[slurm-users] [External] Re: Preemption not working for jobs in higher priority partition

Fri Aug 27 16:13:28 UTC 2021

Thanks for the help all,

We ended up setting up a test slurm controller with 20.11 version and was
able to confirm preemption works across partitions, with the same nodes, as
expected. We updated our prod version from 20.02 to 20.11, while leaving
(for now) the slurmd's at various 20.02.X versions, and preemption began
working again as expected.

There must be a bug in 20.02.X that was preventing it from working like it
should, but I can confirm that it does work under slurmctld 20.11.

On Tue, Aug 24, 2021 at 12:28 PM Michael Robbert <mrobbert at mines.edu> wrote:

> I can confirm that we do preemption based on partition for one of our
> clusters. I will say that we are not using time-based partitions, ours are
> always up and they are based on group node ownership. I wonder if Slurm is
> refusing to preempt a job in a DOWN partition. Maybe try leaving the
> partition UP, but just change the priority of the partition.
>
> One other suggestion would be to turn up the debugging on the Slurm
> controller and/or use DebugFlags. I don’t know for sure which flag would
> give the best data, but I would start with the priority flag. With the
> right debugging turned on the slurmctld.log should give you more data on
> how or why it is making its decisions.
>
>
>
> Mike
>
>
>
> *From: *slurm-users <slurm-users-bounces at lists.schedmd.com> on behalf of
> Russell Jones <arjones85 at gmail.com>
> *Date: *Tuesday, August 24, 2021 at 10:36
> *To: *Slurm User Community List <slurm-users at lists.schedmd.com>
> *Subject: *[External] Re: [slurm-users] Preemption not working for jobs
> in higher priority partition
>
> *CAUTION:* This email originated from outside of the Colorado School of
> Mines organization. Do not click on links or open attachments unless you
> recognize the sender and know the content is safe.
>
>
>
> I have been researching this further and I see other systems that appear
> to be set up the same way we are. Example:
> https://hpcrcf.atlassian.net/wiki/spaces/TCP/pages/733184001/How-to+Use+the+preempt+Partition
> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fhpcrcf.atlassian.net%2Fwiki%2Fspaces%2FTCP%2Fpages%2F733184001%2FHow-to%2BUse%2Bthe%2Bpreempt%2BPartition&data=04%7C01%7Cmrobbert%40mines.edu%7Ca69c3fac8af3497278b508d9671d4700%7C997209e009b346239a4d76afa44a675c%7C0%7C0%7C637654197710622568%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=qqslNuf2I4DxfD4%2FVB53WS0%2FfMUAbEndrsBl9Y2OaL8%3D&reserved=0>
>
>
>
> Any further insight into what may be wrong with our setup is appreciated.
> I am not seeing what is wrong with my config, but it also isn't working
> anymore to allow preemption.
>
>
>
> On Fri, Aug 20, 2021 at 9:46 AM Russell Jones <arjones85 at gmail.com> wrote:
>
> I could have swore I had tested this before implementing it and it worked
> as expected.
>
>
>
> If I am dreaming that testing - is there a way of allowing preemption
> across partitions?
>
>
>
> On Fri, Aug 20, 2021 at 8:40 AM Brian Andrus <toomuchit at gmail.com> wrote:
>
> IIRC, Preemption is determined by partition first, not node.
>
> Since your pending job is in the 'day' partition, it will not preempt
> something in the 'night' partition (even if the node is in both).
>
> Brian Andrus
>
> On 8/19/2021 2:49 PM, Russell Jones wrote:
>
> Hi all,
>
>
> I could use some help to understand why preemption is not working for me
> properly. I have a job blocking other jobs that doesn't make sense to me.
> Any assistance is appreciated, thank you!
>
>
>
>
>
> I have two partitions defined in slurm, a day time and a night time
> pariition:
>
> Day partition - PriorityTier of 5, always Up. Limited resources under this
> QOS.
>
> Night partition - PriorityTier of 5 during night time, during day time set
> to Down and PriorityTier changed to 1. Jobs can be submitted to night queue
> for an unlimited QOS as long as resources are available.
>
> The thought here is jobs can continue to run in the night partition, even
> during the day time, until resources are requested from the day partition.
