UDP performance

[Paul Sijben]

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