COOL: A Cloud-Optimized Structure for MPI Collective Operations
COOL: A Cloud-Optimized Structure for MPI Collective Operations
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COOL：用于 MPI 集体操作的云优化结构
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
S. Al
中科院分区：
文献类型：
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作者：
Mohammed Alfatafta;Zuhair AlSader;S. Al
我们介绍了COOL，一种简单而通用的MPI集合操作结构。Cool可为云中的所有集体操作提供高效设计。然后，我们提出了一个基于COOL的系统设计，实现了常用的集合操作。我们的设计有效地利用了机架内网络，同时最大限度地减少了跨机架通信，从而提高了应用程序的性能和可扩展性。我们使用最新的软件定义网络功能，为I/O密集型集体操作构建最佳网络路径。我们的分析评估表明，我们的设计跨机架施加的网络开销最小。此外，与OpenMPI和MPICH相比，我们的设计将步骤数减少到只有三步，将交换消息的数量减少了N倍(进程总数)，并将网络负载减少了高达一个数量级。这些显著的改进是以少量进程的计算负载适度增加为代价的。
We present COOL, a simple and generic structure for MPI collective operations. COOL enables highly efficient designs for all collective operations in the cloud. We then present a system design based on COOL that implements frequently used collective operations. Our design efficiently uses the intra-rack network while minimizing cross-rack communication, thus improving the application performance and scalability. We use recent software-defined networking capabilities to build optimal network paths for I/O intensive collective operations. Our analytical evaluation shows that our design imposes the least possible network overhead across racks. Furthermore, when compared with OpenMPI and MPICH, our design reduces the number of steps to only three, decreases the number of exchanged messages by a factor of N, the total number of processes, and reduces the network load by up to an order of magnitude. These significant improvements come at the cost of a modest increase in the computation load on a few processes.