摘要

In this paper, we introduce a combinatorial auction-based market model to enable Cloud Service Providers (CSPs) to satisfy complex user requirements collaboratively, where the CSPs are connected in a social network and communication costs among them cannot be ignored. However, in many situations CSPs may lie about their private information in order to maximize their earnings. Therefore, we combine the combinatorial auction with the VCG-auction mechanism to ensure that CSPs do not lie in auction. Based on above market model, we construct a collaborative cloud platform, which is divided into three layers: The user-layer receives requests from end-users, the auction-layer matches the requests with the cloud services provided by the Cloud Service Provider (CSP), and the CSP-layer forms a coalition to improve serving ability to satisfy complex requirements of users. In fact, the aim of the coalition formation is to find suitable partners for a particular CSP, and, we propose two heuristic algorithms for the coalition formation. The Breadth Traversal Algorithm (BTA) and Revised Ant Colony Algorithm (RACA) are proposed to form a coalition when bidding for a single cloud service in the auction. The experimental results show that RACA outperforms the BTA in bid price and our methods work well compared to the existing auction-based method in terms of economic efficiency. Other experiments were conducted to evaluate the impact of the communication cost on coalition formation and to assess the impact of iteration times for the optimal bidding price.