NAME

       sge_priority - Grid Engine job priorities

DESCRIPTION

       Grid  Engine provides a means for controlling job dispatch and run-time priorities. The dispatch priority
       indicates the relative importance of pending jobs and determines the order in which Grid Engine initially
       considers dispatching jobs to queue instances, if the relevant  resources  are  available.   (The  actual
       running  order may be influenced may be influenced by other factors, such as reservations.)  The run-time
       priority determines the CPU allocation that the operating system assigns to jobs.

   JOBS DISPATCH PRIORITY
       A job's dispatch priority (display in the "reduced" output format of qstat(1)), is affected by  a  number
       of factors:

       •  the identity of the submitting user;

       •  the  project under which the job is submitted (or alternatively, the default project of the submitting
          user);

       •  any resources requested by the job;

       •  the job's submit time;

       •  the job's initiation deadline time (if specified);

       •  the -p priority specified for the job (also known as the POSIX priority "pprio").

       The effect of each of these is governed by the overall policy setup, which is split into three  top-level
       contributions.   Each  of  these  is  configured  through  the  sched_conf(5) parameters weight_priority,
       weight_ticket and weight_urgency.  These three parameters control to what degree POSIX  priority,  ticket
       policy,   and   urgency   policy  are  in  effect.  To  facilitate  interpretation,  the  raw  priorities
       ("tckts"/"urg"/"ppri") are normalized ("ntckts"/"nurg"/"npprior") before they are used to  calculate  job
       priorities  ("prio").   Normalization maps each raw urgency/ticket/priority  value into a range between 0
       and 1.

          npprior = normalized(ppri)
          nurg    = normalized(urg)
          ntckts  = normalized(tckts)

          prio    = weight_priority * npprio +
                    weight_urgency  * nurg +
                    weight_ticket   * ntckts

       The higher a job's priority value, the earlier it gets dispatched.

       The urgency policy defines an urgency value for each job. The urgency value
          urg =  rrcontr + wtcontr + dlcontr
       consists of the resource requirement contribution (rrcontr), the waiting time contribution (wtcontr)  and
       the deadline contribution (dlcontr).

       The  resource  requirement  contribution adds up all resource requirements of a job into a single numeric
       value.
          rrcontr = Sum over all(hrr)
       with an hrr for each hard resource request.  Depending on the resource type, two  different  methods  are
       used  to  determine  the  value  to  be  used  for  hrr here. For numeric type resource requests, the hrr
       represents how much of a resource a job requests (on a per-slot basis for PE jobs)  and  how  "important"
       this resource is considered in comparison to other resources. This is expressed by the formula:
          hrr = rurg * assumed_slot_allocation * request
       where  the  resource's  urgency  value  (rurg)  is  as  specified  under urgency in complex(5), the job's
       assumed_slot_allocation represents the number of slots supposedly assigned to the job, and  the  per-slot
       request  is that which was specified using the -l qsub(1) option. For string-type requests the formula is
       simply
          hrr = rurg
       and directly assigns the resource urgency value as specified under urgency in complex(5).

       The waiting time contribution represents a weighted waiting time of the jobs
          wtcontr = waiting_time * weight_waiting_time
       with the waiting time in seconds and the weight_waiting_time value as specified in sched_conf(5).

       The deadline contribution has an increasing effect as jobs approach their deadline initiation  time  (see
       the  -dl  option  in  qsub(1)).   It  is  defined  as  the  quotient  of  the  weight_deadline value from
       sched_conf(5) and the (steadily decreasing) free time in seconds until deadline initiation time
          dlcontr = weight_deadline / free_time
       or is set to 0 for non-deadline jobs.  After the deadline passes,  the  value  is  static  and  equal  to
       weight_deadline.  The qstat(1) -urg option displays urgency information for jobs.

       The  ticket  policy  unites  functional,  override  and  share tree policies in the ticket value (tckts),
       defined as the sum of the specific ticket values (ftckt/otckt/stckt)  for  each  sub-policy  (functional,
       override, share):
           tckts = ftckt + otckt + stckt

       The  ticket  policies  provide  a  broad  range  of  means  for influencing both job dispatch and runtime
       priorities on a per job, per user, per project, and per  department  basis.   The  qstat(1)  -ext  option
       displays ticket information for jobs.

   JOB RUN-TIME PRIORITY
       The  run-time  priority can be dynamically adjusted in order to meet the goals set with the ticket policy
       when execution hosts are over-subscribed. Dynamic run-time priority adjustment can be turned on  globally
       using  reprioritize  in  sge_conf(5)  and reprioritize_interval in sched_conf(5).  If no dynamic run-time
       priority adjustment is done at a host level, the priority specification in queue_conf(5) is in effect.

       Note that urgency and POSIX priorities do not affect runtime priority.

SEE ALSO

       sge_intro(1), complex(5), qstat(1), qsub(1), sched_conf(5), sge_conf(5)

COPYRIGHT

       See sge_intro(1) for a full statement of rights and permissions.

SGE 8.1.3pre                                       2007-01-05                                    SGE_PRIORITY(5)