AIOHTTP - Application.make_handler(...) is deprecated - Adding Multiprocessing

Question

I went down a journey of "How much performance can I squeeze out of a Python web-server?" This lead me to AIOHTTP and uvloop. Still, I could see that AIOHTTP wasn't using my CPU to its full potential. I set out to use multiprocessing with AIOHTTP. I learned that there's a Linux kernel feature that allows multiple processes to share the same TCP port. This lead me to develop the following code (Which works wonderfully):

import asyncio
import os
import socket
import time
from aiohttp import web
from concurrent.futures import ProcessPoolExecutor
from multiprocessing import cpu_count

CPU_COUNT = cpu_count()
print("CPU Count:", CPU_COUNT)


def mk_socket(host="127.0.0.1", port=8000, reuseport=False):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    if reuseport:
        SO_REUSEPORT = 15
        sock.setsockopt(socket.SOL_SOCKET, SO_REUSEPORT, 1)
    sock.bind((host, port))
    return sock


async def handle(request):
    name = request.match_info.get('name', "Anonymous")
    pid = os.getpid()
    text = "{:.2f}: Hello {}! Process {} is treating you\n".format(
        time.time(), name, pid)
    #time.sleep(5)  # intentionally blocking sleep to simulate CPU load
    return web.Response(text=text)


def start_server():
    host = "127.0.0.1"
    port=8000
    reuseport = True
    app = web.Application()
    sock = mk_socket(host, port, reuseport=reuseport)
    app.add_routes([web.get('/', handle),
                    web.get('/{name}', handle)])
    loop = asyncio.get_event_loop()
    coro = loop.create_server(
            protocol_factory=app.make_handler(),
            sock=sock,
        )
    srv = loop.run_until_complete(coro)
    loop.run_forever()


if __name__ == '__main__':
    with ProcessPoolExecutor() as executor:
        for i in range(0, CPU_COUNT):
            executor.submit(start_server)

wrk benchmark of my site before applying this code:

Running 30s test @ http://127.0.0.1:8000/
  12 threads and 400 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency    54.33ms    6.54ms 273.24ms   89.95%
    Req/Sec   608.68    115.97     2.27k    83.63%
  218325 requests in 30.10s, 41.23MB read
  Non-2xx or 3xx responses: 218325
Requests/sec:   7254.17
Transfer/sec:      1.37MB

wrk benchmark after:

Running 30s test @ http://127.0.0.1:8000/
  12 threads and 400 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency    15.96ms    7.27ms  97.29ms   84.78%
    Req/Sec     2.11k   208.30     4.45k    75.50%
  759290 requests in 30.08s, 153.51MB read
Requests/sec:  25242.39
Transfer/sec:      5.10MB

WoW! But there's a problem:

DeprecationWarning: Application.make_handler(...) is deprecated, use AppRunner API instead
  protocol_factory=app.make_handler()

So I tried this:

import asyncio
import os
import socket
import time
from aiohttp import web
from concurrent.futures import ProcessPoolExecutor
from multiprocessing import cpu_count

CPU_COUNT = cpu_count()
print("CPU Count:", CPU_COUNT)

def mk_socket(host="127.0.0.1", port=8000, reuseport=False):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    if reuseport:
        SO_REUSEPORT = 15
        sock.setsockopt(socket.SOL_SOCKET, SO_REUSEPORT, 1)
    sock.bind((host, port))
    return sock

async def handle(request):
    name = request.match_info.get('name', "Anonymous")
    pid = os.getpid()
    text = "{:.2f}: Hello {}! Process {} is treating you\n".format(
        time.time(), name, pid)
    #time.sleep(5)  # intentionally blocking sleep to simulate CPU load
    return web.Response(text=text)

async def start_server():
    host = "127.0.0.1"
    port=8000
    reuseport = True
    app = web.Application()
    sock = mk_socket(host, port, reuseport=reuseport)
    app.add_routes([web.get('/', handle),
                    web.get('/{name}', handle)])

    coro = loop.create_server(
            protocol_factory=app.make_handler(),
            sock=sock,
        )
    runner = web.AppRunner(app)
    await runner.setup()
    srv = web.TCPSite(runner, 'localhost', 8000)
    await srv.start()
    print('Server started at http://127.0.0.1:8000')
    return coro, app, runner

async def finalize(srv, app, runner):
    sock = srv.sockets[0]
    app.loop.remove_reader(sock.fileno())
    sock.close()

