  A fast, efficient and comprehensive monitoring system is a vital part of any
HEP experiment. This paper describes the software framework that will be used
during ATLAS data taking to monitor the state of the data acquisition and the
quality of physics data in the experiment. The framework has been implemented
by the Online Software group of the ATLAS Trigger&Data Acquisition (TDAQ)
project and has already been used for several years in the ATLAS test beams at
CERN. The inter-process communication in the framework is implemented via
CORBA, which provides portability between different operating systems and
programming languages. This paper will describe the design and the most
important aspects of the online monitoring framework implementation. It will
also show some test results, which indicate the performance and scalability of
the current implementation.
