A Reimplementation of the CORBA-based Event Monitoring System For the ATLAS LHC Experiment at CERN

The Atlas Event Monitoring system is a subsystem of the Atlas Online Software, providing a framework for sampling events from different stages of the data flow chain of the ATLAS detector and distributing it to so-called Monitoring Tasks run by physicists. After a short introduction to the ATLAS experiment, the data aquisition project and its different software components and the general purpose of Event Monitoring, this thesis discusses the previous implementation as well as different aspects of the reimplementation that has been done in the context of this thesis. After having done a theoretical analysis of the communication complexity of both implementations and the presentation of practical performance test results captured during the Large Scale Test period a conclusion will be made, showing why the reimplementation is more suitable for actual usage in the final experiment than the previous implementation.