Thanks Moe, I had already made the change you suggested but I was concerned that there was something in the background I was missing.
I will now be able to proceed with confidence. On Tue, Dec 11, 2012 at 3:23 PM, Moe Jette <[email protected]> wrote: > > Hi Brian, > > The FRONT_END_MODE is designed for any system where the slurmd does > not execute on the compute node, for example IBM BlueGene or Cray > systems running ALPS. Since the slurmd does not execute on the compute > nodes, an alternate task launch plugin is required. The launch/runjob > plugin is used for IBM BlueGene/Q systems and launch/aprun for Cray > systems, which cause srun to invoke IBM's runjob command or Cray's > aprun command after translating options appropriately. If you are > using a custom application to launch tasks then a new launch plugin is > probably your best option. > > The FRONT_END_MODE is also used for testing purposes. For that purpose > we let the srun command launch tasks, but only as user SlurmUser or > root. Without this restriction, user could easily cause the slurmd to > directly launch thousands of tasks and quite possibly exceed resources > limits and cause the slurmd daemon to fail. If you want to disable > this check for user SlurmUser or root then comment out the code in > src/slurmctld/proc_req.c around line 1688: > > #if defined HAVE_FRONT_END && !defined HAVE_BGQ && !defined HAVE_CRAY > /* Limited job step support */ > /* Non-super users not permitted to run job steps on front-end. > * A single slurmd can not handle a heavy load. */ > if (!validate_slurm_user(uid)) { > info("Attempt to execute job step by uid=%d", uid); > slurm_send_rc_msg(msg, ESLURM_NO_STEPS); > return; > } > #endif > > Moe > > > Quoting Brian Gilmer <[email protected]>: > >> >> I am trying to build a cluster with Slurm 2.5 using front end mode for >> single node serial jobs. I have compute nodes that are only connected >> via a PCI so I need to use a custom application to launch jobs. I am >> not able to launch jobs using srun either at the command prompt or via >> a batch file. I get: "srun error: Unable to create job step: Job >> steps can not be run on this cluster" or "srun: error: srun task >> launch not supported on this system". I am able to get jobs to launch >> if I use the custom application in a batch file. I am also able to >> get the jobs to launch with srun as root. Looking at the code this is >> all consistent. What I don't quite understand is how is >> front-end-mode supposed to be used given the restrictions. >> >> It would be helpful to get some background on the application of >> front-end-mode. I am also wondering with the new launch plugin if the >> restriction on front-end-mode still apply. >> >> Thanks >> Brian F Gilmer >> BCT-LLC >> >> >> >> -- >> Speak when you are angry--and you will make the best speech you'll >> ever regret. >> - Laurence J. Peter > -- Speak when you are angry--and you will make the best speech you'll ever regret. - Laurence J. Peter
