Preamble
Nginx was designed and developed by lgor Sysoev for the second most visited rambler.ru site in Russia. Since its release in 2004, it has been close to maturity and perfection with the power of open source.
Nginx is rich in functions and can be used as an HTTP server, reverse proxy server, and mail server. Support FastCGI, SSL, Virtual Host, URL Rewrite, Gzip and other functions. And supports many third-party module extensions.
Nginx's stability, feature set, sample configuration files, and low consumption of system resources made him come from behind, with a usage rate of 12.18% of active websites around the world, or about 22.2 million websites.
Niubi is almost the same. If you are not satisfied, you can find such boasting on Baidu Encyclopedia or some books, everywhere.
Nginx common functions
1. Http proxy, reverse proxy: As one of the most commonly used functions of web servers, especially reverse proxy.
Here I give two pictures to explain the forward agent and the response agent. For details, you can read the information.
When Nginx is a reverse proxy, it provides stable performance and can provide flexible configuration forwarding functions. Nginx can adopt different forwarding strategies according to different regular matching, such as going to the file server at the end of the image file, and going to the web server for dynamic pages. play. And Nginx performs error page jumps, abnormal judgments, etc. on the returned results. If the distributed server is abnormal, he can re-forward the request to another server, and then automatically remove the abnormal server.
2. Load balancing
There are two types of load balancing strategies provided by Nginx: built-in strategies and extended strategies. The built-in strategies are round robin, weighted round robin, and IP hash. The expansion strategy is just imaginative. There are only things you can't think of that he can't do. You can refer to all the load balancing algorithms and find them one by one to implement them.
The above three figures, understand the implementation of these three load balancing algorithms
The IP hash algorithm performs a hash operation on the IP requested by the client, and then distributes the request of the same client IP to the same server for processing according to the hash result, which can solve the problem of session non-sharing.
3. Web cache
Nginx可以对不同的文件做不同的缓存处理,配置灵活,并且支持FastCGI_Cache,主要用于对FastCGI的动态程序进行缓存。配合着第三方的ngx_cache_purge,对制定的URL缓存内容可以的进行增删管理。
4、Nginx相关地址
源码:https://trac.nginx.org/nginx/browser
官网:http://www.nginx.org/
Nginx配置文件结构
如果你下载好啦,你的安装文件,不妨打开conf文件夹的nginx.conf文件,Nginx服务器的基础配置,默认的配置也存放在此。
在nginx.conf的注释符号位#
nginx文件的结构,这个对刚入门的同学,可以多看两眼。
默认的config
#user nobody; worker_processes 1; #error_log logs/error.log; #error_log logs/error.log notice; #error_log logs/error.log info; #pid logs/nginx.pid; events { worker_connections 1024; } http { include 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 logs/access.log main; sendfile on; #tcp_nopush on; #keepalive_timeout 0; keepalive_timeout 65; #gzip on; server { listen 80; server_name localhost; #charset koi8-r; #access_log logs/host.access.log main; location / { root html; index index.html index.htm; } #error_page 404 /404.html; # redirect server error pages to the static page /50x.html # error_page 500 502 503 504 /50x.html; location = /50x.html { root html; } # proxy the PHP scripts to Apache listening on 127.0.0.1:80 # #location ~ \.php$ { # proxy_pass http://127.0.0.1; #} # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000 # #location ~ \.php$ { # root html; # fastcgi_pass 127.0.0.1:9000; # fastcgi_index index.php; # fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name; # include fastcgi_params; #} # deny access to .htaccess files, if Apache's document root # concurs with nginx's one # #location ~ /\.ht { # deny all; #} } # another virtual host using mix of IP-, name-, and port-based configuration # #server { # listen 8000; # listen somename:8080; # server_name somename alias another.alias; # location / { # root html; # index index.html index.htm; # } #} # HTTPS server # #server { # listen 443 ssl; # server_name localhost; # ssl_certificate cert.pem; # ssl_certificate_key cert.key; # ssl_session_cache shared:SSL:1m; # ssl_session_timeout 5m; # ssl_ciphers HIGH:!aNULL:!MD5; # ssl_prefer_server_ciphers on; # location / { # root html; # index index.html index.htm; # } #} }
nginx文件结构
... #全局块
events { #events块
...
