Difference between revisions of "Quick Guide to Dirac"

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= Introduction =  
 
= Introduction =  
 
This document describes how to quickly set up a simple Dirac UI client, create a job script and then submit it to a Dirac server for execution. You need to have a valid grid certificate and be a member of a supported VO. You '''do not''' need root access to the machine you are installing the Dirac UI on.
 
This document describes how to quickly set up a simple Dirac UI client, create a job script and then submit it to a Dirac server for execution. You need to have a valid grid certificate and be a member of a supported VO. You '''do not''' need root access to the machine you are installing the Dirac UI on.
 
If you want to check if the dirac server recognizes you, please go to the [https://dirac.gridpp.ac.uk GridPP Dirac Server] and check if your name appears in the bottom right corner with the correct VO associated with it. You can be a member of more than one VO.
 
  
 
* [[DIRAC new user checklist|Checklist for new users]]
 
* [[DIRAC new user checklist|Checklist for new users]]

Revision as of 14:03, 22 September 2015

Note: These instructions have been updated to use the 'new' dirac server at dirac.gridpp.ac.uk. If you are using the 'old' dirac server at dirac.grid.hep.ph.ic.ac.uk, please email Janusz with a cc to lcg-site-admin@imperial.ac.uk in case of problems.

Introduction

This document describes how to quickly set up a simple Dirac UI client, create a job script and then submit it to a Dirac server for execution. You need to have a valid grid certificate and be a member of a supported VO. You do not need root access to the machine you are installing the Dirac UI on.

Getting support

  • Please consider signing up to the gridpp dirac users mailing list: Sign up !
  • For operational issues please consider filing a GGUS ticket. If you set "Notify site" to UKI-LT2-IC-HEP, we'll see it quicker. If you don't know if your issue is operational, just use the mailing list :-)
  • If something isn't working, it may help to include the output from your commands using the debug flag, which can be done with the -ddd flag, e.g.
$ dirac-proxy-init -ddd -g gridpp_user -M

Server URL

The Dirac server is installed at Imperial College. The Web interface is at:

 https://dirac.gridpp.ac.uk

You need a certificate installed in your browser.
To check that you are correctly registered with this dirac instance, check the bottom righthand corner. If this shows you as "visitor" and you cannot change this, you are not registered. In this case, please contact lcg-site-admin@imperial.ac.uk

Dirac client installation

You need an SL6 machine, with your user cert and key located in the $HOME/.globus directory. You also need to be a member of a dirac supported VO.
You can try and run this python script (which indeed should move to a better location): dirac ui install script.
Or you can run the command sequence by hand:

mkdir dirac_ui
cd dirac_ui
wget -np -O dirac-install http://lhcbproject.web.cern.ch/lhcbproject/dist/Dirac_project/dirac-install
chmod u+x dirac-install
./dirac-install -r v6r13p9 -i 27 -g 2015-07-09
source bashrc 
dirac-proxy-init -x (needs user cert password)
dirac-configure -F -S GridPP -C dips://dirac01.grid.hep.ph.ic.ac.uk:9135/Configuration/Server -I
dirac-proxy-init -g [your_vo_goes_here]_user -M (e.g. dirac-proxy-init -g comet.j-parc.jp_user -M)


If you see an error like below then you probably are not registered with the dirac instance.

Could not sync dir Cannot get URL for Framework/BundleDelivery in setup MyDIRAC-Production: Option /DIRAC/Setups/MyDIRAC-Production/Framework is not defined

A note on CA certificates

When you install the dirac UI, the script will automatically download a current copy of these certs for you and store them in [dirac_ui_dir]/etc/grid-security/certificates. This will be sufficient for a couple of weeks of testing. If you are planning on using your dirac UI for longer, you need to update these certificates regularly. Most grid sites maintain a current copy of these files somewhere on their systems and you should link to those (try /etc/grid-security/certificates or at Imperial /vols/grid/certificates -- if in doubt ask your friendly sys admin :-) instead.
To update the certificates/crls by hand run "dirac-admin-get-CAs" after running "source bashrc".

Submitting a 'Hello World' job via dirac

Create a JDL

Now we are ready to create a simple Dirac jdl. Put the lines below into a file Simple.jdl:

[
JobName = "Simple_Job";
Executable = "/bin/ls";
Arguments = "-ltr";
StdOutput = "StdOut";
StdError = "StdErr";
OutputSandbox = {"StdOut","StdErr"};
]

Submit a job

$ dirac-wms-job-submit -f logfile Simple.jdl 
JobID = 236

Check job status:

$ dirac-wms-job-status -f logfile

JobID=236 Status=Waiting; MinorStatus=Pilot Agent Submission; Site=ANY 

and eventually:

$ dirac-wms-job-status -f logfile 
JobID=236 Status=Done; MinorStatus=Execution Complete; Site=LCG.Glasgow.uk;

The jobs can also be monitored using the Web interface. Go to Jobs ->Job monitor You can also submit a job using the Web interface (Tools->Job Launchpad).

Once the job is done, retrieve the output:

$ dirac-wms-job-get-output -f logfile

Back to GridPP Dirac overview page.