Job Start Time Estimates

14.0 Improving User Effectiveness > Job Start Time Estimates

14.4 Job Start Time Estimates

Each user can use the showstart command to display estimated start and completion times. The following example illustrates a typical response from issuing this command:

> showstart orion.13762
job orion.13762 requires 2 procs for 0:33:20
Estimated Rsv based start in                 1:04:55 on Fri Jul 15 12:53:40
Estimated Rsv based completion in            2:44:55 on Fri Jul 15 14:33:40
Estimated Priority based start in            5:14:55 on Fri Jul 15 17:03:40
Estimated Priority based completion in       6:54:55 on Fri Jul 15 18:43:40
Estimated Historical based start in         00:00:00 on Fri Jul 15 11:48:45
Estimated Historical based completion in     1:40:00 on Fri Jul 15 13:28:45
Best Partition: fast

14.4-A Estimation Types

Reservation-Based Estimates

Reservation-based start time estimation incorporates information regarding current administrative, user, and job reservations to determine the earliest time the specified job can allocate the needed resources and start running. In essence, this estimate indicates the earliest time the job will start, assuming this job is the highest priority job in the queue.

For reservation-based estimates, the information provided by this command is more highly accurate if the job is highest priority, if the job has a reservation, or if the majority of the jobs that are of higher priority have reservations. Consequently, site administrators wanting to make decisions based on this information may want to consider using the RESERVATIONDEPTH parameter to increase the number of priority-based reservations. This can be set so that most, or even all, idle jobs receive priority reservations and make the results of this command generally useful. The only caution of this approach is that increasing the RESERVATIONDEPTH parameter more tightly constrains the decisions of the scheduler and may result in slightly lower system utilization (typically less than 8% reduction).

Backlog/Priority Estimates

Priority-based job start analysis determines when the queried job will fit in the queue and determines the estimated amount of time required to complete the jobs currently running or scheduled to run before this job can start.

In all cases, if the job is running, this command returns the time the job starts. If the job already has a reservation, this command returns the start time of the reservation.

Historical Estimates

Historical analysis uses historical queue times for jobs that match a similar processor count and job duration profile. This information is updated on a sliding window that is configurable within moab.cfg.