Compute node partitions

The compute nodes are divided into separate partitions based on their hardware configuration. This is to allow that for example CPU's from different manufacturer generations can be set up with a different billing factor to ensure fair usage accounting (newer CPU's are faster), nodes with more memory (per CPU) are only used for jobs that actually require more memory, and GPU nodes are only used for jobs that require GPU's, etc.

Automatic partition selection

BioCloud is a quite heterogeneous cluster because nodes are purchased at different times, hence their hardware configuration is also different. Furthermore, the number of partitions will only increase in the future as more nodes are added to the cluster at different times, which increases complexity, making it difficult or confusing to submit jobs to the most appropriate partition(s). This can result in an inefficient cluster with longer queue times and wasted computing resources. Therefore, the most appropriate partition for batch jobs is automatically assigned by the SLURM scheduler according to custom logics defined for our specific setup. Manually specifying a partition using the --partition option will have no effect, as it will be overridden. Interactive jobs will always be assigned the interactive partition.

The most appropriate partition is determined by several factors, the most significant of which are the requested memory per CPU ratio and any specified node features. Partitions are allocated according to the defined priority tiers shown in the table below, ensuring that newer (and faster) compute nodes are always selected first before older nodes. Secondly, if all general compute nodes happen to be fully allocated, jobs with only modest memory requirements will still be able to run on compute nodes with extra memory instead, if available. Conversely, jobs that require extra memory per CPU will not be able to run on a general compute node as this can result in unavailable CPUs due to fully allocated memory. In certain situations, the automatically assigned partition may not be optimal, in which case manual intervention by an administrator may be necessary and exceptions can be made if it makes sense depending on the situation.

CPU partitions

Below is a brief overview of all CPU partitions. Details about the exact CPU model, scratch space and node features for each compute node are listed further down.

Overview

Partition	Nodes	Total CPUs	Total memory	Billing factor	Priority tier
interactive	2	512T	3.0 TB	0.5x	-
zen5	3	864T	4.5 TB	1.0x	1st
zen3	8	1312T	6.5 TB	0.5x	2nd
zen5x	2	576T	4.6 TB	1.5x	3rd
zen3x	2	448T	4.0 TB	1.0x	4th
TOTAL	17	3712	19.6 TB

The interactive partition

This partition is reserved for short and small interactive jobs, where users can do data analysis, quick testing, and day-to-day work without having to wait for hours or even days due to queue time. Therefore, no batch jobs will be able to run here, and there is a max CPUs per job limit of 32 to ensure high availability. Ideally, the interactive partition should never be fully utilized. Furthermore, it is optimized for interactive jobs, which are usually very inefficient (e.i. the allocated CPU's do absolutely nothing when you are just typing or clicking around).

Hostname	CPU model	CPUs	Memory	Scratch space	Features
bio-node[16-17]	2x AMD EPYC 9535	128C / 256T	1.5 TB		zen5 epyc9535

Batch job partitions

These partitions are dedicated to non-interactive and efficient batch jobs that can potentially run for a long time. The slim-* nodes generally have less memory per CPU, while the fat-* nodes have more memory per CPU, which is useful for jobs that require a lot of memory. The zen3 and zen5 features indicate the generation of AMD EPYC CPUs used in the nodes.

zen3

Hostname	CPU model	CPUs	Memory	Scratch space	Features
bio-node01	2x AMD EPYC 7713	128C / 256T	1.0 TB	3.5 TB NVMe	zen3 epyc7713 scratch
bio-node02	1x AMD EPYC 7552P	48C / 96T	0.5 TB		zen3 epyc7552p
bio-node[03-06]	2x AMD EPYC 7643	96C / 192T	1.0 TB		zen3 epyc7643
bio-node07	2x AMD EPYC 7643	96C / 192T	1.0 TB	18 TB NVMe	zen3 epyc7643 scratch

zen3x

Hostname	CPU model	CPUs	Memory	Scratch space	Features
bio-node08	2x AMD EPYC 7643	96C / 192T	2.0 TB		zen3 epyc7643
bio-node09	2x AMD EPYC 7713	128C / 256T	2.0 TB	12.8 TB NVMe	zen3 epyc7713

zen5

Hostname	CPU model	CPUs	Memory	Scratch space	Features
bio-node[11-13]	2x AMD EPYC 9565	144C / 288T	1.5 TB		zen5 epyc9565

zen5x

Hostname	CPU model	CPUs	Memory	Scratch space	Features
node[14-15]	2x AMD EPYC 9565	144C / 288T	2.3 TB	12.8 TB NVMe	zen5 epyc9565 scratch

GPU partitions

gpu-a10

Hostname	CPU model	CPUs	Memory	Scratch space	GPU	Features
bio-node10	2x AMD EPYC 7313	32C / 64T	256 GB	3.0 TB NVMe	2xNVIDIA A10	zen3 epyc7313 scratch a10