Mar 21 – 27, 2009
Europe/Prague timezone

The CMS Offline condition database software system

Mar 23, 2009, 2:00 PM
Club A (Prague)

Club A


Prague Congress Centre 5. května 65, 140 00 Prague 4, Czech Republic
oral Software Components, Tools and Databases Software Components, Tools and Databases


Dr Zhen Xie (Princeton University)


Non-event data describing detector conditions change with time and come from different data sources. They are accessible by physicists within the offline event-processing applications for precise calibration of reconstructed data as well as for data-quality control purposes. Over the past three years CMS has developed and deployed a software system managing such data. Object-relational mapping and the relational abstraction layer of the LHC persistency framework are the foundation; the offline condition framework updates and delivers C++ data objects according to their validity. A high-level tag versioning system allows production managers to organize data in hierarchical view. A scripting API in python, command-line tools and a web service serve physicists in daily work. A mini-framework is available for handling data coming from external sources. Efficient data distribution over the worldwide network is guaranteed by a system of hierarchical web caches. The system has been tested and used in all major productions, test-beams and cosmic runs.

Primary authors

Dr Giacomo Govi (Northeastern University) Dr Vincenzo Innocente (CERN) Dr Zhen Xie (Princeton University)

Presentation materials