At 06:29 PM 8/26/02 +0100, Murillo-Garcia Raul wrote: > I've got a server >application running under Windows which reads UDP datagrams and a client >application running under Linux that sends datagrams. It seems that the more >datagrams that arrive to the server network interface the less datagrams >that are read by the application layer. I guess it has something to do with >data dropping due to queue oveflow but I don't know how to prove this, much >less how to overcome it. Which version of Windows, and do you have the source to the "application running under Windows"? Which Linux kernel? What else have you done to determine the bottleneck? If it were me doing this task, I would make damn sure I had provable answers to the following questions: 1) What was the status return for each of the sendto()/sendmsg() calls in the Linux client? 2) Does a sniffer show that all the UDP packets you think you sent actually made it onto the wire? Were they routed correctly? Is there any switch or router that could be overloaded and thus dropping packets? 3) What is the frequency of UDP packets? What is the frequency of collisions on the network? 4) Does the Windows Winsock system see all the UDP packets? If not, how many packets does Winsock see? 5) How much resource (CPU, memory, disk) does the processing of each UDP packet consume? 6) What is the CPU, memory, and disk loading during the UDP packet storm? 7) Is the Windows application threaded, and if so what are the threading limits? 8) Is there a resource lock used by the application to serialize access to something? How long is this lock held? 9) How robust is the error recovery in the application? Can a single request bring the server to its knees? Once you have determined that all the UDP packets have been delivered to the network interface card in the Windows server, you have gone beyond the charter of the linux-net mailing list. Now, if you were to port your server code to a Linux box, we might be able to help you by pointing to diagnostic and debugging aides available in the Linux networking environment. I have included questions 4-9 as a courtesy. Satch - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
