KXC (KyRIC XSEDE/ACCESS Cluster)

How to log in

You can log in after an SSH public key has been inserted into the system by the system administrator. Refer to this guide to request your key to be inserted: Requesting login to ACCESS KyRIC cluster

How to get Help

Submit tickets on https://access-ci.atlassian.net/ and specify "KyRIC" in the Resource Provider input box.

System Overview

Scientific discovery today is being enabled through computational and data intensive research that exploit enormous amounts of available data. KyRIC will advance several exciting research programs across many disciplines, such as Bioinformatics and System Biology Algorithms, Large Graph and Evolutionary Network Analysis, Image Processing, and Computational Modeling and Simulation.

The KyRIC system is a hybrid architecture. It has large memory nodes that are increasingly needed by a wide range of ACCESS researchers, particularly researchers working with big data.

Innovative Components: Large memory nodes with local SSD drives and NFS-mounted scratch.

Award Number: NSF MRI infrastructure award (ACI-1626364)

ACCESS hostname: kxc.ccs.uky.edu

 Figure 1. LCC-KyRIC System

Allocation Information

As an ACCESS computing resource, KyRIC is accessible to ACCESS users who are given time on the system. To obtain an account, users may submit a proposal through the XSEDE Allocation Request System (XRAS) or request a Trial Account.

Interested parties may contact ACCESS User Support (https://access-ci.atlassian.net/) for help with a KyRIC proposal.

System Architecture

The KyRIC hybrid system consists of two subsystems: a 5 nodes cluster, each with 4 10-core processors, 3TB RAM, and a 5TB SSD array;  Each of these nodes have 40 cores (Broadwell class and lntel(R) Xeon(R) CPU E7-4820 v4 @ 2.00GHz with 4 sockets, 10 cores/socket). These 5 dedicated ACCESS nodes will have exclusive access to approximately 300 TB of network attached disk storage. All these compute nodes are interconnected through a 100 Gigabit Ethernet (l00GbE) backbone, and the cluster login and data transfer nodes will be connected through a 100Gb uplink to internet2 for external connections. Due to the use of the 100GbE network, this cluster is for single node jobs only and is not recommended for multi-node jobs, such as those using MPI.

 Login Nodes

To access the login node, after following the instruction in the previous section, run SSH to it from your local machine:

ssh username@kxc-login1.ccs.uky.edu

The login node is what users will directly access in order to submit jobs that will get forwarded to and executed in the compute nodes.

 Data Transfer Node

To access the DTN, run SSH to it from your local machine:

ssh username@kxc-dtn.ccs.uky.edu

This node facilitates the transfer of data in and out of the KyRIC system. Users will log in to this node with the same credentials as for the login nodes.

Compute Nodes

You cannot log in to the compute node from your local machine. When you submit a job, the job gets put into a compute node automatically. In case you need to access the compute node that is running your job, you can ssh to it from the login node

ssh compute-node-hostname

Network

All nodes are interconnected through a 100 Gigabit Ethernet (l00GbE) backbone, and the cluster login and data transfer nodes will be connected through a 100Gb uplink to internet2 for external connections

File Systems

Notes and hints

When you log in to kxc.ccs.uky.edu, you will be assigned one of the two login nodes: kxc-login[1-2].ccs.uky.edu. These nodes are identical in both architecture and software environment. Users should normally log in through kxc.ccs.uky.edu but may specify one of the two nodes directly if they see poor performance.

Do NOT use the login nodes for computationally intensive processes (as in, don't run a program directly such as "python3 myprogram"). These nodes are meant for compilation, file editing, simple data analysis, and other tasks that use minimal compute resources. All computationally demanding jobs should be submitted through SLURM (explained in a later section).

Computing Environment

 Environment Modules

 The Environment Modules package provides for dynamic modification of your shell environment. “Module” commands set, change, or delete environment variables, typically in support of an application. They also let the user choose between different versions of the same software or different combinations of related codes. Several modules that determine the default KyRIC environment are loaded at login time.

 Citizenship

You share KyRIC with other users, and what you do on the system affects others. Exercise good citizenship to ensure that your activity does not adversely impact the system and the research community with whom you share it. Here are some rules of thumb:

• Don’t run jobs on the login nodes.
• Don’t stress the filesystem.
• Do use the debug partition to test out your job submission script.
• Do submit an informative help-desk ticket.

 Managing Data and Transferring Files

 No user data is backed up. Users are responsible for their own backups.

 Each project and user is given a scratch space and home space. A good practice is to write your job’s output into your scratch space. All compute nodes also have a local 5 TB SSD disk attached to it, but this local temporary space is shared among all jobs running on a single node and will be cleaned up (deleted) upon job completion.

 Transferring your Files

KyRIC nodes support the following file transfer protocols.

• scp ( if you have your ssh keys setup)
• rsync (if you have your ssh keys setup)
• Globus (only through DTN node)

Users are encouraged to transfer data using rclone, scp, globus, etc. through the high-speed data transfer node (DTN) and not through the login nodes.

Building Software

Singularity containers are supported. Building a Singularity container requires root access outside of the cluster. If you have a Singularity container ready, you can copy it into the cluster and run your jobs. Most of the software will be provided through singularity containers. Standard GNU and Intel compilers will be provided.

Software

Installed software can be found by running “module avail”.

Job Accounting

KyRIC allocations are made in core-hours. The recommended method for estimating your resource needs for an allocation request is to perform benchmark runs. The core-hours used for a job are calculated by multiplying the number of processor cores used by the wall-clock duration in hours. KyRIC core-hour calculations should assume that all jobs will run in the regular queue and that they are charged for use of all 40 cores on each node.

The Slurm scheduler tracks and charges for usage to a granularity of a few seconds of wall clock time. The system charges only for the resources you use, not those you request. If your job finishes early and exits properly, Slurm will release the node back into the pool of available nodes. Your job will only be charged for as long as you are using the node.

Running Jobs and accessing the Compute Nodes

KyRIC uses the Simple Linux Utility for Resource Management (SLURM) batch environment. When you run in batch mode, you submit jobs to be run on the compute nodes using the sbatch command as described below. Remember that computationally intensive jobs should be run only on the compute nodes and not the login nodes.

The user must create a slurm submission job script and the job can be executed by running “sbatch <jobscript>”

Job Scheduler

Most, if not all, XSEDE resources are running Slurm and this documentation already exists in some form.

Common Slurm Commands

Slurm Job Script Options

 Partitions (Queues)

Table. KyRIC Production Queues

Interactive Sessions

You can also login to the compute node and run the jobs interactively if only the node is allocated to you.

Sample Job Scripts

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#!/bin/bash

#SBATCH --time=00:15:00          # Time limit for the job (REQUIRED).

#SBATCH --job-name=my_test_job              # Job name

#SBATCH --ntasks=1                   # Number of cores for the job. Same as SBATCH -n 1

#SBATCH --partition=normal     # Partition/queue to run the job in. (REQUIRED)

#SBATCH -e slurm-%j.err  # Error file for this job.

#SBATCH -o slurm-%j.out  # Output file for this job.

#SBATCH -A <your project account>  # Project allocation account name (REQUIRED)

./myprogram   # This is the program that will be executed on the compute node. You will substitute this with your scientific application.

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Protected Data

No protected data (such as HIPAA data) are allowed in the cluster.

References

SLURM scheduler:

https://slurm.schedmd.com/documentation.html

Latest documentation:

https://docs.ccs.uky.edu