Commonly used phrases and terms
| Term | Explanation |
|---|---|
| 2-factor authentication | Authentication method using 2 factors for login. The first factor is often a password. The second factor is often a generated token/code. |
| Batch job | A user create script the defines what tasks should be performed. The script is submitted to a job scheduler to be executed on the cluster nodes. |
| Centre storage | Shared file system available on all nodes. LUNARC currently uses an IBM SpectrumScale Parallel file system as center storage resource. |
| Compiler | Compiles source code for languages such as C, C++ and Fortran to executables/machinecode that can be run directly by the processor. |
| Core | Individual processing element, 20-48 per node. Can also be called a CPU. |
| CPU | Central Processing Unit. A processor often contain several CPUs (cores). |
| CPU-time | Refers to the sum of all execution times for all tasks in a parallel job. |
| Disk snapshot | The center storage at LUNARC stores snapshots in time of the entire file structure. This can be used to retrieve files that have been mistakenly been erased. |
| GPU | This denotes a NVIDIA/AMD co-processor. Can be used for both computing as well as graphics. |
| Hardware accelerated graphics | Graphics rendering that using hardware accelerator GPU for drawing in 2D and 3D. |
| HPC | High Performace Computing |
| Job script | See batch job |
| Local disk | Local disk storage for each node. This storage is not shared between the nodes. |
| LUNARC | Lund University NIC Application Research Center |
| LUNARC HPC Desktop | Remote desktop solution provided by LUNARC. |
| Module | A single software package in the module system. Usually denoted by a name/version pair. MYAPP/1.1. |
| Module system | System for organising software installs. Enables multiple version of software to be installed on the same system. LUNARC uses the module system Lmod. |
| MPI | Message Passing Interface - An application programming interface (API) for programming multinode parallel applications. OpenMP/Intel MPI are commonly available implementations of this API |
| Node | A physical computer/server in a compute cluster. |
| OpenGL | Open standard for hardware accelerated graphics. |
| OpenMP | Open Multi-Processing - An application programming interface (API) for shared-memory multi-processing withing a single server/node. |
| OTP | One Time Password |
| OTP-token | Special code generated by the authenticator application Pocket Pass. |
| Parallel job | A job that consists of multiple tasks running on a single or multiple nodes. |
| Partition | Several nodes/servers grouped together in a compute cluster. Usually nodes in a partition share the same properties, such as processor, memory or accelerators. |
| Processor | This denotes a multi-core processor, housing many processing elements/CPU/cores. |
| PuTTY | Graphical SSH client available for Windows. |
| Queue | When submitting a job it will end up in a queue in the schedulerm, waiting for resources to become available. |
| Quota | Amount of disk space allocated for a user. Quotas also limit the number of files a user can create. When applying for a storage project in SUPR, users request both disk space and how many files they will use. |
| SLURM | Simple Linux Utility for Resource Management |
| Socket | This is the “plug” the processor gets plugged into. Used as a synonym for the processor. Usually 2 per node. |
| SSH | Secure Shell - Secure protocol used when connecting to the LUNARC resources. SSH clients are available for Linux, Windows and macOS X. |
| SUPR | SNIC User and Project Repository - Web service for creating project proposals for available resources both at LU and nationally. |
| SUPR Project | Refers to an approved project proposal. |
| SUPR Proposal | Refers to a project proposal not yet submitted for approval in SUPR. |
| Task | This is a software concept. It denotes a process, which is an instance of a running program. It has its own data and instruction stream(s). It can fork multiple threads to increase the computational speed. Serial programs and pure MPI programs do not spawn threads. |
| Thread | This is a software concept. A thread is a stream of instructions executed on the hardware. It is part of a task and shares resources such as data with other threads within the same task. |
| Toolchain | Refers to a specific compiler version with associated libraries for MPI. |
| Walltime | Refers to the real-world (wristwatch, wall-clock) time during which a paralell job executes. |
Author: Jonas Lindemann (LUNARC)
Last Updated: 2022-10-06