Research And Implementation Of RPC Framework Based On RDMA And NVMM

With the continuous development of remote direct memory access(RDMA)technology,more and more data centers choose to use this low-latency and high-throughput method for communication.RDMA transfers part of the calculations originally completed on the CPU to the network card,thereby freeing up the CPU computing power and being able to access the data on the remote memory without the remote CPU being awakened.In addition to RDMA,non-volatile main memory(NVMM)has also been widely adopted by data centers in recent years.By using NVMM,the data center can obtain a storage medium with higher throughput and lower latency than SSD,and the data will not be lost due to power failure.The currently widely used NVMM is Intel(?)Optane(?) Persistent Memory(Intel(?) Optane(?) Persistent Memory)launched by Intel.As a new communication method,RDMA has a completely different programming mode from TCP.The RPC framework needs to be designed according to the characteristics of RDMA to be able to maximize the performance of RDMA.In the data center,when data needs to be written to the remote NVMM,the traditional method is to write the data into the remote memory through RDMA first,and then write the data into the NVMM by waking up the remote machine.This approach will make a redundant copy and increase the load on the remote CPU.In order to be compatible with most data centers(such as Hadoop,Spark,etc.),this article uses JAVA as the development language of the RPC framework.In order to enable JAVA to use RDMA,this article encapsulates and optimizes the C language RDMA call.Using the encapsulated JAVA call,this paper designs a user-mode RPC framework based on RDMA and NVMM.It uses the characteristics of RDMA primitives to achieve advantages such as low context switching and load balancing.Compared with the traditional RPC framework,the RPC framework in this article has the advantages of high throughput,low latency and scalability.And this article also designed a method of directly writing data through RDMA for Optane permanent memory,and combined this method into the RPC framework.