Shulou(Shulou.com)06/01 Report--

This article mainly introduces the daily management of Nginx example analysis, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor with you to understand.

Nginx (pronounced engine x) is a lightweight Web server / reverse proxy server and e-mail (IMAP/POP3) proxy server and is distributed under a BSD-like protocol. Its characteristic is that it occupies less memory and has strong concurrency ability. in fact, the concurrency ability of nginx does perform well in the same type of web server. Chinese mainland uses nginx website users: Sina, NetEase, Tencent and so on. This article briefly describes the basic features of Nginx and a brief description of its configuration file.

I. the working process of Nginx

1. A main process: the main purpose of the main process is to read and evaluate the configuration, start, terminate and maintain the worker process, and create, bind and close sockets. 2. Multiple worker processes: the worker processes web requests. Nginx uses an event-based model and operating system-related mechanisms to effectively allocate requests between work processes. Responsible for parsing the http protocol; providing reverse proxy and filtering functions; nginx any other tasks that can be completed; the number of worker processes is defined in the configuration file, which can be defined as a fixed number, or automatically adjusted according to the number of available CPU cores. 3, cache loader (cache loader): check the cache objects in the cache storage; use cache metadata to establish an in-memory database; receive, input and process connections from the client; 4, cache manager (cache manager): cache invalidation and expiration check; 5, define the working mode of Nginx based on the configuration file and the work of the module is determined in the configuration file. By default, the configuration file is nginx.conf, which is usually located in / usr/local/nginx/conf, / etc/nginx, or / usr/local/etc/nginx directory.

II. Nginx characteristics

1. The modularization feature of Nginx Nginx server is similar to Apache httpd and is built based on modularization. When installing and deploying Nginx servers, you must follow: minimize module installation in order to save the performance impact of useless modules on Nginx and take up system resources. A, divide the Nginx core module functionally: including the Nginx kernel module and the event-driven module http server module: this kind of module includes three types of modules That is, the kernel module and standard module of HTTP and the optional HTTP module b, the third-party module c of the official module is divided from the release module, the optional module (Main and Events) is divided from the optional module of the module, the modular design of Nginx functional characteristics, Good scalability and high reliability master-- > worker low memory consumption 10000 keep-alive connections in Nginx only consume 2.5MB support hot deployment without downtime update configuration files, change log files, update server version basic functions: web server with static resources Ability to cache open file descriptors Reverse proxy server for http, smtp, pop3 protocols, caching, load balancing; support FastCGI (fpm); modularization, non-DSO mechanism, filter zip,SSI and image resizing; support SSL; non-blocking, event-driven, one master to generate one or more worker, each worker responds to n requests; extension function: virtual host based on name and IP Support keepalive support smooth upgrade custom access log, support log buffer to improve log storage performance support url rewrite support path alias support IP-based and user-based access control support rate limit, support concurrency limit Nginx basic architecture: a master process Generate one or more worker event drivers: epoll, kqueue, / dev/poll (event ports) message notification: select, poll, rt signals support sendfile, sendfile64 support AIO support mmap module type: core module Standard HTTP modules Optional HTTP modules Mail modules 3rd party modules

III. Start, stop and reload configuration files of Nginx

1. Start using the command directly. For example,-c is followed by the path and name of the configuration file. If-c is omitted, the default configuration file # / usr/sbin/nginx-c / etc/nginx/nginx.conf is used to start using service. Examples are as follows: # service nginx start2, common management syntax nginx-s signal after startup, where signal can be the following values stop-fast shutdown quit-graceful shutdown reload-reloading the configuration file reopen-reopening the log files3, nginx stop stop-stop quickly, rough mode, no new requests are accepted, and requests that have been processed are forcibly closed. Examples are as follows: # / usr/sbin/nginx-s stop quit-elegant stop No longer accept new requests, wait for the current worker process to complete the current server request, and stop nginx # / usr/sbin/nginx-s quit to close nginx # service nginx stop4 through service, reload the configuration file reload-any changes to the configuration file nginx configuration file will not take effect immediately Need to use the reload command or restart nginx once the main process receives a signal to reload the configuration, it checks the syntax correctness of the new configuration file and tries to apply the new configuration. Otherwise, the main process rolls back the changes and continues to work with the old configuration file. The old worker process, receives the command to close, stops accepting the new connection, and continues to serve the current request, until the current request service is completed, the old worker process exit process signal can be sent to nginx, through Linux/Unix 's kill tool to kill the process. In this case, a signal with a process ID is sent directly to a process. By default, nginx's main process, PID, is written to the nginx.pid file located in the / usr/local/logs or / var/run directory. For example, if the main process ID is 1628 and sends an exit signal that nginx shuts down normally, execute: kill-s QUIT 1628 to reload configuration file # service nginx reload in service mode

