[X2Go-Dev] occurrence of sluggishness in X2Go

[John A. Sullivan III]

On Wed, 2012-06-06 at 10:10 -0400, John A. Sullivan III wrote:
> On Fri, 2012-06-01 at 08:32 +0200, Mike Gabriel wrote:
> > Hi,
> > 
> > just for the record and to let people know about current work focus...
> > 
> > People (esp. John) have reported occurrences of a very sluggish  
> > behaviour of various applications when run in X2Go sessions.
> > 
> > We developers can now confirm this. Ubuntu users reported this  
> > earlier, Debian user can now also experience such a sluggishness.
> > 
> > Reproduce on Debian:
> > 
> >    * add squeeze-backports archive to your system
> >    * install iceweasel (esr version)
> > 
> > This will drag in a libcairo from squeeze backports that is very  
> > probably the cause for making some applications very slow within X2Go  
> > sessions.
> > 
> > Libcairo is used in all GTK applications and is a layer between GTK  
> > and the rendering backend (X11, OpenGL, ...). With some recent version  
> > of libcairo the sluggishness got introduced...
> > 
> > @John: so it is not Nagle, I guess...
> > 
> > Compare: launch gnome-terminal (uses libcairo) on such a system and  
> > xterm (uses direct X11 rendering). Now create some output on standard  
> > out and then scroll back the shell history...
> > 
> > Alex has become aware of this on Linux Day Berlin and he has put it on  
> > his list with high priority to find a solution/workaround for that.
> > 
> <snip>
> Hmm . . . as I think about it, although I eagerly await this fix, I
> believe we are looking at two separate issues.  We are still running
> 3.0.1 series on our production servers and clients because of this issue
> (and some others).  However, I personally run the latest client from
> heuler.  I have the problem on both the latest x2goserver and the old
> 3.0.1-5 x2goserver.  It appears to be a client and not a server issue
> and appeared with the move to libssh.
> 
> The delay is not inconsequential.  We are not talking about a sese of
> sluggishness with a 250ms delay.  We are talking about a 2 to 5 full
> second delay for the final keystrokes or screens to appear.  Everything
> else until the final bit is lightning fast even on WAN links - John
<snip>
I happened to have an old 3.0.1-7 plugin sitting around and tried that.
I observed some of the same naglish behavior so it may not be the
x2goclient.  Unless someone else is experiencing this, I need to
investigate our environment more fully before sending the devs on a
fruitless search - John