ECA rule learning in dynamic environments

Through the development of management and intelligent control systems, we can make useful decision by using incoming data. These systems are used commonly in dynamic environments that some of which are been rule-based architectures. Event–Condition–Action (ECA) rule is one of the types that are used in dynamic environments. ECA rules have been designed for the systems that need automatic response to certain conditions or events. Changes of environmental conditions during the time are important factors impacting a reduction of the effectiveness of these rules which are implied by changing users demands of the systems that vary over time. Also, the rate of the changes in the rules are not known which means we are faced with the lack of information about rate of occurrence of new unknown conditions as a result of dynamics environments. Therefore, an intelligent rule learning is required for ECA rules to maintain the efficiency of the system. To the best knowledge of the authors, ECA rule learning has not been investigated. An intelligent rule learning for ECA rules are studied in this paper and a method is presented by using a combination of multi flexible fuzzy tree (MFlexDT) algorithm and neural network. Hence data loss could be avoided by considering the uncertainty aspect. Owing to runtime, speed, and also stream data in dynamic environments, a hierarchical learning model is proposed. We evaluate the performance of the proposed method for resource management in the Grid and e-commerce as case studies by modeling and simulating. A case study is presented to show the applicability of the proposed method.     

Active Robust Resource Management in Cluster Computing Using Policies

We present an implementation of a policy-based management architecture for emerging communications and computing paradigms such as Active Networks and the Grid. To manage such open, highly distributed and decentralized environments, an approach based on policy concepts is adopted, allowing support for active, dynamic adaptability in network elements, services and end-user applications, as well as achieving decentralization and distribution. We present our flexible, extensible policy and event specifications in XML, and describe our management architecture. One key feature of our approach is the distributed infrastructure: the Directory and the Management Information Distribution system. The second feature is the Resource and Security Management elements residing on the multi-node managed systems. These combine to provide a light-weight, self-organizing management architecture. As an applications example, we describe the implementation of our management system applied to the Application Level Active Networking (ALAN) environment, implemented in the European Commission Information Society Technologies (IST) project ANDROID.     

信息系统中业务规则与约束的时态化研究

在OCL和ECA规则的基础上，通过对业务对象与ECA规则的时态化关系的分析，提出了业务规则与约束的一种时态化扩展建模方法，该方法引入了时态化算子和时间区间等概念来实现对时态化对象和属性的历史信息的引用和时态化建模。     

An agent-based approach for dynamic adjustment of scheduled jobs in computational grids

Grid computing is a newly developed technology for complex systems with large-scale resource sharing, wide-area communication, and multi-institutional collaboration. Grid scheduling is an important infrastructure in the grid computing environment. Most of the existing grids scheduling methods focus on maximizing processor utilization without taking grid load into consideration. This may lead to significant inefficiencies in performance such as large job queues and processing delays. In this paper, we propose a multiagent-based scheduling system for computational grids with a new approach. Agent technology is suitable for a computational grid because of the dynamic, heterogeneous, and autonomous nature of the grid. The main idea of the proposed system is a combination of a static scheduling using a fixed scheduling algorithm and a dynamic adjustment through the autonomous behavior of agents. The superiority of the proposed system, in reducing the load of the grid and minimizing the response time for executing user applications, is demonstrated by simulation experiments.     

异构数据库同步系统的研究与实现

采用“事件－条件－动作”的数据驱动机制实现数据库变更事件的实时获取，通过多个通讯代理协同工作完成异构数据库间的数据一致性维护。     

An Information Service for Grid Virtual Organization: Architecture, Implementation and Evaluation

Information Service is the heart of the entire Grid software infrastructure. It maintains various information in a Grid environment, and provides this information to users on request. We present an Information Service architecture for information capturing, aggregation, and provisioning in a Grid Virtual Organization (VO). This Information Service is a hierarchical structure which consists of VO layer, site layer and resource layer. The architecture defines downloadable and pluggable information sensors for portability and flexibility of information capturing. The meta-data mechanism is incorporated into our Information Service for information organization and management. Experiments were conducted to evaluate the performance of the Information Service, and the results show that the Information Service presents satisfactory scalability with number of users and number of information amount. Our Information Service has been implemented based on the Globus Toolkit as a Grid service compliant to the Open Grid Services Architecture (OGSA) specifications.     

基于XML的分布式异构数据库数据同步系统的研究

采用“事件-条件-动作”的数据驱动机制,利用DBMS的触发器和存储过程实现数据库变更事件的实时获取和XML数据打包,通过多个通讯代理协同工作完成异构数据库间的数据同步传输。     

网格环境中资源发现机制的研究

随着高性能应用需求的迅猛发展,单台高性能计算机已经不能胜任一些超大规模应用问题的解决。这就需要将地理上分布、系统异构的多种计算资源通过高速网络连接起来,共同解决大型应用问题,从而产生了网格（Grid）。但是在网格这种共享资源的集合中,由于资源共享的广泛性,资源的异构性等等都使得资源发现更具有挑战性。目前存在的一些分布式环境中的资源发现大多是基于集中获分布的,由于集中式资源发现不能很好地满足系统的扩充,而分布式资源发现又会产生大量的网络通讯,因此这两种机制将不可避免地结合在一起,即形成分层式资源发现机制。     

