  Increasing number of the cloud-based Internet applications demands for
efficient resource and cost management. This paper proposes a real-time group
auction system for the cloud instance market. The system is designed based on a
combinatorial double auction, and its applicability and effectiveness are
evaluated in terms of resource efficiency and monetary benefits to auction
participants (e.g., cloud users and providers). The proposed auction system
assists them to decide when and how providers allocate their resources to which
users. Furthermore, we propose a distributed algorithm using a group formation
game that determines which users and providers will trade resources by their
cooperative decisions. To find how to allocate the resources, the utility
optimization problem is formulated as a binary integer programming problem, and
the nearly optimal solution is obtained by a heuristic algorithm with quadratic
time complexity. In comparison studies, the proposed real-time group auction
system with cooperation outperforms an individual auction in terms of the
resource efficiency (e.g., the request acceptance rate for users and resource
utilization for providers) and monetary benefits (e.g., average payments for
users and total profits for providers).
