SLAC's role in EXO computing
- Development of DAQ software
- Data transport from WIPP to SLAC
- Data processing at SLAC
- Long term data storage, and data access for collaboration
- Data quality monitoring (at WIPP and SLAC)
- Web interface (developed using FreeHEP software for Fermi, now maintained by SRS group)
- Maintenance of infrastructure including
- Subversion and Sventon (web access to code repository)
- Makefiles and Hudson (automated build system)
- Confluence
- Standard installations of Geant4, CLHEP, ROOT and MySQL
- MySQL databases for daq, data quality, slow control and data handling
- Automated processing pipeline (developed for Fermi, now maintained by SRS group)
- Help develop simulation, reconstruction, analysis, conditions handling software (together with wider collaboration)
- Organize software and data challenge workshops
Challenges
Limited central support for science tools
Historical practice at SLAC has been for tools such as Geant4 and Root to be installed and maintained by each collaboration. This works well when there are a few large collaborations with adequate manpower, but for smaller experiments this is not an efficient way to work. Since we expect more small experiments in PPA in the future we should take this opportunity to develop some improved centralized support for:
- Geant4 and CLHEP
- Root
- MySQL client
At a minimum this should include maintaining several versions of such software in a central location, with documentation and a support plan (for example which OS variant's will be supported now and in the future).
I strongly suggest that an active PPA computing coordinating committee be set up to address these and other related issues in a pro-active way. For this to be of use to EXO it will need to be set up now.
Limited manpower
- DAQ
- Tony Waite (.7)
- JJ Russell (.7)
- Nicole Ackerman
- Ryan
- Slow Control
- Derek
- Data Handling, web infrastructure
- Contribution from SRS group (Dan, Max, Karen) (1?)
- Tony (.15)
- Offline
- Tony (.15)
The manpower available for DAQ, Slow Control and Data Handling look to be OK (assuming planned increase in SRS manpower actually comes to fruition on finite timescale). The manpower available for offline computing is extremely low, especially given the need to support tools like Geant4 as discussed above. For comparison Fermi has at least 6 SLAC FTE (Richard+Leon+Tracy+Joanne+Heather+Tom) working on a more complex but otherwise similar problem. Contribution to offline/analysis software from the collaboration will increase as the hardware/DAQ work wraps up, but with so little SLAC manpower we can not provide any backup if collaboration fails to step in to fill all gaps.