D. Malon (ANL)
As ATLAS begins validation of its computing model in 2004, requirements imposed upon ATLAS data management software move well beyond simple persistence, and beyond the "read a file, write a file" operational model that has sufficed for most simulation production. New functionality is required to support the ATLAS Tier 0 model, and to support deployment in a globally distributed environment in which the preponderance of computing resources--not only CPU cycles but data services as well--reside outside the host laboratory. This paper takes an architectural perspective in describing new developments in ATLAS data management software, including the ATLAS event-level metadata system and related infrastructure, and the mediation services that allow one to distinguish writing from registration and selection from retrieval, in a manner that is consistent both for event data and for time-varying conditions. The ever-broader role of databases and catalogs, and issues relatedto the distributed deployment thereof, are also addressed.