Resource Accounting Policy¶
Starting with the 24th open access grant competition, the accounting policy has been changed from normalized core hours (NCH) to node-hours. This means that it is now required to apply for node hours of the specific cluster and node type:
The accounting runs whenever the nodes are allocated via the Slurm workload manager (the sbatch
, salloc
command), regardless of whether
the nodes are actually used for any calculation. The same rule applies for unspent reservations.
Conversion Table¶
Resources | Conversion for 1 node-hour |
---|---|
Barbora CPU | 36 core-hours |
Barbora GPU | 4 GPU hours |
Barbora FAT | 128 core-hours |
DGX-2 | 16 GPU hours |
Karolina CPU | 128 core-hours |
Karolina GPU | 8 GPU hours |
Karolina FAT | 768 core-hours |
Original Resource Accounting Policy¶
The original policy, as stated below, is still applied to projects from previous grant competitions.
Wall-Clock Core-Hours WCH¶
The wall-clock core-hours (WCH) are the basic metric of computer utilization time. 1 wall-clock core-hour is defined as 1 processor core allocated for 1 hour of wall-clock time. For example, allocating a full node (i.e. 36 cores) on Barbora for 1 hour amounts to 36 wall-clock core-hours.
Normalized Core-Hours NCH¶
The resources subject to accounting are the normalized core-hours (NCH). The normalized core-hours are obtained from WCH by applying a normalization factor:
All jobs are accounted in normalized core-hours, using factor F valid at the time of the execution:
System | F |
---|---|
Karolina | 1.00 |
Barbora CPU | 1.40 |
Barbora GPU | 4.50 |
DGX-2 | 5.50 |
Factors are valid as of July 9, 2022.
The normalized core-hours were introduced to treat systems of different age on equal footing. Normalized core-hour is an accounting tool to discount the legacy systems.
See examples in the Job submission and execution section.
Consumed Resources¶
Check how many core-hours have been consumed. The command it4ifree
is available on cluster login nodes.
$ it4ifree
Projects I am participating in
==============================
PID Days left Total Used WCHs Used NCHs WCHs by me NCHs by me Free
---------- ----------- ------- ----------- ----------- ------------ ------------ -------
OPEN-XX-XX 323 0 5169947 5169947 50001 50001 1292555
Projects I am Primarily Investigating
=====================================
PID Login Used WCHs Used NCHs
---------- ---------- ----------- -----------
OPEN-XX-XX user1 376670 376670
user2 4793277 4793277
Legend
======
WCH = Wall-clock Core Hour
NCH = Normalized Core Hour
The it4ifree
command is a part of the it4i.portal.clients
package, located here.