Load balancing configuration instruction nginx and implement static and dynamic separation, different display pages according to the user to access

An additional Apache configuration file parameters

Bowen's early environment ready reference: blog "nginx simple load balancing"

Load balancing configuration instructions detailed
load balancing module: upstream
functions: load balancing may be defined in the node information backend

Reference configuration (current mode is least_conn)

[root@lb01 conf.d]# cat /etc/nginx/nginx.conf
user  nginx;
worker_processes  1;
error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;
events {
    worker_connections  1024;
}
http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';
    access_log  /var/log/nginx/access.log  main;
    sendfile        on;
    keepalive_timeout  65;
    #include /etc/nginx/conf.d/*.conf;
    upstream oldboy {
     least_conn;
     server 10.0.0.7:80;  
     server 10.0.0.8:80; 
     server 10.0.0.9:80; 
 }
    server {
    listen 80;
    server_name localhost;
    location / {
    proxy_pass  http://oldboy;
  }
 }

}

Function module upstream :( HTTP module in the module configuration in general, there is a back upstream of HTTP} brackets)
Effective way to define the load balancer
1) The default resource allocation polling of: evenly distributed
2) resource allocation information (weight) weight information is arranged to scale

 upstream oldboy {
     server 10.0.0.7:80 weight=10;  
     server 10.0.0.8:80 weight=1; 
     server 10.0.0.9:80; 
 }
    server {
    listen 80;
    server_name localhost;
    location / {
    proxy_pass  http://oldboy;
  }
 }

3) allocate more resources to allocate resources based on the number of server connections will be more leisure least_conn

  upstream oldboy {
     least_conn;
     server 10.0.0.7:80;  
     server 10.0.0.8:80; 
     server 10.0.0.9:80; 
 }
    server {
    listen 80;
    server_name localhost;
    location / {
    proxy_pass  http://oldboy;
  }
 }

4) According to the resource allocation request processing capability: fair The node processing efficiency

5) According to hash algorithm to allocate resources information ip_hash test results is always a web of information, the equivalent of a guest chef in charge of a food table, it has always been a chef in charge.

 upstream oldboy {
     ip_hash; 
     server 10.0.0.7:80;  
     server 10.0.0.8:80; 
     server 10.0.0.9:80; 
 }
    server {
    listen 80;
    server_name localhost;
    location / {
    proxy_pass  http://oldboy;
  }
 }

Back-end node health check LVS no health checks.
Users access the site www.oldboy.com - normal service load balancing --web01 normal response

1) Set the number of visits to a node failure several opportunities (continuous) max_files default value of 1

 upstream oldboy {
     server 10.0.0.7:80 max_fails=3;  
     server 10.0.0.8:80 max_fails=3; 
     server 10.0.0.9:80; 
 }
    server {
    listen 80;
    server_name localhost;
    location / {
    proxy_pass  http://oldboy;
  }
 }

2) Check the settings again after a long timeout nodes to check with the issue of
default is 10s

upstream oldboy {
     server 10.0.0.7:80 max_fails=3 fail_timeout=10s;  
     server 10.0.0.8:80 max_fails=3 fail_timeout=10s; 
     server 10.0.0.9:80; 
 }
    server {
    listen 80;
    server_name localhost;
    location / {
    proxy_pass  http://oldboy;
  }
 }

3) Set Hot Standby server (couples the spare)

  upstream oldboy {
     server 10.0.0.7:80;  
     server 10.0.0.8:80; 
     server 10.0.0.9:80 backup; 
 }
    server {
    listen 80;
    server_name localhost;
    location / {
    proxy_pass  http://oldboy;
  }
 }

反向代理模块：proxy_pass
1）指定调用集群信息
proxy_pass http://oldboy;
2）识别用户请求host信息
proxy_set_header host $host; —设置修改负载均衡HTTP请求报文中请求头内容
调用负载均衡HTTP请求报文中的host提取，并修改为$host （调用用户请求报文中host）

修改web节点信息：
1加载bbs网站信息 （web01 web02 web03）

   vim /etc/nginx/nginx.conf
	  include /etc/nginx/conf.d/www.conf;
      include /etc/nginx/conf.d/bbs.conf;

2 在站点目录下创建首页文件

  web01: 
	  echo  bbs01-info >/html/bbs/index.html 
	  web02
	  echo  bbs02-info >/html/bbs/index.html 
	  web03
	  echo  bbs03-info >/html/bbs/index.html 

提示：这里的bbs.conf文件内容一致；都是：

server {
  listen 80;
  server_name  bbs.oldboy.com;
  location / {
  root  /html/bbs/;
  index  index.html;
} 
}

