A high-performance Two-Phase Multipath scheme for data-center networks

Multipath forwarding has been recently proposed to improve utilization in data centers leveraged by its redundant network design. However, most multipath proposals require significant modifications to the tenants' network stack and therefore are only feasible in private clouds. In this paper, we propose the Two-Phase Multipath (TPM) forwarding scheme for public clouds. The proposal improves tenants' network throughput, whereas keeping unmodified network stack on tenants. Our scheme is composed of a smart offline configuration phase that discover optimal disjoint paths, and a fast online path selection phase that improves flow throughput at run time. A logically centralized manager uses a genetic algorithm to generate and install sets of paths, summarized into trees, during multipath configuration, and a local controller performs the multipath selection based on network usage. We analyze TPM for different workloads and topologies under several scenarios of usage database locations and update policies. The results show that our proposal yields up to 77% throughput gains over previously proposed approaches.