Inter-Data Center RDMA: Challenges, Status, and Future Directions

Remote Direct Memory Access (RDMA) has been widely implemented in data centers (DCs) due to its high-bandwidth, low-latency, and low-overhead characteristics. In recent years, as various applications relying on inter-DC interconnection have continuously emerged, the demand for deploying RDMA across DCs has been on the rise. Numerous studies have focused on intra-DC RDMA. However, research on inter-DC RDMA is relatively scarce, yet it is showing a growing tendency. Inspired by this trend, this article identifies and discusses specific challenges in inter-DC RDMA deployment, such as congestion control and load balancing. Subsequently, it surveys the recent progress in enhancing the applicability of inter-DC RDMA. Finally, it presents future research directions and opportunities. As the first review article focusing on inter-DC RDMA, this article aims to provide valuable insights and guidance for future research in this emerging field. By systematically reviewing the current state of inter-DC RDMA, we hope to establish a foundation that will inspire and direct subsequent studies.