Transaction history-based web service composition for uncertain QoS

The QoS-aware web service composition (WSC) problem constructs a composite web service with the optimal accumulated QoS value. In the real world, this problem encounters some challenges. First, while most QoS-aware WSC techniques make their decisions based on the QoS information published by each service provider, the actual QoS performance at run-time may be inconsistent with the QoS specification due to the dynamic execution environment and intentional/unintentional error in the QoS declaration. Another obstacle is that the QoS-aware WSC problem for large scale instances is intractable to solve since the problem corresponds to a global optimisation problem. Toward these challenges, we propose a novel QoS-aware WSC method based on the real service transaction history of web services, which employs the anytime algorithm technique. In the experiment, our proposal can deal with the uncertain QoS efficiently and identify composite web services with high quality much earlier than the optimal algorithm.