环境准备：

两台安装了keepalived的服务器

ip：192.168.134.170;192.168.134.172

1、安装http服务

yum install httpd -y

2、写一个测试页面

[root@localhost ~]# echo "`hostname -I`,web1 test page. " > /var/www/html/inde
[root@localhost ~]# systemctl start httpd

3、修改keepalived配置文件（/etc/keepalived/keepalived.conf）

主节点
! Configuration File for keepalivedglobal_defs {notification_email {acassen@firewall.locfailover@firewall.locsysadmin@firewall.loc}notification_email_from Alexandre.Cassen@firewall.locsmtp_server 192.168.200.1smtp_connect_timeout 30router_id LVS_DEVEL1
}vrrp_instance VI_1 {state MASTER# nopreemptinterface ens33virtual_router_id 51priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.134.100}
}
备节点：修改优先级和state即可

4、结果

但是此时如果出现了web服务器故障，没有办法进行自动切换。

5、写检查脚本

#!/bin/bashwhile true
dohttp_pid_num=`ps -C httpd --no-header | wc -l`if [ $http_pid_num -eq 0 ]thensystemctl start httpdsleep 2http_pid_num=`ps -C httpd --no-header | wc -l`if [ $http_pid_num -eq 0 ]thensystemctl stop keepalivedfifi
done

6、添加运行（放到后台）==>执行完此步骤后重新启动，再次测试，便可以进行故障切换。

nohup ./check_httpd.sh > nohup.out 2>&1 &