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