Mastering Python Web Deployment: CGI, FastCGI, WSGI, uWSGI & More

Avoid Exposing Your Server

Deploying Python web applications is more complex than PHP because of the variety of tools and limited native server support. Understanding the underlying protocols—CGI, FastCGI, WSGI, uWSGI, and related servers—helps you make informed deployment choices.

CGI (Common Gateway Interface)

CGI defines a standard interface between a web server and external programs. It creates a new process for each request, which leads to high overhead and poor performance under heavy load.

FastCGI

FastCGI improves on CGI by keeping interpreter processes alive, eliminating the fork‑and‑execute cost for each request. It supports multiple persistent processes, reduces memory and CPU usage, and can run on separate hosts, offering at least a five‑fold speed increase over classic CGI.

WSGI (Web Server Gateway Interface)

WSGI is a Python‑specific standard that separates the web server (gateway) from the application/framework. It passes an environment dictionary and a callable to the application, allowing middleware to modify requests, enable multiple apps in one process, and perform load balancing.

uWSGI Protocol

uWSGI is a proprietary protocol used by the uWSGI server, claimed to be up to ten times faster than FastCGI. It implements WSGI, HTTP, and other protocols, and can be extended with plugins written in C, C++, or Objective‑C.

uWSGI Server

The uWSGI project provides a full‑stack solution for deploying distributed web applications. It supports many languages, offers high performance, low memory usage, multi‑app management, detailed logging, and extensive configurability.

Gunicorn

Gunicorn (Green Unicorn) is a pre‑forking Python WSGI server inspired by Ruby’s Unicorn. It works well with Django, runs multiple worker processes, and is lightweight, though it lacks HTTP/1.1 support and can be slower than uWSGI in high‑concurrency scenarios.

Tornado

Tornado is both an asynchronous Python web framework and a non‑blocking HTTP server. It can serve WSGI applications via tornado.wsgi.WSGIContainer when combined with other frameworks like Flask.

wsgiref

Python’s standard library includes wsgiref, a reference implementation of a WSGI server used by Django’s development server.

When deploying a Django project, you typically avoid the built‑in development server and choose uWSGI or Gunicorn (or Tornado) depending on performance needs. A common production setup is Nginx as a reverse proxy and static file server, with uWSGI handling Django and Gunicorn managing Tornado, each supervised by supervisord. Because of Python’s GIL, a multi‑process model (one master, multiple workers) is standard.

Source: titanjf, www.cnblogs.com/titanjf/p/python-web-deploy.html