Computing in Networks: Active System Area Networks

计算和通信的融合产生了基于网络的应用程序的爆炸式增长。可以从基于web的应用程序、交互式模拟、游戏、可视化和协作环境中得出许多例子。目前开发基于网络的应用程序的方法仍然基于以cpu为中心的模型，使用针对单处理器或小规模多处理器应用程序优化的节点架构。这可能导致分布式应用程序的效率低下。这个项目探索了一种支持新兴的基于网络的应用程序的体系结构，在这种体系结构中，选定的应用程序级计算在网络接口（NIs）中执行。重点是作为可行的高性能计算工具出现的工作站网络（NOW）。在此背景下，该项目将支持具有大量计算和数据操作需求的应用程序。这些高性能程序来自三个不同的应用领域：科学模拟、计算机视觉和图像处理以及计算机图形学。支持这些类程序的方法的独特方面是使用可扩展的网络接口，其中扩展涉及在驻留在NIs上的低成本微处理器上以及在现场可编程门阵列（fpga）形式的附加可编程和ni相关硬件上执行的程序。具体来说，该项目将演示(1)使用fpga来实现数据密集型计算，(2)使用NIs的微处理器来处理相关的元信息，并执行计算非密集型操作，最好在“接近”网络时执行。通过开发灵活、可扩展的虚拟通信机，可以实现NIs的可扩展性。该项目将这种增强网络称为主动系统区域网络（ASANs）。关键的研究问题是：(1)理解和证明ASAN比主机cpu更有效地执行选定计算和服务的能力，并探索将某些功能从主机cpu卸载到ASAN的影响和权衡，(2)开发编程模型，使ASAN的计算资源能够有效地和特定于应用程序的使用，以及(3)创建一个低开销且易于扩展的ASAN软件架构。所提出的研究方法是实验性的。它包括一个测试平台的构建，为本工作中研究的三类并行/分布式应用程序所使用的选定NI扩展的实现，以及对结果系统/应用程序性能的性能评估。该方法的成功演示将对未来多媒体网络应用程序的设计、优化和支持方式产生重大影响。

The confluence of computing and communication has produced an explosion of network-based applications. Numerous examples can be drawn from web-based applications, interactive simulations, gaming,visualization, and collaborative environments. Current approaches to the development of network-based applications are still based on a CPU-centric model using node architectures optimized for uniprocessoror small-scale multiprocessor applications. This can lead to significant inefficiencies for distributed applications.This project explores an architecture for the support of emerging network-based applications whereby selected application-level computations are executed within network interfaces (NIs). The focus is onnetworks of workstations (NOW) that have emerged as a viable high performance computational vehicle. Within this context the project will support applications with substantial computation and data manipulationrequirements. Such high performance programs are drawn from three different application domains: scientific simulation, computer vision and image processing, and computer graphics. The unique aspect of theapproach to supporting these classes of programs is the use of extensible network interfaces, where extension concerns programs executed both on the low cost microprocessors resident on NIs and on additional, programmable and NI-associated hardware in the form of field programmable gate arrays (FPGAs). Specifically, the project will demonstrate (1) the use of FPGAs to implement data-intensivecomputations and (2) the use of the NIs' microprocessors to handle associated meta-information and perform computationally non-intensive operations best performed "close" to the network. Extensibility for NIs will be attained by development of a flexible and extensible virtual communication machine. The project refers to such enhanced networks as Active System Area Networks (ASANs).The key research issues are (1) to understand and demonstrate an ASAN's ability to perform selected computations and services more efficiently than host CPUs and to explore the effects and trade-offs of off-loading certain functionality from host CPUs to the ASAN, (2) to develop the programming model that enables the efficient and application-specific use of the ASAN's computational resources, and (3) to create an ASAN software architecture that is low overhead and easily extensible.The approach to the proposed research is experimental. It includes construction of a testbed, implementation of selected NI extensions for use by the three classes of parallel/distributed applications investigated in this work and performance evaluation of the resulting system/application performance. Successful demonstration of theapproach will have a major impact the way future multimedia network applications are designed, optimized, and supported.