The IGRIDA Computing Grid

Overview

IGRIDA is a computing grid available to research teams at IRISA / INRIA, in Rennes. It was designed so as to provide an easy to use platform for code development as well as an efficient computing facility for production runs.

The infrastructure is made of 138 computing nodes (1700 cores). In addition, a shared scratch space of 3.4 TB is available for temporarily storing simulations inputs and outputs. There are also 5 GPU nodes with NVIDIA GPUs. Jobs are scheduled by the OAR resource and task manager. The instantaneous global CPU load of the grid is reported in the following figure:


Monitoring

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Quickstart

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The front-end node gives access to the grid (by means of your LDAP account). Note that this machine is only dedicated to job submission and monitoring, with commands like oarsub, oarstat, oardel, etc. Please do not run any program, any compilation, or anything else on this node. Note that development tools are purposedly not installed on the front-end (for instance, there is no gcc installed).

To log in, just type:

ssh $USER@igrida-oar-frontend

Nota: access to IGRIDA is only allowed with SSH keys. If your SSH access is not configured, please proceed this way:

ssh-keygen -t rsa
ssh-copy-id -i ~/.ssh/id_rsa.pub $USER@sabre

To enable X11 display forwarding, do not forget to add the -X option to your ssh command.

Once you have logged in the front-end, you need to remember that there’s no use just staying here. You are ready to connect to the cluster (the front-end is not a development machine, it’s only a submission server). To proceed further, for example to edit or compile your source code, or to launch some interactive run, you have to ask for an interactive job.

To open such an interactive job, lauch the following command:

oarsub -I -l walltime=0:30:00

The “walltime” option is not compulsory, but remember the default value is only 10 min. With this command, you get access to one core on an interactive node.

To submit a passive job (batch), the typical syntax is:

oarsub -S ./myscript.sh

Detailed examples of the OAR syntax are given in the following tutorial.

Warning

IGRIDA is running under Debian 8 (Jessie) whereas your personal computer station is probably running under Fedora. Therefore you must recompile your code on IGRIDA to run it on the grid.

Contacts

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Public :

Private :