Understanding an ARC Grid Job:
Job Submission
Job Control
Handling Input/Output
Mattias Ellert
Uppsala University

NorduGrid Special Event Track

European Grid Conference

Amsterdam 2005-02-15

Job Submission

Jobs are submitted using the ngsub command

The jobs are described using XRSL attributes

A simple “Hello World” example:

A successful submission returns a job id, e.g.

ngsub ‘&(executable = “/bin/echo”) \

(arguments = “Hello World”) \

(stdout = “hello.txt”)’

gsiftp://atlas.fzk.de:2811/jobs/248111108239645441751019

Job Control

There are several commands that can be used to keep track of jobs

ngstat – returns the current status of the job

ngcat – catenate the stdout or stderr of the job

ngkill – kill a submitted job before it completes

ngresub – kill a job and resubmit it to a different resouce

ngget – get the output of a finished job

Example

Continuing the previous Hello World example:

[ellert@ellert ellert]$ ngstat gsiftp://atlas.fzk.de:2811/jobs/248111108239645441751019

Job gsiftp://atlas.fzk.de:2811/jobs/248111108239645441751019

Status: FINISHED 2005-02-12 21:22:14

[ellert@ellert ellert]$ ngcat gsiftp://atlas.fzk.de:2811/jobs/248111108239645441751019

Hello World

[ellert@ellert ellert]$ ngget gsiftp://atlas.fzk.de:2811/jobs/248111108239645441751019

ngget: downloading files to /home/ellert/248111108239645441751019

ngget: download successful - deleting job from gatekeeper.

[ellert@ellert ellert]$ ls 248111108239645441751019

hello.txt

[ellert@ellert ellert]$

Handling Input/Output

There are several ways to specify input files

local files on the submitting host

stage-in from a file server (gridftp, ftp, http, httpg)

index server (Globus RC, Globus RLS) reference

(inputfiles = (“infile.txt” “file:///tmp/infile.txt”))

(inputfiles = (“infile.txt” “gsiftp://hathi.hep.lu.se/public/test1/infile.txt”))

(inputfiles = (“infile.txt” “rls://rls.nordugrid.org/infile.txt”))

Handling Input/Output (cont’d)

Output files are specified in similar ways

keep the file on the resource for download using ngget

stage-out to a file server (gridftp, httpg)

index server (Globus RC, Globus RLS) registrastion

unless specified the actual file server is automatically selected

(outputfiles = (“outfile.txt” “”))

(outputfiles = (“outfile.txt” “gsiftp://hathi.hep.lu.se/public/test1/outfile.txt”))

(outputfiles = (“outfile.txt” “rls://rls.nordugrid.org/outfile.txt”))

Further Reading

ARC User Guide

http://www.nordugrid.org/documents/userguide.pdf

ARC User Interface manual

http://www.nordugrid.org/documents/NorduGrid-UI.pdf

XRSL manual

http://www.nordugrid.org/documents/xrsl.pdf

2005-02-12T01:54:20