- slurm-users - lists.schedmd.com

Feature request: Max Jobs Per Minute
by Ransom, Geoffrey M. 16 Sep '24

16 Sep '24

Hello We have another batch of new users and some more batches of large array jobs with very short runtimes due to errors in the jobs or just by design. Trying to deal with these issues, Setting ArrayTaskThrottle and user education, I had a thought that it would be very nice to have a limit on how many jobs can start in a given minute for users, so if they posted a 200000 array job with 15 second tasks then the scheduler wouldn't launch more than a 100 or 200 per minute and be less likely to bog down, but if they had longer runtimes (1 hour +) it would take a few extra minutes to start using all the resources they are allowed to but not add much overall delay to the whole set of jobs. I thought about adding something to our CLI filter, but usually these jobs are asking for a runtime of 3-4 hours even though they run for <30 seconds so the submit options don't indicate the problem jobs ahead of time. We currently limit our users to %80 of the available resources which is way more than slurm needs to bog down with fast turnover jobs, but we have users who complain that they can't use that other 20% when the cluster is not busy so putting in lower default restrictions is not currently an option. Has this already been discussed and isn't feasible for technical reasons? (Not finding anything like this yet searching the archives) I think slurm used have a feature request severity on their bug submission site. Is there a severity level they prefer to have suggested requests like this? Thanks

2 2

Detailed locations for SLUG'24
by Bjørn-Helge Mevik 10 Sep '24

10 Sep '24

Dear all SLUG attendees! The information about which buildings/addresses the SLUG reception and presentations are to be held is not very visible on the https://slug24.splashthat.com. There is a map there with all locations (https://www.google.com/maps/d/u/0/edit?mid=1bcGaTiW0TNB5noQsjQ3ulctzKuqlGrQ…) but I've gotten questions about it, so: The reception on Wednesday will be held in the top floor of Oslo Science Park (Forskningsparken). Address: Gaustadalléen 21. There will be someone in the reception who can point you in the right direction. The presentations will be held in auditorium 3 in Helga Engs Hus ("Helga Eng's House"). Address: Sem Sælands vei 7. Lunch will be in the canteen in the same building. The closest subway station to both these buildings is Blindern Subway Station (Blindern T-banestasjon). Looking forward to see you there! -- Regards, Bjørn-Helge Mevik, dr. scient, Department for Research Computing, University of Oslo

1 1

Issue with cgroup v2 when IgnoreSystemd=yes
by Honoré Bergeron 09 Sep '24

09 Sep '24

Hi, This is a follow-up from https://groups.google.com/g/slurm-users/c/JI3UkbCtj3U, but as I could not find any progress, I am opening a new thread. When setting IgnoreSystemd=yes in cgroup.conf, I have the error: error: common_file_write_content: unable to open '/sys/fs/cgroup/system.slice/cgroup.subtree_control' for writing: No such file or directory error: Cannot enable cpuset in /sys/fs/cgroup/system.slice/cgroup.subtree_control: No such file or directory error: common_file_write_content: unable to open '/sys/fs/cgroup/system.slice/cgroup.subtree_control' for writing: No such file or directory error: Cannot enable memory in /sys/fs/cgroup/system.slice/cgroup.subtree_control: No such file or directory error: common_file_write_content: unable to open '/sys/fs/cgroup/system.slice/cgroup.subtree_control' for writing: No such file or directory error: Cannot enable cpu in /sys/fs/cgroup/system.slice/cgroup.subtree_control: No such file or directory error: Could not create scope directory /sys/fs/cgroup/system.slice/slurmstepd.scope: No such file or directory error: Couldn't load specified plugin name for cgroup/v2: Plugin init() callback failed error: cannot create cgroup context for cgroup/v2 error: Unable to initialize cgroup plugin error: slurmd initialization failed I wrote a patch that solves this issue: --- cgroup_v2.c.orig 2024-09-02 13:18:21.376312875 +0200 +++ cgroup_v2.c 2024-09-02 13:22:00.516986953 +0200 @@ -43,6 +43,7 @@ #include <sys/inotify.h> #include <poll.h> #include <unistd.h> +#include <libgen.h> #include "slurm/slurm.h" #include "slurm/slurm_errno.h" @@ -743,11 +744,33 @@ return SLURM_SUCCESS; } +static int _mkdir(const char *path, mode_t mode) +{ + int rc; + char *dir, *pdir; + + dir = strdup(path); + if (dir == NULL) { + return ENOMEM; + } + pdir = dirname(dir); + if (strcmp(pdir, path) != 0) { + rc = _mkdir(pdir, mode); + if (rc && (errno != EEXIST)) { + free(dir); + return rc; + } + } + rc = mkdir(path, mode); + free(dir); + return rc; +} + static int _init_new_scope(char *scope_path) { int rc; - rc = mkdir(scope_path, 0755); + rc = _mkdir(scope_path, 0755); if (rc && (errno != EEXIST)) { error("Could not create scope directory %s: %m", scope_path); return SLURM_ERROR; This patch concerns the file src/plugins/cgroup/v2/cgroup_v2.c. Am I missing something ? Cheers, Honoré.

