Economics‐inspired decentralized control approach for adaptive grid services and applications

Grid technologies facilitate innovative applications among dynamic virtual organizations, while the ability to deploy, manage, and properly remain functioning via traditional approaches has been exceeded by the complexity of the next generation of grid systems. An important method for addressing this challenge may require nature‐inspired computing paradigms. This technique will entail construction of a bottom‐up multiagent system; however, the appropriate implementation mechanism is under consideration in order for the autonomous and distributed agents to emerge as a controlled grid service or application. A credit card management service in economic interactions is considered in this article for a decentralized control approach. This consideration is based on a preliminarily developed ecological network‐based grid middleware that has features desired for the next generation grid systems. The control scheme, design, and implementation of the credit card management service are presented in detail. The simulation results show that (1) agents are accountable for their activities such as behavior invocation, service provision, and resource utilization and (2) generated services or applications adapt well to dynamically changing environments such as agent amounts as well as partial failure of agents. The approach presented herein is beneficial for building autonomous and adaptive grid applications and services. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 1269–1288, 2006.     

CONNECTING MIGRATION METHOD IN A MOBILE AGENT SYSTEM

Connecting migration in mobile agent systems is to support continuous and transparent communication operations between mobile agents. This article presents the design and implementation of a reliable connecting migration mechanism that provides exactly one delivery for all transmitted data during agent migration. We implemented this mechanism and named it AgentSocket in a VPNAgent system used in the VPN security mechanism. It is a pure middleware implementation, without requiring modification of Java virtual machines.     

Revisiting the Anatomy and Physiology of the Grid

A domain-specific software architecture (DSSA) represents an effective, generalized, reusable solution to constructing software systems within a given application domain. In this paper, we revisit the widely cited DSSA for the domain of grid computing. We have studied systems in this domain over the last ten years. During this time, we have repeatedly observed that, while individual grid systems are widely used and deemed successful, the grid DSSA is actually underspecified to the point where providing a precise answer regarding what makes a software system a grid system is nearly impossible. Moreover, every one of the existing purported grid technologies actually violates the published grid DSSA. In response to this, based on an analysis of the source code, documentation, and usage of eighteen of the most pervasive grid technologies, we have significantly refined the original grid DSSA. We demonstrate that this DSSA much more closely matches the grid technologies studied. Our refinements allow us to more definitively identify a software system as a grid technology, and distinguish it from software libraries, middleware, and frameworks.     

基于移动Agent的战术Ad hoc网络通信中间件设计

提出了一个基于移动Agent的战术Adhoe网络通信中间件,用于战场资源分配和信息传输.将OLSR路由协议整合到中间件系统以支持战术Adhoc网络的快速高效寻址.设计了移动Agent在资源协调分配和网络连接中的迁移和工作机制.该中间件能够在战术Ad hoc网络拓扑结构动态变化的情况下,有效地解决通信失效和资源分配最优化问题.     

A grid computing based approach for the power system dynamic security assessment

This paper addresses the problem of parallel dynamic security assessment applications from static homogeneous cluster environment to dynamic heterogeneous grid environment. Functional parallelism and data parallelism are supported by each of the message passing interface model and TCP/IP model. To consider the differences in heterogeneous computing resources and complexity of large-scale power system communities, a kernel-based multilevel algorithm is proposed for network partitioning. Since the bottleneck in distributed computation is low speed network communication, a bi-level latency exploitation technique is introduced for numerically solving system differential equations. The proposed grid-based implementation includes the core simulation engine, grid computing middleware, a Python interface and Python front-end utilities. Tests for a 39-bus network, a 4000-bus network and a 10,000-bus network are reported, and the results of these experiments demonstrate that the proposed scheme is able to execute the distributed simulations on computational grid infrastructure and provide efficient parallelism.     

Middleware infrastructure for parallel and distributed programming models in heterogeneous systems

We introduce a middleware infrastructure that provides software services for developing and deploying high-performance parallel programming models and distributed applications on clusters and networked heterogeneous systems. This middleware infrastructure utilizes distributed agents residing on the participating machines and communicating with one another to perform the required functions. An intensive study of the parallel programming models in Java has helped identify the common requirements for a runtime support environment, which we used to define the middleware functionality. A Java-based prototype, based on this architecture, has been developed along with a Java object-passing interface (JOPI) class library. Since this system is written completely in Java, it is portable and allows executing programs in parallel across multiple heterogeneous platforms. With the middleware infrastructure, users need not deal with the mechanisms of deploying and loading user classes on the heterogeneous system. Moreover, details of scheduling, controlling, monitoring, and executing user jobs are hidden, while the management of system resources is made transparent to the user. Such uniform services are essential for facilitating the development and deployment of scalable high-performance Java applications on clusters and heterogeneous systems. An initial deployment of a parallel Java programming model over a heterogeneous, distributed system shows good performance results. In addition, a framework for the agents' startup mechanism and organization is introduced to provide scalable deployment and communication among the agents.     

