Systems based on Service-Oriented Architecture are called service-based systems (SBS), and comprise of computing services offered by various organizations. Users of SBS often require these services to be composed into complex workflows to perform their high-level tasks. The users usually have certain expectations on the overall QoS of their workflows. Due to the highly dynamic environments of SBS, in which temporary unavailability or qualitydegradation of services may occur frequently and unexpectedly, monitoring the execution of workflows in SBS is necessary, and should be done in distributed and proactive manner. In this paper, a virtual machine-based architecture for the execution, monitoring and control of workflows in SBS is presented. Based on this architecture, an approach to automated generation of workflow monitors for adaptive distributed execution monitoring of workflows in SBS is discussed
Stephen S. Yau, Dazhi Huang, Luping Zhu