[FreeNX-kNX] FreeNX & NoMachine Player - Connection Issues

Sat Jan 19 03:17:26 UTC 2013

I'm getting sporadic behavior trying to connect NoMachine Player (the replacement for NX Client in the 4.x NoMachine release) with a FreeNX-based server.  First, let me state that getting NX Player working with FreeNX is a must - we need to connect Mac clients to our servers, and, since the only Intel-based version of the NX Client for Mac is NX Player 4.x, going back to the 3.5 client is not an option, at least for Mac-based clients.  So, for those who would suggest using the "known good" versions of NX Client 3.5.x, that's not really feasible in my situation.

So, here are the software versions I'm using:
- OpenSuSE 12.1
- FreeNX 0.7.3, plus a few patches
- NX 3.5.0
- NX Player 4.0.181 Preview 6 (currently on Linux)

As far as the client goes, I can successfully connect my NX Player client to the NoMachine Virtual Workstation for Linux 4.x preview software, so I'm fairly certain that network issues can be ruled out here.  Also, I can successfully connect to FreeNX running on CentOS5, so it actually seems to be some interaction here between FreeNX and something in OpenSuSE.  Hopefully someone can point out what, or at least help me better nail it down.  Here's what I'm seeing:

- Connections fail *most* of the time - maybe 1 connection in 10 works perfectly fine, but the rest fail with the exact same error.
- It does not matter what Window Manager I try to use - KDE4, XFCE4, GNOME - all seem to fail equally well.
- This is not trying to resume an existing session, just create a new one.
- I've tried local users and network users on my systems, and that doesn't really seem to make a difference, either, so not a home directory, LDAP, or NFS issue.
- I see the following message on the screen on NXPlayer when I try to create a new, GNOME, for example, session:
The connection with the server was lost.
Error is 22: Invalid argument.

- If I choose the option to save the logs and then go look at the session logs, I see the following:
28343 5201 19:57:45 290.914 ProxyParser/ProxyParser: ERROR! Invalid protocol string 'bye
NXPROXY-1.5.0-3.5.0' in remote options.
Error: Invalid protocol string 'bye
NXPROXY-1.5.0-3.5.0' in remote options.
28343 5201 19:57:45 290.954 ProxySession/Threadable: WARNING! Aborting threadable 0xb4e28c60.
28343 5201 19:57:45 290.975 ProxySession/Threadable: WARNING! Error is 22, 'Invalid argument'.
28343 5201 19:57:45 290.985 ProxySession/Threadable: WARNING! Threadable 0xb4e28c60 aborted.
28343 5201 19:57:45 290.993 ProxySession/Threadable: WARNING! Setting error in threadable 0xb4e28c60.
28343 5201 19:57:45 291.001 ProxySession/Threadable: Restoring context from threadable 0xb4e28c60.
28343 5201 19:57:45 291.064 Entropy:       FM T 0   
Session: Session terminated at 'Fri Jan 18 19:57:45 2013'.
28343 5201 19:57:45 291.234 ClientTransResetCallback: WARNING! The NX transport terminated with error '22' 'Invalid argument'.
28343 5201 19:57:45 291.250 Dispatcher: ERROR! Bad pointer '0' in method 'Dispatcher::removeObject()' context [A].
Error: Bad pointer '0' in method 'Dispatcher::removeObject()' context [A].
28343 28343 19:57:45 329.305 ClientSession: Exiting from the client transport loop.
28343 28343 19:57:45 329.362 ClientSession: The transport closed with reset '1' error '22'.
28343 28343 19:57:45 329.395 ClientSession: Session at 0x82cff28 failed.
28343 28343 19:57:45 329.413 ClientSession: Failing reason is 'The connection with the server was lost.

Error is 22: Invalid argument.'.