The role of communication systems in smart grids: Architectures,technical solutions and research challenges

The purpose of this survey is to present a critical overview of smart grid concepts, with a special focus on the role that communication, networking and middleware technologies will have in the transformation of existing electric power systems into smart grids. First of all we elaborate on the key technological, economical and societal drivers for the development of smart grids. By adopting a data-centric perspective we present a conceptual model of communication systems for smart grids, and we identify functional components, technologies, network topologies and communication services that are needed to support smart grid communications. Then, we introduce the fundamental research challenges in this field including communication reliability and timeliness, QoS support, data management services, and autonomic behaviors. Finally, we discuss the main solutions proposed in the literature for each of them, and we identify possible future research directions.     

基于NESSUS的NTP协议的通信中间件研究

随着分布式系统技术的快速发展,三层架构的分布式系统是未来发展的主要方向,通信中间件是三层架构的分布式系统不可或缺的一层。通信中间件能扩大分布式系统的规模、支持更多的用户与服务器连接、简化用户与服务器的通信过程、保证客户机与服务器的通信过程更安全和实现跨平台使用。虽然目前存在有比较成熟的ACE和ICE通信中间件等,但是也存在一个问题--开发三层架构分布式系统的设计人员必须了解其繁多的功能和复杂的操作,然而有时候很多功能是不需要的。所以设计一款小型化、高效化的通信中间件对于开发者来说变得尤为重要。国际上一种比较流行的网络漏洞扫描系统NESSUS是一种基于C/S和B/S结构的分布式系统,其客户机和服务器之间的通信是建立在NTP（Nessus Transfer Protocol）传输协议之上的。文章重点研究NESSUS客户机和服务器之间是如何交互通信的,把通信模块封装并提供中间件接口,同时引入消息发送/接收队列缓冲池技术和SSL组件,提出一套小型的、高效的、安全的、跨平台的通信中间件,它也适用于其他客户机/服务器的三层架构的分布式系统。     

Middleware services for P2P computing in wireless grid networks

Advances in network architecture are changing application and service delivery. The wireless industry, for example, now talks of service grids - collections of separate wireless services collated from across the network. However, with current limitations in mobile device capabilities, a scalable and efficient middleware platform is essential. The authors' new middleware architecture, called scalable inter-grid network adaptation layers (signal), integrates mobile devices with existing grid platforms to conduct peer-to-peer operations through proxy-based systems. Combining mobile P2P applications with grid technologies could ultimately give mobile devices the power of supercomputers.     

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.     

Resource conscious development of middleware for control environments: a case of CORBA-based middleware for the CAN bus systems

While it is imperative to exploit middleware technologies in developing software for distributed embedded control systems, it is also necessary to tailor them to meet the stringent resource constraints and performance requirements of embedded control systems. In this paper, we propose a CORBA-based middleware for Controller Area Network (CAN) bus systems. Our design goals are to reduce the memory footprint and remote method invocation overhead of the middleware and make it support group communication that is often needed in embedded control systems. To achieve these, we develop a transport protocol on the CAN and a group communication scheme based on the publisher/subscriber model by realizing subject-based addressing that utilizes the message filtering mechanism of the CAN. We also customize the method invocation and message passing protocol of CORBA so that CORBA method invocations are efficiently serviced on a low-bandwidth network such as the CAN. This customization includes packed data encoding and variable-length integer encoding for compact representation of IDL data types.We have implemented our CORBA-based middleware using GNU ORBit. We report on the memory footprint and method invocation latency of our implementation.     

