[X2Go-User] Can sessions of one user on different hosts collide?

Holger Krause Holger.Krause at med.uni-duesseldorf.de
Thu Aug 7 21:11:41 CEST 2014


Dear list,

On four debian wheezy machines I have X2Go server running without any problems 
since several weeks. There are about twenty users regularly connecting from 
their personal windows PCs. Usually at any given time on every server there 
are a handful of active/paused sessions running concurrently. The home 
directories are exported via NFS from a file server and shared among the X2Go 
servers.

Today, one user ('abbasi') told me, that since one or two weeks, he can only 
have one active connection to two of the servers (named 'lucas' and 'perrin') 
at a time, while before he could have active connections to both of them in 
parallel. Let me demonstrate an example with the error messages he gets. An 
extract of his session logs I put at the end of this mail.

Initially the user has one (LXDE) session running on both, 'lucas' and 
'perrin', but only the connection to 'perrin' is open (at 17:35).

17:36 User resumes session on 'lucas', which lets the 'perrin' connection 
close.

17:38 User resumes session on 'perrin'. The x2go client maintaining the 
connection to 'lucas' yields an error message labeled 'X2Go - 50': "No 
response received from the remote server. Do you want to terminate the current 
session? (Yes/No)" With no answer given, a second error message pops up some 
seconds later: "The connection with the remote server was shut down. Please 
check the state of your network connection. (OK)".

Later on the user terminated LXDE on 'perrin' and logged in again, again 
loosing the connection to 'lucas'. Output of x2golistsessions_root is:

root at perrin:~# x2golistsessions_root |grep abbasi
23451|abbasi-50-1407426323_stDLXDE_dp32|50|perrin|S|2014-08-07T17:45:24|
ab801814ece01b66cf5b9095ef08d537|134.99.208.12|30001|30002|
2014-08-07T17:50:07|abbasi|10878|30003|

root at lucas:/tmp# x2golistsessions_root |grep abbasi
31315|abbasi-50-1401721407_stDLXDE_dp32|50|lucas|S|2014-06-02T17:03:27|
2e6c06bec50eb7f89b1d165590a0a54d|134.99.208.12|30001|30002|
2014-08-07T17:45:27|abbasi|5715851|30003|

What got my attention is, the sessions on both servers coincidentally having 
the same <port> (50), <gr_port> (30001) and <snd_port> (30002). Could this 
lead to confusion for the 'peer proxy' mentioned in the 'Error:' line in the 
'lucas'-log?

Looking forward to any suggestion, how to improve this situation. Thanks in 
advance!

Holger

----
root at lucas:/tmp/.x2go-abbasi# tail -f session-C-
abbasi-50-1401721407_stDLXDE_dp32.log
----
Session: Resuming session at 'Thu Aug  7 17:36:15 2014'.
Info: Proxy running in server mode with pid '31315'.
Info: Waiting for connection from 'localhost' on port '30001'.
Info: Accepted connection from '127.0.0.1'.
Info: Connection with remote proxy completed.
Info: Using LAN link parameters 1536/24/1/0.
Info: Using agent parameters 5000/0/50/0/0.
Info: Using pack method '16m-jpeg-9' with session 'unix-kde-depth_32'.
Info: Not using NX delta compression.
Info: Not using ZLIB data compression.
Info: Not using ZLIB stream compression.
Info: Not using a persistent cache.
Info: Listening to X11 connections on display ':50'.
Info: Established X client connection.
Info: Using shared memory parameters 1/1/0/0K.
nxagentInitAndCheckVisuals: WARNING! Ignoring not matched DirectColor visual.
[... LINE ABOVE REPEATED 31 TIMES ...]
Info: Not using local device configuration changes.
keyboard file created
SessionPath not defined
Session: Session resumed at 'Thu Aug  7 17:36:17 2014'.
Info: Screen [0] resized to geometry [800x600] fullscreen [0].
Info: Screen [0] resized to geometry [1440x848] fullscreen [0].
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 'Thu Aug  7 17:38:44 2014'.
Session: Suspending session at 'Thu Aug  7 17:38:44 2014'.
Session: Session suspended at 'Thu Aug  7 17:38:44 2014'.
Session: Resuming session at 'Thu Aug  7 17:42:27 2014'.
Info: Proxy running in server mode with pid '31315'.
Info: Waiting for connection from 'localhost' on port '30001'.
Info: Accepted connection from '127.0.0.1'.
Info: Connection with remote proxy completed.
Info: Using LAN link parameters 1536/24/1/0.
Info: Using agent parameters 5000/0/50/0/0.
Info: Using pack method '16m-jpeg-9' with session 'unix-kde-depth_32'.
Info: Not using NX delta compression.
Info: Not using ZLIB data compression.
Info: Not using ZLIB stream compression.
Info: Not using a persistent cache.
Info: Listening to X11 connections on display ':50'.
Info: Established X client connection.
Info: Using shared memory parameters 1/1/0/0K.
nxagentInitAndCheckVisuals: WARNING! Ignoring not matched DirectColor visual.
[... LINE ABOVE REPEATED 31 TIMES ...]
Info: Not using local device configuration changes.
keyboard file created
SessionPath not defined
Session: Session resumed at 'Thu Aug  7 17:42:30 2014'.
Info: Screen [0] resized to geometry [800x600] fullscreen [0].
Info: Screen [0] resized to geometry [1204x791] fullscreen [0].
Info: Screen [0] resized to geometry [1440x848] fullscreen [0].
Info: Screen [0] resized to geometry [1204x791] fullscreen [0].
Info: Screen [0] resized to geometry [1440x848] fullscreen [0].
Session: Suspending session at 'Thu Aug  7 17:43:11 2014'.
Info: Waiting the cleanup timeout to complete.
Session: Session suspended at 'Thu Aug  7 17:43:12 2014'.
Session: Resuming session at 'Thu Aug  7 17:43:25 2014'.
Info: Proxy running in server mode with pid '31315'.
Info: Waiting for connection from 'localhost' on port '30001'.
Info: Accepted connection from '127.0.0.1'.
Info: Connection with remote proxy completed.
Info: Using LAN link parameters 1536/24/1/0.
Info: Using agent parameters 5000/0/50/0/0.
Info: Using pack method '16m-jpeg-9' with session 'unix-kde-depth_32'.
Info: Not using NX delta compression.
Info: Not using ZLIB data compression.
Info: Not using ZLIB stream compression.
Info: Not using a persistent cache.
Info: Listening to X11 connections on display ':50'.
Info: Established X client connection.
Info: Using shared memory parameters 1/1/0/0K.
nxagentInitAndCheckVisuals: WARNING! Ignoring not matched DirectColor visual.
[... LINE ABOVE REPEATED 31 TIMES ...]
Info: Not using local device configuration changes.
keyboard file created
SessionPath not defined
Session: Session resumed at 'Thu Aug  7 17:43:27 2014'.
Info: Screen [0] resized to geometry [800x600] fullscreen [0].
Info: Screen [0] resized to geometry [784x562] fullscreen [0].
Info: Screen [0] resized to geometry [1440x848] fullscreen [0].
Info: Screen [0] resized to geometry [784x562] fullscreen [0].
Session: Suspending session at 'Thu Aug  7 17:43:44 2014'.
Info: Waiting the cleanup timeout to complete.
Session: Session suspended at 'Thu Aug  7 17:43:45 2014'.

