AliEn - EDG Interoperability in ALICE

TL;DR

This paper presents an interface enabling interoperability between AliEn, a GRID system for CERN's ALICE experiment, and the European Data Grid, facilitating job submission and data management across systems.

Contribution

The paper introduces a novel interface design that connects AliEn with EDG, allowing seamless resource sharing and data access between the two GRID environments.

Findings

Prototype successfully deployed on testbeds

AliEn and EDG data are accessible and manageable across systems

Interoperability enhances resource utilization and data integrity

Abstract

AliEn (ALICE Environment) is a GRID-like system for large scale job submission and distributed data management developed and used in the context of ALICE, the CERN LHC heavy-ion experiment. With the aim of exploiting upcoming Grid resources to run AliEn-managed jobs and store the produced data, the problem of AliEn-EDG interoperability was addressed and an in-terface was designed. One or more EDG (European Data Grid) User Interface machines run the AliEn software suite (Cluster Monitor, Storage Element and Computing Element), and act as interface nodes between the systems. An EDG Resource Broker is seen by the AliEn server as a single Computing Element, while the EDG storage is seen by AliEn as a single, large Storage Element; files produced in EDG sites are registered in both the EDG Replica Catalogue and in the AliEn Data Catalogue, thus ensuring accessibility from both worlds. In fact, both registrations are required: the AliEn one is used for the data management, the EDG one to guarantee the integrity and access to EDG produced data. A prototype interface has been successfully deployed using the ALICE AliEn Server and the EDG and DataTAG Testbeds.