Requirements for a COTS software component: A case study

The goal of the GUARDS project is to design and develop a generic fault-tolerant computer architecture that can be built from predefined standardised components. The architecture favours the use of commercial off-the-shelf (COTS) hardware and software components. However, the assessment and selection of COTS components is a non-trivial task as it requires balancing a myriad of requirements from end-users and the preliminary architecture design. In this paper, we present the requirements and assessment criteria for a specific COTS software component, the operating system kernel. As an interface specification constitutes a major compatibility criterion for the selection of COTS components in GUARDS, a particular emphasis is placed on operating system conformance to the POSIX 1003.1 standard. We discuss the general lessons learned from the assessment process and raise a number of questions relevant to the assessment of any COTS software component.     

An active-architecture approach to COTS integration

COTS software products are increasingly becoming standard components for building integrated information systems. At the same time, the growth of electronic trading, turbulent market conditions, and a project-style approach to business have created a demand for information systems that can be rapidly adapted to changing business process demands. However, the ongoing development of COTS products is unpredictable as their developers and source code are rarely available. Flexible information systems use COTS components because they cost-effectively supply required component functionality. A software architecture can capture a system design as a set of interacting components and capture the role of COTS software in "implementing" certain components.     

空间探测中基于COTS部件的软件容错技术

随着航天活动的发展,空间探测任务对于高性能计算的需求越来越明显,高性能的空间超级计算机成为决定下一代空间探测计划成败的关键之一。专用的防辐射计算部件不仅价格昂贵,而且在性能上远远落后于同时代的商用部件（COTS）。使用软件容错技术在COTS部件上搭建空间超级计算机,在达到和专用防辐射部件同样的容错效果的前提下,能够大幅度降低成本,提高性能和性能／功耗比。美国国家宇航局和斯坦福大学的实验已经验证,使用COTS部件有助于实现低成本高效能的下一代空间科学探测计划。     

Requirements engineering changes for COTS-intensive systems

COTS products (hardware, software, components, subsystems, and so on) are becoming part of the solution for evermore-complex systems. This means you must make changes in any overall system development lifecycle model as well as in the processes and methods you use to define, design, construct, and validate these systems. In particular, requirements engineering and management must undergo process changes.     

Value-based processes for COTS-based applications

Economic imperatives are changing the nature of software development processes to reflect both the opportunities and challenges of using COTS products. Processes are increasingly moving away from the time-consuming composition of custom software from lines of code (although these processes still apply for developing the COTS products themselves) toward assessment, tailoring, and integration of COTS or other reusable components. Two factors are driving this change: COTS or other reusable components can provide significant user capabilities within limited costs and development time, and more COTS products are becoming available to provide needed user functions.     

面向GJB1188A接口的通用武器模拟器设计

为满足不同类型武器挂载模拟的需求,基于GJB 1188A接口,设计了一个通用武器模拟器,该模拟器采用COTS硬件设计方案、Windows+RTX的实时性解决方案、软件分层设计和基于计算机插件技术的武器仿真插件等全套解决方法,在确保性能满足要求的情况下,通过新增武器仿真插件,灵活地扩展系统功能,有效地提高了设备的通用性。该武器模拟器已经成功完成试验验证,具有很大的实用性和推广价值。     

Real-time adaptive resource management

Distributed mission-critical environments employ a mixture of hard and soft real-time applications that usually expect a guaranteed range of quality of service (QoS). These applications have different levels of criticality and varied structures ranging from periodic independent tasks to distributed pipelines or event-driven modules. The underlying distributed system must evolve and adapt to the high variability in resource demands that competing applications impose. The current industry trend is to use commercial off-the-shelf (COTS) hardware and software components to build distributed environments for mission-critical applications. The paper considers how adding a middleware layer above the COTS components facilitates consistent management of system resources, decreases system complexity, and reduces development costs     

Synthesizing safe control-command systems out of reusable components

This paper presents a safe design method for control-command embedded systems. It investigates the problem of building control-command systems out of Commercial off the shelf (COTS) components. The design method proposed uses in synergy the formal verification (FV) and the Discrete Controller Synthesis (DCS) techniques. COTS are formally specified using temporal logic and/or executable observers. New functions are built by assembling COTS together. As the COTS assembly operation is seldom error-free, behavioral incompatibilities may persist between COTS. For these reasons, COTS assemblies need to be formally verified and if errors are found, an automatic correction is attempted using DCS. The control-command code generated by DCS needs hardware specific post-processing: a structural decomposition, followed by a controllability assessment, followed by a dedicated formal verification step, ensuring that no spurious behavior is added by DCS. The resulting system is ready for hardware (e.g. FPGA) implementation.     

