基于分层实时网络的复杂虚拟试验支撑环境

针对复杂虚拟试验分层实时系统中对实时性、可靠性的不同要求,为了解决异构网络的通讯问题,借鉴了虚拟共享内存特性,分别设计和实现了反射内存网中间件VMICVSM、以太网中间件EVSM和桥接网关;结合某导弹系统的分布式仿真试验,给出了分层实时网络的设计方案,对两种中间件及网关的实时传输性能进行了测试,满足了应用中不同实时性的要求。     

基于RT-TCP/IP的虚拟试验通信平台研究

网络是虚拟试验系统环境的重要组成部分.以某军工虚拟试验系统为背景,基于RT-TCP/IP和虚拟共享内存机制实现了虚拟试验通信平台.分析了RTX实时操作子系统和RT-TCP/IP的实时性能,论证了使用RT-TCP/IP协议构建虚拟试验局域网的可行性;设计并实现了实时以太网虚拟共享内存中间件(RTEVSM).在RTX环境下对RTEVSM中间件的数据传输延迟、抖动性等性能指标进行了测试,与在Windows-NT环境下性能指标进行对比,验证了系统在RTX环境下具有较强的实时性和传输可靠性.应用结果表明,本方案对实时性要求高的分布虚拟试验系统搭建具有一定的实用价值.     

虚拟试验支撑框架VITA研究与实现

虚拟试验验证技术可为复杂航天产品的试验验证提供有效的技术支撑。结合航天产品研制过程对虚拟试验验证技术的需求,开展了虚拟试验支撑框架VITA研究与实现;VITA系统由运行中间件及系列辅助工具集组成,实现对虚拟试验应用系统“试验设计-试验运行-试验分析”全生命周期的支持;全面介绍了VITA运行中间件、集成开发环境、试验设计、试验调度管理、试验记录与回放、试验结果分析、试验数据管理、异构网关、硬件网关等各模块的实现方案,给出了其在航天复杂产品试验系统互联中的应用情况;实践表明VITA支持对产品关键系统的技术性能验证,有效解决了产品难以开展大系统联合试验的难题,后续将完善跨平台功能、提升实时性指标,实现产品化推广。     

分布式虚拟实验室的信息传输技术

分布式虚拟实验室中各个节点的实验数据是由分布在网络中的所有节点共享的,在虚拟实验的过程中,网络中传输的数据信息较大。针对分布式虚拟实验室的大流量和高实时性特点及时透明数据交互的需求,采用分层结构设计了基于UDP协议的数据传输层,并以中间件的形式予以实现。阐述了分布式虚拟环境的网络底层构造及传输协议的中间件实现方法。     

中间件体系结构的集成研究

研究中间件体系结构设计的关键技术和集成机制,介绍基于反身映射技术和构件技术的中间件体系结构,以航空航天某虚拟试验实时软总线项目为研究背景,提出通过增加网关节点解决虚拟试验系统网络异构、软件异构和操作系统异构的集成方法。实验结果表明,该集成方法可以提高系统的实时性和确定性,应用效果较好。     

基于VSM中间件的分布式试验与测试系统的通信技术

测试产品的复杂程度和现代化程度的不断提高,使得其设计、研制和维护日益依赖于先进的试验与测试手段。针对分布式测试系统的大流量和高实时性特点及对透明数据交互的需求,在比较了现有的几种通信方法的优缺点基础上,采用虚拟共享内存中间件来构造分布式测试系统。阐述了虚拟共享内存中间件的结构、功能及如何利用虚拟共享内存中间件来实现分布式试验与测试系统的数据通信。     

基于VSM的分布仿真软件适配器研究

为满足针对航空、航天领域的大规模虚拟实验的要求,在认真研究适配器技术和基于以太网的VSM(虚拟共享内存)中间件的基础上,提出构造一种基于VSM机制的分布式仿真软件适配器和实时网VSM中间件来扩展已有的以太网VSM中间件的技术.根据松耦合系统与紧耦合系统的不同仿真需求,采用松耦合适配器和紧耦合适配器两种适配器对以太网VSM中间件进行浅层和深层两个层次的扩充.其中松耦合适配器已经在实际中得到应用,并取得了良好的效果.     

