nginx+keepalive搭配负载均衡
1.maste主机:192.168.20.112
slaver备机:192.168.20.137
VIP(虚拟IP，用于外网访问):192.168.20.100
2.安装nginx
3.安装keepalive
tar -zxvf keepalived-1.2.15.tar.gz
cd keepalived-1.2.15
./configure
make
make install
4.软连接
ln -s /usr/local/etc/keepalived/ /etc/
ln -s /usr/local/sbin/keepalived /usr/sbin/
ln -s /usr/local/etc/rc.d/init.d/keepalived /etc/init.d/
ln -s /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
5.修改主机keepalived配置文件
vim /etc/keepalived/keepalived.conf
global_defs {
notification_email {
}
notification_email_from root@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state master #定义为主机
interface eth0
virtual_router_id 51
macst_src_ip 192.168.20.137 #主机的IP
priority 100 #定义优先级
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.20.100 #虚拟的IP，用于访问外网
}
}
6.修改备机的keepalive的配置文件
vim /etc/keepalived/keepalived.conf
global_defs {
notification_email {
}
notification_email_from root@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_instance VI_1 {
state slaver
interface eth0
virtual_router_id 51
macst_src_ip 192.168.20.137
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.20.100
}
}
7.重启主备机keepalived服务
service keepalived restart
8.不启动keepalived服务，ping 192.168.20.100是不通的，重启后才能ping通。这个时候虚拟IP就绑定到主机上了。
9.查看tail -f /var/log/message
可以看到主备机的日志都已经启动了vrrp虚拟路由冗余协议。
10.通过ip addr查看虚拟IP是否已经绑定在主机上
可以看到已经绑定在主机了。
这样nginx + keepalive的搭建就完成了。
11.通过VIP访问：
http://192.168.20.100/ 发现显示的是主机的IP.
然后在把主机的nginx和keepalived关闭，看是否可以切换到备机
的确可以切换到备机
12.弄个监控脚本来监测nginx的服务,一旦主机的nginx停止掉，会马上停止主机的keepalived，然后切换到备机。
vim check_nginx.sh
#!/bin/bash
#
nginx=`ps -C nginx --no-header | wc -l`
if [ $nginx -eq 0 ]
then
service nginx restart >> /dev/null
echo "nginx 已经正常重启工作中"
sleep 3
else
echo "nginx 正常运行中..."
keepalived=`ps -C nginx --no-header | wc -l`
if [ $keepalived -eq 0 ]
then
service keepalived stop >> /dev/null
echo "已经正常停止keepalived服务"
else
echo "keepalived 仍处于运行状态..."
fi
fi
13.让脚本每隔多久监测一次
15 * * * * /home/scripts/check_nginx.sh &> /dev/null