DELPHI data preservation activity
Changes since 2002
Many years after the end of the experiment IT services are changing, and the software stack has to adapt to that to ensure the continued accessibility of the DELPHI data. Changes in services include:
At the same time new services have arrived which replace the functionality of these disappearing services.
- With CentOS7 the Fortran compiler g77 will finally disappear and is replaced by gfortran.
- Support of LSF is stopped at the end of 2018.
- The role of CASTOR has changed. RFIO clients (like rfcp) are gone.
- AFS is being phased out.
- old binaries no longer work due to change in glibc. This requires re-compilation and linking of the affected libraries and executables.
- EOS is taking over functionality from CASTOR and AFS
- HTCondor replaces LSF
- CVMFS is widely used for world-wide read-only sharing of software. It is available at all GRID sides, and works as well on PCs outside CERN.
New DELPHI software stack
Based on the software CD created in 2002 a new software stack has been created. It is the default on CentOS7 (eg. lxplus7.cern.ch), and is also available for testing on SLC6 (lxplus).
The new software stack has no remaining dependencies on AFS, LSF or CASTOR. It works fine outside CERN as well. Currently, the following operating systems are supported:
- All DELPHI data has been copied from CASTOR to EOS. On lxplus and lxbatch it can be directly accessed from /eos/experiment/delphi. The CASTOR tape copy (2 copies) remains intact for archiving and disaster recovery.
- Access to DELPHI data requires valid kerberos credentials for an account which is registered in the CERN unix group XX.
- The default compiler is gfortran. All libraries have been re-compiled using this version.
- The sources of the main components of the software stack have been transfered to https://gitlab.cern.ch/delphi . Any changes applied to the libraries for data preservation are tracked in the git history.
- Thanks to the help of the DPHEP initiative, OPAL and the CERN IT department we have received updated libraries for GPHIGS. Various bugs have been fixed in DELGRA which makes it more stable now than it used to be on Linux.
- The licensing conditions for GPHIGS have changed. We have only one run time license and one developer license available which we have to share with OPAL. See below on how to use it.
- All DELPHI libraries and sources are available on /cvmfs/delphi.
Setting up the software locally:
- ScientificCERNSLC-6 (SLC6). This is compatible with SL6.
- CentOS-7 and compatible
- To run the stack locally, you need to have the 32bit X11 and gfortran libraries installed, eg you need gfortran-multilib for Ubuntu.
- To initialise this software stack, it is enough to source /cvmfs/delphi.cern.ch/setup.sh or /cvmfs/delphi.cern.ch/setup.csh, (depending on the shell).
- If you want to run delgra locally, you need to buy a GPHIGS run-time license from FEI S.A.S., 3 Impasse Rudolf Diesel BP 50227 33708 MERIGNAC FRANCE. Install the tar ball you got for example in /opt and set the environment variable OPGS_HOME to point to this location (which includes the license file).
- The correct flavor is automatically selected, based on the output of the command "lsb_release -a".
Using and testing
On Centos7 (eg lxplus7.cern.ch) the new software stack is the default. On lxplus you can test it by manually sourcing /cvmfs/delphi.cern.ch/setup.sh or /cvmfs/delphi.cern.ch/setup.csh, depending on your shell.
Caveats and things to be done
Tasks still to be performed are tracked in the DPHEP JIRA task tracker. Input to any of the tickets is very welcome. Some remarks:
- The only remaining AFS dependency of the software stack left is related to the GPHIGS license file which is restricted to CERN nodes. If you want to run DELGRA outside CERN you have to buy a GPHIGS license. See https://gitlab.cern.ch/delphi/delgra for any details.
- A large part of the documentation is still on AFS, specifically internal notes, theses etc.
- DELPHI web pages are still hosted on AFS. They will need to be moved to /eos. This will be transparent for the users.
- It would be nice to add some more complex sample analyses to the new stack. Suggestions for that are welcome!
Notes on the event display DELGRA
To run DELGRA locally, you must buy a license and the runtime environmnent from FEI. You can run DELGRA at CERN as well, however, there are some restrictions.
At this point in time it is very difficult to do meaningful in depth tests of the stack. If you use it please do cross checks with old archived data, and report any problems to email@example.com
Links and references
Last modified: Tue Dec 4 11:36:37 CET 2018