1 0

Configuration for nodes with different TmpFs locations and TmpDisk sizes
by Jake Longo 06 Sep '24

06 Sep '24

Hi, We have a number of machines in our compute cluster that have larger disks available for local data. I would like to add them to the same partition as the rest of the nodes but assign them a larger TmpDisk value which would allow users to request a larger tmp and land on those machines. The main hurdle is that (for reasons beyond my control) the larger local disks are on a special mount point /largertmp whereas the rest of the compute cluster uses the vanilla /tmp. I can't see an obvious way to make this work as the TmpFs value appears to be global only and attempting to set TmpDisk to a value larger than TmpFs for those nodes will put the machine into an invalid state. I couldn't see any similar support tickets or anything in the mail archive but I wouldn't have thought it would be that unusual to do this. Thanks in advance! Jake

2 1

salloc not starting shell despite LaunchParameters=use_interactive_step
by Loris Bennett 06 Sep '24

06 Sep '24

Hi, With $ salloc --version slurm 23.11.10 and $ grep LaunchParameters /etc/slurm/slurm.conf LaunchParameters=use_interactive_step the following $ salloc --partition=interactive --ntasks=1 --time=00:03:00 --mem=1000 --qos=standard salloc: Granted job allocation 18928869 salloc: Nodes c001 are ready for job creates a job $ squeue --me JOBID PARTITION NAME USER ST TIME NODES NODELIST(REASON) 18928779 interacti interact loris R 1:05 1 c001 but causes the terminal to block. From a second terminal I can log into the compute node: $ ssh c001 [13:39:36] loris@c001 (1000) ~ Is that the expected behaviour or should salloc return a shell directly on the compute node (like srun --pty /bin/bash -l used to do)? Cheers, Loris -- Dr. Loris Bennett (Herr/Mr) FUB-IT, Freie Universität Berlin

5 8

Nodelist syntax and semantics
by Jackson, Gary L. 05 Sep '24

05 Sep '24

Is there a description of the “nodelist” syntax and semantics somewhere other than the source code? By “nodelist” I mean expressions like “name[000,099-100]” and how this one, for example, expands to “name000, name099, name100”. -- Gary

2 1

Configuration for nodes with different TmpFs locations and TmpDisk sizes
by Jake Longo 05 Sep '24

05 Sep '24

Hi all, We have a number of machines in our compute cluster that have larger disks available for local data. I would like to add them to the same partition as the rest of the nodes but assign them a larger TmpDisk value which would allow users to request a larger tmp and land on those machines. The main hurdle is that (for reasons beyond my control) the larger local disks are on a special mount point /largertmp whereas the rest of the compute cluster uses the vanilla /tmp. I can't see an obvious way to make this work as the TmpFs value appears to be global only and attempting to set TmpDisk to a value larger than TmpFs for those nodes will put the machine into an invalid state. I couldn't see any similar support tickets or anything in the mail archive but I wouldn't have thought it would be that unusual to do this. Thanks in advance! Jake

