Problem with writing fast UDP server

Krzysztof Retel Krzysztof.Retel at googlemail.com
Thu Nov 20 11:24:20 EST 2008


On Nov 20, 4:00 pm, bieff... at gmail.com wrote:
> On 20 Nov, 16:03, Krzysztof Retel <Krzysztof.Re... at googlemail.com>
> wrote:
>
>
>
> > Hi guys,
>
> > I am struggling writing fast UDP server. It has to handle around 10000
> > UDP packets per second. I started building that with non blocking
> > socket and threads. Unfortunately my approach does not work at all.
> > I wrote a simple case test: client and server. The client sends 2200
> > packets within 0.137447118759 secs. The tcpdump received 2189 packets,
> > which is not bad at all.
> > But the server only handles 700 -- 870 packets, when it is non-
> > blocking, and only 670 – 700 received with blocking sockets.
> > The client and the server are working within the same local network
> > and tcpdump shows pretty correct amount of packets received.
>
> > I included a bit of the code of the UDP server.
>
> > class PacketReceive(threading.Thread):
> >     def __init__(self, tname, socket, queue):
> >         self._tname = tname
> >         self._socket = socket
> >         self._queue = queue
> >         threading.Thread.__init__(self, name=self._tname)
>
> >     def run(self):
> >         print 'Started thread: ', self.getName()
> >         cnt = 1
> >         cnt_msgs = 0
> >         while True:
> >             try:
> >                 data = self._socket.recv(512)
> >                 msg = data
> >                 cnt_msgs += 1
> >                 total += 1
> >                 # self._queue.put(msg)
> >                 print  'thread: %s, cnt_msgs: %d' % (self.getName(),
> > cnt_msgs)
> >             except:
> >                 pass
>
> > I was also using Queue, but this didn't help neither.
> > Any idea what I am doing wrong?
>
> > I was reading that Python socket modules was causing some delays with
> > TCP server. They recomended to set up  socket option for nondelays:
> > "sock.setsockopt(SOL_TCP, TCP_NODELAY, 1) ". I couldn't find any
> > similar option for UDP type sockets.
> > Is there anything I have to change in socket options to make it
> > working faster?
> > Why the server can't process all incomming packets? Is there a bug in
> > the socket layer? btw. I am using Python 2.5 on Ubuntu 8.10.
>
> > Cheers
> > K
>
> Stupid question: did you try removing the print (e.g. printing once
> every 100 messages) ?

:) Of course I did Nothing has changed

I wonder if there is a kind of setting for socket to allow no delays?



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