VIA(Virtual Interface Architecture)上的软件DSM系统实现和性能

在由高性能PC搭建的Linux机群系统上，传统的网络接口体系结构引入了巨大的软件处理开销，无法满足虚拟共享存储并行应用对通信带宽、延迟和进程间同步的需求．用户级网络接口标准——虚拟接口体系结构(Vilxual Interface Architecture，VIA)与传统的网络接口体系结构相比，在软件协议开销、通信关键路径上操作系统的干预程度、通信和计算的重叠程度以及实现零拷贝等方面，具有明显的优势．通过在传统网络通信接口和VIA通信接口上虚拟共享存储系统的性能对比，采用VIA网络接口体系结构可有效地提高虚拟共享存储系统的性能和可扩展性．     

一种内核级VIA的设计

VIA(VirtualInterfaceArchitecture)是用户级集群通信工业标准。对VIA做了扩展,将其引入到网络存储领域,实现了内核级VIA,并且在Linux系统平台上进行了测试。和用户级VIA相比,内核级VIA全面提高了存储系统节点和服务器间通信性能。尤其是对于 512字节以下小数据包,延迟至少降低 30%。     

数据传输模式对用户态通信的性能影响分析

用户态通信允许应用程序从应用层直接访问网络接口，主机与网络接口之间的数据传输模式对协议性能有重要影响．有效的数据传输模式可以减少数据拷贝次数，降低数据传输开销，尽可能将网络硬件的高性能反映到用户层．本文详细分析了通信系统开销来源，讨论了Myrinet网络环境下不同数据传输模式的实现与特点，测试并分析了不同数据传输模式对用户态通信性能的影响，并给出了相应的适用环境．     

内核级VIA的实现

VIA是用户级集群通信工业标准。本文对VIA做了扩展,将其引入到网络存储领域,实现了内核级VIA,并且在Linux系统平台上进行了测试。和用户级VIA相比,内核级VIA全面 提高了存储系统节点和服务器间通信性能,尤其是对于512字节以下小数据包,延迟至少降低30％。     

VIABM的评测分析报告

VIA是一种用户层通信系统框架，它已成为集群用户层通信领域的工业标准。为了以同一种标准测评各种不同的VIA实现，设计并实现了VIABM，并对测试结果进行了分析。     

面向航电综合系统的先锋光纤传输网实时通信的研究

VIA是个能降低软件开销的用户级通信协议,针对航电系统对传输网络通信的实时性提出了很高的要求,在分析VIA原理的基础上,对硬件进行了少许修改,把VIA引入航电网络,针对面向航电的先锋光纤传输网卡实现了一个精简的类VIA的通信协议。该协议根据VIA的基本原理并结合先锋网卡的特点,通过减少陷入内核的次数,尽量消除数据挎贝,缩短数据传输的关键路径来提通信速率。通过实验验证,引入VIA技术后,可大大降低通信过程中的软件开销,降低通信延迟,提高通信网络的实时性。     

基于核态Socket的网络块设备研究

本文描述了一种适用于集群系统的网络块设备的实现方案。这种方案基于新型的VIA结构，在核态实现一层Socket，使得基于TCP／IP的网络块设备(NBD)可以很方便地移植到VIA的网络上。该方案消除了TCP／IP协议栈的软件开销，也减少了核态与用户态的数据拷贝和上下文切换的开销。     

VIA及其在Myrinet上的一种实现

VIA是一种用户层通信模型，是当今集群系统通信的工业标准，能够提供低延迟、高带宽的数据传输，文中介绍并分析了VIA规范的产生背景和原理，并以Berkeley大学的一种实现方案为例，具体说明其实现细节。     

基于VI的高性能网卡XUNI的设计与实现

VIA是用户级集群系统工业标准.深入研究了VIA的规范和协议,设计和实现了一种高性能的用户级网卡--XUNI(PCI-X based user lever network interface),达到高带宽、低延迟,系统具有良好的计算通信重叠性.该网卡可以用于集群系统,也非常适用于高速网络存储系统.     

.NET框架中的驱动程序应用技术

．NET给我们提供了一个非常丰富的类库实现Windows应用程序的用户态功能，即系统ring3级的功能。当然，实现用户态功能也可以使用[DllIport(“dllname．Dll”)]来调用WINAPI或者用户DLL中的函数。然而如果应用程序需要用到驱动程序应该怎么办呢?怎样使自己的．NET程序控制扩展名为sys或vxd的驱动程序并实现和驱动程序的通信，从而使自己的．NET应用程序实现．NET框架中无法实现的系统核心态(ring0级)的功能?这正是本文要解答的问题。     

MyVIA：一种基于Myrinet的VIA设计与实现

1.背景近年来工业技术的进步,促进了集群技术的形成与发展,成为当今计算机技术研究的热点。在集群技术中,网络通信是很重要的一个环节,一个高效、可靠的网络通信层,是集群系统的底层基石。在集群系统中,各主机之间通信频繁,通信量大,延迟小,     

