Component Connectors with QoS Guarantees

Connectors have emerged as a powerful concept for composition and coordination of concurrent activities encapsulated as components and services. Compositional coordination models and languages serve as a means to formally specify and implement component and service connectors. They support largescale distributed applications by allowing construction of complex component connectors out of simpler ones. Modelling, analysis, and ensuring end-to-end Quality of Service (QoS) represent key concerns in such large-scale distributed applications. In this paper we introduce a compositional model of QoS, called Quantitative Constraint Automata, that reflects the underlying architecture of component/service composition represented by the Reo connector circuits. These can support compositional reasoning about component/service connectors, modelled as Reo circuits with QoS properties.