Could anyone please explain pros/cons when using WSGI VS uWSGI with Nginx.
Currently i am building up a production server for the Django website which i have prepared but unable to decide whether should i go with WSGI or uWSGI. Could you please explain in detail what differentiates each configuration? Which configuration should scale the best?
Thanks in advance
Ok, guys this confusion is because of lack of detail from several sources, and the naming of these protocols, and what WSGI actually is.
Summary:
- WSGI and uwsgi both ARE protocols, not servers. It is used to communicate with web servers for load balancing and especially to take advantage of extra features that pure HTTP can not provide. So far Nginx and Cherokee have implemented this protocol.
- uWSGI is a server and one of the protocols it implements is WSGI (do not confuse the uwsgi protocol with the uWSGI server). WSGI is a Python specification. There are several implementations of the WSGI specification and it's intended to be used for more than just application servers/web servers, but there are quite a few WSGI application servers (ie. CherryPy, which also happens to have a production ready WSGI compliant web server, if you weren't confused enough already!).
- Comparing uwsgi to WSGI is comparing oranges to apples.
It is generally best to run Python in a separate process from your main web server. That way, the web server can have lots of tiny threads that serve static content really fast, while your separate Python processes will be big and heavyweight and each be running their own Python interpreter. So plain WSGI
is bad, because it bloats every single one of your nginx threads with a big Python interpreter. Using flup
or gunicorn
or uWSGI
behind nginx
is much better, because that frees up nginx to simply serve content, and lets you choose how many tiny light nginx threads to run, independently of your choice of how many heavyweight Python threads you bring up to serve dynamic content. People seem very happy with gunicorn
at the moment, but any of those three options should work fine.
Going forward, it also frees you up to move the Python to another server when load starts to get serious.
I believe this right here http://flask.pocoo.org/docs/deploying/uwsgi/ is a good answer to clear up the confusion. The question isnt silly, happens to anyone who sees the two terms and has no prior info on how things work outside of mod_PHP world (for e.g. nothing against php or folks)
The site does well to explain in practical terms what is needed and what is the difference as well as a good deployment example for nginx.
This blog post is a very detailed comparison of alot of Python WSGI servers, with a summary and some recommendations at the end.