工业控制网络协议与IPv6协议的一种转换方法

在企业自动化系统中,上层企业管理和生产监控大多采用以太网,下层车间现场大多采用现场总线,上下层各自采用不同的网络体系结构和协议.为了远程监控生产现场,实现异构网络的数据通信,需要构建合适的协议转换网关.通过对工业控制网络协议与IPv6协议的研究,提出了异构网络协议转换网关模型,并给出了一种基于中间件技术的工业控制网络与以太网的协议转换网关系统的设计方案,满足了底层工业控制网络与上层管理网络互联的应用要求.     

基于虚拟接入物联网中间件平台的设计与应用

提出一种基于虚拟接入的物联网中间件平台VAM(Virtual Access Middleware)。通过引入虚拟接入层,将异构的传感网络协议转换为中间件平台的内部协议,从而屏蔽了传感网络的异构性,为应用层访问异构无线传感网络提供统一的访问平台。详细介绍此中间件平台虚拟接入模块以及平台通信协议的设计,并通过在水质监测系统下的应用,验证了VAM中间件的可行性,降低了应用层软件开发的复杂度。     

基于RTX的复杂虚拟试验分层实时网络环境研究

复杂实时仿真系统中不同层次对实时性、可靠性要求各不相同;网络和操作系统是该类系统环境的重要组成部分;针对硬件在回路试验的实时需求,提出了基于RTX下的反射内存网的半实物接入网络,构建了基于RT-TCP/IP的虚拟试验局域网;其操作系统层面,设计为弱实时任务在Windows内核上运行,而强实时任务分布在RTX内核之上;文中对各层面的实时性进行了测试,分析了层面间的实时性约束;结合某飞行试验系统的虚拟试验,给出了具体的设计方案,满足了应用中不同实时性的要求。     

SDSN@RT: A middleware environment for single-instance multitenant cloud applications

With the single-instance multitenancy (SIMT) model for composite Software-as-a-Service (SaaS) applications, a single composite application instance can host multiple tenants, yielding the benefits of better service and resource utilization and reduced operational cost for the SaaS provider. An SIMT application needs to share services and their aggregation (the application) among its tenants while supporting variations in the functional and performance requirements of the tenants. The SaaS provider requires a middleware environment that can deploy, enact, and manage a designed SIMT application, to achieve the varied requirements of the different tenants in a controlled manner. This paper presents the SDSN@RT (software-defined service networks at runtime) middleware environment that can meet the aforementioned requirements. SDSN@RT represents an SIMT composite cloud application as a multitenant service network, where the same service network simultaneously hosts a set of virtual service networks, one for each tenant. A service network connects a set of services and coordinates the interactions between them. A virtual service network realizes the requirements for a specific tenant and can be deployed, configured, and logically isolated in the service network at runtime. SDSN@RT also supports the monitoring and runtime changes of the deployed multitenant service networks. We show the feasibility of SDSN@RT with a prototype implementation and demonstrate its capabilities to host SIMT applications and support their changes with a case study. The performance study of the prototype implementation shows that the runtime capabilities of our middleware incur little overhead.     

高性能时间序列数据库网络中间件研究

本文研究了时间序列数据库网络中间件,总结分析了常见的网络中间件特点.根据时间序列数据库的高性能要求,对网络中间件的关键技术进行了研究,采用多个Reactor和Thread Pool的并发模型来提高线程并发度,并提出了多帧消息格式,实现消息协议的动态扩展.最后在PCS-9000时间序列数据库中实现了相关的网络中间件,达到了预期的性能指标要求.     

