Title :
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
fDate :
4/1/2008 12:00:00 AM
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;
Journal_Title :
Nuclear Science, IEEE Transactions on
DOI :
10.1109/TNS.2008.918521