}
http #http块
{
... #http全局块
server #server块
{
... #server全局块
location [PATTERN] #location块
{
...
}
location [PATTERN]
{
...
}
}
server
{
...
}
... #http全局块
}
1、全局块:配置影响nginx全局的指令。一般有运行nginx服务器的用户组,nginx进程pid存放路径,日志存放路径,配置文件引入,允许生成worker process数等。
2、events块:配置影响nginx服务器或与用户的网络连接。有每个进程的最大连接数,选取哪种事件驱动模型处理连接请求,是否允许同时接受多个网路连接,开启多个网络连接序列化等。
3、http块:可以嵌套多个server,配置代理,缓存,日志定义等绝大多数功能和第三方模块的配置。如文件引入,mime-type定义,日志自定义,是否使用sendfile传输文件,连接超时时间,单连接请求数等。
4、server块:配置虚拟主机的相关参数,一个http中可以有多个server。
5、location块:配置请求的路由,以及各种页面的处理情况。
下面给大家上一个配置文件,作为理解,同时也配入我搭建的一台测试机中,给大家示例。
########### 每个指令必须有分号结束。################# #user administrator administrators; #配置用户或者组,默认为nobody nobody。 #worker_processes 2; #允许生成的进程数,默认为1 #pid /nginx/pid/nginx.pid; #指定nginx进程运行文件存放地址 error_log log/error.log debug; #制定日志路径,级别。这个设置可以放入全局块,http块,server块,级别以此为:debug|info|notice|warn|error|crit|alert|emerg events { accept_mutex on; #设置网路连接序列化,防止惊群现象发生,默认为on multi_accept on; #设置一个进程是否同时接受多个网络连接,默认为off #use epoll; #事件驱动模型,select|poll|kqueue|epoll|resig|/dev/poll|eventport worker_connections 1024; #最大连接数,默认为512 } http { include mime.types; #文件扩展名与文件类型映射表 default_type application/octet-stream; #默认文件类型,默认为text/plain #access_log off; #取消服务日志 log_format myFormat '$remote_addr–$remote_user [$time_local] $request $status $body_bytes_sent $http_referer $http_user_agent $http_x_forwarded_for'; #自定义格式 access_log log/access.log myFormat; #combined为日志格式的默认值 sendfile on; #允许sendfile方式传输文件,默认为off,可以在http块,server块,location块。 sendfile_max_chunk 100k; #每个进程每次调用传输数量不能大于设定的值,默认为0,即不设上限。 keepalive_timeout 65; #连接超时时间,默认为75s,可以在http,server,location块。 upstream mysvr { server 127.0.0.1:7878; server 192.168.10.121:3333 backup; #热备 } error_page 404 https://www.baidu.com; #错误页 server { keepalive_requests 120; #单连接请求上限次数。 listen 4545; #监听端口 server_name 127.0.0.1; #监听地址 location ~*^.+$ { #请求的url过滤,正则匹配,~为区分大小写,~*为不区分大小写。 #root path; #根目录 #index vv.txt; #设置默认页 proxy_pass http://mysvr; #请求转向mysvr 定义的服务器列表 deny 127.0.0.1; #拒绝的ip allow 172.18.5.54; #允许的ip } } }
上面是nginx的基本配置,需要注意的有以下几点:
1、1.$remote_addr 与$http_x_forwarded_for 用以记录客户端的ip地址; 2.$remote_user :用来记录客户端用户名称; 3.$time_local : 用来记录访问时间与时区;4.$request : 用来记录请求的url与http协议;
5.$status : 用来记录请求状态;成功是200, 6.$body_bytes_s ent :记录发送给客户端文件主体内容大小;7.$http_referer :用来记录从那个页面链接访问过来的; 8.$http_user_agent :记录客户端浏览器的相关信息;
2、惊群现象:一个网路连接到来,多个睡眠的进程被同事叫醒,但只有一个进程能获得链接,这样会影响系统性能。
3、每个指令必须有分号结束。
总结
如果你在开发过程中使用啦这些技术,或者你要使用遇到啦什么问题,欢迎加入左上角的群,我们一起讨论学习,本篇未完待续。