A JEE RESTful service to access Conditions Data in ATLAS

Usage of Conditions Data in ATLAS is extensive for offline reconstruction and analysis (for example: alignment, calibration, data quality). The system is based on the LCG Conditions Database infrastructure, with read and write access via an ad hoc C++ API (COOL), a system which was developed before Run 1 data taking began. The infrastructure dictates that the data is organized into separate schemas (assigned to subsystems/groups storing distinct and independent sets of conditions), making it difficult to access information from several schemas at the same time. We have thus created PL/SQL functions containing queries to provide content extraction at multi-schema level. The PL/SQL API has been exposed to external clients by means of an intermediate java application server (JBoss), where an application delivering access to the DB via RESTful services has been deployed. The services allow navigation over multiple schema content, via simple URLs. The queried data can be retrieved either in XML or JSON formats, via simple clients (curl, wget or Web browsers).