    #await handler.finish_connections(1.0)
    await runner.cleanup()
    srv.close()
    await srv.wait_closed()
    await app.finish()

def init():
    loop = asyncio.get_event_loop()
    srv, app, runner = loop.run_until_complete(init)
    try:
        loop.run_forever()
    except KeyboardInterrupt:
        loop.run_until_complete((finalize(srv, app, runner)))


if __name__ == '__main__':
    with ProcessPoolExecutor() as executor:
        for i in range(0, CPU_COUNT):
            executor.submit(init)

which is obviously incomplete becuase coro isn't being used. I'm not sure where to integrate the socket with AppRunner. Answer should show original example modified to use App Runner.

Answer 1

As it's my first time using coroutines and aiohttp, I may be wrong, but it seems to work with a SockSite:

#!/usr/bin/env python

import asyncio
import os
import socket
import time
import traceback
from aiohttp import web
from concurrent.futures import ProcessPoolExecutor
from multiprocessing import cpu_count

CPU_COUNT = cpu_count()
print("CPU Count:", CPU_COUNT)

def mk_socket(host="127.0.0.1", port=9090, reuseport=False):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    if reuseport:
        SO_REUSEPORT = 15
        sock.setsockopt(socket.SOL_SOCKET, SO_REUSEPORT, 1)
    sock.bind((host, port))
    return sock

async def handle(request):
    name = request.match_info.get('name', "Anonymous")
    pid = os.getpid()
    text = "{:.2f}: Hello {}! Process {} is treating you\n".format(
        time.time(), name, pid)
    #time.sleep(5)  # intentionally blocking sleep to simulate CPU load
    return web.Response(text=text)

async def start_server():
    try:
        host = "127.0.0.1"
        port=9090
        reuseport = True
        app = web.Application()
        app.add_routes([web.get('/', handle),
                        web.get('/{name}', handle)])
        runner = web.AppRunner(app)
        await runner.setup()
        sock = mk_socket(host, port, reuseport=reuseport)
        srv = web.SockSite(runner, sock)
        await srv.start()
        print('Server started at http://127.0.0.1:9090')
        return srv, app, runner
    except Exception:
        traceback.print_exc()
        raise

async def finalize(srv, app, runner):
    sock = srv.sockets[0]
    app.loop.remove_reader(sock.fileno())
    sock.close()

    #await handler.finish_connections(1.0)
    await runner.cleanup()
    srv.close()
    await srv.wait_closed()
    await app.finish()

def init():
    loop = asyncio.get_event_loop()
    srv, app, runner = loop.run_until_complete(start_server())
    try:
        loop.run_forever()
    except KeyboardInterrupt:
        loop.run_until_complete((finalize(srv, app, runner)))


if __name__ == '__main__':
    with ProcessPoolExecutor() as executor:
        for i in range(0, CPU_COUNT):
            executor.submit(init)

Eventually:

>curl http://127.0.0.1:9090
1580741746.47: Hello Anonymous! Process 54623 is treating you
>curl http://127.0.0.1:9090
1580741747.05: Hello Anonymous! Process 54620 is treating you
>curl http://127.0.0.1:9090
1580741747.77: Hello Anonymous! Process 54619 is treating you
>curl http://127.0.0.1:9090
1580741748.36: Hello Anonymous! Process 54621 is treating you

I also added a log in the finalize routine and it seems correctly triggered.

Edit: And, out of curiosity, I gave it a try on an older kernel and I confirm it doesn't work when the option is enabled (it works with False).