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

[Mike Gabriel]

Hi Holger,

On  Do 07 Aug 2014 21:11:41 CEST, Holger Krause wrote:

> 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

this maybe relates to a known NX issue when homes are on NFS. Sessions  
become unresponsive there sometimes.

For X2Go Server 4.0.1.16 (to be released soon) we have moved all NX  
related session stuff from $HOME to $TMP for that very reason.

The occurences of the same ports are not relevant here, I reckon.  
Ports have to be unique per server, not per user.

Greets,
Mike

-- 

DAS-NETZWERKTEAM
mike gabriel, herweg 7, 24357 fleckeby
fon: +49 (1520) 1976 148

GnuPG Key ID 0x25771B31
mail: mike.gabriel at das-netzwerkteam.de, http://das-netzwerkteam.de

freeBusy:
https://mail.das-netzwerkteam.de/freebusy/m.gabriel%40das-netzwerkteam.de.xfb
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 819 bytes
Desc: Digitale PGP-Signatur
URL: <http://lists.x2go.org/pipermail/x2go-user/attachments/20140808/e24e8e7c/attachment.pgp>