A Stackelberg game for distributed formation of business-driven services communities

Abstract

With the advent of cloud computing and the rapid increase in the number of deployed services, the competition between functionally-similar Web services is increasingly governing the markets of services. For example, Amazon and Google are in an intense competition to dominate the market of cloud-based Web services. Such a highly competitive environment motivates and sometimes obliges services to abandon their pure competitive strategies and adopt a cooperative behavior in order to increase their business opportunities and survive in the market. Several approaches have been advanced in the literature to model the cooperation among Web services in a community-based environment. However, the existing approaches suffer from two main drawbacks that limit their effectiveness in the real-world services market. First, they rely on a centralized architecture wherein a master entity is responsible for regulating the community formation process, which creates a single point of failure. Second, they ignore the business potential of the services and treat all of those services in the same way, which demotivates the participation of the well-positioned ones in such communities. To tackle these problems, we distinguish in this paper between two types of services: leaders and followers. Leaders are those services that enjoy high reputation, market share, and capacity of handling requests; whereas followers are those services that cannot compete against the leaders. Thereafter, we model the community formation problem as a virtual trading market between these two types of services and propose a distributed Stackelberg game for this purpose. Promisingly, the proposed model gives guidance to a cooperative model that can be applied in the real markets of Web services in order to achieve higher performance, efficient services compositions, and better resources utilization. The performance of the model is analyzed using a real-life flight booking dataset that includes 2507 services operating on the Web. Simulation results show that the proposed model is able to increase the satisfaction of Web services in terms of gained payoff and reputation and the satisfaction of users in terms of quality of service provided to their requests compared to the existing models, namely the one-stage game theoretical model and a heuristic model.