Job Accounting on Rhea
Print this article
Jobs on Rhea are scheduled in full node increments; a node’s cores cannot be allocated to multiple jobs. Because the OLCF charges based on what a job makes unavailable to other users, a job is charged for an entire node even if it uses only one core on a node. To simplify the process, users are given a multiples of entire nodes through PBS.
Viewing Allocation Utilization
Projects are allocated time on Rhea in units of node-hours. This is separate from a project’s Titan or Eos allocation, and usage of Rhea does not count against that allocation. This page describes how such units are calculated, and how users can access more detailed information on their relevant allocations.
The node-hour charge for each batch job will be calculated as follows:
node-hours = nodes requested * ( batch job endtime - batch job starttime )
Where batch job starttime is the time the job moves into a running state, and batch job endtime is the time the job exits a running state.
A batch job’s usage is calculated solely on requested nodes and the batch job’s start and end time. The number of cores actually used within any particular node within the batch job is not used in the calculation. For example, if a job requests (6) nodes through the batch script, runs for (1) hour, uses only (2) CPU cores per node, the job will still be charged for 6 nodes * 1 hour = 6 node-hours.
Utilization is calculated daily using batch jobs which complete between 00:00 and 23:59 of the previous day. For example, if a job moves into a run state on Tuesday and completes Wednesday, the job’s utilization will be recorded Thursday. Only batch jobs which write an end record are used to calculate utilization. Batch jobs which do not write end records due to system failure or other reasons are not used when calculating utilization.
Each user may view usage for projects on which they are members from the command line tool
showusage and the My OLCF site.
On the Command Line via
showusage utility can be used to view your usage from January 01 through midnight of the previous day. For example:
$ showusage Usage: Project Totals
Project Allocation Usage Remaining Usage _________________|______________|___________|____________|______________ abc123 | 20000 | 126.3 | 19873.7 | 1560.80
-h option will list more usage details.
On the Web via My OLCF
More detailed metrics may be found on each project’s usage section of the My OLCF site.
The following information is available for each project:
- YTD usage by system, subproject, and project member
- Monthly usage by system, subproject, and project member
- YTD usage by job size groupings for each system, subproject, and project member
- Weekly usage by job size groupings for each system, and subproject
- Batch system priorities by project and subproject
- Project members
The My OLCF site is provided to aid in the utilization and management of OLCF allocations. If you have any questions or have a request for additional data, please contact the OLCF User Assistance Center.