Scalable failover method for Data Center Networks using OpenFlow

With the emergence of significant amounts of mobile and cloud services, the scale of Data Center Networks (DCNs) has been growing rapidly. A DCN has different network requirements compared to a traditional Internet Protocol (IP) network, and the existing Ethernet/IP style protocols constrain the DCNs scalability and its manageability. In this paper, we present a scalable failover method for large scale DCNs. Because most of the current DCNs are managed in a logically centralized manner with a specialized topology and growth model, we adopt Fat-Tree [1] as the reference DCN topology and design our failover method using an OpenFlow-based approach. Further, to provide scalability, we design our failover algorithm in a local optimal manner, with which only three switches must be modified for handling a single fault, regardless of the size of the target network. We evaluate our failover method in terms of failover time by varying the network size and load balancing capability during failover. The experiment results show that our method scales well, even for a large-scale DCN with more than ten thousands hosts.