Resources Allocation Policy
The resources are allocated to the job in a fair-share fashion, subject to constraints set by the queue and resources available to the Project. The Fair-share at Anselm ensures that individual users may consume approximately equal amount of resources per week. Detailed information in the Job scheduling section. The resources are accessible via several queues for queueing the jobs. The queues provide prioritized and exclusive access to the computational resources. Following table provides the queue partitioning overview:
Check the queue status at https://extranet.it4i.cz/anselm/
|queue||active project||project resources||nodes||min ncpus||priority||authorization||walltime|
|qexp||no||none required||2 reserved, 31 totalincluding MIC, GPU and FAT nodes||1||150||no||1 h|
|qprod||yes||0||178 nodes w/o accelerator||16||0||no||24/48 h|
|qlong||yes||0||60 nodes w/o accelerator||16||0||no||72/144 h|
|qnvidia, qmic||yes||0||23 nvidia nodes, 4 mic nodes||16||200||yes||24/48 h|
|qfat||yes||0||2 fat nodes||16||200||yes||24/144 h|
|qfree||yes||none required||178 w/o accelerator||16||-1024||no||12 h|
The qfree queue is not free of charge. Normal accounting applies. However, it allows for utilization of free resources, once a Project exhausted all its allocated computational resources. This does not apply for Directors Discreation's projects (DD projects) by default. Usage of qfree after exhaustion of DD projects computational resources is allowed after request for this queue.
The qexp queue is equipped with the nodes not having the very same CPU clock speed. Should you need the very same CPU speed, you have to select the proper nodes during the PSB job submission.
- qexp, the Express queue: This queue is dedicated for testing and running very small jobs. It is not required to specify a project to enter the qexp. There are 2 nodes always reserved for this queue (w/o accelerator), maximum 8 nodes are available via the qexp for a particular user, from a pool of nodes containing Nvidia accelerated nodes (cn181-203), MIC accelerated nodes (cn204-207) and Fat nodes with 512GB RAM (cn208-209). This enables to test and tune also accelerated code or code with higher RAM requirements. The nodes may be allocated on per core basis. No special authorization is required to use it. The maximum runtime in qexp is 1 hour.
- qprod, the Production queue: This queue is intended for normal production runs. It is required that active project with nonzero remaining resources is specified to enter the qprod. All nodes may be accessed via the qprod queue, except the reserved ones. 178 nodes without accelerator are included. Full nodes, 16 cores per node are allocated. The queue runs with medium priority and no special authorization is required to use it. The maximum runtime in qprod is 48 hours.
- qlong, the Long queue: This queue is intended for long production runs. It is required that active project with nonzero remaining resources is specified to enter the qlong. Only 60 nodes without acceleration may be accessed via the qlong queue. Full nodes, 16 cores per node are allocated. The queue runs with medium priority and no special authorization is required to use it. The maximum runtime in qlong is 144 hours (three times of the standard qprod time - 3 x 48 h).
- qnvidia, qmic, qfat, the Dedicated queues: The queue qnvidia is dedicated to access the Nvidia accelerated nodes, the qmic to access MIC nodes and qfat the Fat nodes. It is required that active project with nonzero remaining resources is specified to enter these queues. 23 nvidia, 4 mic and 2 fat nodes are included. Full nodes, 16 cores per node are allocated. The queues run with very high priority, the jobs will be scheduled before the jobs coming from the qexp queue. An PI needs explicitly ask support for authorization to enter the dedicated queues for all users associated to her/his Project.
- qfree, The Free resource queue: The queue qfree is intended for utilization of free resources, after a Project exhausted all its allocated computational resources (Does not apply to DD projects by default. DD projects have to request for persmission on qfree after exhaustion of computational resources.). It is required that active project is specified to enter the queue, however no remaining resources are required. Consumed resources will be accounted to the Project. Only 178 nodes without accelerator may be accessed from this queue. Full nodes, 16 cores per node are allocated. The queue runs with very low priority and no special authorization is required to use it. The maximum runtime in qfree is 12 hours.
The job wall clock time defaults to half the maximum time, see table above. Longer wall time limits can be set manually, see examples.
Jobs that exceed the reserved wall clock time (Req'd Time) get killed automatically. Wall clock time limit can be changed for queuing jobs (state Q) using the qalter command, however can not be changed for a running job (state R).
Anselm users may check current queue configuration at https://extranet.it4i.cz/anselm/queues.
Check the status of jobs, queues and compute nodes at https://extranet.it4i.cz/anselm/
Display the queue status on Anselm:
$ qstat -q
The PBS allocation overview may be obtained also using the rspbs command.
$ rspbs Usage: rspbs [options] Options: --version show program's version number and exit -h, --help show this help message and exit --get-node-ncpu-chart Print chart of allocated ncpus per node --summary Print summary --get-server-details Print server --get-queues Print queues --get-queues-details Print queues details --get-reservations Print reservations --get-reservations-details Print reservations details --get-nodes Print nodes of PBS complex --get-nodeset Print nodeset of PBS complex --get-nodes-details Print nodes details --get-jobs Print jobs --get-jobs-details Print jobs details --get-jobs-check-params Print jobid, job state, session_id, user, nodes --get-users Print users of jobs --get-allocated-nodes Print allocated nodes of jobs --get-allocated-nodeset Print allocated nodeset of jobs --get-node-users Print node users --get-node-jobs Print node jobs --get-node-ncpus Print number of ncpus per node --get-node-allocated-ncpus Print number of allocated ncpus per node --get-node-qlist Print node qlist --get-node-ibswitch Print node ibswitch --get-user-nodes Print user nodes --get-user-nodeset Print user nodeset --get-user-jobs Print user jobs --get-user-jobc Print number of jobs per user --get-user-nodec Print number of allocated nodes per user --get-user-ncpus Print number of allocated ncpus per user --get-qlist-nodes Print qlist nodes --get-qlist-nodeset Print qlist nodeset --get-ibswitch-nodes Print ibswitch nodes --get-ibswitch-nodeset Print ibswitch nodeset --state=STATE Only for given job state --jobid=JOBID Only for given job ID --user=USER Only for given user --node=NODE Only for given node --nodestate=NODESTATE Only for given node state (affects only --get-node* --get-qlist-* --get-ibswitch-* actions) --incl-finished Include finished jobs
Resources Accounting Policy
The resources that are currently subject to accounting are the core-hours. The core-hours are accounted on the wall clock basis. The accounting runs whenever the computational cores are allocated or blocked via the PBS Pro workload manager (the qsub command), regardless of whether the cores are actually used for any calculation. 1 core-hour is defined as 1 processor core allocated for 1 hour of wall clock time. Allocating a full node (16 cores) for 1 hour accounts to 16 core-hours. See example in the Job submission and execution section.
Check Consumed Resources
The it4ifree command is a part of it4i.portal.clients package, located here: https://pypi.python.org/pypi/it4i.portal.clients
User may check at any time, how many core-hours have been consumed by himself/herself and his/her projects. The command is available on clusters' login nodes.
$ it4ifree Password: PID Total Used ...by me Free -------- ------- ------ -------- ------- OPEN-0-0 1500000 400644 225265 1099356 DD-13-1 10000 2606 2606 7394