基于Agent的网格互连结构

目前有许多论坛、试验环境和研究项目都在进行网格技术的研究，但这些研究都自成体系，采用的技术各不相同，这些网格系统不能互连、互通、互操作．为了解决这一问题，本文提出基于Agent的网格互连结构，把Agent技术和网格技术结合起采，对网格互连的安全机制和资源管理机制进行了研究，并给出了网格互连结构的设计．在本文提出的结构解决了Inter—Domain网格安全机制不同的问题、Inter—Domain网格资源共享的问题，可实现Inter—Domain网格单点登录（Single—Sign—On）和代表（Delegation），具有通用、简单、高效、分布式等优点．     

分布式资源共享的网格信息服务

网格技术使得广泛的大规模的资源共享成为可能。在如此分布、多样、动态的网格环境中,信息服务成为任何网格软件框架的重要部分,它为发现和监控提供了最根本的机制,也因此为系统规划应用行为奠定了基础。介绍的信息服务系统结构,明确了底层查询和注册协议以及优化方法,从而简了化单个实体纳入（包括支持不同查询语言和发现策略的集合索引）信息结构的过程。     

Implementing ECA rules in an active database

Traditional database systems are designed to manage large volumes of data, but rule support is generally not a strong feature. On the other hand, expert systems have the deductive capability to manage rule processing. A coupling between these two systems to support advanced database applications results in what is termed an active database. An approach to implementing active database systems is to represent knowledge as Event–Condition–Action (ECA) rules. ECA rules determine when and how to react to different kinds of events. This paper focuses on the different type of events supported by an active database CLOSE. A set of primitive and composite events is presented together with examples of their application. Event detection in this system is also discussed.     

用P2P技术改进网格信息服务

本文根据网格资源信息的特点阐述了由高度分布式的信息提供者和集合目录组成的网格信息服务基本框架。并分析了它的基础LDAP（Lightweight Directory Access Protocol）协议，指出LDAP目录本质是一种分布式的数据库。由于网格信息系统中LDAP目录信息树的动态刷新与复制的频繁发生，我们已提出用环形扩展和线形扩展策略来大幅度提高系统效率；在此基础上，本文进一步提出了文件分块复制法的思想把LDAP数据库文件分成若干块，在多个LDAP服务器端点间并行复制，最后实践证明，它大幅度提高了以LDAP目录分布式数据库为基础与核心的网格信息服务系统的并行效率。     

VEGA Infrastructure for Resource Discovery in Grids

Grids enable users to share and access large collections and various types of re-sources in wide areas, and how to locate resources in such dynamic, heterogeneous and autonomousdistributed environments is a key and challenging issue. In this paper, a three-level decentralizedand dynamic VEGA Infrastructure for Resource Discovery (VIRD) is proposed. In this architec-ture, every Border Grid Resource Name Server (BGRNS) or Grid Resource Name Server (GRNS)has its own local policies, governing information organization, management and searching. Changesin resource information are propagated dynamically among GRNS servers according to a link-state-like algorithm. A client can query its designated GRNS either recursively or iteratively. Optimizing techniques, such as shortcut, are adopted to make the dynamic framework more flexible and effi-cient. A simulator called SimVIRD is developed to verify the proposed architecture and algorithm.q.Experiment results indicate that this architecture could deliver good scalability and performance for grid resource discovery.     

基于情景分析的ECA规则提取方法研究

事件条件动作(ECA)规则的提取方法难以规范化,导致其生成过程过于复杂。为此,提出一种基于情景分析的ECA规则提取方法。定义ECA规则中事件、条件和动作的模板规范以及ECA规则的语法结构,采用情景分析法进行研究分析,并做一致性检测。实例分析结果表明,该方法能规范ECA规则的提取过程,保证ECA规则的准确性。     

Grid平台上的NGS编译技术

随着网络技术的发展,在异构平台上使用共同的计算和信息资源将很快成为可能。Grid(网格)就是这样一种提供资源共享的新兴平台,而在其之上的下一代软件程序(NGS)则对编译器提出了新的挑战犤1犦。未来Grid平台上的编译系统将是能够进行动态编译和优化,根据实时系统以及网络的性能不断进行自我调整的软件模型,同时它还能为具有自适应性的应用程序提供编译支持。     

SIG中的资源监控系统

空间信息网格（SIG）是一个广域分布的信息基础设施,发现与共享闲置资源是其主要功能之一。为了实现这一目标,必须实现资源监控系统来聚集和分发资源的状态信息。介绍了在SIG中实现的资源监控系统——SIGRMS。该系统遵循GMA架构,实现了局部监控服务（LMS）和全局监控服务（GMS）。系统采用模块化设计,具有灵活的可配置性,可扩展性和高可用性。详细介绍了SIGRMS模块化的体系结构、灵活可扩展的信息模板和推拉式的通信方式,并描述了它的实现,最后总结了SIGRMS的特点。     

基于经济模型的资源代理

网格计算是为解决大规模资源密集型问题而提出的新一代计算平台,是当前并行和分布处理技术的一个发展方向,而资源管理是计算网格的关键技术之一。对各种各样可利用资源的整合和管理是网格应用的基础,而资源的分布性、动态性、异构性、自治性和需要协调一致性使得网格资源的管理调度成为一个棘手的问题。目前基于市场的经济资源管理和调度算法非常适合计算网格中的资源管理问题,但有调度价格不能更改、负载平衡等问题。文中提出了“网格环境下基于经济模型的资源代理”,依靠多维QoS指导的调度策略和经济模型的启发式调节资源价格,改进和优化计算网格资源的分配。