2 1

Make a job pending in the plugin
by benjamin.jin＠bos-semi.com 05 Sep '24

05 Sep '24

Hello all, I am tyring to build a custom plugin to force some jobs to be pended. In the official document, `ESLURM*` errors are only valid for `job_submit_lua`. I tried to send `ESLURM_JOB_PENDING`, but it only rejects the job submission. Does anyone know how to pend a job in job_submit plugin? Thanks.

2 1

Bug? sbatch not respecting MaxMemPerNode setting
by Angel de Vicente 05 Sep '24

05 Sep '24

Hello, we found an issue with Slurm 24.05.1 and the MaxMemPerNode setting. Slurm is installed in a single workstation, and thus, the number of nodes is just 1. The relevant sections in slurm.conf read: ,---- | EnforcePartLimits=ALL | PartitionName=short Nodes=..... State=UP Default=YES MaxTime=2-00:00:00 MaxCPUsPerNode=76 MaxMemPerNode=231000 OverSubscribe=FORCE:1 `---- Now, if I submit a job requesting 76 CPUs and each one needing 4000M (for a total of 304000M), Slurm does indeed respect the MaxMemPerNode setting and the job is not submitted in the following cases ("-N 1" is not really necessary, as there is only one node): ,---- | $ sbatch -N 1 -n 1 -c 76 -p short --mem-per-cpu=4000M test.batch | sbatch: error: Batch job submission failed: Memory required by task is not available | | $ sbatch -N 1 -n 76 -c 1 -p short --mem-per-cpu=4000M test.batch | sbatch: error: Batch job submission failed: Memory required by task is not available | | $ sbatch -n 1 -c 76 -p short --mem-per-cpu=4000M test.batch | sbatch: error: Batch job submission failed: Memory required by task is not available `---- But with this submission Slurm is happy: ,---- | $ sbatch -n 76 -c 1 -p short --mem-per-cpu=4000M test.batch | Submitted batch job 133982 `---- and the slurmjobcomp.log file does indeed tell me that the memory went above MaxMemPerNode: ,---- | JobId=133982 UserId=......(10487) GroupId=domain users(2000) Name=test JobState=CANCELLED Partition=short TimeLimit=45 StartTime=2024-09-04T09:11:17 EndTime=2024-09-04T09:11:24 NodeList=...... NodeCnt=1 ProcCnt=76 WorkDir=/tmp/. ReservationName= Tres=cpu=76,mem=304000M,node=1,billing=76 Account=ddgroup QOS=domino WcKey= Cluster=...... SubmitTime=2024-09-04T09:11:17 EligibleTime=2024-09-04T09:11:17 DerivedExitCode=0:0 ExitCode=0:0 `---- What is the best way to report issues like this to the Slurm developers? I thought of adding it to https://support.schedmd.com/ but it is not clear to me if that page is only meant for Slurm users with a Support Contract? Cheers, -- Ángel de Vicente Research Software Engineer (Supercomputing and BigData) Instituto de Astrofísica de Canarias (https://www.iac.es/en)

2 3

Slurm Remote Task Launch
by Bhaskar Chakraborty 04 Sep '24

04 Sep '24

Hello, I have a slurm job which needs to launch multiple tasks across the allocated hosts for the job. My criteria is that most of the tasks need to be launched from within the main task launchedby slurm in the launch compute node. So, if the allocated hosts are h1, h2 & h3 with h1 being the main launcher node then theinitial task, say launchTask, launched in h1 will need to launch RemoteTask1, RemoteTask2 in h2 & h3 at somepoint during execution. Can I use srun from inside launchTask to do so? If yes, what would be the syntax / args?If no, then what alternative I have other than using rsh/ssh which mayn't be available in the cluster. Thanks in advance! Regards,Bhaskar.

1 0