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doku:vsc4_queue

Queue | Partition setup on VSC-4

On VSC-4, the type of hardware and the quality of service (QOS) where the jobs run on may be selected. Nodes of the same type of hardware are grouped to partitions, the QOS defines the maximum run time of a job and the number and type of allocable nodes.

Hardware types

There is one type of compute node, which comes in three different memory version, 96 GB, 384 GB and 768 GB.

On VSC-4, the hardware is grouped into so-called ➠ partitions:

partition name description
mem_0096 default, nodes with 96 GB of memory
mem_0384 nodes with 384 GB of memory
mem_0768 nodes with 768 GB of memory
adm_test reserved for the admin team
jupyter reserved for the JupyterHub

Quality of service (QOS)

Access to node partitions is granted by the so-called ➠ quality of service (QOS). The QOSs constrain the number of allocatable nodes and limit job wall time. The naming scheme of the QOSs is: <project_type>_<memoryConfig>

The QOSs that are assigned to a specific user can be viewed with:

sacctmgr show user `id -u` withassoc format=user,defaultaccount,account,qos%40s,defaultqos%20s

The default QOS and all QOSs usable are also shown right after login.

Generally, it can be distinguished in QOS defined on the generally available compute nodes (mem_0096/mem_0384/mem_0768) and on private nodes. Furthermore, there is a distinction whether a project still has available computing time or if the computing time has already been consumed. In the latter case, jobs of this project are running with low job priority and reduced maximum run time limit in the ➠ idle queue.

The ➠ devel queue (devel_0096) gives fast feed-back to the user if her or his job is running. It is possible to connect to the node where the actual job is running and to directly monitor the job, e.g., for the purpose of checking if the threads/processes are doing what is expected. This might be recommended before sending the job to one of the 'computing' queues.

Run time limits

The QOS's hard run time limits
mem_0096 / mem_0384 / mem_0768 72h (3 days)
idle_0096 / idle_0384 / idle_0768 24h (1 day)
private queues p….._0… up to 240h (10 days)
devel_0096 (up to 5 nodes available) 10min

The QOS's run time limits can also be requested via the command

sacctmgr show qos  format=name%20s,priority,grpnodes,maxwall,description%40s

SLURM allows for setting a run time limit below the default QOS's run time limit. After the specified time is elapsed, the job is killed:

#SBATCH --time=<time> 

Acceptable time formats include “minutes”, “minutes:seconds”, “hours:minutes:seconds”, “days-hours”, “days-hours:minutes” and “days-hours:minutes:seconds”.

sbatch parameters

For submitting jobs, three parameters are important:

#SBATCH --partition=mem_xxxx
#SBATCH --qos=xxxxx_xxxx
#SBATCH --account=xxxxxx

The core hours will be charged to the specified account. If not specified, the default account (sacctmgr show user `id -u` withassoc format=defaultaccount) will be used.

ordinary projects

For ordinary projects the QOSs are:

QOS name gives access to partition description
mem_0096 mem_0096 default
mem_0384 mem_0384
mem_0768 mem_0768
devel_0096 5 nodes on mem_0096
examples
#SBATCH --partition=mem_0096
#SBATCH --qos=mem_0096   
#SBATCH --account=p7xxxx   
  • Note that partition, qos, and account have to fit together.
  • If the account is not given, the default account (sacctmgr show user `id -u` withassoc format=defaultaccount) will be used.
  • If partition and qos are not given, default values are mem_0096 for both.

private nodes projects

example
#SBATCH --partition=mem_0384
#SBATCH --qos=p7xxx_xxxx
#SBATCH --account=p7xxxx 
doku/vsc4_queue.txt · Last modified: 2021/09/14 12:54 by goldenberg