----

root at perrin:/tmp/.x2go-abbasi# tail -f session-C-
abbasi-50-1404746618_stDLXDE_dp32.log                                                                                                                                           
Info: Using shared memory parameters 1/1/0/0K.                                                                                                                                                                                   
Info: Not using local device configuration changes.                                                                                                                                                                              
keyboard file created                                                                                                                                                                                                            
Session: Session resumed at 'Thu Aug  7 16:49:58 2014'.                                                                                                                                                                          
Info: Screen [0] resized to geometry [800x600] fullscreen [0].                                                                                                                                                                   
Info: Screen [0] resized to geometry [1440x848] fullscreen [0].                                                                                                                                                                  
Session: Resuming session at 'Thu Aug  7 17:20:01 2014'.                                                                                                                                                                         
Session: Display failure detected at 'Thu Aug  7 17:20:05 2014'.                                                                                                                                                                 
Session: Suspending session at 'Thu Aug  7 17:20:05 2014'.                                                                                                                                                                       
Session: Session suspended at 'Thu Aug  7 17:20:05 2014'.                                                                                                                                                                        
Session: Resuming session at 'Thu Aug  7 17:30:08 2014'.                                                                                                                                                                         
Info: Using shared memory parameters 1/1/0/0K.
Info: Not using local device configuration changes.
keyboard file created
Session: Session resumed at 'Thu Aug  7 17:30:14 2014'.
Info: Screen [0] resized to geometry [800x600] fullscreen [0].
Info: Screen [0] resized to geometry [1440x848] fullscreen [0].
Session: Suspending session at 'Thu Aug  7 17:35:59 2014'.
Session: Session suspended at 'Thu Aug  7 17:36:00 2014'.
Session: Resuming session at 'Thu Aug  7 17:38:43 2014'.
Info: Using shared memory parameters 1/1/0/0K.
Info: Not using local device configuration changes.
keyboard file created
Session: Session resumed at 'Thu Aug  7 17:38:49 2014'.
Info: Screen [0] resized to geometry [800x600] fullscreen [0].
Session: Resuming session at 'Thu Aug  7 17:42:16 2014'.
Session: Display failure detected at 'Thu Aug  7 17:42:20 2014'.
Session: Suspending session at 'Thu Aug  7 17:42:20 2014'.
Session: Session suspended at 'Thu Aug  7 17:42:20 2014'.
Session: Resuming session at 'Thu Aug  7 17:44:04 2014'.
Info: Using shared memory parameters 1/1/0/0K.
Info: Not using local device configuration changes.
keyboard file created
Session: Session resumed at 'Thu Aug  7 17:44:10 2014'.
Info: Screen [0] resized to geometry [800x600] fullscreen [0].
Info: Screen [0] resized to geometry [1440x848] fullscreen [0].
Session: Terminating session at 'Thu Aug  7 17:44:44 2014'.
Session: Session terminated at 'Thu Aug  7 17:44:45 2014'.


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