Updated 2019-06-14

Glossary of Common Terms

Term Simple Definition Extended Definition
computer cluster A group of connected computers. A computer cluster is a single logical unit consisting of multiple computers that are linked through a local area network (LAN). The connected computers essentially act as a single, much more reliable and faster machine.
node A single computer within a cluster. A node is each accessible unit (computer) through a point of intersection/connection within a network.
head node A node that allows users to access a cluster. A head node is a unit (computer) that users log into in order to run applications on the cluster.
compute node A node that does work assigned to it. A compute node is a cluster-connected computer designed to execute applications.
job An indivisible set of work done by a cluster. Each job will be executed on a set of compute nodes. A job is an individual instruction set executed by a node, often used to execute programs or scripts.
interactive job A job that, when running, allows the user to interact directly with the compute nodes assigned to the job. An interactive job is a job that allows users direct access to a node for immediate execution and real-time results.
batch job A job that runs in the background. A batch job is a group of jobs that run without user intervention.
scheduler A program that decides when each job will run and what resources will be assigned to each job. A scheduler is software that manages access to compute nodes to schedule and track all job-related tasks. We use Moab.
resource manager A program that monitors each compute node and reports what resources (CPU, memory, disk) on each node are available for use. A resource manager is software that manages the computational resources to improve overall utilization and administration of cluster usage. We use Torque.
terminal A text-based interface where commands are typed and executed. Examples include editing a job script or submitting a job. A terminal is a hardware or software method of communications that handles the input/output environment to local or remote computational resources.
X Window System Software that allows graphical-interface applications to execute on the cluster. X Window system is a software terminal often used for graphic user interface (GUI) access. Display, keyboard, mouse use X server software to render images.
queue A wait list of jobs. A queue is a portion of computational resources which accept and process a prioritized job list.
FoRCE FoRCE is the GT-purchased cluster available to any researcher on campus. Force is a community queue that includes compute nodes, some with attached GPUs, some with large memory capacity and some with local storage. FoRCE stands for Force Research Computing Environment. Don't just rely on your targeting computer, use the FoRCE.
compiler Software that translates human-understandable instructions to computer-understandable instructions. A compiler is a software program that processes high-level programming code into a low level machine language, and is generally used to increase the speed of computation.
infrastructure All of the needed hardware, software, and network stuff for IT services. Infrastructure is the composite hardware, software, network resources and services required for the existence, operation and management of an enterprise IT environment.
module Software used to load/unload other installed (potentially incompatible) programs. A module is a means of modifying the user shell environment, typically used to switch between different, incompatible versions of software conveniently.
PBS A system that uses both schedulers and resource managers to run jobs. Portable Batch System is a job scheduling system used by schedulers (Moab) and resource managers (Torque).