[X2Go-User] Large latency when opening a new session

[Laurent Pouilloux]

Dear X2go-users,

for almost 2 years we are using X2GO with VirtualGL to provides 
visualization tool on our computing facility and it is very efficient 
tool. However, we are facing a problem with our current setup that seems 
related to the number of users connected.

We have a machine built on a Dell R730 server (40 cores, 512 GB, Quadro 
P2000) installed on Centos 7.
X2go is installed from EPEL repository, in version 4.0.1.22

For about one month, establishing the connection is very slow. As you 
can see in the log file below, it waits two minutes before to start a 
first session (lpouillo-1103-1526465870_stDXFCE_dp24) that does not seem 
to work then create a second one about 10 minutes 
later(C-lpouillo-1159-1527588238_stDXFCE_dp24)

This error seems correlated with the number of active users, including 
pts (when it is > 80) but I don't see any limits (max pty, max open 
files, or in x2goserver.conf which is the one by default) that is reached.


Do you have any idea on how to diagnose/solve the problem ?
Tell me if you need more information.

Best regards,

Laurent Pouilloux



Ex :
May 29 11:54:14 visu systemd-logind: New session 17176 of user lpouillo.
May 29 11:54:14 visu systemd: Started Session 17176 of user lpouillo.
May 29 11:54:14 visu systemd: Starting Session 17176 of user lpouillo.
May 29 11:56:10 visu /usr/bin/x2gosuspend-session: x2gosuspend-session 
called with options: lpouillo-1103-1526465870_stDXFCE_dp24
May 29 11:56:11 visu /usr/bin/x2goserver-run-extensions: 
x2goserver-run-extensions called with options: 
lpouillo-1103-1526465870_stDXFCE_dp24 pre-suspend
May 29 11:56:11 visu /usr/bin/x2goumount-session[136078]: 
x2goumount-session has been called with options: 
lpouillo-1103-1526465870_stDXFCE_dp24
May 29 11:56:30 visu /usr/bin/x2gosuspend-session: x2gosuspend-session 
called with options: lpouillo-1103-1526465870_stDXFCE_dp24
May 29 11:56:30 visu /usr/bin/x2goserver-run-extensions: 
x2goserver-run-extensions called with options: 
lpouillo-1103-1526465870_stDXFCE_dp24 pre-suspend
May 29 11:56:31 visu /usr/bin/x2goumount-session[138594]: 
x2goumount-session has been called with options: 
lpouillo-1103-1526465870_stDXFCE_dp24
May 29 11:56:50 visu /usr/bin/x2gosuspend-session: x2gosuspend-session 
called with options: lpouillo-1103-1526465870_stDXFCE_dp24
May 29 11:56:50 visu /usr/bin/x2goserver-run-extensions: 
x2goserver-run-extensions called with options: 
lpouillo-1103-1526465870_stDXFCE_dp24 pre-suspend
May 29 11:56:50 visu /usr/bin/x2goumount-session[141127]: 
x2goumount-session has been called with options: 
lpouillo-1103-1526465870_stDXFCE_dp24
May 29 12:04:00 visu /usr/bin/x2gostartagent: successfully started X2Go 
agent session with ID lpouillo-1159-1527588238_stDXFCE_dp24
May 29 12:04:02 visu /usr/bin/x2gomountdirs[514]: successfully mounted 
lpouillo at 127.0.0.1:61406/home/lpouillo/SRC to 
/tmp/.x2go-lpouillo/media/disk/_home_lpouillo_SRC
May 29 12:04:02 visu /usr/bin/x2gosetkeyboard: Setting X keyboard 
according to 
/home/lmfa/lpouillo/.x2go/C-lpouillo-1159-1527588238_stDXFCE_dp24/keyboard
May 29 12:04:03 visu /usr/bin/x2gomountdirs[514]: successfully mounted 
lpouillo at 127.0.0.1:61406/home/lpouillo/.x2go/S-lpouillo-1159-1527588238_stDXFCE_dp24/spool 
to /tmp/.x2go-lpouillo/spool/C-lpouillo-1159-1527588238_stDXFCE_dp24

-- 
Ingénieur en Calcul Scientifique
Laboratoire de Mécanique des Fluides et d'Acoustique
École Centrale de Lyon
36 Avenue Guy de Collongue, 69130 Écully
Batiment I11 - Bureau 11097W
Tél : 	04.72.18.61.57