On Wed, 2013-05-22, Matt Jones wrote: > On Wed, May 22, 2013 at 3:46 AM, loial <jldunn2...@gmail.com> wrote: > >> I have a sockets client that is connecting to a printer and occassionally >> getting the error "104 Connection reset by peer" >> >> I have not been able to diagnose what is causing this. Is there any >> additional traceing I can do(either within my python code or on the >> network) to establish what is causing this error? >> >> Currently I am simply trapping socket.erruor >> >> Python version is 2.6
> This typically indicates that the "peer" at the other end of the tcp > connection severed the session without the typical FIN packet. I.e. by sending a RST (reset) instead. Yes, that's what "Connection reset by peer" means. I don't think there are any other causes for this signal. A server application can cause a reset explicitly, or if it crashes the OS will send one for it, as part of the resource cleanup. Also, if you're behind a cheap NATing gateway, I think it may send fake RSTs if it has lost track of the TCP session. > If you're > treating the printer as a "blackbox" then there really isn't anything you > can do here except catch the exception and attempt to reconnect. Yes. Note that there *may* be some uncertainty re: "did the printer process the last request before the reset or not?" E.g. I wouldn't endlessly retry printing a 100-page document in that case. /Jorgen -- // Jorgen Grahn <grahn@ Oo o. . . \X/ snipabacken.se> O o . -- http://mail.python.org/mailman/listinfo/python-list
