Traffic Control for RDMA-Enabled Data Center Networks: A Survey

Data centers, the infrastructure of cloud computing, have been widely deployed around the world to accommodate the increasing cloud computing demands. A data center network (DCN) connects tens or hundreds of thousands of servers in the data center and uses a traffic control scheme to enable the data transmission among servers. Various new applications in cloud present new requirements on traffic control of DCNs, such as low latency and high throughput. Existing traffic control schemes in DCNs suffer from the complicated kernel processing and cannot satisfy the requirements. Remote direct memory access (RDMA), which bypasses the kernel processing to enable fast memory moving across a network, is recognized as a promising solution. In this article, we present a survey of traffic control schemes for traditional RDMA, traditional DCNs, and RDMA-enabled DCNs and explain their limitations. We also differentiate the existing schemes from congestion control, performance, and components. In order to encourage future research, we point out some potential research directions of this research.