Research On Realization And Observation Of Congestion Control In InfiniBand Network

InfiniBand (IB) is a high-bandwidth and low-latency switching technique. It notonly has wide applications in the field of high-performance computing, but also hasbeen gradually concerned in the area of research and engineering implementation ofdata center network. In contrast to Ethernet, IB has more reliable QoS guarantee byusing link-layer flow control based on the credit and end-to-end congestion controlbased on Explicit Congestion Notification (ECN).There have been few studies of IB congestion control (CC) mechanisms about theimpact on the end-to-end transmission performance, especially in a multi-tenant datacenter environment. Reasonable CC parameter configuration is important to achieveefficient allocation of network bandwidth. Therefore, mastering IB CC mechanism iscrucial to optimize IB network end-to-end transmission performance and efficientbandwidth allocation. To meet the demand of IB CC research, this paper has made deepresearches about IB CC behavior measurement methods and the observation platformdesignment. Contributions and the main work of this dissertation can be concluded asfollows:Firstly, we analyze IB CC mechanism in-depth, including the causes of IB networkcongestion, congestion back-spread mechanism, algorithm of congestion marking inswitches, the congestion marking feedback mechanism and rate adjustment mechanismbased on congestion marking in channel adapter.Secondly, for generating the controlled congestion in IB network, we develop acentral control traffic generator—CTBG, and establish an observation platform CCOP(Congestion Control Observation Platform) based on IB switch and channel adapterhardware developed by our team, with the help of using ibdump and wiresharkopen-source software. CCOP can observation and analysis the IB CC marking andtransmission performance under the different CC parameter configurations.Lastly, since the operation of CCOP doesn’t have an obvious impact on theperformance of IB network transmission through our comparison and analysis of thenetwork performance, we verify the accuracy of CCOP towards performanceobservation. Then we measure IB network transmission performance under the differentCC parameter configurations based on CCOP environment.In summary, this paper proposes an IB CC observation platform—CCOP,and it canefficiently support researches of IB CC mechanism and performance optimization.