Prototype for a Generic Thin-Client Remote Analysis Environment for CMS

• Main Authors: C. D. Steenberg, J. J. Bunn, T. M. Hickey, K. Holtman, I. Legrand, V. Litvin, H. B. Newman, A. Samar, S. Singh, R. Wilkinson
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: remote analysis; distributed data access; grid; Orca
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.125.7888; http://clarens.sourceforge.net/docs/clarens_chep_sept_2001_paper.pdf

The multi-tiered architecture of the highly-distributed CMS computing systems necessitates a flexible data distribution and analysis environment. We describe a prototype analysis environment which functions efficiently over wide area networks using a server installed at the Caltech/UCSD Tier 2 prototype to analyze CMS data stored at various locations using a thin client. The analysis environment is based on existing HEP (Anaphe) and CMS (CARF, ORCA, IGUANA) software technology on the server accessed from a variety of clients. A Java Analysis Studio (JAS, from SLAC) plug-in is being developed as a reference client. The server is operated as a “black box” on the proto-Tier2 system. ORCA Objectivity databases (e.g. an existing large CMS Muon sample) are hosted on the master and slave nodes, and remote clients can request processing of queries across the server nodes, and get the histogram results returned and rendered in the client The server is implemented using pure C++, and use XML-RPC as a language-neutral transport. This has several benefits, including much better scalability, better integration with CARF/ORCA, and importantly, makes the work directly useful to other non-Java general-purpose analysis and presentation tools such as Hippodraw, Lizard, or ROOT.