Does Django scale?
I'm building a web application with Django. The reasons I chose Django were:
- I wanted to work with free/open-source tools.
- I like Python and feel it's a long-term language, whereas regarding Ruby I wasn't sure, and PHP seemed like a huge hassle to learn.
- I'm building a prototype for an idea and wasn't thinking too much about the future. Development speed was the main factor, and I already knew Python.
- I knew the migration to Google App Engine would be easier should I choose to do so in the future.
- I heard Django was "nice".
Now that I'm getting closer to thinking about publishing my work, I start being concerned about scale. The only information I found about the scaling capabilities of Django is provided by the Django team (I'm not saying anything to disregard them, but this is clearly not objective information...).
My questions:
- What's the "largest" site that's built on Django today? (I measure size mostly by user traffic)
- Can Django deal with 100,000 users daily, each visiting the site for a couple of hours?
- Could a site like Stack Overflow run on Django?
Answer
"What are the largest sites built on Django today?"
There isn't any single place that collects information about traffic on Django built sites, so I'll have to take a stab at it using data from various locations. First, we have a list of Django sites on the front page of the main Django project page and then a list of Django built sites at djangosites.org. Going through the lists and picking some that I know have decent traffic we see:
Instagram: What Powers Instagram: Hundreds of Instances, Dozens of Technologies.
Pinterest: Alexa rank 37 (21.4.2015) and 70 Million users in 2013
tabblo.com: 44k daily visits, see Ned Batchelder's posts Infrastructure for modern web sites.
chesspark.com: Alexa rank about 179k.
pownce.com (no longer active): alexa rank about 65k. Mike Malone of Pownce, in his EuroDjangoCon presentation on Scaling Django Web Apps says "hundreds of hits per second". This is a very good presentation on how to scale Django, and makes some good points including (current) shortcomings in Django scalability.
HP had a site built with Django 1.5: ePrint center. However, as for novemer/2015 the entire website was migrated and this link is just a redirect. This website was a world-wide service attending subscription to Instant Ink and related services HP offered (*).
"Can Django deal with 100,000 users daily, each visiting the site for a couple of hours?"
Yes, see above.
"Could a site like Stack Overflow run on Django?"
My gut feeling is yes but, as others answered and Mike Malone mentions in his presentation, database design is critical. Strong proof might also be found at www.cnprog.com if we can find any reliable traffic stats. Anyway, it's not just something that will happen by throwing together a bunch of Django models :)
There are, of course, many more sites and bloggers of interest, but I have got to stop somewhere!
Blog post about Using Django to build high-traffic site michaelmoore.com described as a top 10,000 website. Quantcast stats and compete.com stats.
(*) The author of the edit, including such reference, used to work as outsourced developer in that project.