Anatomy of UDP and M-VIA for cluster communication

High interprocess communication latency is detrimental to parallel and grid computing. Over the years, the network bandwidth has increased rapidly while the end-to-end latency has not decreased much. This is because the latency is dominated by the protocol software execution time in the kernel instead of the raw transmission time over the link. In this paper, we perform an anatomical analysis of the complete communication path between a sender and a receiver through measurements. We present an in-depth evaluation of various components of the UDP protocol over Fast Ethernet. Virtual Interface Architecture (VIA) protocol has been recently proposed to overcome the software overhead of the TCP/UDP/IP protocol. We analyze M-VIA, a modular VIA implementation for Linux over Ethernet, and compare its performance with UDP. The aim of our experiments is to present the protocol overheads in details rather than to suggest new techniques to reduce overheads.     

一种基于Myrinet LANai9硬件支持的VIA原型实现

VIA定义了一种低延迟、高带宽的数据传输模型，成为集群系统通讯技术的工业标准。本文介绍VIA的产生背景和结构特征，详细阐述了清华大学在Myrinet LANai9硬件上实现 的VIA原型－MyVIA2，最后给出了几种用户层通信软件的测试结果和比较分析。     

Design and implementation of efficient communication abstractions on the Virtual Interface Architecture: Stream sockets and RPC experience

The emergence and standardization of system area networks (SANs) has provided distributed applications with a medium for high‐bandwidth, low‐latency communication. Standard user‐level networking architecture such as the Virtual Interface (VI) Architecture enables distributed applications to perform low overhead communication over SANs. The VI Architecture significantly reduces system processing overheads and provides each consumer process with a protected, directly accessible interface to the network hardware. Developing distributed applications using low‐level primitives provided by user‐level networking architecture like the VI Architecture is complex and requires significant effort. This paper describes how high‐level communication paradigms like stream sockets and remote procedure call (RPC) can be efficiently built over the VI Architecture. To evaluate performance benefits for standard client–server and multi‐threaded environments, our focus is on off‐the‐shelf sockets and RPC interfaces and commercially available VI Architecture‐based SANs. The key design techniques developed in this paper include credit‐based flow control, decentralized user‐level protocol processing, caching of pinned communication buffers, and deferred processing of completed send operations. In the experimental evaluation, the one‐way bandwidth achieved by stream sockets over VI Architecture was three to four times better than the bandwidth achieved by running legacy protocols over the same interconnect. On the same SAN, high‐performance stream sockets and RPC over VI Architecture achieve significantly better (between 2× and 3× less) latency than conventional stream sockets and RPC over standard networking protocols in a Windows NT? 4.0 environment. Furthermore, our high‐performance RPC transparently improved the network performance of the distributed component object model (DCOM) by a factor of two to three. Copyright © 2001 John Wiley & Sons, Ltd.     

A high-speed and low-cost storage architecture based on virtual interface

Over the years, the network storage bandwidth has increased rapidly while the node-to-node latency has not decreased much. This is because the latency is dominated by the protocol software execution time in the kernel, instead of by the raw transmission time over the link. Virtual Interface (VI) protocol has been proposed to overcome the software overhead of the TCP/IP. In this paper, we introduce another new technology vSCSI (VI-attached SCSI) to compete with iSCSI in LAN (Local Area Networks) environment, and compare performance of vSCSI and iSCSI experimentally. Meanwhile, we present a Virtual Interface Storage Architecture (VISA) as a new network storage architecture which uses vSCSI as the network communication protocol. Then, we can take advantage of VI’s superior performance over TCP/IP in LAN environment. Also, actually we have implemented and measured our data transport and Remote Procedure Call (RPC) layer over VI. The aim of our design and implementation is to put forward new techniques to reduce overheads.     

Evolution of the virtual interface architecture

To provide a faster path between applications and the network, researchers have advocated removing the operating system kernel and its centralized networking stack from the critical path and creating a user level network interface. With these interfaces, designers can tailor the communication layers each process uses to the demands of that process. Consequently, applications can send and receive network packets without operating system intervention, which greatly decreases communication latency and increases network throughput. Unfortunately, the diversity of approaches and lack of consensus has stalled progress in refining research results into products-a prerequisite to the widespread adoption of these interfaces. Recently, however, Intel, Microsoft, and Compaq have introduced the Virtual Interface Architecture, an emerging standard for cluster or system area networks. Products based on the VIA have already surfaced, notably GigaNet's GNN1000 network interface. As more products appear, research into application level issues can proceed and the technology of user level network interfaces should mature. Several prototypes-among them Cornell University's U-Net2-have heavily influenced the VIA. We describe the architectural issues and design trade-offs at the core of these prototype designs