The computing platform¶
The computing platform accessible by the job scheduler is composed of Linux computing servers. It is composed of three main use cases:
- The HTC platform (High-Throughput Computing)
- is suitable for running most of traditional HEP mono or multi-core applications: it accounts for most of the computing power made available at CC-IN2P3.
- The HPC platform (High-Performance Computing)
- of smaller capacity, is designed to accommodate parallel computing. It is composed of a set of servers connected in InfiniBand, which allows an effective communication inter-servers via the use of MPI libraries.
- The GPU platform
- is composed of a group of servers equipped with graphic cards to accommodate vector calculation applications.
To know the technical characteristics of the compute servers, please refer to the page Compute servers configuration.
The scheduler is the only entry point common to all users to submit jobs on the computing platform. Its role is to receive jobs submitted by users, to schedule them and submit them for execution on an appropriate and available computing server.
The main goal is to use the computing resources (CPU, GPU, memory, disk space) in the most efficient way possible. The sharing of all resources for all users allows optimal use of the entire computing platform.
In general, a job is a task (or set of tasks) that the user wants to run on the servers of the computing platform. This task can be an executable file, a set of commands, a script, and so on. A job can be developed and tested on interactive servers before being massively submitted to the computing platform.
CC-IN2P3 will change its scheduling software from Grid Engine (GE) to Slurm.
Throughout the transition phase, the documentation for the old and the new scheduler will be available at the same time. We invite both new and experienced users to give their feedback on the new scheduler to our user support.
The Slurm system is conceptually very close to GE, as the similarities in these two softwares command lines demonstrate. Please refer to this link to “translate” the main GE commands in Slurm commands.