Speaker
Description
Unprecedented size and complexity of the ATLAS experiment required
adoption of a new approach for online monitoring system development as
many requirements for this system were not known in advance due to the
innovative nature of the project.
The ATLAS online monitoring facility has been designed as a modular
system consisting of a number of independent components, which can
interact with one another via a set of well defined interfaces. The
system has been developed using open source software and is based on
the two in-house developed highly scalable distributed services for
message passing and information exchange, which can deal with
information of arbitrary types. The other monitoring components use
these services to implement high-level facilities, like for example
Monitoring Data Archiving and Data Quality Assessment, as well as end
user interfaces like the Data Quality and Online Histogramming
displays.
This presentation will describe the online monitoring system design
and evolution for the first two data taking periods showing how the
chosen approach allowed the system to be gradually extended during
operation in a non-disruptive way by adding more high level tools and
frameworks as requirements evolved.