3 访问测试过程（lb01）
注意：这个是在负载均衡服务器作为用户进行访问的。也就是没有负载均衡，用户直接网站时。一切正常。

[root@lb01 conf.d]# curl -H host:bbs.oldboy.com  10.0.0.7
web01-info
[root@lb01 conf.d]# curl -H host:bbs.oldboy.com  10.0.0.7
bbs01-info
[root@lb01 conf.d]# curl -H host:bbs.oldboy.com  10.0.0.8
bbs02-info
[root@lb01 conf.d]# curl -H host:bbs.oldboy.com  10.0.0.9
bbs03-info
[root@lb01 conf.d]# curl -H host:www.oldboy.com  10.0.0.9
web03-info
[root@lb01 conf.d]# curl -H host:www.oldboy.com  10.0.0.8
web02-info
[root@lb01 conf.d]# curl -H host:www.oldboy.com  10.0.0.7
web01-info

如果是用户经过负载均衡在访问网站时：（在web服务器作为用户，访问负载服务器）

[root@web01 conf.d]# curl -H host:bbs.oldboy.com  10.0.0.31
web02-info
[root@web01 conf.d]# curl -H host:bbs.oldboy.com  10.0.0.31
web01-info
[root@web01 conf.d]# curl -H host:bbs.oldboy.com  10.0.0.31
web02-info
[root@web01 conf.d]# curl -H host:www.oldboy.com  10.0.0.31
web01-info
[root@web01 conf.d]# curl -H host:www.oldboy.com  10.0.0.31
web02-info
[root@web01 conf.d]# curl -H host:www.oldboy.com  10.0.0.31

出现了问题：怎么访问bbs出现www的页面？？？
原因：因为两个网址都符合四层的匹配条件，然后因为在主配置文件中的文件加载顺序的原因，导致访问不同域名仍然出现同一个服务器内容。最直接的原因是因为post头部携带的信息发生了改变，不再是一开始指定的www.oldboy.com信息（默认修改为了oldboy信息）

nginx.conf中include位置越靠前越优先加载
如果include是*.conf,则根据字母顺序优先级匹配

而负载均衡的识别host头部信息的作用就可以解决这个问题

负载均衡配置：

    upstream oldboy {
     server 10.0.0.7:80;  
     server 10.0.0.8:80; 
     server 10.0.0.9:80 backup; 
 }
    server {
    listen 80;
    server_name localhost;
    location / {
    proxy_pass  http://oldboy;
    proxy_set_header host $host;
  }
 }

再次测试：

[root@web01 conf.d]# curl -H host:www.oldboy.com  10.0.0.31
web01-info
[root@web01 conf.d]# curl -H host:www.oldboy.com  10.0.0.31
web02-info
[root@web01 conf.d]# curl -H host:bbs.oldboy.com  10.0.0.31
bbs01-info
[root@web01 conf.d]# curl -H host:bbs.oldboy.com  10.0.0.31
bbs02-info
[root@web01 conf.d]# curl -H host:bbs.oldboy.com  10.0.0.31
bbs01-info

一切正常。利用负载均衡可以加载不同网站页面。

3）识别用户真实IP地址信息
$http_x_forwarded for —日志格式变量用于记录真实用户IP地址

	 用户访问  --- 负载均衡(记录用户IP地址)  --- web服务器(查看用户IP地址)
	                HTTP请求报文(IP地址信息)  --> 识别真实用户地址 

proxy_set_header —设置负载均衡请求头的信息
proxy_set_header X-Forwarded-For $remoe_addr;

负载均衡配置：

   upstream oldboy {
     server 10.0.0.7:80;  
     server 10.0.0.8:80; 
     server 10.0.0.9:80 backup; 
 }
    server {
    listen 80;
    server_name localhost;
    location / {
    proxy_pass  http://oldboy;
    proxy_set_header host $host;
    proxy_set_header X-Forwarded-For $remote_addr;
  }
 }

这个配置好以后在日志中查看真实的IP地址。
注意：如图所示，访问负载均衡，负载均衡将访问给到了第一台web01服务器，那么在web01的服务器上查看日志才能看到真实IP地址，不能是在负载均衡的服务器上查看日志。那样是看不到的。

日志信息如下：

10.0.0.31 - - [17/Feb/2020:09:31:09 -0500] "GET / HTTP/1.0" 200 11 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.117 Safari/537.36" "10.0.0.1"
10.0.0.31 - - [17/Feb/2020:09:31:09 -0500] "GET / HTTP/1.0" 200 11 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.117 Safari/537.36" "10.0.0.1"
10.0.0.31 - - [17/Feb/2020:09:35:00 -0500] "GET / HTTP/1.0" 200 11 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.117 Safari/537.36" "10.0.0.1"

