On Tue, Mar 19, 2013 at 12:16 PM, Charles Mills <[email protected]> wrote:
> I've got a problem that is defying my ability to find it. I have a product > that uses sendto() to send UDP messages (datagrams). At one and perhaps two > z/OS 1.12 customers I have seen a problem in which what appear to be > perfectly good sendto()'s send a datagram that never arrives at its > destination. (Of course, the lack of error feedback is a known > characteristic of UDP.) > > UDP does not guarantee delivery of packets or the order in which packets are received. It is up to the application to manage those issues. > Version x.1 of my product does not exhibit this behavior. Version x.2 does. > There is relatively little difference between how the two issue sendto(). I > have never seen the problem on my development machine, including under z/OS > 1.12. > > It is definitely not a firewall or other external issue because Version x.1 > works fine. You bring it down and bring Version x.2 up with the same > parameters and it works for a little while and then 100% of the messages > start disappearing. You bring it down and bring x.1 back up and all is > well. > Similar TCP/IP code does not seem to have the same problem. > > Yes, obviously it could be your basic program bug and I am of course > working > the heck out of that angle. I'm not asking this list to debug code it has > not seen. The code is way too complex to post here meaningfully. > > But does this problem ring a bell with anyone? I am not the most skilled in > the world at searching for APARs. Does anyone else want to spend 5 minutes > and see if you can find anything? > > Thanks much, > Charles > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
