Starting from quarter 03/2022, the two NHR centers

• NHR@ZIB and
• NHR@Göttingen

account in the new unit core hours. Both NHR centers provide computational resources primarily to scientific institutions in Germany under public law. The details regarding the policies for resource allocation and payment are prescribed by the Fees And Regulations on the HLRN webpage Zulassungs- und Entgeltordnung considering the unit conversion 1 NPL = 6.86 core hour.

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Content

Project account

NHR center NHR@ZIB follows NHR-wide regulations.

• A User Account accesses a project account containing units of core hour. A project account can be a Test Project or a Compute Project.
• A batch job on the compute system is charged by a number of core hour to measure the usage.
• Usage of persistent storage including the tape library are currently not accounted.

Charge rates

The NHR centers operate different types of compute nodes (HLRN-IV system) organized in partitions, see Hardware. The charge rates for the partitions are given in the table.

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standard96

standard96:test

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large96

large96:test

large96:shared

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192

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medium40

medium40:test

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large40

large40:test

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Job charge

The charge for a batch job on a HLRN system is a number of NPLs and is calculated from the number of nodes reserved for the jobNHR@ZIB operates system Lise with different Compute partitions. Properties for available (slurm-)partitions you find on the pages

• Slurm partition CPU CLX,
• Slurm partition GPU A100, and
• GPU PVC partition.

Each partition holds a specific charge rate.

1: Practically the charge is a very small number (close to zero).

Job charge

The charge of core hours for a batch job depends on the number of nodes, the wallclock time used by the job, and the charge rate for the job nodespartition used. For a batch job with

• num a number of nodes n,

• running with a wallclock time of t hours, and

• on a partition with a charge rate charge_p

the job charge charge_j yields

charge_j = numn * t * charge_p

Batch jobs running in the partition large96:shared access a subset of cores on a node. For a reservation of cores, the number of nodes is the appropriate node fraction.

CPUh and NPL relation

Depends on the core/node type and the number of physical cores used per node:

14 NPL   ≡ 1 standard96-node x 1 hour (our definition, see table above)

≙ 96 standard-cpu (if all cores are used) x 1 hour

= 96 standard-cpuh

→

1 NPL ~ 6.857 standard-cpuh

1 NPL ~ 6.857 cpuh (standard96)

NPL accounts

Running batch jobs with a user account, the user can access different NPL accounts in general. HLRN distinguishes between

• personal accounts and
• project accounts

User account

In the HLRN each user account is attached to a personal NPL account. Both accounts, the user account and the personal account, share the same name but their purpose is different. The user account is the account on the Linux operation system and is used to control e.g. permissions to data files. The personal account is a bank account containing NPL.

At the beginning of each quarter the personal account is granted by 10000 NPL  during the lifetime of the user account. In reasonable and exceptional cases, the grant of the personal account can be extended to 40000 NPL per quarter. For that please contact your consultant. At the end of each quarter all remaining NPL in the personal account are dropped.

Project account

A HLRN compute project holds a project NPL account. The project account is a bank account containing NPL for the project.

At the beginning of each quarter the account is granted by the number of NPL following the funding decision for the compute project. Unused NPL are transfered to the subsequent quarter, but only one time.

In case of problems with NPL in the project account please look at Application types or contact your consultant. This might affect the

• application for additional NPL,
• movement NPL between quarters.

Batch job and account

Batch jobs are submitted by a user account to the compute system. For each job the user chooses the account that will be charged by the job.

• For the user account the default NPL account is defined on the link Informationen zu Ihrer Kennung/Account information of the HLRN service portal. At the beginning of the user account lifetime the default NPL account is the personal account.

• The user controls the NPL account for a job using the Slurm option --account at submit time.

To charge the account myaccount
add the following line to the job script. 
#SBATCH --account=myaccount

After job script submission the batch system checks the NPL account for account coverage and authorizes the job for scheduling. Otherwise the job rejected.