Hi Robert, On Fr 09 Mai 2014 15:24:10 CEST, Robert Izzard wrote: > Package: x2goserver > Version: 4.0.15-0~847 > > (x2goserver: 4.0.15-0~847~~ubuntu12.04.1 on Ubuntu Linux 12.04.4 LTS > kernel 3.8.0-39-generic, > x2goclient: 4.0.15-0~847~ubuntu14.04.1 on Ubuntu Linux 14.04 LTS > kernel 3.14.3-031403-generic) >   > Please note: I have labelled package x2goserver, but the bug is > displayed on x2goclient even though I *think* the bug is in the > server somewhere (see below). > > Sometimes after an abrupt (e.g. CTRL-C, probably also network > failure or laptop sleep/wake cycle) termination of x2goclient, I > cannot reconnect to the server. I get errors such as the dreaded > "Failure negotiating the session in stage '7'." and "Error: Wrong > version or invalid session authentication cookie." instead. > > I am connecting through a proxy using ssh key-based > authentication (using "Try auto-login" with "ssh-agent or default > ssh key" on the proxy, although switching to password made no > difference). I can connect with ssh through the proxy with no > problem. I can *start* an x2go session with no problem. I can > restart a session with no problem *provided I cleanly exit > x2goclient* (e.g. by clicking on the close button on the window). > If I exit x2goclient with a CTRL-C in the terminal, I cannot > connect again. Note that I can connect to an NX session through > the proxy without any problem and this does not have the same > problem when CTRL-C. > > Steps to repeat: > 1) On the client, open a new desktop on the server using > x2goclient. (I am running KDE but I doubt it matters). > 2) On the client, press CTRL-C to stop x2goclient. > 3) On the client, try to reconnect -- it fails with errors (which > are very hard to copy-paste as they go so fast, this is a bug in > the GUI): > > ------------------------ > NXPROXY - Version 3.5.0 > > Copyright (C) 2001, 2010 NoMachine. > > See http://www.nomachine.com/ for more information. > Info: Proxy running in client mode with pid '7219'. > Session: Starting session at 'Thu May 8 17:33:51 2014'. > Info: Connecting to remote host 'localhost:31007'. > Info: Connection to remote proxy 'localhost:31007' established. > Error: The remote NX proxy closed the connection. > Error: Failure negotiating the session in stage '7'. > Error: Wrong version or invalid session authentication cookie. > Session: Terminating session at 'Thu May 8 17:33:51 2014'. > Session: Session terminated at 'Thu May 8 17:33:51 2014'. > ------------------------ > > At this point the CPU usage of x2goclient jumps to 100% and I > have to kill it (although the GUI continues to respond). This is > just a minor annoyance at the moment. > > And in .x2go/SESSION_ID/sessions on the client, similar warnings: > > ------------------------ > > Loop: PANIC! No shutdown of proxy link performed by remote proxy. > Loop: PANIC! The remote NX proxy closed the connection. > Loop: PANIC! Failure negotiating the session in stage '7'. > Loop: PANIC! Wrong version or invalid session authentication cookie. > ------------------------ > > The server clearly detects the disconnect in its session.log, > followed by “Display failure detected” errors on attempted > reconnect: > > ----------------------- > running as X2Go Agent > > NXAGENT - Version 3.5.0 > > Copyright (C) 2001, 2011 NoMachine. > > See http://www.nomachine.com/ for more information. > > Info: Agent running with pid '17414'. > Session: Starting session at 'Fri May 9 14:44:26 2014'. > Info: Proxy running in server mode with pid '17414'. > Info: Waiting for connection from 'localhost' on port '30004'. > Info: Accepted connection from '127.0.0.1'. > Info: Connection with remote proxy completed. > Info: Using ADSL link parameters 512/24/1/0. > Info: Using agent parameters 5000/10/50/0/0. > Info: Using cache parameters 4/4096KB/8192KB/8192KB. > Info: Using pack method '16m-png-9' with session > 'unix-kde-depth_24'. > Info: Using ZLIB data