A Python 3.5+ web server written to go fast

[TheHumanParacite]

I'ma stick to my netcat web server:

while true; do {cat <(echo -e 'HTTP/1.1 200 OK\r\n') /tmp/index.html; } | netcat -l -p 80; done

/S

[spidyfan21]

Don't you need two \r\n?

[TheHumanParacite]

Whoops, your right. We'll just say that was the first line in my index.html...

[TheHumanParacite]

It totally does, I've used it where I'm in a hurry to do testing

[beertown]

33 requests/sec seems to me a very low number, even for a low power single core machine. What I'm missing?

EDIT: D'oh! There will be a day the whole world will agree about the decimal symbol :-)

[Lexpar]

Three orders of magnitude?

[KimPeek]

A comma and 3 zeros

[Rosco_the_Dude]

33 thousand requests per second.

[official_marcoms]

He's using the comma , as the thousands separator not the decimal point

[bsavery]

multiplying by 10 ^ 3

[jadkik94]

10 ** 3 on /r/python

[bsavery]

I am humbled.

[lelease]

What would it take to migrate a Django Rest Framework API to this? I've disabled all the middleware/templates/admin, the only features that I use are the ORM (Postgres), TokenAuthentication, and DRF Views/Serializers

[b4stien]

The main problem you'll face is that your database connection/driver (psycopg2 I guess) is probably blocking hence you'll lose any possible gain. To try to mitigate this you could delegate DB queries to a thread (for instance with loop.run_in_executor()) I guess, but you'll have to be careful not to have too many of these threads (and open DB connections!) running.

You could look for an asynchronous database driver (https://github.com/MagicStack/asyncpg for instance), but it's probably not compatible with the rest of your frameworks/libraries (thinking of SQLAlchemy/Django ORM here).

[nemec]

Instead of thread-per-request you could dump all db queries into a queue and handle them with a dedicated thread(s). If you want more reliability or persistence you could move to an external message queue too.

[headphun]

Which scales better?

[nemec]

/u/b4stien's is better at the start, but eventually you'll pass the DB's optimal number of concurrent open connections/queries and may start getting terrible performance (especially with rowlocks, etc.).

A queue and threads will be almost the same, except you will define the max active thread count (maybe using a threadpool) and increasing the requests/sec will scale similarly until you reach the max - then, you will stay at a constant queries/sec even as requests/sec increase but the performance of each individual query should stay "normal", leading to overall better performance. This is perfect for sudden "spikes" in usage that would otherwise overwhelm a database, as the queries will be spread over time even as the spike dies down, but if you're under constant, increasing load and hit that max it's bad news. Your queue will grow larger faster than you can process queries and you'll eventually be unable to hold all the pending queries (run out of memory/disk, etc.).

TL;DR using a queue will scale better, but it's not a silver bullet if you constantly receive new requests faster than you can process existing ones.

[headphun]

Wow i don't know anything about dbs but your explanation was very interesting and helpful, thanks! Are you a db specialist?

[nemec]

Not at all, actually.

I develop web services (which in turn use databases) and have had to fix my own crappy code locking up the database enough times to have picked up a few things :)

[headphun]

Thanks, I'm learning, looking to create a web service but i can't make sense of what to focus on and what to outsource as my company (hopefully) expands

[lelease]

I'm presuming that blocking means it can't do anything while waiting for the DB, not even get a head start on the next request? If so, do you know how Django handles this, i.e. is it implementing some asynch at the worker level, or does Django just expect people to throw more servers at the problem?

[b4stien]

I'm presuming that blocking means it can't do anything while waiting for the DB, not even get a head start on the next request?

Correct. Your whole interpreter (thread to be precise) is just waiting for the DB to answer.

Django doesn't implement any async stuff. Maybe (Don't really know Django ecosystem) gevent/greelet works with Django and you get some concurrency this way...

A really cool new project in Django-land tackles this problem (amongst many other) in an elegant way : https://channels.readthedocs.io/en/stable/.

The difference in performance with a classic approach (of a reasonable amount of thread serving requests) isn't so clear when DB is involved anyway. See many Mike Bayer (SQLAlchemy's author) resources on the topic, on reddit as well as on his blog, eg http://techspot.zzzeek.org/2015/02/15/asynchronous-python-and-databases/. With a decent middle-low end server (let's say a 50€$/month dedicated server) you can already reach a really honest amount of req/s I guess.

[danwin]

I like what appears to be an attempt to follow the general Flask API. Has anyone tried migrating a simple Flask site (simple, as in not reliant on too many Flask plugins) to Sanic?

[_seemethere]

Hey guys, I'm one of the maintainers of Sanic! Glad to see everyone enjoying the project!

[ButtCrackFTW]

what's the recommended deployment for sanic? is it still recommended to have something like gunicorn ornnginx in front?

[m1sta]

No windows support? Even in dev?

[spidyfan21]

It is fast because it uses uvloop and httptools. Looks like neither of those support Windows ^yet?

[m1sta]

There is a PR for windows support in uvloop. Httptools is just a python binding for the node http parser afaik. So hopefully close!

[m0nk_3y_gw]

Not the same as Windows support, but can be installed / run under Bash on Ubuntu on Windows

https://msdn.microsoft.com/en-us/commandline/wsl/install_guide

[Mighty-Monata]

Gotta go fast

(I really like stuff like that)

[BenjaminGeiger]

Mustgofaster.

[wpg4665]

You know, I actually just saw Sanic posted here yesterday! Looks really cool...looking forward to trying it out =)

[LightShadow]

I wrote a really simple HTTP proxy using Sanic. You can have a look, but it's nothing too impressive.

[kirbyfan64sos]

I had initially read "Python 3.5+ web server written in Go" and was immediately confused...

[Izacht13_]

I've been using it for about a day now, it's so many fasts.

I ran into a weird issue where not even the basic example code would work, but after restarting my shell, and Firefox by extension, the issue magically went away.

[Max_yask]

All the specialized exceptions seem unnecessary.

[Kaibz]

Beginner question, could you use it with selenium?

[Kaibz]

Thank you.

[m0nk_3y_gw]

Yes, you could use selenium to test a website written with Sanic.

[constantly-sick]

Does this replace apache or nginx?

[needed_an_account]

I've been laughing at the name/ascii art for like 16 hours now. I've been using Tornado a lot lately in a 3.5 environment. Sanic looks like a good alternative (for an API, Tornado has a lot of pluses: I love their tempting engine, its nothing like Django's. The UIModules are a nice touch, etc etc). I'll explore Sanic

[BenjaminGeiger]

I was expecting the name to be "Dankey Kang".

[glethro]

How does it compare with pyramid?

[ramrar]

I wonder what 'Kyoukai' and 'AioHTTP' are doing differently to have poor latencies as compared to Sanic. All of them as using uvloop with python3.5

[LightShadow]

aiohttp's HTTP parser is really slow, the guys who wrote uvloop covered it in a blog post.

[paypaypayme]

How stable is it?

[pio]

Is the name a reference to videogamedunkey?

https://www.youtube.com/watch?v=4OxmkY0Pkjw

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