(Sorry PyPy guys!)
I dont have numbers/charts to pull up for this right now, but I was testing it out to see if I could push more cpu on a server, and the memory cost was insane for the minimal test case.
Twisted also is not a web server, it's a framework. Same with Tornado, and honestly, the same with gevent/etc.
There's a ticket I opened on the PyPy tracker, but this is sort of expected if I understand JITs correctly.
I didn't exhaustively benchmark it, but the initial results were too far outside the bounds of my limitations.
Of what he was seeing without PyPy.
He doesn't want advice on how to lower that. He wants to get the same memory usage or better out of the box.
e.g. 20% faster execution for 100% more memory
In my case it was 15% faster execution (give or take), with a 400% memory increase.
This was on a simple view which did nothing, so it's hard to tell how it'd handle more complex views in the app.
Either way this is a huge detour from what this actual topic is about, whether you use PyPy or CPython
I'm optimizing for my application. If you want to use PyPy, use it. I couldn't care less.
If I was having a hard time already maxing CPU due to memory constraints, how does switching to something that will use a very large amount of memory (relative to the CPU gains) make any sense at all? Do you really think "more complex code" is going to use less memory?
If you want benchmarks, go find some, or go create some. It has absolutely nothing to do with the gains I'm pointing out by simple webserver choices and minor tuning.
$ twistd -n web --wsgi your.wsgi.app