4)负载均衡健康检查并不能对页面信息做检测检查，如何处理
实现对网站页面进行健康检查
proxy_next_upstream error | timeout | invalid_header | http_500 | http_502 | http_503 | http_504 | http_403 | http_404 | http_429

解决：监控网站页面是否正常，负载均衡只返回用户正确页面。
如下的配置中：
如果页面出现403的错误，那么负载就不会将请求发送给他，保证用户看不到出错页面。

负载配置信息：

    upstream oldboy {
     server 10.0.0.7:80;  
     server 10.0.0.8:80; 
     server 10.0.0.9:80 backup; 
 }
    server {
    listen 80;
    server_name localhost;
    location / {
    proxy_pass  http://oldboy;
    proxy_set_header host $host;
    proxy_set_header X-Forwarded-For $remote_addr;
    proxy_next_upstream  error  timeout invalid_header  http_403;
  }
 }

负载均衡企业中实际应用
1)实现网站动静分离过程
动静分离的架构 --URI信息不同
访问URI信息 静态资源 —静态集群
访问URI信息 动态资源 ----动态集群

架构环境规划:
	   用户请求（URI）	处理请求服务器	                 站点目录	        功能
       /upload	        10.0.0.8:80 (upload)	         html/www/upload	upload服务器
       /static	        10.0.0.7:80 (static)	         html/www/static	static静态服务器
       /             	10.0.0.9:80 (默认)	             html/www	        默认

第一个历程：在后端节点上创建不同集群节点资源
· 上传集群节点配置: 10.0.0.8
编写nginx.conf / 修改站点目录
www - server 站点目录 /html/www/upload

   mkdir /html/www/upload -p
         echo upload-page > /html/www/upload/index.html

   · 静态集群节点配置: 10.0.0.7
     编写nginx.conf / 修改站点目录
	 www - server  站点目录 /html/www/static/

 mkdir /html/www/static
         echo static-page >/html/www/static/index.html

第二个历程：修改负载均衡j节点的配置文件

    upstream  upload {
    server  10.0.0.8:80;
}
    upstream   static { 
    server  10.0.0.7:80;
}
    upstream   default {
    server   10.0.0.9:80;
}
    server  { 
    listen  80;
    server_name  localhost;
    location  /upload { 
    proxy_pass    http://upload;
    proxy_set_header host  $host;
    proxy_set_header X-Forwarded-For  $remote_addr;   
}
    location /static {
    proxy_pass    http://static;
    proxy_set_header  host  $host;
    proxy_set_header X-Forwarded-For  $remote_addr;   
    proxy_next_upstream  error timeout invalid_header  http_403;   
}
    location / {
              proxy_pass    http://default;
              proxy_set_header host $host;
              proxy_set_header X-Forwarded-For $remote_addr;
              proxy_next_upstream  error timeout invalid_header  http_403;
          }
}
}

Third course: In fact, there is no third course, but error-prone, and put this to put down here.
web01The www.conf profile

[root@web01 static]# cat /etc/nginx/conf.d/www.conf 
server {
  listen 80;
  server_name  www.oldboy.com;
  location / {
  root  /html/www/;
  index  index.html;
} 
}

web02The www.conf profile

server {
  listen 80;
  server_name  www.oldboy.com;
  location / {
  root  /html/www/;
  index  index.html;
} 
}

Note 新添加的文件后属主属组是否和/html/www下面the same.
Note:单点配置IP地址以及动态静态划分和负载主配置文件中指定的是否一样 .

2) to achieve different depending on the display page the UE

   架构环境规划
   手机端集群  iphone   10.0.0.7    显示页面信息  iphone-page
   电脑端集群  PC       10.0.0.8    显示页面信息  PC-page

First course: Configuring load balancing node information

   iphone集群中的节点: 10.0.0.7
   echo iphone-page > /html/www/index.html

   PC集群中的节点: 10.0.0.8
   echo PC-page > /html/www/index.html 	 

Second course: load balancing configuration information

   upstream PC {
          server 10.0.0.8:80;
   }
   upstream iphone {
      server 10.0.0.7:80;
   }
   
   server {
      listen        80;
      server_name   localhost;
      location / {
          if ($http_user_agent ~* "iphone|Android") {
             proxy_pass    http://iphone;
          }
          if ($http_user_agent ~* "chrome") {
             proxy_pass    http://PC;
          }
          proxy_set_header host $host;
          proxy_set_header X-Forwarded-For $remote_addr;
          proxy_next_upstream  error timeout invalid_header  http_403;
      }
   }