IV. Nginx configuration file structure

1. Configuration description a, nginx configuration file is composed of different modules, through the modular way to achieve different functions. B. configuration instructions are divided into simple instructions and block instructions. A simple instruction, including the name, separates the arguments with spaces and ends with a semicolon (;). C. A block instruction is composed of one or more simple instructions with the same structure, using a set of {} parentheses to indicate the end of the block. D, context: the instruction of a block contains curly braces of other instructions, which are called contexts (for example, event, HTTP, server, and location). Any instruction placed outside the context of the configuration file is considered to be in the main context. E, check the configuration file syntax: nginx-t f, specify the configuration file to be loaded by nginx: nginx-c 2, the configuration file constitutes Nginx configuration file structure is mainly composed of the following parts. . Events # Events is used to configure IO models, such as epoll, kqueue, select, or poll, which are required modules. {. } http # http context is designed to configure modules for http {# including client class instructions, file IO class instructions, hash class instructions, socket class instructions, etc. Server # is used to define attributes related to virtual servers. Common instructions include backlog, rcvbuf, bind and sndbuf. } server {. }. } 3. Basic nginx.conf configuration description # more / etc/nginx/nginx.conf#user nobody; # specifies the user and group worker_processes 1 running the worker process; # the number of worker threads; usually the number of physical CPU cores minus 1 # error_log logs/error.log; # configuration error log file location and logging level # error_log logs/error.log notice;# can be used in main, http, server and location contexts # error_log logs/error.log info; # syntax format is error_log file | stderr [debug | info | notice | warn | error | crit | emerg] # pid logs/nginx.pid; # specify the pid storage path events {worker_connections 1024; the maximum number of concurrent requests that each worker process can respond to } 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"; # this section is used to set the format and location of the access log # access_log logs/access.log main; sendfile on # tcp_nopush on; # keepalive_timeout 0; keepalive_timeout 65; # timeout for keeping a connection. Default is 65s # gzip on; # whether to enable gzip compression server {listen 80; # define listening port Author:Leshami server_name localhost; # define listening host Blog: http://blog.csdn.net/leshami # charset koi8-r # define character set # access_log logs/host.access.log main; # access log file storage path location / {# location is usually used in the context of server to set the access attributes of a URI. Location can be nested. Root html; # default home page file location, where is currently the relative path, / etc/nginx/html index index.html index.htm; # first page file order, if index.html cannot be found, find index.htm} # the following section redirects the error page # error_page 404 / 404.html according to the http status code # redirect server error pages to the static page / 50x.html # error_page 500 502 503 504 / 50x.html; location = / 50x.html {root html;}}

5. Get Nginx help

[root@wms] # nginx-hnginx version: nginx/1.8.0Usage: nginx [-? hvVtq] [- s signal] [- c filename] [- p prefix] [- g directives] Options: -,-h: this help-v: show version and exit-V: show version and configure options then exit-t: test configuration and exit-Q: suppress non-error messages during configuration testing-s signal: send signal to a master process: stop, quit, reopen Reload-p prefix: set prefix path (default: / etc/nginx/)-c filename: set configuration file (default: / etc/nginx/nginx.conf)-g directives: set global directives out of configuration file Thank you for reading this article carefully I hope the article "sample Analysis of Nginx Daily Management" shared by the editor will be helpful to you. At the same time, I also hope that you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.