Nginx is a high-performance open source web server and reverse proxy server, which is lightweight and highly scalable. The following is a detailed explanation of the principle and deployment method of Nginx:
**Nginx's principle:**
1. Handling concurrent requests: Nginx uses an event-driven asynchronous architecture to handle a large number of concurrent requests by using a small number of worker threads. Each worker thread receives and processes requests through an event model (such as epoll or kqueue) instead of the traditional one-thread-one-connection model.
2. Reverse proxy: Nginx can be used as a reverse proxy server to forward requests from the client to the backend application server. It can evenly distribute requests to multiple application servers according to the load balancing algorithm to improve system performance and reliability.
3. Static file service: Nginx can efficiently provide static file services, cache files and return them directly to the client, reducing the pressure on the back-end application server.
4. SSL/TLS encryption: Nginx supports SSL/TLS protocol, which can provide secure HTTPS connection and encrypted communication.
5. Dynamic modules: Nginx supports extending its functions by loading dynamic modules, and can flexibly add new modules as needed.
**Nginx deployment method:**
1. Installation: First, you need to install Nginx on the server. The exact installation method varies by operating system. For example, under Ubuntu, you can use the apt command to install: `sudo apt install nginx`.
2. Configuration: The main configuration file of Nginx is `nginx.conf`. You can configure the behavior of Nginx by editing this file, such as listening port, reverse proxy rules, cache configuration, etc. Additionally, you can create configuration files in the `sites-available` directory to define different sites.
3. Start and reload: After the installation is complete, you can start Nginx with the command `sudo service nginx start`. If you have modified the configuration file, you can use `sudo service nginx reload` command to reload the configuration file to make it take effect.
4. Static file service: By default, Nginx will put static files in the `/var/www/html/` directory, you can put the files you need to provide in this directory, and access them through the server IP or domain name These static files.
5. Reverse proxy configuration: If you need to forward requests to the backend application server, you can add reverse proxy rules to the configuration file. For example, the `proxy_pass` directive can be used to forward requests to specific backend servers.
6. HTTPS configuration: If you need to enable the HTTPS protocol, you need to obtain an SSL certificate and configure the certificate and private key into Nginx. You can then add the relevant SSL/TLS configuration in the configuration file.
Please note that the above is only a description of the basic deployment methods of Nginx. Nginx has more advanced functions and configuration options. You can refer to official documents or other resources to learn and use Nginx in depth.