Hi All,
we are trying to implement preemption in one of our partitions so we can run priority jobs on it and suspend the ones running on the partition and resume once the priority job is done. We have read through the Slurm documentation and did the configuration, but somehow we can not make it work. We tried other preemption like cancel which works fine, but Suspend isn't working. The jobs with higher priority which should suspend other jobs stays as pending and waiting for resources. We are using a QOS to assign priority to the job and also configuring the QOS so it can preempt certain other QOSs. this is the output of our scontrol show config :
AccountingStorageBackupHost = (null) AccountingStorageEnforce = associations,limits,qos AccountingStorageHost   = -Some-server- AccountingStorageExternalHost = (null) AccountingStorageParameters = (null) AccountingStoragePort   = 6819 AccountingStorageTRES   = cpu,mem,energy,node,billing,fs/disk,vmem,pages AccountingStorageType   = accounting_storage/slurmdbd AccountingStorageUser   = N/A AccountingStoreFlags    = job_comment,job_env,job_extra,job_script AcctGatherEnergyType    = (null) AcctGatherFilesystemType = (null) AcctGatherInterconnectType = (null) AcctGatherNodeFreq      = 0 sec AcctGatherProfileType   = (null) AllowSpecResourcesUsage = No AuthAltTypes            = (null) AuthAltParameters       = (null) AuthInfo                = (null) AuthType                = auth/munge BatchStartTimeout       = 10 sec BcastExclude            = /lib,/usr/lib,/lib64,/usr/lib64 BcastParameters         = (null) BOOT_TIME               = 2024-03-15T13:32:05 BurstBufferType         = (null) CliFilterPlugins        = (null) ClusterName             = cluster CommunicationParameters = (null) CompleteWait            = 0 sec CoreSpecPlugin          = (null) CpuFreqDef              = Unknown CpuFreqGovernors        = OnDemand,Performance,UserSpace CredType                = cred/munge DebugFlags              = (null) DefMemPerCPU            = 3500 DependencyParameters    = (null) DisableRootJobs         = Yes EioTimeout              = 60 EnforcePartLimits       = ALL Epilog                  = (null) EpilogMsgTime           = 2000 usec EpilogSlurmctld         = (null) ExtSensorsType          = (null) ExtSensorsFreq          = 0 sec FairShareDampeningFactor = 1 FederationParameters    = (null) FirstJobId              = 1 GetEnvTimeout           = 2 sec GresTypes               = gpu GpuFreqDef              = (null) GroupUpdateForce        = 1 GroupUpdateTime         = 600 sec HASH_VAL                = Match HealthCheckInterval     = 300 sec HealthCheckNodeState    = ANY HealthCheckProgram      = /usr/sbin/nhc InactiveLimit           = 0 sec InteractiveStepOptions  = --interactive --preserve-env --pty $SHELL JobAcctGatherFrequency  = 30 JobAcctGatherType       = jobacct_gather/linux JobAcctGatherParams     = (null) JobCompHost             = localhost JobCompLoc              = (null) JobCompParams           = (null) JobCompPort             = 0 JobCompType             = (null) JobCompUser             = root JobContainerType        = (null) JobDefaults             = (null) JobFileAppend           = 0 JobRequeue              = 1 JobSubmitPlugins        = lua KillOnBadExit           = 0 KillWait                = 30 sec LaunchParameters        = (null) Licenses                = (null) LogTimeFormat           = iso8601_ms MailDomain              = (null) MailProg                = /bin/mail MaxArraySize            = 1001 MaxBatchRequeue         = 5 MaxDBDMsgs              = 20024 MaxJobCount             = 10000 MaxJobId                = 67043328 MaxMemPerNode           = UNLIMITED MaxNodeCount            = 6 MaxStepCount            = 40000 MaxTasksPerNode         = 512 MCSPlugin               = (null) MCSParameters           = (null) MessageTimeout          = 10 sec MinJobAge               = 300 sec MpiDefault              = pmix_v2 MpiParams               = (null) NEXT_JOB_ID             = 3626 NodeFeaturesPlugins     = (null) OverTimeLimit           = 0 min PluginDir               = /usr/lib64/slurm PlugStackConfig         = (null) PowerParameters         = (null) PowerPlugin             = (null) PreemptMode             = GANG,SUSPEND PreemptParameters       = (null) PreemptType             = preempt/qos PreemptExemptTime       = 00:00:00 PrEpParameters          = (null) PrEpPlugins             = prep/script PriorityParameters      = (null) PrioritySiteFactorParameters = (null) PrioritySiteFactorPlugin = (null) PriorityDecayHalfLife   = 7-00:00:00 PriorityCalcPeriod      = 00:05:00 PriorityFavorSmall      = No PriorityFlags           = PriorityMaxAge          = 7-00:00:00 PriorityUsageResetPeriod = NONE PriorityType            = priority/multifactor PriorityWeightAge       = 0 PriorityWeightAssoc     = 0 PriorityWeightFairShare = 0 PriorityWeightJobSize   = 0 PriorityWeightPartition = 0 PriorityWeightQOS       = 5000 PriorityWeightTRES      = (null) PrivateData             = none ProctrackType           = proctrack/cgroup Prolog                  = (null) PrologEpilogTimeout     = 65534 PrologSlurmctld         = (null) PrologFlags             = (null) PropagatePrioProcess    = 0 PropagateResourceLimits = ALL PropagateResourceLimitsExcept = (null) RebootProgram           = /etc/slurm/slurmupdate.sh ReconfigFlags           = (null) RequeueExit             = (null) RequeueExitHold         = (null) ResumeFailProgram       = (null) ResumeProgram           = (null) ResumeRate              = 300 nodes/min ResumeTimeout           = 60 sec ResvEpilog              = (null) ResvOverRun             = 0 min ResvProlog              = (null) ReturnToService         = 1 SchedulerParameters     = bf_max_job_user=2 SchedulerTimeSlice      = 30 sec SchedulerType           = sched/backfill ScronParameters         = (null) SelectType              = select/cons_tres SelectTypeParameters    = CR_CORE_MEMORY SlurmUser               = slurm(888) SlurmctldAddr           = (null) SlurmctldDebug          = info SlurmctldHost[0]        = -some-server- SlurmctldLogFile        = /var/log/slurm/slurmctld.log SlurmctldPort           = 6817 SlurmctldSyslogDebug    = (null) SlurmctldPrimaryOffProg = (null) SlurmctldPrimaryOnProg  = (null) SlurmctldTimeout        = 120 sec SlurmctldParameters     = (null) SlurmdDebug             = info SlurmdLogFile           = /var/log/slurm/slurmd.log SlurmdParameters        = (null) SlurmdPidFile           = /var/run/slurmd.pid SlurmdPort              = 6818 SlurmdSpoolDir          = /var/spool/slurm SlurmdSyslogDebug       = (null) SlurmdTimeout           = 300 sec SlurmdUser              = root(0) SlurmSchedLogFile       = (null) SlurmSchedLogLevel      = 0 SlurmctldPidFile        = /var/run/slurmctld.pid SLURM_CONF              = /etc/slurm/slurm.conf SLURM_VERSION           = 23.11.1 SrunEpilog              = (null) SrunPortRange           = 0-0 SrunProlog              = (null) StateSaveLocation       = /var/spool/slurmctld SuspendExcNodes         = (null) SuspendExcParts         = (null) SuspendExcStates        = (null) SuspendProgram          = (null) SuspendRate             = 60 nodes/min SuspendTime             = INFINITE SuspendTimeout          = 30 sec SwitchParameters        = (null) SwitchType              = (null) TaskEpilog              = (null) TaskPlugin              = task/cgroup,task/affinity