CMS Alignment and Calibration Framework - Setup and First Experiences with Data

Precise and prompt alignment and calibration will be crucial to the performance of the CMS detector. A software and computing infrastructure has been commissioned, which accomplishes both tasks in a swift and reliable manner. First, incoming data from the experiment is processed and skimmed automatically at the Tier-0 site. Reduction of data size is of prime interest in this stage, to ensure efficient use of computing facilities and fast turnaround-times. Second, a versatile computing farm (CERN Analysis Farm) enables a fast execution of the alignment and calibration workflows. Both steps are coordinated and carried out for a large number of interdependent processes. The resulting database payloads are used for all subsequent reconstruction steps, providing optimised measurement precision to physics analysis. The framework is described alongside to the validation of its implementation. To this end some results using cosmic data taken in 2008 are shown.