Impacts of Scheduling Algorithms in Services on Collective End-to-End Execution Time Characteristics of Web Service Workflows

Web services usually compose to workflows to satisfy complex demands. End-to-end execution time is widely seen as a key quality metric of web service workflows. That will be affected by many factors. This paper focuses on impacts of an important factor -- scheduling algorithm in services -- on collective end-to-end time characteristics of a set of web service workflows. We develop a novel simulator, in which workflows are simulated to execute. Impacts of different scheduling algorithms are evaluated through comparing simulation results. Simulation results indicate that maximal and average end-toend execution time of most workflows when using "earliest deadline first" (EDF) scheduling algorithm in services is significant shorter than that when using widely used "first in, first out" (FIFO) scheduling algorithm.