Incollection,
QoS-aware Complex Service Composition in SOA-based Systems
SOA Infrastructure Tools: Concepts and Methods, Poznań University of Economics Press, Poznań, Poland, (2010)
Abstract
In this work, a method for the QoS-aware complex service composition in SOA-based systems is presented. The considered complex service composition process consists of three stages: complex service structure, scenario and plan composition. Complex service structure contains a set of required functionalities and precedence relations between them, and is derived directly from a service level agreement. Service scenario is derived from service structure by choosing the optimal (in the sense of certain quality criterion) order of execution of required functionalities. Finally, a service plan emerges from a scenario by choosing the best versions of atomic services for the delivery of required functionalities. For such distinguished composition process methods for complex service scenario and execution plan optimization are proposed. Optimization of a complex service scenario is based on the analysis of possible parallel executions of required functionalities. In order to deliver required level of the quality of service, well known QoS assurance models (i.e.: best effort, integrated services and differentiated services) are applied in the process of complex service execution plan optimization.
