Nginx

• master进程和worker进程

• work工作原理：work process最好设置成cpu数

• worker_connection:

• HTTP服务器

   # worker对应进程的用户名，可设置nginx,nobody。master默认root
   user nginx;
  
   http {
       # 每个server块就相当于一个虚拟主机
       server {
           listen       80;
           server_name  localhost;
           client_max_body_size 1024M;
  
           location / {
               # http://localhost/ 指向/usr/local/var/www/index.html
               # http://localhost/test.html  指向/usr/local/var/www/html/test.html
               # / 匹配到/test.html 从而使root + /test.html = /usr/local/var/www/html/test.html
               root   /usr/local/var/www/html;
               index  index.html index.htm;
           }
       }
   }
  

• 静态服务器

  http {
      server {
          listen       80;
          server_name  localhost;
  		
          # 设置变量
          set $doc_root /usr/local/var/www;
  		# = 精确匹配
          # ^~ 前缀匹配。如果匹配成功，则不再匹配其他location
          # ~ 正则匹配，区分大小写
          # ~* 正则匹配，不区分大小写
          # / 通用匹配
          
          # 访问http://localhost/images/test.jpg会映射到/usr/local/var/www/images/test.jpg
          # ^~ /images/ 匹配到root+/images/test.jpg
          location ^~ /images/ {
              root $doc_root;
         }
  	   # http://localhost/test.jpg会映射到/usr/local/var/www/images/test.jpg
         location ~* \.(gif|jpg|jpeg|png|bmp|ico|swf|css|js)$ {
             root $doc_root/img;
         }
      }
  }
  

• 反向代理

  server {
      listen       80;
      server_name  localhost;
  
      location / {
          proxy_pass http://localhost:8081;
          proxy_set_header Host $host:$server_port;
          # 设置用户ip地址
          proxy_set_header X-Forwarded-For $remote_addr;
          # 当请求服务器出错去寻找其他服务器
          proxy_next_upstream error timeout invalid_header http_500 http_502 http_503; 
      }
  
  }  
  

• 负载均衡

  upstream web_servers {
      # 默认轮询
      server localhost:8081;  
      server localhost:8082; 
      # 权重
      server localhost:8081 weight=1;
      server localhost:8082 weight=3;
      server localhost:8083 weight=4 backup;  
      # ip_hash 每个请求按访问ip的hash结果分配，这样每个访客固定访问一个后端服务器，可以解决session的问题
      ip_hash;
      server localhost:8080;
      server localhost:8081;
  }
  
  server {
      listen       80;
      server_name  localhost;
      #access_log  logs/host.access.log  main;
  
  
      location / {
          proxy_pass http://web_servers;
          # 必须指定Header Host
          proxy_set_header Host $host:$server_port;
      }
   }
  

• 动静分离

  upstream web_servers {  
       server localhost:8081;  
       server localhost:8082;  
  }
  
  server {
      listen       80;
      server_name  localhost;
  
      set $doc_root /usr/local/var/www;
  
      location ~* \.(gif|jpg|jpeg|png|bmp|ico|swf|css|js)$ {
         root $doc_root/img;
      }
  
      location / {
          proxy_pass http://web_servers;
          # 必须指定Header Host
          proxy_set_header Host $host:$server_port;
      }
  
      error_page 500 502 503 504  /50x.html;  
      location = /50x.html {  
          root $doc_root;
      }
  
   }