Design And Implementation Of 10GBE-based RDMA

Although RDMA technology solves the problems of high data delay caused by the complicated message processing flow in the traditional Socket communication mechanism due to its core bypass,zero copy and other excellent features;However,with the Ethernet communication rate from gigabit to 10 gigabit,or even higher rates;the traditional RDMA communication method for network packet processing flow has gradually become the bottleneck of its communication efficiency.In traditional RDMA communication,only one piece of data in a continuous memory space can be transferred at a time.As a result,many operations such as connection establishment and system interruption are required to transmit non-continuous spatial data,and the transmission capability of 10 Gigabit Ethernet cannot be fully utilized.This thesis is to solve the problems of low network bandwidth utilization and high communication delay caused by the inability to transmit multiple non-continuous spatial data at one time in traditional RDMA communication.A chain DMA controller based on the PCI Express bus is used to aggregate the discrete data in the system memory into the RDMA cache,which greatly reduces the number of interactions between the RDMA network card and the computer system.At the same time,in order to solve the problems caused by the establishment of the connection and the increase in the amount of information during data storage after the use of the chain DMA controller.It is modified on the basis of the traditional RDMA communication method,and the descriptor table pointer is used to construct the RDMA work request;in order to take into account the limitation of the length of the Ethernet message and the requirement to correctly separate the stored data,a new data is added to the protocol stack The method of dividing and slicing different sources to ensure that data in different spaces can be stored in the correct memory space.In this thesis,this communication method is implemented on the FPGA in hardware,and several test cases are designed for the function points of RDMA to test their functions and stability.The test results show that the communication method realizes the aggregate transmission of multiple data,reducing the number of RDMA connection establishment and DMA interruption times;for 128-byte data frames,the Ethernet bandwidth utilization rate is increased by 255%;128 pieces of data The average delay is reduced by 57%.The RDMA communication method proposed in this thesis can effectively solve the problem of high data delay caused by frequent connection establishment,improve the communication efficiency of RDMA in the 10 Gigabit Ethernet environment,and demonstrates the transmission superior to the traditional RDMA communication method.performance.