Stupid reply. Reverse name resolution. But surely that would only affect the initial setup of a connection not the data stream.
I suggest strace of a graphical application on a computer node. You might be able to spot where any hangs are On Fri, Jun 6, 2025, 3:57 PM Simon Andrews via slurm-users < slurm-users@lists.schedmd.com> wrote: > Thanks for the suggestions – some interesting links to read. We already > have an option to run graphical sessions from the head node using Apache > Guacamole which works well, but that still requires X11 to talk to the > compute nodes. We don’t have a full desktop stack on the compute nodes and > just want to run individual applications. > > > > The issue isn’t network bandwidth – I can launch two graphical instances, > one via ssh and the other via srun at the same time on the same compute > node and ssh is great but srun is terrible. We do route through the head > node (the compute nodes aren’t directly addressable) but the overall > traffic on the head node is pretty modest. > > > > I’m not really sure how the X11 plugin works (assuming it’s not just doing > ssh X tunnelling) to try to think what else could be limiting here. > > > > Simon. > > > > *From:* Jason Simms <jsim...@swarthmore.edu> > *Sent:* 06 June 2025 13:52 > *To:* Hadrian Djohari <hx...@case.edu> > *Cc:* John Hearns <hear...@gmail.com>; Simon Andrews < > simon.andr...@babraham.ac.uk>; slurm-users@lists.schedmd.com > *Subject:* Re: [slurm-users] Re: X11 performance terrible using plugin > > > > > > *CAUTION:* This email originated outside of the Organisation. Please help > to keep us safe and do not click links or open attachments unless you > recognise the sender and know the content is safe. > > > > It may or may not be an appropriate solution for your use cases, but I > second using Open OnDemand and its virtual desktop. It is FAR more > performant than X11 through Slurm/SSH. > > *Jason L. Simms, Ph.D., M.P.H.* > > Research Computing Manager > > Swarthmore College > Information Technology Services > > (610) 328-8102 > > > > > > On Fri, Jun 6, 2025 at 8:40 AM Hadrian Djohari via slurm-users < > slurm-users@lists.schedmd.com> wrote: > > Or use Open OnDemand platform for the interactive Desktop. > > https://openondemand.org/ > <https://url6.mailanyone.net/scanner?m=1uNWYr-0000000Ah4a-3xXq&d=4%7Cmail%2F90%2F1749214200%2F1uNWYr-0000000Ah4a-3xXq%7Cin6i%7C57e1b682%7C10448314%7C12652688%7C6842E4993D26BA50F5233A708F1CC36D&o=%2Fphtp%3A%2Fotsanendemnod%2Fgro.&s=EpUt8bBKDs4r2Hlhft-LHnAqgKk> > > > > On Fri, Jun 6, 2025 at 8:37 AM John Hearns via slurm-users < > slurm-users@lists.schedmd.com> wrote: > > Simon, I have had success in the past by using NICE DCV (now owned by AWS > but you can get licenses for on prem) > https://www.ni-sp.com/products/nice-dcv > <https://url6.mailanyone.net/scanner?m=1uNWYr-0000000Ah4a-3xXq&d=4%7Cmail%2F90%2F1749214200%2F1uNWYr-0000000Ah4a-3xXq%7Cin6i%7C57e1b682%7C10448314%7C12652688%7C6842E4993D26BA50F5233A708F1CC36D&o=%2Fphtw%3A%2Fwts.iw.ospcn-crm%2Fsdutpovcd-ecin%2F&s=0xITGmLDGBVZzX4ADMnCbbAoi9o> > > An alternative would be VirtualGL > > Altair Access (though more likely to work with PBS!) > https://altair.com/access\ > <https://url6.mailanyone.net/scanner?m=1uNWYr-0000000Ah4a-3xXq&d=4%7Cmail%2F90%2F1749214200%2F1uNWYr-0000000Ah4a-3xXq%7Cin6i%7C57e1b682%7C10448314%7C12652688%7C6842E4993D26BA50F5233A708F1CC36D&o=%2Fphtl%3A%2Fatsmrtaaco%2Fi.C5%25ssecc&s=hLyv7Imbgx1A9uZG5XigVjAQneQ> > > > > > > > > On Fri, 6 Jun 2025 at 10:42, Simon Andrews via slurm-users < > slurm-users@lists.schedmd.com> wrote: > > On our cluster we’ve noticed that if we use the native x11 slurm plugin > (PrologFlags=x11) then X applications work, but are really slow and > unresponsive. Even opening menus on graphical application is painfully > slow. > > > > On the same system if I do a direct ssh connection with ssh -YC from the > head node the same applications are quick and responsive. > > > > Any suggestions for what might be causing this, and how I can get the > native x11 to have the same responsiveness as a direct ssh connection? > > > > Many thanks > > > > Simon. > > > -- > slurm-users mailing list -- slurm-users@lists.schedmd.com > To unsubscribe send an email to slurm-users-le...@lists.schedmd.com > > > -- > slurm-users mailing list -- slurm-users@lists.schedmd.com > To unsubscribe send an email to slurm-users-le...@lists.schedmd.com > > > > -- > > Hadrian Djohari > Director of Advanced Research Computing, [U]Tech > Case Western Reserve University > (W): 216-368-0395 > (M): 216-798-7490 > > > -- > slurm-users mailing list -- slurm-users@lists.schedmd.com > To unsubscribe send an email to slurm-users-le...@lists.schedmd.com > > ------------------------------ > > This email has been scanned for spam & viruses. If you believe this email > should have been stopped by our filters, click here > <https://portal-uk.mailanyone.net/index.html#/outer/reportspam?token=dXNlcj1zaW1vbi5hbmRyZXdzQGJhYnJhaGFtLmFjLnVrO3RzPTE3NDkyMTQzNjI7dXVpZD02ODQyRTQ5OTNEMjZCQTUwRjUyMzNBNzA4RjFDQzM2RDt0b2tlbj0zMWVmM2VlNzAzMjgxYTc3ZTNmZmQ5ZWFjYWVhNGM1NDMzNWI1MTI4Ow%3D%3D> > to report it. > > -- > slurm-users mailing list -- slurm-users@lists.schedmd.com > To unsubscribe send an email to slurm-users-le...@lists.schedmd.com >
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