2.3 Launching and Managing Jobs Quick Start

This section provides a brief description of some of the many ways to launch jobs, manage jobs, and get information about jobs on an HP XC system. This section is intended only as a quick overview about some basic ways of running and managing jobs. Full information and details about the HP XC job launch environment are provided in the SLURM chapter (Chapter 6) and the LSF chapter (Chapter 7) of this manual.

2.3.1 Introduction

As described in Section 1.4, SLURM and LSF cooperate to run and manage jobs on the HP XC system, combining LSF’s powerful and flexible scheduling functionality with SLURM’s scalable parallel job launching capabilities.

SLURM is the low-level resource manager and job launcher, and performs processor allocation for jobs. LSF gathers information about the cluster from SLURM — when a job is ready to be launched, LSF creates a SLURM node allocation and dispatches the job to that allocation.

Although jobs can be launched directly using SLURM, it is recommended that you use LSF to take advantage of its scheduling and job management capabilities. SLURM options can be added to the LSF job launch command line to further define job launch requirements. The HP-MPI mpirun command and its options can be used within LSF to launch jobs that require MPI’s high-performance message-passing capabilities.

When the HP XC system is installed, a SLURM partition of nodes is created to contain LSF jobs. This partition is called the lsf partition.

When a job is submitted to LSF, the LSF scheduler prioritizes the job and waits until the required resources (compute nodes from the lsf partition) are available.

When the requested resources are available for the job, LSF-HPC creates a SLURM allocation of nodes on behalf of the user, sets the SLURM JobID for the allocation, and dispatches the job with the LSF-HPC JOB_STARTER script to the first allocated node.

A detailed explanation of how SLURM and LSF interact to launch and manage jobs is provided in Section 7.1.4.

2.3.2 Getting Information About Queues

The LSF bqueues command lists the configured job queues in LSF. By default, bqueues returns the following information about all queues: queue name, queue priority, queue status, job slot statistics, and job state statistics.

To get information about queues, enter the bqueues as follows:

$ bqueues

Refer to Section 7.3.4 for more information about using this command and a sample of its output.

2.3.3 Getting Information About Resources

The LSF bhosts, lshosts, and lsload commands are quick ways to get information about system resources. LSF daemons run on only one node in the HP XC system, so the bhosts and lshosts commands will list one host — which represents all the resources of the HP XC system. The total number of processors for that host should be equal to the total number of processors assigned to the SLURM lsf partition.

•The LSF bhosts command provides a summary of the jobs on the system and information about the current state of LSF.

$ bhosts

Refer to Section 7.3.1 for more information about using this command and a sample of its output.

Using the System 2-7