On Wed, Nov 14, 2018 at 8:17 PM <yk+bug+x2go@64.re> wrote:
Package: x2goserver Version: 4.0.1.0
I put this in the x2goserver section but I'm not quite sure if it's the right component that suffers from this issue.
In my company, we recently began to experience an issue similar to the one reported in archived bug #673 [1] and on the X2Go-User list [2] back in 2015. The manifestation of the issue is that when a session is suspended, our program that runs in a terminal inside the session is slowed down to a near stop, and abruptly recovers its original speed when the session is resumed. There seems to be a link with graphical components though, and my guess is it's the output scrolling in the terminal that is stalled, and by way of consequence slowing down the rest of the program downstream. To confirm the involvement of the graphics, I tried running glxgears as a test, and while it runs at about 1000 fps while the session is attached, it drops at about 3 fps (!) when suspended. This behaviour is reproducible on a freshly installed CentOS 7 VM; I can provide a VirtualBox VM on which I ran the glxgears test.
...
A quick search for this issue raised at least 2 third parties experiencing the issue; one university [3] announced dropping x2go as of October 2018 because of this, and another [4] is listing it as a known issue, albeit maybe in 2015.
Oh, they should have asked before dropping X2go!
I hope we can find a source for this problem, it's quite critical for us.
That has been implemented on purpose by nomachine to take some load off the server. You can disable that via the sleep option: sleep=<int> delay X server operations when suspended (provided in msec), set to 0 to keep nxagent session fully functional when suspended (e.g. useful when mirroring an nxagent session via VNC)
You can set this sleep to 0 in /etc/x2go/x2goagent.options on the server with the following line: X2GO_NXAGENT_DEFAULT_OPTIONS="-options nx/nx,sleep=0"
This in non-obvious and should be a client option instead... Can you please try if that helps for your setup?
Uli