nginx+keepalive搭配负载均衡

weewee

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 {
     xxx@163.com


   }
   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 {
    xxxx@163.com


   }
   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