Research On MPI Collectives Optimization Over Free Space Optical Network

HPC(High Performance Computing)is widely used in some fields,such as weather forecasting and aerospace.MPI(Message Passing Interface)is the de facto standard in HPC domain.Collective communication efficiency has become the key factor of affecting the performance of parallel applications.Free space optical communication technology has the characteristics of high bandwidth,low latency and natural broadcast.It has great potential benefits to improve the performance of collective communication,and it is of important research value.In this paper,we focus on the optimization of MPI collective communication based on free space optical communication technology,and the main research contents are as follows:First,the optimization of MPI collective communication is thoroughly studied,and the work of MPI collective communication optimization is summarized.Then the development of high performance interconnects and wireless communication technology is introduced.Second,based on the free space optical communication technology,a dedicated broadcast network of 2D-Mesh topology is designed,and based on the network,the topology-aware broadcast algorithm(abbreviated as TAB)and topology-aware scatter algorithm(abbreviated as TAS)are proposed,TAB and TAS algorithm can significantly improve the performance of broadcast and scatter operation by leveraging the underlying network.Third,based on the MPICH,an extended software architecture,called MPICH-COLL,is proposed,then the design and implementation of MPI_Bcast and MPI_Scatter are carried out.Finally,a cluster prototype system based on the free space optical broadcast network is engineered.Then the performance of TAB and TAS algorithm are tested under the prototype system.Experimental results indicate that the TAB algorithm can significantly improve the performance of broadcast,and the TAS algorithm has some performance improvement for the scatter.