- If I look at the logs on the server (with logging turned up a bit), I see:
bye
Bye
NX> 999 Bye
Info: Closing connection to slave with pid 27540.
nxnode_reader: 1001 Bye.
1001 Bye.
nxnode_reader: NX> 1004 Error: NX Agent exited with exit status 1. To troubleshoot set SESSION_LOG_CLEAN=0 in node.conf and investigate "/home/nxtest/.nx/F-C-se003945-11000-7CE6ABAB93B40AE2CB8303E679FBE39C/session". You might also want to try: ssh -X myserver; /usr/bin/nxnode --agent to test the basic functionality. Session log follows:
NX> 1004 Error: NX Agent exited with exit status 1. To troubleshoot set SESSION_LOG_CLEAN=0 in node.conf and investigate "/home/nxtest/.nx/F-C-se003945-11000-7CE6ABAB93B40AE2CB8303E679FBE39C/session". You might also want to try: ssh -X myserver; /usr/bin/nxnode --agent to test the basic functionality. Session log follows:
nxnode_reader: NX> 1006 Session status: closed
NX> 1006 Session status: closed
server_nxnode_echo: NX> 596 Session startup failed.
NX> 596 Session startup failed.
server_nxnode_echo: NX> 1004 Error: NX Agent exited with exit status 1. To troubleshoot set SESSION_LOG_CLEAN=0 in node.conf and investigate "/home/nxtest/.nx/F-C-se003945-11000-7CE6ABAB93B40AE2CB8303E679FBE39C/session". You might also want to try: ssh -X myserver; /usr/bin/nxnode --agent to test the basic functionality. Session log follows:
session_close 7CE6ABAB93B40AE2CB8303E679FBE39C
server_nxnode_echo: NX> 1006 Session status: closed
nxnode_reader: NX> 1001 Bye.
NX> 1001 Bye.
server_nxnode_echo: NX> 1001 Bye.
Info: Closing connection to slave with pid 27540.

- Finally, if I look at the user-specific logs mentioned, I see:
Error: The remote NX proxy closed the connection.
Error: Failure negotiating the session in stage '10'.
Error: Aborting session with 'Unable to open display 'nx/nx,options=/home/nxtest/.nx/C-se003945-11000-7CE6ABAB93B40AE2CB8303E679FBE39C/options:11000''.
Session: Aborting session at 'Fri Jan 18 19:57:45 2013'.
Session: Session aborted at 'Fri Jan 18 19:57:45 2013'.
xrdb: Connection refused
xrdb: Can't open display ':11000'
/usr/bin/startxfce4: X server already running on display :11000
xrdb: Connection refused
xrdb: Can't open display ':11000'
xscreensaver: 19:57:45: Can't open display: :11000
xscreensaver: 19:57:45: running as nxtest/users (120/100)

xscreensaver: 19:57:45: Errors at startup are usually authorization problems.
              But you're not logging in as root (good!) so something
              else must be wrong.  Did you read the manual and the FAQ?

              http://www.jwz.org/xscreensaver/faq.html
              http://www.jwz.org/xscreensaver/man.html

** ERROR **: Cannot open display: 
/etc/xdg/xfce4/xinitrc: line 159: 28167 Trace/breakpoint trap   xfce4-session

So, can anyone shed any light on what's going on here??  First, it seems like the server and client are both pointing the finger at each other saying it's the other's fault.  But then there's this error about Unable to open display??  I should also note that I have tried and successfully been able to do the "ssh -X <hostname> nxagent" test - works fine, once it's running I can open up items inside that display, etc.  Also, on NXPlayer, if I do a custom session and specify xterm as the command to run, that seems to work every time.  So, perhaps it's a timing thing - the window manager trying to start before X is available, or maybe X is timing out too fast before the window manager can start?  Also, what happens in "Stage '10'"?  This is a fairly consistent error - failure negotiating the session in stage '10' - but I cannot find any reference to this error around, nor can I figure out what stage 10 is supposed to be.

Thanks, in advance,
Nick

--------
This e-mail may contain confidential and privileged material for the sole use of the intended recipient.  If this email is not intended for you, or you are not responsible for the delivery of this message to the intended recipient, please note that this message may contain SEAKR Engineering (SEAKR) Privileged/Proprietary Information.  In such a case, you are strictly prohibited from downloading, photocopying, distributing or otherwise using this message, its contents or attachments in any way.  If you have received this message in error, please notify us immediately by replying to this e-mail and delete the message from your mailbox.  Information contained in this message that does not relate to the business of SEAKR is neither endorsed by nor attributable to SEAKR.