Keepalived 双主热备

由于双机热备会有一台机器正常状态下会一直闲置，造成资源浪费，
通过双主热备吧所有机器都使用起来。
原理就是域名绑定多个虚拟 ip 通过 DNS 轮询，每个实例绑定一个相对于自己是 Master 的虚拟 ip，
并且实例间互为主备关系

实例一配置：

global_defs {
   router_id keep_171
}
vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.161
    }
}
vrrp_instance VI_2 {
    state BACKUP
    interface ens33
    virtual_router_id 52
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.162
    }
}

实例二配置

global_defs {
   router_id keep_172
}
vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.161
    }
}
vrrp_instance VI_2 {
    state MASTER
    interface ens33
    virtual_router_id 52
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.162
    }
}

重启两条Keepalived

# 重启Keepalived
systemctl restart keepalived