基于PC104结构的龙芯1A嵌入式控制模块设计

PC104是一种工业计算机总线标准,PC104与国产化CPU(中央处理器)结合实现PC104嵌入式控制模块是一种新的应用需求.针对这种需求对PC104结构以及国产的“龙芯”1A芯片进行研究,从原理上结合二者特点,再利用高密度布局布线方式设计完成了基于PC104的国产嵌入式控制模块.对模块的功能和性能分别进行测试分析可得,模块化方式的嵌入式控制系统和普通嵌入式控制系统在性能和功能上表现一致,更有便于拓展外设功能的优点,而且可直接用于具有抗震加固特性的机箱,比较适用于未来的工业以及军事应用.     

Multiprogrammed non-blocking checkpoints in support of optimistic simulation on myrinet clusters

CCL (checkpointing and communication library) is a software layer in support of optimistic parallel discrete event simulation (PDES) on myrinet-based COTS clusters. Beyond classical low latency message delivery functionalities, this library implements CPU offloaded, non-blocking (asynchronous) checkpointing functionalities based on data transfer capabilities provided by a programmable DMA engine on board of myrinet network cards. These functionalities are unique since optimistic simulation systems conventionally rely on checkpointing implemented as a synchronous, CPU-based data copy. Releases of CCL up to v2.4 only support monoprogrammed non-blocking checkpoints. This forces re-synchronization between CPU and DMA activities, which is a potential source of overhead, each time a new checkpoint request must be issued at the simulation application level while the last issued one is still being carried out by the DMA engine. In this paper we present a redesigned release of CCL (v3.0) that, exploiting hardware capabilities of more advanced myrinet clusters, supports multiprogrammed non-blocking checkpoints. The multiprogrammed approach allows higher degree of concurrency between checkpointing and other simulation specific operations carried out by the CPU, with benefits on performance. We also report the results of the experimental evaluation of those benefits for the case of a Personal Communication System (PCS) simulation application, selected as a real world test-bed.     

基于COTS器件的高费效比商业卫星计算机研究

对国内外基于COTS(Commercial Off-The-Shelf)器件的商业卫星计算机进行了研究。针对商业卫星公司对卫星可靠性、运算性能、成本控制、研发周期等要求和实际空间运行环境,分析了目前国内外商用卫星的设计模式和特点,提出一种基于汽车级COTS器件的商业卫星单板计算机系统。在可靠性设计上采用了EDAC、双核Lock-Step等技术,选用单粒子免疫的器件的MRAM和反熔丝FPGA,在保证计算机系统安全性、可靠性、成本控制和运算性能的同时,避免了多核或多处理器冗余加固方案导致的额外软件开发成本,缩短产品研发周期。研究对基于COTS器件的商业卫星计算机的可靠性设计有一定参考价值。     

基于Xilinx SoPC的可重构嵌入式计算系统的研究与设计

由于应用种类、实时性以及处理效率等要求,高性能嵌入式计算硬件平台需要具备相当的计算能力以及一定的适应性。为此提出了一种基于Xilinx FPGA的动态可重构的片上系统设计方案。系统采用专用硬件来执行计算密集型任务,运用动态可重构技术来支持硬件处理模块功能的动态配置。研究了Xilinx可编程片上系统上的3种硬件加速方案:CPU协处理器、PLB扩展加速器和MPMC扩展加速器。实验数据表明MPMC加速器性能最优。在Vir-tex5 FPGA器件上实现了可动态重构的MPMC加速器,以128位AES加密、解密两个功能模块为例,从硬件资源占用率、重构延时等角度考察了可重构系统的特点。     

Assessing COTS software in a certifiable safety-critical domain

Abstract.  Commercial off-the-shelf (COTS) software solutions have become commonplace in many domains, including the military, because they can provide standardized functionality with more responsiveness, a shorter time-to-market and at lower costs than custom-made solutions. In one domain, however, that of certifiable safety-critical applications, COTS software has not been adopted. One particular type of certifiable safety-critical domain, the civil air transport industry, is under pressure to reduce cost and time-to-market while simultaneously increasing safety. Therefore, the use of COTS software, rather than exclusive reliance on custom-made software, would appear to be a solution worthy of investigation. This study examines the certifiability of COTS software, its technical feasibility in this environment, and the ability to achieve the expected responsiveness, time-to-market and cost benefits. A detailed evaluation of COTS software and domain-specific certification requirements is used to demonstrate that the certification of COTS-based systems is possible. A prototype COTS-based system (built upon a number of COTS components) is created to illustrate the technical feasibility of such a system in the civil air transport domain. Expected benefits from COTS solutions are evaluated both by examining process artefacts from the development of the COTS-based system and by comparing this development process with the domain's traditional custom-development process.     

