginx负载均衡机高可用

环境说明

系统信息	主机名	IP
CentOS7	wyt1	192.168.179.128
CentOS7	wyt2	192.168.179.129

keepalived安装

配置主keepalived

关闭防火墙及selinux

[root@wyt1 ~]# systemctl disable --now firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[root@wyt1 ~]# setenforce 0
[root@wyt1 ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config

配置网络源

[root@wyt1 ~]# curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
[root@wyt1 ~]# sed -i 's/\$releasever/7/g' /etc/yum.repos.d/CentOS-Base.repo
[root@wyt1 ~]# sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo
[root@wyt1 ~]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
[root@wyt1 ~]# yum -y install  vim wget gcc gcc-c++

安装keepalived

[root@wyt1 ~]# yum -y install keepalived

查看安装生成的文件

[root@wyt1 ~]# rpm -ql keepalived
/etc/keepalived  //配置目录
/etc/keepalived/keepalived.conf  //此为主配置文件
/etc/sysconfig/keepalived
/usr/bin/genhash
/usr/lib/systemd/system/keepalived.service //此为服务控制文件
/usr/libexec/keepalived
/usr/sbin/keepalived

配置备keepalived

关闭防火墙及selinux

[root@wyt1 ~]# systemctl disable --now firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[root@wyt1 ~]# setenforce 0
[root@wyt1 ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config

配置网络源

[root@wyt1 ~]# curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
[root@wyt1 ~]# sed -i 's/\$releasever/7/g' /etc/yum.repos.d/CentOS-Base.repo
[root@wyt1 ~]# sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo
[root@wyt1 ~]# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
[root@wyt1 ~]# yum -y install  vim wget gcc gcc-c++

安装keepalived

[root@wyt1 ~]# yum -y install keepalived

配置httpd

在主上面配置httpd

[root@wyt1 ~]# cd /var/www/html/
[root@wyt1 html]# echo '01' > index.html
[root@wyt1 html]# systemctl start httpd
[root@wyt1 html]# ss -antl
State       Recv-Q Send-Q Local Address:Port               Peer Address:Port              
LISTEN      0      100    127.0.0.1:25                      *:*                  
LISTEN      0      128         *:22                      *:*                  
LISTEN      0      100     [::1]:25                   [::]:*                  
LISTEN      0      128      [::]:80                   [::]:*                  
LISTEN      0      128      [::]:22                   [::]:*  

在备上面配置httpd

[root@wyt2 ~]# cd /var/www/html/
[root@wyt2 html]# echo '02' > index.html
[root@wyt2 html]# systemctl start httpd
[root@wyt2 html]# ss -antl
State       Recv-Q Send-Q Local Address:Port               Peer Address:Port              
LISTEN      0      100    127.0.0.1:25                      *:*                  
LISTEN      0      128         *:22                      *:*                  
LISTEN      0      100     [::1]:25                   [::]:*                  
LISTEN      0      128      [::]:80                   [::]:*                  
LISTEN      0      128      [::]:22                   [::]:*       

keepalived配置

配置主keepalived

[root@wyt1 ~]# cd /etc/keepalived/
[root@wyt1 keepalived]# ls
keepalived.conf
[root@wyt1 keepalived]# cp keepalived.conf{,-bak} //备份
[root@wyt1 keepalived]# ls
keepalived.conf  keepalived.conf-bak
[root@wyt1 keepalived]# > keepalived.conf //清空
[root@wyt1 keepalived]# vim keepalived.conf
! Configuration File for keepalived

global_defs {
   router_id lb01
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.179.200
    }
}

virtual_server 192.168.179.200 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
    persistence_timeout 50
    protocol TCP

    real_server 192.168.179.128 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }

    real_server 192.168.179.129 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

[root@wyt1 keepalived]# systemctl enable --now keepalived
Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service.

配置备keepalived

[root@wyt2 ~]# cd /etc/keepalived/
[root@wyt2 keepalived]# ls
keepalived.conf
[root@wyt2 keepalived]# cp keepalived.conf{,-bak}
[root@wyt2 keepalived]# ls
keepalived.conf  keepalived.conf-bak
[root@wyt2 keepalived]# > keepalived.conf
[root@wyt2 keepalived]# vim keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id lb02
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
! Configuration File for keepalived

global_defs {
   router_id lb02
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.179.200
    }
}

virtual_server 192.168.179.200 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
    persistence_timeout 50
    protocol TCP

    real_server 192.168.179.128 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }

    real_server 192.168.179.129 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

[root@wyt2 keepalived]# systemctl enable --now keepalived
Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service.                  

