Co-scheduling of advance and immediate bandwidth reservations for inter-data center transfer

As scientific applications and business services increasingly migrate to clouds, big data of various types with different priorities need to be transferred between geographically distributed cloud-based data centers. It has become a critical task for Cloud Service Providers (CSP) to fully utilize the expensive bandwidth resources of the links connecting such data centers while guaranteeing users’ Quality of Experience (QoE). Most high-performance networks based on software-defined networking (SDN) provide the capability of advance bandwidth reservation. This paper focuses on the scheduling of multiple user requests of two different types with different priorities, namely, advance bandwidth reservation with a lower priority and immediate bandwidth reservation with a higher priority, to maximize the total satisfaction of user requests. We formulate this co-scheduling problem as a generic optimization problem, which is shown to be NP-complete. We design a heuristic algorithm to maximize the number of successfully scheduled requests and minimize the number of preempted advance reservation requests, while minimizing the completion time of each request. Extensive simulation results show that our scheduling scheme significantly outperforms greedy approaches in terms of user satisfaction degree.