README

# Create a big file (sparse)
truncate --size=100G huge.bin

# check the stuff to make sure it's not a virus
cat *.py *.sh

# Run this in one terminal
./twisted_0_stream_server.py

# Run this in another
./twisted_1_proxy_server.py

# Run this in yet another, repeat as needed to observe the heap growth of the other(s)
./twisted_2_client

# Run htop/top/... to watch the above scripts

twisted_0_stream_server.py

#!/usr/bin/env python
# -*- coding: utf-8 vi:noet
# Serves a huge file, to be created by using
# truncate --size=100G huge.bin

import klein
import twisted.web.static

class WebService(object):
	app = klein.Klein()

	@app.route('/huge.bin', branch=True)
	def get_static(self, request):
		res = twisted.web.static.File("huge.bin")
		return res

if __name__ == '__main__':
	ws = WebService()
	ws.app.run(
	 "0.0.0.0", 8001,
	)

twisted_1_proxy_server.py

#!/usr/bin/env python
# -*- coding: utf-8 vi:noet
# Serves a huge file, to be created by using
# truncate --size=100G huge.bin

import klein
import treq
import twisted.web.static

class WebService(object):
	app = klein.Klein()

	@app.route('/', methods=("GET",))
	def get_proxy(self, request):
		def stream_response(response, r):
			for key, values in response.headers.getAllRawHeaders():
				for value in values:
					request.setHeader(key, value)
			request.setResponseCode(200)
			def collector(data, *args, **kw):
				if request._disconnected:
					print("Warning, client was disconnected, stopping download!")
					r.finish()
					return
				return request.write(data)

			d = treq.collect(response, collector)
			d.addCallback(lambda _: request.finish())
			return d

		url = "http://localhost:8001/huge.bin"
		req_upstream = treq.request(request.method, url)
		req_upstream.addCallback(stream_response, req_upstream)
		return req_upstream

if __name__ == '__main__':
	ws = WebService()
	ws.app.run(
	 "0.0.0.0", 8002,
	)

twisted_2_client.sh

#!/bin/sh

for x in $(seq 1 1 100); do
	( curl --silent http://localhost:8002/ | head --bytes=1048576 > /dev/null & );
done