面向开放移动网络环境的新一代中间件技术研究

结合现有网络计算环境的特点,对适用于开放、移动网络环境的新一代中间件技术进行了研究。在分析今天网络环境关键特征的基础上,提出了新一代中间件系统需要满足的技术需求;从所针对的问题角度对新一代中间件系统面临的主要挑战进行了详细的讨论,包括上下文感知、环境自适应、开放式协作、服务发现和普适互操作等,并给出了一些解决方案。     

中间件技术的研究

计算机以及网络通信技术的发展使得中间件技术取得了长足的进步，出现了许多有关中间件的软件开发理论、标准协议以及各种商业软件产品。随着信息系统越来越以网络为中心进行开发和演化，中间件技术将扮演更加重要的角色。本文介绍了中间件领域的发展现状，主要分析了当前中间件领域中主流的DOC技术和正在兴起的Web Services、Grid／OGSA技术．并且我们根据未来分布式系统的多种需求，探讨了中间件领域将面临的挑战。     

数据库中间件技术及在三层客户机／服务器模型中的实现

研究和分析了常用各种数据库中间件的工作原理以及各自的优缺点,在此基础上,提出并讨论了三层客户机／服务器环境下的一个具体应用实例。对其所采有的关键技术和设计思想进行了详细的分析。     

Intelligent service processing in common USN middleware

The Ubiquitous sensor network (USN) is composed of several heterogeneous sensors with a variety of characteristics. An application based on the sensor network also has various requirements to provide services to users. Therefore it is important to develop the common USN middleware for flexible integration between the sensor networks and applications. Especially, this paper focuses on intelligent service management which is one of the main functions of USN middleware. Several applications in the sensor network environment support not only monitoring services, but also sensor-based context-awareness and intelligent services. In many applications, however, approaches to support intelligent services depend on the application because the standard method has been undefined yet. Therefore this paper proposes a common method for processing intelligent services in USN middleware independent of an application. The proposed method is implemented and evaluated as a component of USN middleware.     

Arcademis: a framework for object‐oriented communication middleware development

This paper presents Arcademis, a Java‐based framework for communication middleware development. Arcademis consists of a set of abstract classes, interfaces and concrete components that define the general architecture of middleware systems. Its main objective is to support the implementation of non‐monolithic and easily configurable middleware platforms. Arcademis can be used by middleware developers to deploy systems that meet the requirements of a particular network or technology. Instances of Arcademis can also be customized by distributed systems engineers to meet the requirements of a particular application. For example, new transport protocols, connection management policies, authentication algorithms or invocation semantics can be easily configured in middleware platforms derived from Arcademis. In order to illustrate the use of the framework, the paper describes the RME system, a middleware derived from Arcademis that adds a remote method invocation service to the CLDC configuration of Java 2 Micro Edition (J2ME). Copyright © 2006 John Wiley & Sons, Ltd.     

A lightweight middleware framework for vehicle networking application

There is a growing need for Vehicle Networking Applications (VNAs) development that does not require users to learn the details of VNA data processing and message transfer. VNAs have some special requirements differing from other general‐purpose applications, such as real‐time performance, extensibility, compatibility, and reusability. To meet with these requirements of the VNAs, we propose a lightweight middleware framework for VNAs in this article. In the middle framework, we design multi‐layer middleware architecture to separate VNAs from the software platform and to improve the adaptability for the heterogeneous network and various vehicle networking communication protocols. Meanwhile, the middleware architecture consists of fixed and exchangeable modules to improve the middleware reusability. And the component bus is presented in a framework to standardize component interfaces to improve the extensibility of middleware. The framework has an efficient and simple structure to guarantee the real‐time performance of data processing and message transferring. This middleware also provides a uniform communication mechanism to be compatible with other existing middleware. In this article, we describe the design ideas and the composition of each module in the middleware framework, and analyze the data flow in communication process. We also develop the middleware prototypes to verify the feasibility of the middleware framework. Copyright © 2015 John Wiley & Sons, Ltd.