查看VIP在哪里

在主上面查看

[root@wyt1 keepalived]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:b3:0c:45 brd ff:ff:ff:ff:ff:ff
    inet 192.168.179.128/24 brd 192.168.179.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.179.200/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:feb3:c45/64 scope link 
       valid_lft forever preferred_lft forever       

在备上面查看

[root@wyt2 keepalived]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:ff:51:47 brd ff:ff:ff:ff:ff:ff
    inet 192.168.179.129/24 brd 192.168.179.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:feff:5147/64 scope link 
       valid_lft forever preferred_lft forever

让keepalived监控httpd负载均衡机

keepalived通过脚本来监控nginx负载均衡机的状态

在主上编写脚本

[root@wyt1 ~]# mkdir /scripts
[root@wyt1 ~]# cd /scripts/
[root@wyt1 scripts]#  vim check_httpd.sh
#!/bin/bash
httpd_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bhttpd\b'|wc -l)
if [ $httpd_status -lt 1 ];then
    systemctl stop keepalived

[root@wyt1 scripts]# vim notify.sh
#!/bin/bash
VIP=$2
case "$1" in
  master)
        httpd_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bhttpd\b'|wc -l)
        if [ $httpd_status -lt 1 ];then
            systemctl start httpd
        fi
  ;;
  backup)
        httpd_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bhttpd\b'|wc -l)
        if [ $httpd_status -gt 0 ];then
            systemctl stop httpd
        fi
  ;;
  *)
        echo "Usage:$0 master|backup VIP"
  ;;
esac

[root@wyt1 scripts]# chmod +x *.sh //给脚本执行权限
[root@wyt1 scripts]# ll
总用量 8
-rwxr-xr-x 1 root root 142 8月   5 15:57 check_httpd.sh
-rwxr-xr-x 1 root root 434 8月   5 15:59 notify.sh

在备上编写脚本

[root@wyt2 ~]# mkdir /scripts
[root@wyt2 ~]# cd /scripts/
[root@wyt2 scripts]# vim notify.sh 

#!/bin/bash
VIP=$2
case "$1" in
  master)
        httpd_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bhttpd\b'|wc -l)
        if [ $httpd_status -lt 1 ];then
            systemctl start httpd
        fi
  ;;
  backup)
        httpd_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bhttpd\b'|wc -l)
        if [ $httpd_status -gt 0 ];then
            systemctl stop httpd
        fi
  ;;
  *)
        echo "Usage:$0 master|backup VIP"
  ;;
esac
[root@wyt1 scripts]# chmod +x notify.sh //给脚本执行权限
[root@wyt2 scripts]# ll
总用量 4
-rwxr-xr-x 1 root root 434 8月   6 01:17 notify.sh

配置keepalived加入监控脚本的配置

配置主keepalived

[root@wyt1 ~]# vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id lb01
}

vrrp_script httpd_check {
    script "/scripts/check_httpd.sh"
    interval 1
    weight -30
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.179.200
    }
    track_script {
        httpd_check
    }
    notify_master "/scripts/notify.sh master 192.168.179.200"
    notify_backup "/scripts/notify.sh backup 192.168.179.200"
}

virtual_server 192.168.179.200 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
    persistence_timeout 50
    protocol TCP

    real_server 192.168.179.128 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }

    real_server 192.168.179.129 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

[root@wyt1 ~]# systemctl restart keepalived //重启服务

配置备keepalived

! Configuration File for keepalived

global_defs {
   router_id lb02
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.179.200
    }
    notify_master "/scripts/notify.sh master 192.168.179.200"
    notify_backup "/scripts/notify.sh backup 192.168.179.200"
}

virtual_server 192.168.179.200 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
    persistence_timeout 50
    protocol TCP

    real_server 192.168.179.128 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }

    real_server 192.168.179.129 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

[root@wyt2 ~]# systemctl restart keepalived //重启服务

验证

[root@wyt1 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:b3:0c:45 brd ff:ff:ff:ff:ff:ff
    inet 192.168.179.128/24 brd 192.168.179.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.179.200/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:feb3:c45/64 scope link 
       valid_lft forever preferred_lft forever

关闭主上的httpd，在访问

[root@wyt1 ~]# systemctl stop httpd
[root@wyt1 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:b3:0c:45 brd ff:ff:ff:ff:ff:ff
    inet 192.168.179.128/24 brd 192.168.179.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:feb3:c45/64 scope link 
       valid_lft forever preferred_lft forever

查看主VIP转移到备上面

[root@wyt2 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:ff:51:47 brd ff:ff:ff:ff:ff:ff
    inet 192.168.179.129/24 brd 192.168.179.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.179.200/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:feff:5147/64 scope link 
       valid_lft forever preferred_lft forever      

使用systemctl stop keepalived时可能出现进程杀不干净的情况，从而导致vip无法转移到备，解决方法如下

[root@wyt1 ~]# vim /usr/lib/systemd/system/keepalived.service
[Unit]
Description=LVS and VRRP High Availability Monitor
After=syslog.target network-online.target
[Service]
Type=forking
PIDFile=/var/run/keepalived.pid
#KillMode=process           //将此行注释，注释后默认关闭所有进程，process只关闭父进程，killmode的默认值是control-group，意思时所有进程都会被干掉
EnvironmentFile=-/etc/sysconfig/keepalived
ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS
ExecReload=/bin/kill -HUP $MAINPID
[Install]
WantedBy=multi-user.target
[root@wyt1 ~]# systemctl daemon-reload