Submitting a Job

Overview

Questions

• How do you submit jobs using a scheduling program like HTCondor?

Objectives

• Write a list describing what information the scheduler needs to know.

• Create a submit file from a template.

• Explain what each line of the submit file does.

Log in

This page has information about how to log into the submit server. If you already have an account in CHTC, log into the submit server where your account was created. If you don’t already have a CHTC account, you’ll be logging into learn.chtc.wisc.edu.

Information Wanted

Before we go further, what information do you think the scheduler needs to know to run your job successfully? Make a list with your neighbor.

Information in Submit File

The submit file needs to contain the following information:

• What to run
• What files and software you need
• How many standard resources you need (CPUs, memory, disk)
• Where to record data about the job
• Special requirements: GPUs, access to Gluster, a certain operating system
• How many jobs you want to run

Sample Submit File

This is a sample HTCondor submit file that includes all the information from the list above for a simple job.

universe = vanilla

log = hello-chtc_$(Cluster).log
error = hello-chtc_$(Cluster)_$(Process).err
output = hello-chtc_$(Cluster)_$(Process).out

executable = hello-chtc.sh
arguments = $(Process)

should_transfer_files = YES
when_to_transfer_output = ON_EXIT
# transfer_input_files = file1,/absolute/pathto/file2,etc

request_cpus = 1
request_memory = 1GB
request_disk = 1MB

queue 3

The executable (which we’ll create below) is what we want the job to actually run. For this example, it will be a simple shell script. Our script will also take a single argument, which is provided by the arguments line. The log, output and error files all track information printed by the job or about the job (and we’ll learn more after we submit the job).

The “transfer files” lines all tell HTCondor what to do with output and input files. We’ll cover the transfer_input_files line in a later part of the lesson.

The request_ lines tell HTCondor how many resources on the computer that you need to run your jobs.

The final queue statement actually creates a job when the submit file is submitted. In this example, queue 3 means that three separate jobs will be submitted. These jobs will each have a unique “Process” number assigned by HTCondor, and wherever you see $(Process) in the submit file above, that variable will be replaced by the process number for that job.

Create a submit file

Create a file called hello-chtc.sub as shown above.

Sample Executable

#!/bin/bash

echo "Hello CHTC from Job $1 running on `whoami`@`hostname`"
ls -lh
sleep 120

Create the executable

Create a file called hello-chtc.sh as shown above. Give it executable permissions by running:

chmod +x hello-chtc.sh

Key Points

• A submit file tells the job scheduler information like resource requirements, software and data requirements, and what commands to run.