[Python-ideas] Async API: some code to review

[Richard Oudkerk]

On 30/10/2012 8:24pm, Guido van Rossum wrote:
> Here's another unscientific benchmark: I wrote a stupid "http" server
> (stupider than echosvr.py actually) that accepts HTTP requests and
> responds with the shortest possible "200 Ok" response. This should
> provide an adequate benchmark of how fast the event loop, scheduler,
> and transport are at accepting and closing connections (and reading
> and writing small amounts). On my linux box at work, over localhost,
> it seems I can handle 10K requests (sent using 'ab' over localhost) in
> 1.6 seconds. Is that good or bad? The box has insane amounts of memory
> and 12 cores (?) and rates at around 115K pystones.

I tried the simple single threaded benchmark below on my laptop.

                                        | Connections/sec
---------------------------------------+-----------------
Linux                                  |   6000-11000
Linux in a VM (with 1 cpu assigned)    |         4600
Windows                                |         1400

On Windows this sometimes failed with:

   OSError: [WinError 10055] An operation on a socket could not
   be performed because the system lacked sufficient buffer
   space or because a queue was full


import socket, time, sys, argparse

N = 10000

def server():
     l = socket.socket()
     l.bind(('127.0.0.1', 0))
     l.listen(100)
     print('listening on port', l.getsockname()[1])
     while True:
         a, _ = l.accept()
         data = a.recv(20)
         a.sendall(data.upper())
         a.close()

def client(port):
     start = time.time()
     for i in range(N):
         with socket.socket() as c:
             c.connect(('127.0.0.1', port))
             c.sendall(b'foo')
             res = c.recv(20)
             assert res == b'FOO'
             c.close()
     elapsed = time.time() - start
     print("elapsed=%s, connections/sec=%s" % (elapsed, N/elapsed))

parser = argparse.ArgumentParser()
parser.add_argument('--port', type=int, default=None,
                     help='port to connect to')
args = parser.parse_args()

if args.port is not None:
     client(args.port)
else:
     server()

--
Richard