A Flexible Directory Query Language for the Efficient Processing of Service Composition Queries
Walter Binder (University of Lugano, Switzerland), Ion Constantinescu (Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland) and Boi Faltings (Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland)
Copyright: © 2008
Service composition is a major challenge in an open environment populated by large numbers of heterogeneous services. In such a setting, the efficient interaction of directory-based service discovery with service composition engines is crucial. In this article we present a Java-based directory that offers special functionality enabling effective service composition. In order to optimize the interaction of the directory with different service composition algorithms exploiting application-specific heuristics, the directory supports user-defined selection and ranking functions written in a declarative query language. Inside the directory queries are transformed and compiled to JVM bytecode which is dynamically linked into the directory. The compiled query enables a best-first search of matching directory entries, efficiently pruning the search space.