Optimizing sockets to 1000 requests/sec? (Was: Sockets and messaging services)

[Steve Holden]

"Stephen" <shriek at gmx.co.uk> wrote ...
> Thanks for the help, Cezary
>
> > >>But when NUMTHREADS = 20, half the threads die with this error :
> > >>Unhandled exception in thread:
> > >>Traceback (most recent call last):
> > >>  File "<stdin>", line 6, in send_request
> > >>  File "<string>", line 1, in connect
> > >>socket.error: (10061, 'Connection refused')
> >
> > If you are has clients and a server on the same machine, it is possible,
> > that server it does not have enough time to accept connections on a
> > listen socket.
>
> If I understand you correctly, then the server receives a
> request, creates a thread to deal with it. But the server
> is so busy creating threads to deal with incoming requests,
> that some other requests are ignored.
>
> > By default only 5 connections can wait to be accepted -
> > if more appears, they are refused by your operating system. You can
> > raise this number, but there are limits on some OS-es.
> >
> > So, for really testing server you should launch clients from another
> > machine(s).
>
> Sorry, you've lost me here. If the server can't generate
> threads quick enough to deal with the incoming connections,
> how will moving the clients to another machine give the
> server more time (except perhaps in introducing a network
> delay) ?
>
Well, for a start it will ensure that the server gets more of the CPU time,
and reduce the strain on the transport layer at the server.
>
> > For building high-performance server check:
> > http://www.nightmare.com/medusa/
> >
> > Medusa combines asyncore with threads for optimal performance.
>
> I had found the asyncore/asynchat method a little strange
> but just downloaded the medusa package and there's a lot of
> good documentation in the source. The included chat_server
> example looks like a good starting point. Will try that.
>
> Sam also provides a great page of reference material. Excellent.
>
Yes, asyncore/asynchat are heroes of the Python networking world.

regards
 Steve
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