A policy-based approach for strong mobility of composed Web services

This paper presents a flexible, portable, and transparent solution for strong mobility of composed Web services relying on policy-oriented techniques. The proposed approach provides a checkpoint solution based on automatic code instrumentation using correct source code transformation rules. This checkpoint technique permits to save the execution state of a mobile orchestration process as well as the execution states of its orchestrated partners. Thus, after migration, only non-executed codes will be resumed. In addition, our approach enables dynamic adaptation of the employed checkpointing and mobility techniques using aspects. For that, we use policies allowing dynamic selection of the used checkpointing and mobility techniques according to the execution context. Moreover, the proposed solution includes a module allowing the determination of the checkpointing interval satisfying QoS requirements. Experimentations show the efficiency of the proposed solution.