keepalive 通过心跳线 确认 线上IP是否存活 若心跳线 断开。 则主动激活ip
安装keepalive
yum-y install popt popt-devel
cd/data/software
wget http://www.keepalived.org/software/keepalived-1.2.8.tar.gzcd/data/src
tar zxf../software/keepalived-1.2.8.tar.gz
cd keepalived-1.2.8
./configure--prefix=/usr/local/keepalived--sysconf=/etc
make&&make install
cp/usr/local/keepalived/sbin/keepalived/bin/chkconfig--add keepalived#设置开机启动chkconfig keepalived on
#启动keepalive服务
/etc/init.d/keepalived start
#keepalived 配置文件修改
vi /etc/keepalived/keepalived.conf
--------------------------file--------------------------------
! Configuration File for keepalived
global_defs {
}
vrrp_script chk_nginx {
#必须放在track代码的上方，否则无效，测试了几次是这个情况
script "killall -0 nginx"
#用shell命令检查nginx服务是否存在
interval 1
#时间间隔为1秒检测一次
weight -15
#当nginx的进程不存在了，就把当前的权重-15
}
vrrp_instance VI_1 {
state MASTER
#主LVS是MASTER,从主机时此项要改为BACKUP，要大写
interface enp4s0
#LVS监控的网络接口
virtual_router_id 51
#同一实例下virtual_router_id必须相同，MASTRE/BACKUP 设置值要一样
priority 100
#定义优先级，数字越大，优先级越高，把此份Conf拷贝到另一台机器上时，设置的priority值要比MASTRE权重值低
advert_int 1
#MASTER与BACKUP负载均衡器之间同步检查的时间间隔，单位是秒
authentication {
auth_type PASS
auth_pass 123123
#验证类型和密码，有PASS和AH两种，一般用PASS，据说AH有问题，认证密码主备服务器之间一定要一致，否则出错
}
virtual_ipaddress {
192.168.1.2
#设置虚拟IP,可以有多个地址，每个地址占一行，不需掩码。注意：这个 ip 必须与我们在 lvs 客户端设定的vip相一致
}
track_script {
chk_nginx
#引用上面的vrrp_script定义的脚本名称
}
notify_master "/etc/keepalived/changemail.py master"
notify_backup "/etc/keepalived/changemail.py backup"
notify_fault "/etc/keepalived/changemail.py fault"
#指定当切换到主、备及故障状态时，执行的脚本
}
--------------------------file--------------------------------
/etc/init.d/keepalived restart
or
service keepalived restart
这里请注意，当keepalived启动后，我们可以用命令：
ip add (centos7) or ifconfig