> Jobs would then be requeued/canceled in the night partition to
> satisfy those requirements.
>
>
>
> Current output of "scontrol show part" :
>
> PartitionName=day
>
>    AllowGroups=ALL AllowAccounts=ALL AllowQos=ALL
>
>    AllocNodes=ALL Default=NO QoS=part_day
>
>    DefaultTime=NONE DisableRootJobs=NO ExclusiveUser=NO GraceTime=0
> Hidden=NO
>
>    MaxNodes=UNLIMITED MaxTime=1-00:00:00 MinNodes=0 LLN=NO
> MaxCPUsPerNode=UNLIMITED
>
>    Nodes=cluster-r1n[01-13],cluster-r2n[01-08]
>
>    PriorityJobFactor=1 PriorityTier=5 RootOnly=NO ReqResv=NO
> OverSubscribe=NO
>
>    OverTimeLimit=NONE PreemptMode=REQUEUE
>
>    State=UP TotalCPUs=336 TotalNodes=21 SelectTypeParameters=NONE
>
>    JobDefaults=(null)
>
>    DefMemPerNode=UNLIMITED MaxMemPerNode=UNLIMITED
>
>
>
> PartitionName=night
>
>    AllowGroups=ALL AllowAccounts=ALL AllowQos=ALL
>
>    AllocNodes=ALL Default=NO QoS=part_night
>
>    DefaultTime=NONE DisableRootJobs=NO ExclusiveUser=NO GraceTime=0
> Hidden=NO
>
>    MaxNodes=22 MaxTime=7-00:00:00 MinNodes=0 LLN=NO
> MaxCPUsPerNode=UNLIMITED
>
>    Nodes=cluster-r1n[01-13],cluster-r2n[01-08]
>
>    PriorityJobFactor=1 PriorityTier=1 RootOnly=NO ReqResv=NO
> OverSubscribe=NO
>
>    OverTimeLimit=NONE PreemptMode=REQUEUE
>
>    State=DOWN TotalCPUs=336 TotalNodes=21 SelectTypeParameters=NONE
>
>    JobDefaults=(null)
>
>    DefMemPerNode=UNLIMITED MaxMemPerNode=UNLIMITED
>
>
>
>
> I currently have a job in the night partition that is blocking jobs in the
> day partition, even though the day partition has a PriorityTier of 5, and
> night partition is Down with a PriorityTier of 1.
>
> My current slurm.conf preemption settings are:
>
> PreemptMode=REQUEUE
>
> PreemptType=preempt/partition_prio
>
>
>
> The blocking job's scontrol show job output is:
>
> JobId=105713 JobName=jobname
>
>    Priority=1986 Nice=0 Account=xxx QOS=normal
>
>    JobState=RUNNING Reason=None Dependency=(null)
>
>    Requeue=1 Restarts=0 BatchFlag=1 Reboot=0 ExitCode=0:0
>
>    RunTime=17:49:39 TimeLimit=7-00:00:00 TimeMin=N/A
>
>    SubmitTime=2021-08-18T22:36:36 EligibleTime=2021-08-18T22:36:36
>
>    AccrueTime=2021-08-18T22:36:36
>
>    StartTime=2021-08-18T22:36:39 EndTime=2021-08-25T22:36:39 Deadline=N/A
>
>    PreemptEligibleTime=2021-08-18T22:36:39 PreemptTime=None
>
>    SuspendTime=None SecsPreSuspend=0 LastSchedEval=2021-08-18T22:36:39
>
>    Partition=night AllocNode:Sid=cluster-1:1341505
>
>    ReqNodeList=(null) ExcNodeList=(null)
>
>    NodeList=cluster-r1n[12-13],cluster-r2n[04-06]
>
>    BatchHost=cluster-r1n12
>
>    NumNodes=5 NumCPUs=80 NumTasks=5 CPUs/Task=1 ReqB:S:C:T=0:0:*:*
>
>    TRES=cpu=80,node=5,billing=80,gres/gpu=20
>
>    Socks/Node=* NtasksPerN:B:S:C=0:0:*:* CoreSpec=*
>
>    MinCPUsNode=1 MinMemoryNode=0 MinTmpDiskNode=0
>
>    Features=(null) DelayBoot=00:00:00
>
>    OverSubscribe=NO Contiguous=0 Licenses=(null) Network=(null)
>
>
>
> The job that is being blocked:
>
> JobId=105876 JobName=bash
>
>    Priority=2103 Nice=0 Account=xxx QOS=normal
>
>    JobState=PENDING
> Reason=Nodes_required_for_job_are_DOWN,_DRAINED_or_reserved_for_jobs_in_higher_priority_partitions
> Dependency=(null)
>
>    Requeue=1 Restarts=0 BatchFlag=0 Reboot=0 ExitCode=0:0
>
>    RunTime=00:00:00 TimeLimit=1-00:00:00 TimeMin=N/A
>
>    SubmitTime=2021-08-19T16:19:23 EligibleTime=2021-08-19T16:19:23
>
>    AccrueTime=2021-08-19T16:19:23
>
>    StartTime=Unknown EndTime=Unknown Deadline=N/A
>
>    SuspendTime=None SecsPreSuspend=0 LastSchedEval=2021-08-19T16:26:43
>
>    Partition=day AllocNode:Sid=cluster-1:2776451
>
>    ReqNodeList=(null) ExcNodeList=(null)
>
>    NodeList=(null)
>
>    NumNodes=3 NumCPUs=40 NumTasks=40 CPUs/Task=1 ReqB:S:C:T=0:0:*:*
>
>    TRES=cpu=40,node=1,billing=40
>
>    Socks/Node=* NtasksPerN:B:S:C=0:0:*:* CoreSpec=*
>
>    MinCPUsNode=1 MinMemoryNode=0 MinTmpDiskNode=0
>
>    Features=(null) DelayBoot=00:00:00
>
>    OverSubscribe=NO Contiguous=0 Licenses=(null) Network=(null)
>
>
>
>
>
> Why is the day job not preempting the night job?
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.schedmd.com/pipermail/slurm-users/attachments/20210827/a8465623/attachment-0001.htm>