Requirements engineering for COTS based systems

In spite of the increasing use of commercial off-the-shelf (COTS) products for system development, there is little consideration on how to acquire requirements for COTS products, how to select COTS components and how to assemble them to comply to these requirements. The paper addresses the issue of the requirements engineering process for COTS components acquisition and assembly. It proposes an approach based on the notion of requirements maps and assembly strategies and demonstrates the approach with the selection of a CASE tool.     

体系结构内可编程数据平面方法

随着互联网与云计算的发展,越来越多的应用被从本地迁移到云端,这些应用最终被运行在共享的数据中心.受到数据中心应用复杂并且需求多变特征的影响,传统体系结构中的部分硬件部件(如共享末级缓存、内存控制器、I/O控制器等)固定功能的设计不能很好地满足这些混合多应用的场景需求.为满足这类应用场景的需求,计算机体系结构需要提供一种可编程硬件机制,使得硬件功能能够根据应用需求的变化进行调整.提出了一种可编程数据平面方法：通过在现有硬件部件中增加可编程处理器,使用执行固件代码的方式对硬件的请求进行处理,并通过更新数据平面处理器固件的方式实现硬件功能的扩展.该方法在FPGA原型系统中进行验证,其结果表明,该方法并没有给系统性能带来严重的影响,只使用有限的资源即可为硬件增加更为灵活的可编程能力,使其能够适应应用需求复杂多变的场景.     

Guest Editors' Introduction: Integrating COTS into the Development Process

Building and evolving software systems is an arduous, costly, lengthy, and complex task. The resulting systems are similarly complex. We're thus constantly searching for ways to reduce such costs, time, and complexity while increasing system functionality and quality. One strategy that originally seemed promising was the notion of "buy not build." Using COTS products is one way to implement this strategy, because software development then becomes the process of "simply" integrating COTS components. However, it turns out that dealing with COTS is a high-risk activity for a variety of reasons.     

基于异构计算平台的规则处理器的设计与实现

对于身份认证机制中的安全字符串恢复,字典结合变换规则是一种常用的方法。通过变换规则的处理,可以快速生成大量具有针对性的新字符串供验证使用。但是,规则的处理过程复杂,对处理性能、系统功耗等有很高的要求,现有的工具和研究都是基于软件方式进行处理,难以满足实际恢复系统的需求。为此,文中提出了基于异构计算平台的规则处理器技术,首次使用可重构FPGA硬件加速规则的处理过程,同时使用ARM通用计算核心进行规则处理过程的配置、管理、监控等工作,并在Xilinx Zynq XC7Z030芯片上进行了具体实现。实验结果表明,在典型情况下,该混合架构的规则处理器相比于单纯使用ARM通用计算核心,性能提升了214倍,规则处理器的运行性能优于Intel i7-6700 CPU,性能功耗比相比NVIDIA GeForce GTX 1080 Ti GPU有1.4~2.1倍的提升,相比CPU有70倍的提升,有效提升了规则处理的速率和能效。实验数据充分说明,基于异构计算平台,采用硬件加速的规则处理器有效解决了规则处理中的速率和能效问题,可以满足实际工程需求,为整个安全字符串恢复系统的设计奠定了基础。     

Identifying and classifying processes (traditional and soft factors) that support COTS component selection: a case study

COTS-Based Systems (CBS) development focuses on building large software systems by integrating previously existing software components. CBS success depends on successful evaluation and selection of Commercial-Off-The-Shelf (COTS) software components to fit customer requirements. Literature shows that successful selecction of off-the-shelf systems to fit customer requirements remains problematic. This paper presents the outcome of a study aimed at using a social-technical approach to identify and classify processes (including traditional and soft factors) that support COTS software selection. The identified factors and lessons learnt from the case study assisted in elaborating and further development of Social-Technical Approach to COTS Evaluation framework (STACE).     

可重构多核片上系统体系结构综述

可重构片上多核系统利用不同粒度、不同耦合度的可重构资源,充分开发资源的并行性,兼顾硬件计算的高性能及软件实现的灵活性,且复用特性使其具备开发设计成本降低、产品面市时间缩短的优势。介绍可重构计算系统概念及其分类,从系统级层面回顾可重构多核片上系统体系结构的研究进展,讨论未来的研究趋势及需要关注的关键问题。     

基于国产化图形芯片JM5400的座舱显示系统设计

综合化、数字化和智能化是座舱显示系统的发展趋势,高性能低功耗图形处理芯片是实现这种需求的核心部件之一。在分析现代战机对座舱显控系统的需求基础上,给出了一个基于国产化图形处理芯片JM5400、国产化CPU、国产化操作系统的座舱显示控制系统设计方案,并已成功应用于实际系统,可满足装备国产化、信息安全化的要求。