UDP performance

[Martin P. Hellwig]

Paul Sijben wrote:
> I am stumped by the following problem. I have a large multi-threaded
> server accepting communications on one UDP port (chosen for its supposed
> speed).
> 
> I have been profiling the code and found that the UDP communication is
> my biggest drain on performance! Communication where the client and the
> server are on the same machine still takes 300ms or sometimes much more
> per packet on an Athlon64 3000+ running Linux (Fedora Core 5 x64).
> 
> I must be doing something wrong and would really appreciate feedback on
> my code below:
> 
> I open the server port with
> 
> 	self.s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
> 	self.s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
> 	self.s.bind((myaddress, myport))
> 
> I then open a client port with
> 
> 	self.s=socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
> 	self.s.connect((host, port))
> 
> the client sends data with
> 
> 	self.s.sendall(data)
> 
> and the server with
> 
> 	self.s.sendto(data,link.remoteaddress)
> 
> both receive with
> 
> buf, address = socket.recvfrom(8192)
> 
> The sender and receiver are in separate threads (threading.Thread).
> 
> Does anyone know what is going wrong here, the socket communication, the
> thread scheduling?
> 
> Paul Sijben
> 

Is the connection 1:1 i.e. the receiving end receives data only from one 
sender at the time? And how do you handle lost packages in your application?

-- 
mph