Shulou(Shulou.com)06/02 Report--

Nginx is a high-performance HTTP and reverse proxy server known for its high stability, rich feature set, sample configuration files, and low system resource consumption.

Nginx features handle static files, index files and automatic indexing; open file descriptor buffering. No cache reverse proxy acceleration, simple load balancing and fault tolerance. FastCGI, simple load balancing and fault tolerance. Modular structure. Including gzipping, byte ranges, chunked responses, and SSI-filter and other filter. If FastCGI or another proxy server processes multiple SSI that exist in a single page, the process can be run in parallel without waiting for each other. Support SSL and TLSSNI. Main applications 1. Static HTTP server

First of all, Nginx is a HTTP server, which can present static files (such as HTML, pictures) on the server to the client through the HTTP protocol.

Configuration:

Server {listen 80; # port number location / {root / usr/share/nginx/html; # static file path}}

2. Reverse proxy server

What is a reverse proxy?

The client could have accessed a website application server directly through the HTTP protocol. If the webmaster adds a Nginx in the middle, the client requests Nginx,Nginx to request the application server, and then returns the result to the client, then Nginx is the reverse proxy server.

Configuration:

Server {listen 80; location / {proxy_pass http://192.168.20.1:8080; # Application Server HTTP address}}

Since the server can be accessed directly by HTTP, why add a reverse proxy in the middle, isn't it unnecessary? What is the purpose of reverse proxy? Continue to look down, the following load balancing, virtual hosts, are based on reverse proxy implementation, of course, reverse proxy functions are not only these.

3. Load balancing

When the number of visits to the website is very large, the webmaster is happy to make money at the same time. Because the website is getting slower and slower, one server is no longer enough. Therefore, the same application is deployed on multiple servers, and the requests of a large number of users are assigned to multiple machines for processing. At the same time, the advantage is that if one of the servers goes down, as long as there are other servers running normally, it will not affect the use of users.

When we make a major upgrade to our website, we can't just shut down all the servers and then upgrade them. Usually we shut down some servers in batches to upgrade the website, and when there is a user's request, it will be assigned to other machines that are still running. When the previously turned-off machines are updated, turn them on again, and then turn off some machines in batches, such as the above cycle, until all the machines are updated. In this way, it will not affect the use of users.

Nginx can achieve load balancing through reverse proxy.

Configuration:

Upstream myapp {server 192.168.20.1 server 8080; # Application Server 1 server 192.168.20.2 http://myapp; 8080; # Application Server 2} server {listen 80; location / {proxy_pass Server}}

4. Virtual host

The website has a large number of visitors and needs load balancing. However, not all websites are so good, and some sites, due to the small number of visitors, need to save costs and deploy multiple sites on the same server.

For example, www.aaa.com and www.bbb.com are deployed on the same server, and the two domain names are resolved to the same IP address, but through the two domain names, users can open two completely different websites without affecting each other, just like visiting two servers, so they are called two virtual hosts.

Configuration:

Server {listen 80 default_server; server_name _; return 444; # filter requests from other domain names and return 444 status code} server {listen 80; server_name www.aaa.com; # www.aaa.com domain name location / {proxy_pass http://localhost:8080; # corresponding port number 8080}} server {listen 80 Server_name www.bbb.com; # www.bbb.com domain name location / {proxy_pass http://localhost:8081; # corresponding to port number 8081}}

An application is opened on the server 8080 and 8081 respectively. The client accesses through different domain names and can reverse proxy to the corresponding application server according to server_name.

The principle of virtual host is realized by whether the Host in the HTTP request header matches server_name. Interested students can study the HTTP protocol.

In addition, the server_name configuration can also filter someone to maliciously point certain domain names to your host server.

5 、 FastCGI

Nginx itself does not support languages such as PHP, but it can use FastCGI to throw requests to certain languages or frameworks for processing (such as PHP, Python, Perl).

Server {listen 80; location ~\. Php$ {include fastcgi_params; fastcgi_param SCRIPT_FILENAME / PHP file path $fastcgi_script_name; # PHP file path fastcgi_pass 127.0.0.1 location 9000; # PHP-FPM address and port number # another way: fastcgi_pass unix:/var/run/php5-fpm.sock }}

In the configuration, requests that end with .php are handed over to PHP-FPM for processing through FashCGI, and PHP-FPM is a FastCGI manager for PHP. Other materials are available for FashCGI, which are not covered in this article.

What's the difference between fastcgi_pass and proxy_pass? The following picture shows you clearly:

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