keepalived配置双机热备

keepalived 安装

rpm -ivh keepalived-1.2.13-5.el6_6.x86_64.rpm 

配置文件

master

/etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   enable_script_security
   script_user root
   router_id 158
}
vrrp_script chk_health
{
    script "/etc/keepalived/check_n.sh"
    interval 10
    weight -2
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 158
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        chk_health
    }
    virtual_ipaddress {
        192.168.1.160/24
    }
}

backup

/etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   enable_script_security
   script_user root
   router_id 156
}
vrrp_script chk_health
{
    script "/etc/keepalived/check_n.sh"
    interval 10
    weight -2
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 156
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        chk_health
    }
    virtual_ipaddress {
        192.168.1.160/24
    }
}

监听脚本

#!/bin/bash
a=`netstat -anp | grep :80\  | wc -l`
#a=`ps -ef | grep nginx | grep -v grep | wc -l`
echo $a
if [ $a -ge 1 ] ;then
  exit 0
else
  killall keepalived;
  exit 1
fi

配合监听的端口打开不可配置默认开机启动

/etc/rc.local

screen -dmS sso /usr/local/bin/sso  
#先启动程序停两秒在启动keepalived
#，防止未开启端口导致的keepalived关闭
sleep 2
systemctl start keepalived.service

注意事项

​虚拟路由ID（virtual_router_id）​：主备必须一致，确保属于同一组。
​优先级（priority）​：主服务器需高于备服务器（如100 vs 90）。
​认证密码（auth_pass）​：主备需相同，防止非法节点接入。
​心跳间隔（advert_int）​：默认1秒，可调整但主备需一致。
router_id:主机和备机全局唯一

防火墙开启组网

# bond0 是做bond的逻辑网卡，默认配置ifconfig网卡名称即可
firewall-cmd --direct --permanent --add-rule ipv4 filter INPUT 0 \
--in-interface bond0 \
--destination 224.0.0.18 \
--protocol vrrp -j ACCEPT

firewall-cmd  --reload