Web Services Allocation Guided by Reputation in Distributed SOA-Based Environments

Web services have become one of the easiest ways to fulfill a wide range of tasks in multiple domains of work. Their availability has increased significantly through Service-Oriented Distributed Environments that have become standard platforms for their deployment. At the same time, the clients impose their own constraints and expectations from services and require from the service providers the best replica to satisfy these constraints. The main objective of this paper is implementing a model that can effectively and accurately determine the best endpoint of a web service deployed in a distributed environment depending on the constraints of the client that invoked it and the capabilities of each replica. While each service offers different functions and each client may have different preferences for these functions, our method is independent from the services´ features and computes the best replica using properties that define quality (processing time), business constraints (service price) and client´s feedback (reputation), properties available for every service. The model is purely mathematical and will produce the same results for the same values of these criteria regardless of the particular functionality of the service invoked. The algorithm behind the model also takes into account the properties specific to distributed environments such as the client´s location or the load limitations of the system on which the replica is deployed. This paper describes this algorithm, along with its architecture of the system that implements the model and the tests conducted.