Towards a Redundancy-Aware Network Stack for Data Centers

In this paper, we make a case for a redundancy-aware network stack (RANS) for data centers. In RANS, applications expose information about replicas to the network, which in turn, uses duplicate requests to improve performance of typical applications by enabling them to effectively avoid stragglers. At the heart of RANS is the use of duplicate-aware scheduling, which ensures that duplicate-requests do not overload the system and disturb any primary requests. We highlight the challenges and opportunities present at different layers of RANS, from new interfaces that capture replicas and their semantics, to in-network mechanisms that deal with duplicates. Our preliminary evaluation shows the promise of duplicate-aware scheduling in improving performance of typical data center applications.