# SLURM: A Highly Scalable Resource Manager

SLURM is an open-source resource manager designed for Linux clusters of all sizes. It provides three key functions. First it allocates exclusive and/or non-exclusive access to resources (computer nodes) to users for some duration of time so they can perform work. Second, it provides a framework for starting, executing, and monitoring work (typically a parallel job) on a set of allocated nodes. Finally, it arbitrates conflicting requests for resources by managing a queue of pending work.

SLURM is not a sophisticated batch system, but it does provide an Applications Programming Interface (API) for integration with external schedulers such as The Maui Scheduler. While other resource managers do exist, SLURM is unique in several respects:

- Its source code is freely available under the GNU General Public License.
- It is designed to operate in a heterogeneous cluster with up to 16,384 nodes.
- It is portable; written in C with a GNU autoconf configuration engine. While initially written for Linux, other UNIX-like operating systems should be easy porting targets. A plugin mechanism exists to support various interconnects, authentication mechanisms, schedulers, etc.
- SLURM is highly tolerant of system failures, including failure of the node executing its control functions.
- It is simple enough for the motivated end user to understand its source and add functionality.

SLURM provides resource management on about 1000 computers world-wide including many of the most powerful computers in the world including:

- BlueGene/L with 65,536 dual-processor compute nodes
- Thunder a Linux cluster with 1024 nodes each having four Itanium2 processors
- ASC Purple an IBM SP/AIX cluster with about 1500 nodes each having eight Power5 processors

As of January 2006, SLURM has been downloaded over 2400 times to over 500 distinct sites in 34 countries. SLURM is also distributed and supported by Hewlett-Packard as the resource manager in their XC System Software.

Last modified 20 January 2006