Measurement based analysis of temporal behaviour as support for scheduling problems in parallel and distributed real-time systems

Static analysis, based on scheduling techniques, provides the most typical approach for validation of real-time systems. However, in the case of complex real-time systems such as parallel and distributed systems, many simplifications are made in order to make analysis tractable. This means that even if the system can be statically validated, the real behaviour of the system in execution may be different enough from its theoretical behaviour to make it invalid. In these cases, an analysis based on measurement of the system in execution constitutes an invaluable aid to the static analysis. This article describes a methodology for the analysis of the temporal behaviour of parallel and distributed real-time systems with end-toend constraints. The analysis is based on the measurement of a prototype of the system in execution and is supported by a behavioural model. The main components of the model are the sequences of activities throughout the system tasks (transactions), which are carried out in response to input events, causing the corresponding output events. Thus, the temporal behaviour of the system is viewed as a set of real-time transactions competing for the available resources. This article also includes experimental results of applying the methodology to the analysis of a well-known case study.