TaskPluginParam         = none TaskProlog              = (null) TCPTimeout              = 2 sec TmpFS                   = /tmp TopologyParam           = (null) TopologyPlugin          = topology/default TrackWCKey              = No TreeWidth               = 16 UsePam                  = No UnkillableStepProgram   = (null) UnkillableStepTimeout   = 60 sec VSizeFactor             = 0 percent WaitTime                = 0 sec X11Parameters           = (null) Cgroup Support Configuration: AllowedRAMSpace         = 100.0% AllowedSwapSpace        = 0.0% CgroupMountpoint        = /sys/fs/cgroup CgroupPlugin            = autodetect ConstrainCores          = yes ConstrainDevices        = yes ConstrainRAMSpace       = yes ConstrainSwapSpace      = no EnableControllers       = no IgnoreSystemd           = no IgnoreSystemdOnFailure  = no MaxRAMPercent           = 100.0% MaxSwapPercent          = 100.0% MemorySwappiness        = (null) MinRAMSpace             = 30 MB MPI Plugins Configuration: PMIxCliTmpDirBase       = (null) PMIxCollFence           = (null) PMIxDebug               = 0 PMIxDirectConn          = yes PMIxDirectConnEarly     = no PMIxDirectConnUCX       = no PMIxDirectSameArch      = no PMIxEnv                 = (null) PMIxFenceBarrier        = no PMIxNetDevicesUCX       = (null) PMIxTimeout             = 300 PMIxTlsUCX              = (null)
the partition is configured like:
PartitionName=test-partition   AllowGroups=sysadmin,users AllowAccounts=ALL AllowQos=ALL   AllocNodes=ALL Default=NO QoS=N/A   DefaultTime=NONE DisableRootJobs=YES ExclusiveUser=NO GraceTime=0 Hidden=NO   MaxNodes=UNLIMITED MaxTime=UNLIMITED MinNodes=0 LLN=NO MaxCPUsPerNode=UNLIMITED MaxCPUsPerSocket=UNLIMITED   Nodes=vserv-[275-277]   PriorityJobFactor=1 PriorityTier=100 RootOnly=NO ReqResv=NO OverSubscribe=FORCE:1   OverTimeLimit=NONE PreemptMode=GANG,SUSPEND   State=UP TotalCPUs=32 TotalNodes=4 SelectTypeParameters=NONE   JobDefaults=(null)   DefMemPerNode=UNLIMITED MaxMemPerNode=UNLIMITED   TRES=cpu=32,mem=304933M,node=4,billing=32
Our QOS looks like this:
|      Name | Priority | GraceTime |  Preempt  | PreemptMode |          Flags  | UsageFactor |   MaxTRESPU     | MaxJobsPU | MaxSubmitPU |-----------|----------|-----------|-----------|-------------|-----------------|-------------|-----------------|-----------|----------- | normal    |    50    | 00:00:00  |           |   cluster   |                 |  1.000000   |                 |    20     |    50 | preempter |   1000   | 00:00:00  | preempted |  gang,suspe+|                 |  1.000000   |                 |           |      | preempted |      0   | 00:00:00  |           | gang,suspe+ |     OverPartQOS |  1.000000   | cpu=100,node=10 |           |          
I can provide more configs if needed. Do you guys see anything strange? Or any property to be set?
This is the state of the queue:
|JOBID             | QOS       | ST      | TIME      |  NODELIST(REASON)    | PARTITION       | PRIORITY |
| ----------------  ----------- --------- ----------- ---------------------- ----------------- ----------| | 3629             | preempted | PD      | 0:00      |  (Resources)         | test-partition  |    1     |   | 3627             | preempted | R       | 0:20      |  vserv-276           | test-partition  |    1     |    | 3628             | preempted | R       | 0:20      |  vserv-277           | test-partition  |    1     |    | 3626             | preempted | R       | 0:27      |  vserv-275           | test-partition  |    1     |    | 3630             | preempter | PD      | 0:00      |  (Resources)         | test-partition  |   5000   |
any advice is welcomed.


Regards,

Nischey Verma



Nischey Verma