Torque

General

Torque is a job scheduler. It is responsible for monitoring and controlling the workload of the batch system of a supercomputer and assigns resources to jobs. This system is aimed at bigger applications that need a lot of resources in terms of memory and execution time and cannot be directly accessed by the user, as opposed to login nodes. Applications to execute have to be specified in a jobscript that is submitted to the batch system by the user via a scheduler (like Torque).

Job Submission

This command submits the job you defined in your jobscript to the batch system:

$ qsub jobscript.sh

Just like any other incoming job, your job will first be queued. Then, the scheduler decides when your job will be run. The more resources your job requires, the longer it may be waiting to execute.

You can check the current status of your submitted jobs and their job ids with the following shell command. The most common states for a job are queued Q (job waits for free nodes), running R (the jobscript is currently being executed) or on hold H (job is currently stopped, but does not wait for resources). The command also shows the elapsed time since your job has started running and the time limit.

$ qstat -u <user_id>

In case you submitted a job on accident or realised that your job might not be running correctly, you can always remove it from the queue or terminate it when running by typing:

$ qdel <job_id>

#PBS Usage

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Jobscript Examples

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References

Overview of how to write a jobscript for Torque

Job submission on Torque

Guide to the Torque scheduler