A. Fanfani

CMS offline web tools

We describe a relatively new effort within CMS to converge on a set of web based tools, using state of the art industry techniques, to engage with the CMS offline computing system. CMS collaborators require tools to monitor various components of the computing system and interact with the system itself. The current state of the various CMS web tools is described along side current planned developments. The CMS collaboration comprises of nearly 3000 people from all over the world. As well as its collaborators, its computing resources are spread all over globe and are accessed via the LHC grid to run analysis, large scale production and data transfer tasks. Due to the distributed nature of collaborators effective provision of collaborative tools is essential to maximise physics exploitation of the CMS experiment, especially when the size of the CMS data set is considered. CMS has chosen to provide such tools over the world wide web as a top level service, enabling all members of the collaboration to interact with the various offline computing components. Traditionally web interfaces have been added in HEP experiments as an afterthought. In the CMS offline we have decided to put web interfaces, and the development of a common CMS web framework, on an equal footing with the rest of the offline development. Tools exist within CMS to transfer and catalogue data (PhEDEx and DBS/DLS), run Monte Carlo production (ProdAgent) and submit analysis (CRAB). Effective human interfaces to these systems are required for users with different agendas and practical knowledge of the systems to effectively use the CMS computing system. The CMS web tools project aims to provide a consistent interface to all these tools.

CMS Monte Carlo production in the WLCG computing Grid

Monte Carlo production in CMS has received a major boost in performance and scale since the past CHEP06 conference. The production system has been re-engineered in order to incorporate the experience gained in running the previous system and to integrate production with the new CMS event data model, data management system and data processing framework. The system is interfaced to the two major computing Grids used by CMS, the LHC Computing Grid (LCG) and the Open Science Grid (OSG). Operational experience and integration aspects of the new CMS Monte Carlo production system is presented together with an analysis of production statistics. The new system automatically handles job submission, resource monitoring, job queuing, job distribution according to the available resources, data merging, registration of data into the data bookkeeping, data location, data transfer and placement systems. Compared to the previous production system automation, reliability and performance have been considerably improved. A more efficient use of computing resources and a better handling of the inherent Grid unreliability have resulted in an increase of production scale by about an order of magnitude, capable of running in parallel at the order of ten thousand jobs and yielding more than two million events per day.