Real Time Global Tests of the ALICE High Level Trigger Data Transport Framework

Author

Becker, B. ; Chattopadhyay, S. ; Cicalò, C. ; Cleymans, J. ; de Vaux, G. ; Fearick, R.W. ; Lindenstruth, V. ; Richter, M. ; Röhrich, D. ; Staley, F. ; Steinbeck, T.M. ; Szostak, A. ; Tilsner, H. ; Weis, R. ; Vilakazi, Z.Z.

Author_Institution

INFN Sezione di Cagliari, Cittadella Univ. di Monseratto, Cagliari

Volume

55

Issue

2

fYear

2008

fDate

4/1/2008 12:00:00 AM

Firstpage

703

Lastpage

709

Abstract

The High Level Trigger (HLT) system of the ALICE experiment is an online event filter and trigger system designed for input bandwidths of up to 25 GB/s at event rates of up to 1 kHz. The system is designed as a scalable PC cluster, implementing several hundred nodes. The transport of data in the system is handled by an object-oriented data flow framework operating on the basis of the publisher-subscriber principle, being designed fully pipelined with lowest processing overhead and communication latency in the cluster. In this paper, we report the latest measurements where this framework has been operated on five different sites over a global north-south link extending more than 10,000 km, processing a ldquoreal-timerdquo data flow.

Keywords

high energy physics instrumentation computing; nuclear electronics; real-time systems; ALICE; high-level trigger data transport; object-oriented data flow; publisher-subscriber principle; real time global tests; real-time data flow; scalable PC cluster; Africa; Bandwidth; Collision mitigation; Delay; Filters; Fluid flow measurement; Large Hadron Collider; Object oriented modeling; Physics; Testing; Distributed computing; event filter; online processing; publisher–subscriber; trigger;

fLanguage

English

Journal_Title

Nuclear Science, IEEE Transactions on

Publisher

ieee

ISSN

0018-9499

Type

jour

DOI

10.1109/TNS.2008.918521

Filename

4484222