Resource Accounting Policy¶

Starting with the 24^th 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 PBS Pro workload manager (the qsub command), regardless of whether the nodes are actually used for any calculation.

Conversion Table¶

Resources	Conversion for 1 node-hour
Barbora CPU	36 core-hours
Barbora GPU	4 GPU core-hours
Barbora FAT	128 core-hours
DGX-2	16 GPU core-hours
Karolina CPU	128 core-hours
Karolina GPU	8 GPU core-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:

$NCH = F*WCH$

All jobs are accounted in normalized core-hours, using factor F valid at the time of the execution:

System	F	Validity
Karolina	1.00	2021-08-02 to 2022-09-06
Barbora CPU	1.40	2020-02-01 to 2022-09-06
Barbora GPU	4.50	2020-04-01 to 2022-09-06
DGX-2	5.50	2020-04-01 to 2022-09-06

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.