compression 1/1/32. > Info: Using ZLIB stream compression 4/4. > Info: No suitable cache file found. > Info: Listening to X11 connections on display ':51'. > Info: Established X client connection. > Info: Using shared memory parameters 1/1/1/2048K. > Info: Using alpha channel in render extension. > Info: Not using local device configuration changes. > keyboard file created > SessionPath not defined > Session: Session started at 'Fri May 9 14:44:27 2014'. > Error: Failure reading from the peer proxy. > Error: Connection with remote peer broken. > Error: Please check the state of your network and retry. > Session: Display failure detected at 'Fri May 9 14:44:44 2014'. > Session: Suspending session at 'Fri May 9 14:44:44 2014'. > Session: Session suspended at 'Fri May 9 14:44:44 2014'. > Session: Resuming session at 'Fri May 9 14:45:11 2014'. > Info: Proxy running in server mode with pid '17414'. > Info: Waiting for connection from 'localhost' on port '30004'. > Info: Aborting the procedure due to signal '1'. > Session: Display failure detected at 'Fri May 9 14:45:27 2014'. > Session: Suspending session at 'Fri May 9 14:45:27 2014'. > Session: Session suspended at 'Fri May 9 14:45:27 2014'. > -------------- > > In .x2go/C-SESSION_ID/session.log on the server, I now have the > following text repeated over and over: > > Session: Suspending session at 'Fri May 9 15:08:49 2014'. > [then hundreds or thousands of times, with later timestamps] > > > > The problem appears to be with the file > /var/lib/x2go/x2go_sessions on the server. If I back this up > *before* hitting CTRL-C on the client, then do the CTRL-C, then > reinstate the backup, I can restart the session with no problems. > Clearly this is beyond the ability of a normal user (without root > on the server) and is not really a fix, even if it does work. > > > > It seems that there is a problem with the x2go_sessions file on > the server being corrupted in some way when the remote session is > abruptly disconnected. This is a failure bad enough for me to > stop using x2go and go back to NX. > > * Backing up this file all the time is not an option. > > * Deleting this file and continuing, as suggested at > http://bugs.x2go.org/cgi-bin/bugreport.cgi?bug=323, is not an > option. > > * Note that unlink suggested in > http://bugs.x2go.org/cgi-bin/bugreport.cgi?bug=323, there is no > *server* crash. > > * I have tried the other options at > http://bugs.x2go.org/cgi-bin/bugreport.cgi?bug=323, none apply > here (e.g. permissions are fine). > > * The action that precipitates the problem is on the *client* > side. > > * Note also that the network itself is not at fault: I can > connect from a laptop in the same office (but on a different > subnet) as the server, or from home to the proxy server direct. > Same problem. > > * This seems similar to > http://bugs.x2go.org/cgi-bin/bugreport.cgi?bug=101 but the fixes > are more than a year ago and presumably (?) are in the latest > x2goclient already. > > * No amount of calls to x2gosuspend-session or x2goresume-session > on the appropriate session makes any difference. > > * If I suspend the session with x2gosuspend-session, attempting > to connect *does* set the session into the “Running” state (just > as x2goresume-session). The error seems to occur after this. > > Thanks for all your help x2go team, I hope we can fix this > because I'd like to recommend x2go for my colleagues. This is all very interesting!!!! Can you please check one more thing? If the connection failure occurs: leave the sessions db file as it is, but restart the server's SSH daemon and try to resume then. Does that also solve the resumption problem? Thanks, Mike -- DAS-NETZWERKTEAM mike gabriel, herweg 7, 24357 fleckeby fon: +49 (1520) 1976 148 GnuPG Key ID 0x25771B31 mail: mike.gabriel@das-netzwerkteam.de, http://das-netzwerkteam.de freeBusy: https://mail.das-netzwerkteam.de/freebusy/m.gabriel%40das-netzwerkteam.de.xfb