Nginx+Apache

Nginx+Apache其实就是Nginx做前端，Apache做后端。

Nginx高并发，Proxy功能强效率高，占用系统资源少；Apache的功能模块比较多，Apache在高并发时对队列的处理比FastCGI（Nginx需要通过fastcgi等方式运行php）更好，并且在处理动态php页面时，mod_php也比php-cgi更稳定更高效。

这里工作模式大致可以分为两种

第一种
由Nginx来接收客户端的请求，如果是动态页面请求，就交给Apache（LAMP、tomcat）处理，然后经由Nginx再返回给客户端，其余的请求，则由Nginx自己处理，然后把结果返回给客户端。

第二种
Nginx只做Proxy功能，所有的请求都交给Apache,Tomcat等处理。

web群集部署apache

1.xftp上传文件

2.环境设置

可以使用yum安装gcc gcc-c++ make pcre-devel expat-devel perl
80号端口没有被占用

netstat -anpt | grep 80

4台设备在同一网段（可以相互通信；ping测试）
关闭防火墙

systemctl stop firewalld
setenforce 0

3.脚本安装apache

#!/bin/bash
#apache的编译安装和配置
tar xf apr-1.6.2.tar.gz 
tar xf apr-util-1.6.0.tar.gz 
tar xf httpd-2.4.29.tar.bz2 
mv apr-1.6.2 httpd-2.4.29/srclib/apr
mv apr-util-1.6.0 httpd-2.4.29/srclib/apr-util
yum -y install gcc gcc-c++ make pcre-devel expat-devel perl
cd httpd-2.4.29/
 ./configure --prefix=/usr/local/httpd --enable-so --enable-rewrite --enable-charset-lite --enable-cgi
make && make install
cd
cp /usr/local/httpd/bin/apachectl /etc/init.d/httpd
sed -i -e '2i#chkconfig: 35 85 21' /etc/init.d/httpd
sed -i -e '3i#description: Apache HTTP Server' /etc/init.d/httpd
chkconfig --add httpd
ln -s /usr/local/httpd/bin/* /usr/bin/
ln -s /usr/local/httpd/conf/httpd.conf /etc/

4.执行脚本，测试

systemctl start httpd
curl http://localhost

Nginx部署

1.xftp上传文件

2.nginx编译安装脚本

#!/bin/bash
#nginx编译安装

yum -y install gcc gcc-c++ make pcre pcre-devel zlib zlib-devel
useradd -M -s /sbin/nologin nginx
tar xf nginx-1.12.2.tar.gz
cd nginx-1.12.2/
 ./configure \
--prefix=/usr/local/nginx \
--user=nginx \
--group=nginx \
--with-http_stub_status_module
make && make install
ln -s /usr/local/nginx/sbin/nginx /usr/local/sbin/
ln -s /usr/local/nginx/conf/nginx.conf /etc/
nginx -t

出现下面两行，说明安装成功

3.安装keepalived

tar xf keepalived-2.0.13.tar.gz
yum -y install gcc gcc-c++ make popt-devel kernel-devel openssl-devel

编译安装

cd keepalived-2.0.13
./configure --prefix=/
make && make install

加入系统管理服务

cp keepalived/etc/init.d/keepalived /etc/init.d/
systemctl enable keepalived.service

编辑配置文件

1.nginx.conf

vi /etc/nginx.conf

添加服务器池，当服务器池不能处理时，转到本机

    upstream httpd_server {
        server 192.168.2.20:80 weight=1;
        server 192.168.2.22:80 weight=1;
        server 127.0.0.1 backup;
    }

注释原本的

添加新的location

        location / {
            proxy_pass http://httpd_server;
            proxy_set_header Host $http_host;
        }

如果后端真是的服务器设置有类似防盗链或者根据http请求头中的host字段来进行路由或判断功能的话，如果反向代理层的nginx不重写请求头中的host字段，将会导致请求失败，报400错误，所以需要添加host头，将头信息返回服务器
proxy_set_header Host $http_host;

2.keepalived配置

vi /etc/keepalived/keepalived.conf

global_defs {
   router_id Nginx_01
   }

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
    chk_http_port
    }

    virtual_ipaddress {
        192.168.2.100
    }
}

备用nginx配置

! Configuration File for keepalived

global_defs {
   router_id Nginx_02
   }

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 145
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }

    virtual_ipaddress {
        192.168.2.100
    }
}

3.测试

重启测试

开启nginx：nginx
重启nginx：killall -1 nginx
重启keepalived：systemctl restart keepalived

关闭主nginx上的keepalived

systemctl stop keepalived.service 

查看备用nginx