Περίληψη:
ALICE (A Large Ion Collider Experiment) is the heavy-ion detector
designed to study the physics of strongly interacting matter and the
quark-gluon plasma at the CERN Large Hadron Collider (LHC). The ALICE
Data Acquisition system (DAQ) is made of a large number of distributed
hardware and software components, which rely on several online
databases: the configuration database. describing the counting room
machines, some detector-specific electronics settings and the DAQ and
Experiment Control System runtime parameters; the to database. centrally
collecting reports front running processes, the experiment logbook.
tracking the run statistics filled automatically and the operator
entries; the online archive of constantly updated data quality
monitoring reports; the File indexing, services, including the status of
transient files for permanent storage and the calibration results for
offline export; the user guides (Wiki), test databases to check the
interfaces with external components; reference data sets used to restore
known configurations. With 35 GB of online data hosted on a MySQL server
and organized in more than 500 relational tables for a total of 40
million rows, this information is populated and accessible through
various frontends. including C library for efficient repetitive access.
Tcl/TK GUIs for configuration editors and to browser. HTML/PHP pages for
the logbook, and command line tools for scripting and expert debugging.
Exhaustive hardware benchmarks have been conducted to select the
appropriate database server architecture. Secure access from private and
general networks was implemented. Ad-hoc monitoring, and backup
mechanisms have been designed and deployed. We discuss the
implementation of these complex databases and how the inhomogeneous
requirements have been addressed. We also review the performance
analysis outcome after more than one year in production and show results
of data mining from this central information source.
Συγγραφείς:
Altini, V.
Carena, F.
Carena, W.
Chapeland, S.
Barroso,
V. Chibante
Costa, F.
Divia, R.
Frauman, M.
Fuchs, U.
and Makhlyueva, I.
Rademakers, O.
Navarro, D. Rodriguez and
Roukoutakis, F.
Schossmaier, K.
Soos, C.
Telesca, A. and
Vyvre, P. Vande
von Haller, B.
ALICE Collaboration
