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

TL;DR

This paper describes the setup and implementation of a local Tier 2 computing center at Golias for the STAR experiment, enhancing data processing efficiency and analysis capabilities for the Prague heavy-ions group.

Contribution

It presents a comprehensive case study of establishing a functional Tier 2 site, including solutions for storage, analysis, and data transfer, tailored to local infrastructure constraints.

Findings

Improved data access and analysis efficiency at Golias.

Successful integration of local analysis framework with storage system.

Automated data transfer tools enhanced dataset movement from Tier 0 to Tier 2.

Abstract

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. 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. 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. Tier 2 computing center was set up at a Regional Computing Center for Particle Physics called "Golias". We report on our experience in setting up a fully functional Tier 2 center and 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).