A progressive topology rconfiguration algorithm in optical data center networks

In recent years there has been an exponential growth in the traffic of cloud data centers networks (DCNs). More and more users are outsourcing their computing demands and services to DCNs. To handle such increases in the workload and traffic in a scalable manner, many technologies have been proposed to provide dynamic topology to the network so as to adapt to the traffic. One representative is the optical switching architecture (OSA) as it provides tremendous flexibility. However, OSA requires too much time (10 ms) to reconfigure the topology. Reconfiguring the topology in one step not only brings much performance degradation to the delay sensitive flows, but also incurs large traffic losses in high throughput low latency DCNs. Therefore, a progressive topology reconfiguration scheme is required to guarantee the performance of delay sensitive flows and reduce the traffic loss. To this end, we propose a topology management algorithm (TMA) in this paper to design such a progressive topology reconfiguration scheme. With TMA, a sequence of intermediate topologies and routing schemes are derived. We leverage these intermediate topologies to realize the reconfiguration progressively, while maintaining the topology connectivity and reducing the total traffic loss during the topology reconfiguration. Through extensive real-trace driven simulation experiments, we find that TMA can reduce the traffic loss during topology reconfiguration with little computational overhead..