What role does Gunicorn play in deploying Python applications and why is it necessary?

Gunicorn is a WSGI HTTP server for Python applications. Its main role is to accept HTTP requests from clients and pass them to the Python application, acting as an intermediary layer between the web server (such as Nginx) and the application itself.

Why is it needed:

• Python applications, especially those written using frameworks like Django or Flask, are not designed for direct internet interaction and multithreading.
• Gunicorn launches multiple worker processes that handle requests in parallel, increasing performance and stability.
• It manages the application's lifecycle, restarting workers in case of failures.

Example of running a Flask application with Gunicorn:

gunicorn myapp:app --workers 3

Here, myapp is the module with the application, and app is the Flask object. Gunicorn will create 3 worker processes to handle requests.