本文写于 2015 年。
Keepalived 是在传统网络中，常用的网络容灾方案。

CentOS 6.5 64bit

Keepalived v1.2.19

安装

wget http://www.keepalived.org/software/keepalived-1.2.19.tar.gz

tar -zxvf keepalived-1.2.19.tar.gz

sudo yum install -y openssl openssl-devel

./configure --prefix=/work/admin/keepalived
make
make install

配置

vim /work/admin/keepalived/etc/keepalived/keepalived.conf

主机

! Configuration File for keepalived

global_defs {
   notification_email {
     mail@server.com
   }
   notification_email_from mail@server.com
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id AGENT
}

vrrp_script chk_haproxy {
   script "nc -w 0 192.168.80.194 8309"
   interval 3
   weight -20
   fall 3
   rise 2
}

vrrp_instance VI_196 {
    state MASTER
    interface eth0
    virtual_router_id 196
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.80.196
    }

    track_script {
        chk_haproxy
    }
}

备机

! Configuration File for keepalived

global_defs {
   notification_email {
     mail@server.com
   }
   notification_email_from mail@server.com
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id AGENT
}

vrrp_script chk_haproxy {
   script "nc -w 0 192.168.80.195 8309"
   interval 3
   weight -20
   fall 3
   rise 2
}


vrrp_instance VI_196 {
    state BACKUP
    interface eth0
    virtual_router_id 196
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        192.168.80.196
    }

    track_script {
        chk_haproxy
    }

}

防火墙

防火墙开放vrrp协议：
vim /etc/sysconfig/iptables
新增一行：-A INPUT -p vrrp -j ACCEPT
保存后，重启iptables

启动

sudo /work/admin/keepalived/sbin/keepalived -f /work/admin/keepalived/etc/keepalived/keepalived.conf

检查keepalived运行状况：
vim /var/log/messages