Hi everyone,
I'm trying to get X11 forwarding working on my cluster. I've read some
of the threads and web posts on X11 forwarding and most of the common
issues I'm finding seem to pertain to older versions of Slurm.
I log in from my workstation to the login node with ssh -X. I have x11
apps installed on a test compute node, j-096. Here is what I see:
>From the config.log when I built slurm:
$ grep X11 config.log
configure:19906: checking whether Slurm internal X11 support is enabled
| #define WITH_SLURM_X11 1
| #define WITH_SLURM_X11 1
| #define WITH_SLURM_X11 1
#define WITH_SLURM_X11 1
>From the login node:
$ scontrol show config | grep X11
PrologFlags = Alloc,Contain,X11
X11Parameters = home_xauthority
$ grep ^X11 /etc/ssh/sshd_config
X11Forwarding yes
X11UseLocalhost no
Here is what I see when I try to run "xclock" on my test node:
$ srun --x11 -w j-096 xclock
Error: Can't open display: localhost:64.0
srun: error: j-096: task 0: Exited with exit code 1
>From the sshd_config on the test node:
$ grep ^X11 /etc/ssh/sshd_config
X11Forwarding yes
We are using hostbased ssh authentication in this cluster.
>From the slurmd.log on the test node:
[2022-10-05T13:29:51.065] [2822.extern] X11 forwarding established on
DISPLAY=j-096:64.0
[2022-10-05T13:29:51.165] launch task StepId=2822.0 request from UID:8348
GID:100 HOST:172.16.100.132 PORT:58948
[2022-10-05T13:29:51.165] task/affinity: lllp_distribution: JobId=2822 auto
binding off: mask_cpu
[2022-10-05T13:29:51.311] [2822.extern] error: _x11_socket_read:
slurm_open_msg_conn(127.0.0.1:34811): Connection refused
[2022-10-05T13:29:51.330] [2822.0] done with job
[2022-10-05T13:29:51.346] [2822.extern] done with job
[2022-10-05T13:29:51.436] [2822.extern] x11 forwarding shutdown complete
Is the issue the two different DISPLAY values, i.e. j-096:64.0
vs. localhost:64.0. Not sure how/where to reconcile these? I have tried
with and without "X11UseLocalhost no" on the login node.
Best wishes,
Allan
