| ¡¡ | Chinese Journal of Computers Full Text |
| Title | Instance Migration in Dynamic Evolution of Web Service Compositions |
| Authors | SONG Wei MA Xiao-Xing LU Jian |
| Address | (State Key Laboratory for Novel Software Technology, Nanjing University, Nanjing 210093) (Institute of Computer Software, Nanjing University, Nanjing 210093) |
| Year | 2009 |
| Issue | No.9(1816¡ª1831) |
| Abstract & Background | Abstract Constructing new, value-added Web services by composing existing ones is stepping into the mainstream of software development. To adapt to the open environments and optimize the inner business processes, Web service compositions often need to evolve dynamically. To maximize the benefit of the evolvement, as many running instances as possible should be migrated to the new version of the service composition specification. However not all running instances can migrate safely because some dynamic change bugs (e.g., deadlocks) could occur after these instances have migrated to the new version. This paper presents a framework to support the dynamic evolution of Web service compositions under which a new formal migratability criterion is proposed. It also proposes the algorithm to check whether an instance of a service composition can migrate to the new version and- if so- the algorithm can also obtain the corresponding target state under the new version where the suspended instance can resume its execution after migration. Compared with the existing migratability criteria in the literature, the authors¡¯ criterion allows migrations of more running instances without introducing potential dynamic change bugs. Lastly, a case study based on a travel agency application is also included to demonstrate the effectiveness and feasibility of the proposed approach. Keywords Web service composition; dynamic evolution; instance-level migration; migratability criterion; Petri nets |