4.1. Getting started with FCC distributed computing

4.1.1. Registering to the FCC VO

The standard Grid VO registration procedure should be followed to be enable to use the resources connected with the FCC VO.

Note

You need to use a browser where you have installed your certificate and the CERN CA certificates. Firefox usually works fine, Google Chrome usually does not work. Safari might also work.

4.1.2. Enabling DIRAC

DIRAC available on CernVM-FS. To enable the relevant applications and scripts, the following setup script needs first to be sourced

source /cvmfs/clicdp.cern.ch/DIRAC/bashrc

To submit jobs through DIRAC a proxy needs to be created and uploaded:

dirac-proxy-init -g fcc_user

A successful creation looks like this:

Generating proxy...
Enter Certificate password:
Added VOMS attribute /fcc
Uploading proxy..
Proxy generated:
subject      : /DC=ch/DC=cern/OU=Organic Units/OU=Users/CN=ganis/CN=393971/CN=Gerardo Ganis/CN=2178341058/CN=3000266373
issuer       : /DC=ch/DC=cern/OU=Organic Units/OU=Users/CN=ganis/CN=393971/CN=Gerardo Ganis/CN=2178341058
identity     : /DC=ch/DC=cern/OU=Organic Units/OU=Users/CN=ganis/CN=393971/CN=Gerardo Ganis
timeleft     : 23:53:58
DIRAC group  : fcc_user
path         : /tmp/x509up_u2759
username     : ganis
properties   : NormalUser
VOMS         : True
VOMS fqan    : ['/fcc']

Proxies uploaded:
 DN                                                                           | Group | Until (GMT)
 /DC=ch/DC=cern/OU=Organic Units/OU=Users/CN=ganis/CN=393971/CN=Gerardo Ganis |  | 2022/05/13 12:12

The last section shows the valid proxies upload to the DIRAC system. It can also be checked with

dirac-proxy-info -m

with output similar to

subject      : /DC=ch/DC=cern/OU=Organic Units/OU=Users/CN=ganis/CN=393971/CN=Gerardo Ganis/CN=2178341058/CN=3000266373
issuer       : /DC=ch/DC=cern/OU=Organic Units/OU=Users/CN=ganis/CN=393971/CN=Gerardo Ganis/CN=2178341058
identity     : /DC=ch/DC=cern/OU=Organic Units/OU=Users/CN=ganis/CN=393971/CN=Gerardo Ganis
timeleft     : 23:50:40
DIRAC group  : fcc_user
path         : /tmp/x509up_u2759
username     : ganis
properties   : NormalUser
VOMS         : True
VOMS fqan    : ['/fcc']
== Proxies uploaded ==
DN                                                                           | Group | Until (GMT)
/DC=ch/DC=cern/OU=Organic Units/OU=Users/CN=ganis/CN=393971/CN=Gerardo Ganis |  | 2022/05/13 12:12

If everything worked fine, your proxy should be mapped to the fcc001 user. This can be checked this way:

export EOS_MGM_URL=root://eospublic.cern.ch
XrdSecPROTOCOL=gsi,unix eos whoami

the result should look similar to this:

Virtual Identity: uid=140035 (99,140035) gid=2855 (99,2855) [authz:gsi] host=lxplus743.cern.ch domain=cern.ch geo-location=0513

At CERN the uid of fcc001 is 140035.

4.1.3. The web portal

The DIRAC web portal is available to check the status of things. It shows all the jobs submmited and the files registered. Some example screenshot is shown below.

Note

As for the VO registration, you need to use a browser where you have installed your certificate and the CERN CA certificates. Firefox usually works fine, Google Chrome usually does not work. Safari might also work.