利用MOM实现移动代理基础通信机制的研究

移动代理之间的基础通信机制是该领域中的一个关键问题，但在当前的各种移动代理产品中，代理之间的基础通信机制存在两个问题：一是代理本身承担了通信过程中的所有任务，使得代理的开发和维护变得复杂；二是对异步通信的支持不够灵活．本文采用了中间件的思想，将通信的发起和处理进行了分离，开发了一个面向消息的中间什，解决了上述问题，具有很高的应用价值和一定的理论价值．     

基于代理的网格计算中间件

WADE系统是基于代理技术实现的一个可屏蔽异构和分布性的动态自适应的校园计算网格，提出了基于代理技术在校园网络内实现并行计算的方法，详细论述了基于代理的网格计算中间件的体系结构和主要模块功能，阐述了利用代理实现异构编译、协同计算的过程，给出了代理的Java实现方法，利用软件代理实现网格计算中间件，可以解决异构计算平台下多种并行编程环境的协同计算问题，为用户提供统一的服务接口，这将大大增强系统的可用性。     

A grid middleware for distributed Java computing with MPI binding and process migration supports

“Grid” computing has emerged as an important new research field. With years of efforts, grid researchers have successfully developed grid technologies including security solutions,resource management protocols, information query protocols, and data management services. How-ever, as the ultimate goal of grid computing is to design an infrastructure which supports dynarnic,cross-organizational resource sharing, there is a need of solutions for efficient and transparent task re-scheduling in the grid. In this research, a new grid middleware is proposed, called G-JavaMPI. This middleware adds the parallel computing capability of Java to the grid with the support of a Grid-enabled message passing interface (MPI) for inter-process communication between Java processes executed at dif-ferent grid points. A special feature of the proposed G-JavaMPI is the support of Java process migration with post-migration message redirection. With these supports, it is possible to migrate executing Java process from site to site for continuous computation, if some site is scheduled to be turned down for system reconfiguration. Moreover, the proposed G-JavaMPI middleware is very portable since it requires no modification of underlying OS, Java virtual machine, and MPI package. Preliminary performance tests have been conducted. The proposed mechanisms have shown good migration efficiency in a simulated grid environment.     

一种发布订阅中间件的设计

设计一种基于主题发布订阅机制的中间件。发布/订阅机制能够提供一对多和多对多的异步通信模式,能使通信的各个参与者在时间和空间上完全解耦,能很好地满足大规模分布式系统松耦合通信的需求。对该中间件的网络数据传输延迟作测试。     

分层网络结构在虚拟试验环境中的应用研究

针对虚拟试验分层系统中对可靠性的不同要求,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;结合某飞行器系统的分布式仿真试验,给出了分层网络的设计方案,对两种中间件及网关的实时传递性能进行了测试,满足了应用中不同实时性的要求。     

A hybrid real-time agent platform for fault-tolerant,embedded applications

This paper describes an agent platform based on the Foundation for Intelligent Physical Systems Abstract Architecture, which, together with a highly fault tolerant, bio-inspired hardware architecture, aims to increase the reliability of future, low-cost satellites. To achieve the stringent operational requirements imposed by the real-time and resource-constrained environment of a satellite, the Hybrid Agent Real-Time Platform (HARP) distinguishes itself from other platforms in three areas. Firstly, the HARP middleware uses discrete processors, instead of virtual machines or interpreters, as its agent execution environment. This has the advantage of reducing the agency memory footprint and enabling agents to perform real-time tasks. Secondly, the HARP communication stack makes use of ISO-TP over CAN 2.0A as its transfer level protocol, cutting out resource-intensive layers such as HTTP and IIOP. In addition, the communication stack allows real-time CAN traffic to share the network and be given priority over Agent Communication Language messages. Finally, the HARP middleware embeds a peer-to-peer task manager in each agency, allowing systems which are built using the bio-inspired Artificial Stem Cell Architecture and HARP middleware to autonomously reconfigure in the event of failures. The detailed design of the HARP middleware is given, together with details of an implementation of the HARP middleware on a set of prototype satellite hardware. The performance and scaling potential of the middleware, determined through a set of physical experiments, provide evidence of the practical feasibility of the proposed architecture.     

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。     

Distributed Shared Arrays: An Integration of Message Passing and Multithreading on SMP Clusters

This paper presents a Distributed Shared Array runtime system to support Java-compliant multithreaded programming on clusters of symmetric multiprocessors (SMPs). As a hybrid of message passing and shared address space programming models, the DSA programming model allows programmers to explicitly control data distribution so as to take advantage of the deep memory hierarchy, while relieving them from error-prone orchestration of communication and synchronization at run-time. The DSA system is developed as an integral component of mobility support middleware for grid computing so that DSA-based virtual machines can be reconfigured to adapt to the varying resource supplies or demand over the course of a computation. The DSA runtime system also features a directory-based cache coherence protocol in support of replication of user-defined sharing granularity and a communication proxy mechanism for reducing network contention. We demonstrate the programmability of the model in a number of parallel applications and evaluate its performance on a cluster of SMP servers, in particular, the impact of the coherence granularity.