Leveraging an open source serverless framework for high energy physics computing

Abstract

CERN (Centre Europeen pour la Recherce Nucleaire) is the largest research centre for high energy physics (HEP). It offers unique computational challenges as a result of the large amount of data generated by the large hadron collider. CERN has developed and supports a software called ROOT, which is the de facto standard for HEP data analysis. This framework offers a high-level and easy-to-use interface called RDataFrame, which allows managing and processing large data sets. In recent years, its functionality has been extended to take advantage of distributed computing capabilities. Thanks to its declarative programming model, the user-facing API can be decoupled from the actual execution backend. This decoupling allows physical analysis to scale automatically to thousands of computational cores over various types of distributed resources. In fact, the distributed RDataFrame module already supports the use of established general industry engines such as Apache Spark or Dask. Notwithstanding the foregoing, these current solutions will not be sufficient to meet future requirements in terms of the amount of data that the new projected accelerators will generate. It is of interest, for this reason, to investigate a different approach, the one offered by serverless computing. Based on a first prototype using AWS Lambda, this work presents the creation of a new backend for RDataFrame distributed over the OSCAR tool, an open source framework that supports serverless computing. The implementation introduces new ways, relative to the AWS Lambda-based prototype, to synchronize the work of functions.

Serverless Strategies and Tools in the Cloud Computing Continuum

“…The decoupling of RDataFrame as a processing interface for ROOT allows custom implementations to support new backends for processing large data sets. Indeed, for the implementation of OSCAR as a backend for RDataFrame, a collaboration has been carried out in the study conducted by Padulano et al [148], which aims to analyse the use of Serverless tools to support the distributed processing of large amounts of data through ROOT. The implementation has been undertaken by defining the objects needed to implement the RDataFrame interface through the appropriate calls to the OSCAR API and uploading and downloading files to the MinIO storage system.…”

“…In addition, the coordinated reduction process has been analysed to optimise the processing. Figure 6.4 [148] shows the interaction between the different components implemented.…”