Modeling Distributed Computing Infrastructures for HEP Applications

¹ Karlsruhe Institute of Technology, Kaiserstraße 12, 76131 Karlsruhe, Germany
² University of Hawai’i at Ma¯noa, 2500 Campus Road, Honolulu, HI 96822-2217, USA
³ Alma Mater Studiorum - Università di Bologna, Via Zamboni, 33, 40126 Bologna BO, Italy
⁴ Istituto Nazionale Di Fisica Nucleare, Viale Berti Pichat, 6/2, 40127 Bologna BO, Italy
⁵ Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37830, USA

^* e-mail: maximilian.horzela@kit.edu
^** e-mail: henric@hawaii.edu
^*** e-mail: manuel.giffels@kit.edu
^**** e-mail: artur.gottmann@kit.edu
^† e-mail: robin.hofsaess@kit.edu
^‡ e-mail: g.quast@kit.edu
^§ e-mail: simone.rossitisbeni@unibo.it
^*¶ e-mail: achim.streit@kit.edu
^∥ e-mail: suterf@ornl.gov

Published online: 6 May 2024

Abstract

Predicting the performance of various infrastructure design options in complex federated infrastructures with computing sites distributed over a wide area network that support a plethora of users and workflows, such as the Worldwide LHC Computing Grid (WLCG), is not trivial. Due to the complexity and size of these infrastructures, it is not feasible to deploy experimental test-beds at large scales merely for the purpose of comparing and evaluating alternate designs. An alternative is to study the behaviours of these systems using simulation. This approach has been used successfully in the past to identify efficient and practical infrastructure designs for High Energy Physics (HEP). A prominent example is the Monarc simulation framework, which was used to study the initial structure of the WLCG. New simulation capabilities are needed to simulate large-scale heterogeneous computing systems with complex networks, data access and caching patterns. A modern tool to simulate HEP workloads that execute on distributed computing infrastructures based on the SimGrid and WRENCH simulation frameworks is outlined. Studies of its accuracy and scalability are presented using HEP as a case-study. Hypothetical adjustments to prevailing computing architectures in HEP are studied providing insights into the dynamics of a part of the WLCG and candidates for improvements.