SN0490 : Setting up a STAR Tier 2 Site at Golias/Prague Farm

Author(s):Petr Chaloupka, Pavel Jakl, Jan Kapitan, Jérôme Lauret, Michal Zerola
Date:May. 13, 2009
File(s): STAR_tier2.pdf

High Energy Nuclear Physics (HENP) collaborations’ experience show that the computing resources available at a single site are often neither sufficient nor satisfy the need of remote collaborators eager to carry their analysis in the fastest and most convenient way. From latencies in the network connectivity to the lack of interactivity, work at distant computing centers is often inefficient. Having fully functional software stack on local resources is a strong enabler of science opportunities for any local group who can afford the time investment. The situation becomes more complex as vast amount of data are often needed to perform meaningful analysis.
Prague’s heavy-ions group participating in STAR experiment at RHIC has been a strong advocate of local computing as the most efficient means of data processing and physics analyses. To create an environment where science can freely thrive, a Tier 2 computing center was set up at a Regional Computing Center for Particle Physics called ”Golias”. It is the biggest farm in the Czech Republic fully dedicated for particle physics experiments.
We report on our experience in setting up a fully functional Tier 2 center leveraging the minimal locally available human and financial resources. We discuss the solutions chosen to address storage space and analysis issues and the impact on the farms overall functionality. This includes a locally built STAR analysis framework, integration with a local DPM system (a cost effective storage solution), the influence of the availability and quality of the network connection to Tier 0 via a dedicated CESNET/ESnet link and the development of light-weight yet fully automated data transfer tools allowing the movement of entire datasets from BNL (Tier 0) to Golias (Tier 2). We will summarize the impact of the gained computing performance on the efficiency of the local physics group at offline physics analysis and show the feasibility of such a solution that can used by other groups as well.

Submitted: CHEP2009
Status: Published (see also arXiv:0906.2883v2)
Ref: Petr Chaloupka, J. Kapitan, J. Lauret, M. Zerola, 2010 J. Phys.: Conf. Ser. 219 072031

Keywords:Tier2, Prague, Golias, DPM, SUMS, storage, regional center, xrootd