The Creation and Evolution of the US ATLAS Shared Analysis Facilities

Prior to the start of the LHC Run 3, the US ATLAS Software and Computing operations program established three shared Tier 3 Analysis Facilities (AFs). The newest AF was established at the University of Chicago in the past year, joining the existing AFs at Brookhaven National Lab and SLAC National Accelerator Lab. In this paper, we will describe both the common and unique aspects of these three AFs, and the resulting distributed facility from the user’s perspective, including how we monitor and measure the AFs. The common elements include enabling easy access via Federated ID, file sharing via EOS, provisioning of similar Jupyter environments using common Jupyter kernels and containerization, and efforts to centralize documentation and user support channels. The unique components we will cover are driven in turn by the requirements, expertise and resources at each individual site. Finally, we will highlight how the US AFs are collaborating with other ATLAS and LHC wide (IRIS-HEP and HSF) user analysis support activities, evaluating tools like ServiceX and Coffea-Casa.

在大型强子对撞机（LHC）第3轮运行开始之前，美国阿特拉斯（ATLAS）软件与计算操作项目建立了三个共享的三级分析设施（AFs）。最新的一个分析设施于去年在芝加哥大学建成，加入了布鲁克海文国家实验室和斯坦福直线加速器中心（SLAC）国家加速器实验室已有的分析设施。在本文中，我们将从用户的角度描述这三个分析设施的共同和独特之处，以及由此形成的分布式设施，包括我们如何监测和评估这些分析设施。共同要素包括通过联合身份（Federated ID）实现便捷访问，通过EOS进行文件共享，使用通用的朱庇特（Jupyter）内核和容器化提供类似的朱庇特环境，以及努力集中文档和用户支持渠道。我们将介绍的独特组件则依次由每个站点的需求、专业知识和资源所驱动。最后，我们将强调美国的分析设施如何与其他阿特拉斯项目以及大型强子对撞机范围内（IRIS - HEP和HSF）的用户分析支持活动进行协作，评估像ServiceX和Coffea - Casa这样的工具。