23.0 Preemption > Preemption tasks > Canceling jobs with preemption

Conventions

23.1.1 Canceling jobs with preemption

To preempt jobs using CANCEL

  1. Make the following configurations to the moab.cfg file:
    1. Set GUARANTEEDPREEMPTION to TRUE. (This causes Moab to lock PREEMPTOR jobs until JOBRETRYTIME expires.)
    2. Make sure that JOBNODEMATCHPOLICY is not set to EXACTNODE, which is not currently supported for preemption (for more information, see Testing and troubleshooting preemption).
    3. Set PREEMPTPOLICY to CANCEL (for more information, see PREEMPTPOLICY types).
    4. Make sure that the PREEMPTEE job has a lower priority than the PREEMPTOR job (for more information, see Preemption flags).
  2. For example:

    GUARANTEEDPREEMPTION TRUE
    PREEMPTPOLICY CANCEL
     
    QOSCFG[test1] QFLAGS=PREEMPTEE MEMBERULIST=john PRIORITY=100
    QOSCFG[test2] QFLAGS=PREEMPTOR MEMBERULIST=john PRIORITY=10000
  3. Submit a job to the preemptee QoS (test1). For example:
  4. [john@g06]# echo sleep 600 | msub -l walltime=600 -l qos=test1 -l procs=128

    (Optional) Examine the following output for showq:

    Moab.7
    [john@g06]# showq
     
    active jobs------------------------
    JOBID     USERNAME    STATE      PROCS     REMAINING     STARTTIME
    Moab.7    john        Running    128       00:01:59      Thu Nov 10 12:28:44
     
    1 active job     128 of 128 processors in use by local jobs (100.00%)
                     2 of 2 nodes active (100.00%)
     
    eligible jobs----------------------
    JOBID     USERNAME    STATE     PROCS      WCLIMIT       QUEUETIME
     
    0 eligible jobs
     
    blocked jobs-----------------------
    JOBID     USERNAME    STATE     PROCS      WCLIMIT       QUEUETIME
     
    0 blocked jobs
     
    Total job: 1
  5. Now submit a job to the preemptor QoS (test2). For example:
  6. [john@g06]$ echo sleep 120 | msub -l procs=128,walltime=120 -l qos=test2

    (Optional) Examine the following output for showq:

    Moab.8
    [john@g06]# showq
     
    active jobs------------------------
    JOBID     USERNAME    STATE      PROCS     REMAINING     STARTTIME
    Moab.7    john        Canceling  128       00:01:56      Thu Nov 10 12:28:44
    Moab.8    john        Running    128       00:02:00      Thu Nov 10 12:28:48
     
    2 active jobs 128 of 128 processors in use by local jobs (100.00%)
                  2 of 2 nodes active (100.00%)
     
    eligible jobs----------------------
    JOBID     USERNAME    STATE     PROCS      WCLIMIT       QUEUETIME
     
    0 eligible jobs
     
    blocked jobs-----------------------
    JOBID     USERNAME    STATE     PROCS      WCLIMIT       QUEUETIME
     
    0 blocked jobs
     
    Total jobs: 2

    Note that test1 is canceled when test2 is submitted.

    (Optional) Examine the checkjob outputs for these two jobs:

    [john@g06]$ checkjob Moab.9
    job Moab.9
     
    State: Removed
    Completetion Code: -1 Time: Thu Nov 10 12:28:48
    Creds: user:john group:john qos:test1
    WallTime: 00:00:02 of 00:02:00
    SubmitTime: Thu Nov 10 12:28:44
    (Time Queued Total: 00:00:07 Eligible: 00:00:00)
     
    Total Requested Tasks: 128
     
    Req[0] TaskCount: 128 Partition: licenses
    NodeCount: 2
     
    Allocated Nodes:
    node[01-02]*64
     
     
    IWD: /opt/native
    SubmitDir: /opt/native
    Executable: /opt/native/spool/moab.job.UFe8sQ
    
    StartCount: 1
    Flags: GLOBALQUEUE,PROCSPECIFIED
    Attr: PREEMPTEE
    StartPriority: 100 

    Note that the preempted job has been removed.

    [john@g06]$ checkjob Moab.10
    job Moab.10
     
    State: Running
    Creds: user:john group:john qos:test2
    WallTime: 00:00:00 of 00:02:00
    SubmitTime: Thu Nov 10 12:36:31
    (Time Queued Total: 00:00:00 Eligible: 00:00:00)
     
    StartTime: Thu Nov 10 12:28:48
    Total Requested Tasks: 128
     
    Req[0] TaskCount: 128 Partition: licenses
     
    Allocated Nodes:
    node[01-02]*64
     
     
    IWD: /opt/native
    SubmitDir: /opt/native
    Executable: /opt/native/spool/moab.job.CZavjU
     
    StartCount: 1
    Flags: HASPREEMPTED,PREEMPTOR,GLOBALQUEUE,PROCSPECIFIED
    StartPriority: 10000
    Reservation 'Moab.10' (-00:00:07 -> 00:01:53 Duration: 00:02:00)

Related topics