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1.
一种面向服务的异步消息中间件的设计   总被引:2,自引:0,他引:2  
赵革科  常炳国 《计算机应用》2009,29(8):2312-2314
采用开放式标准的面向服务架构SOA是有效解决大规模企业应用集成的重要技术,但是SOA对异步传输和可靠为特征的复杂网络应用支持不足。传统消息中间件MOM虽具有松耦合和异步传输特性,但大多适用于企业内部集成,且其扩展性和灵活性不足,难以拓展到大规模网络环境。在全面吸收SOA和MOM的技术优点基础上,设计了一种面向服务的异步消息中间件体系结构,并研究了消息传输算法,服务重组和安全服务等关键技术。结合移动电子商务应用集成,验证了面向服务的异步消息中间件的扩展性、灵活性和有效性。  相似文献   

2.
The complexity of developing and deploying context-aware pervasive-computing applications calls for distributed software infrastructures that assist applications to collect, aggregate, and disseminate contextual data. In this paper, we motivate a data-centric design for such an infrastructure to support context-aware applications. Our middleware system, Solar, treats contextual data sources as stream publishers. The core of Solar is a scalable and self-organizing peer-to-peer overlay to support data-driven services. We describe how different services can be systematically integrated on top of the Solar overlay and evaluate the resource discovery and data-dissemination services. We also discuss our experience and lessons learned when using Solar to support several implemented scenarios. We conclude that a data-centric infrastructure is necessary to facilitate both the development and deployment of context-aware pervasive-computing applications.  相似文献   

3.
Reconfigurable context-sensitive middleware for pervasive computing   总被引:7,自引:0,他引:7  
Context-sensitive applications need data from sensors, devices, and user actions, and might need ad hoc communication support to dynamically discover new devices and engage in spontaneous information exchange. Reconfigurable Context-Sensitive Middleware facilitates the development and runtime operations of context-sensitive pervasive computing software.  相似文献   

4.
Mobile computing requires an advanced infrastructure that integrates suitable support protocols, mechanisms, and tools. This mobility middleware should dynamically reallocate and trace mobile users and terminals and permit communication and coordination of mobile entities. In addition, open and untrusted environments must overcome system heterogeneity and grant the appropriate security level. Solutions to these issues require compliance with standards to interoperate with different systems and legacy components and a reliable security infrastructure based on standard cryptographic mechanisms and tools. Many proposals suggest using mobile agent technology middleware to address these issues. A mobile agent moves entities in execution together with code and achieved state, making it possible to upgrade distributed computing environments without suspending service. We propose three mobile computing services: user virtual environment (UVE), mobile virtual terminal (MVT), and virtual resource management (VRM). UVE provides users with a uniform view of their working environments independent of current locations and specific terminals. MVT extends traditional terminal mobility by preserving the terminal execution state for restoration at new locations, including active processes and subscribed services. VRM permits mobile users and terminals to maintain access to resources and services by automatically requalifying the bindings and moving specific resources or services to permit load balancing and replication  相似文献   

5.
CONFIIT (Computation Over Network with Finite number of Independent and Irregular Tasks) is a purely decentralized peer-to-peer middleware for grid computing. This paper presents CONFIIT main features and how it deals with topology changes and communication faults. To illustrate CONFIIT operation, we demonstrate how the car-sequencing problem can be solved in a distributed environment.  相似文献   

6.
李会斌  张武  李睿阳 《计算机工程与设计》2007,28(5):1075-1077,1095
随着网格计算技术的发展和Web Services技术的出现,使得整合各种计算资源解决具有重大挑战性的科学和工程计算问题成为可能.在对已有的应用于高性能计算的网格计算系统Netsolve进行研究的基础上,结合Web Services技术提出了一种用于高性能计算的网格系统,并且在初步实现的基础上,探讨了系统的优缺点.  相似文献   

7.
In this paper, we describe two distributed, data intensive applications that were demonstrated at iGrid 2005 (iGrid Demonstration US109 and iGrid Demonstration US121). One involves transporting astronomical data from the Sloan Digital Sky Survey (SDSS) and the other involves computing histograms from multiple high-volume data streams. Both rely on newly developed data transport and data mining middleware. Specifically, we describe a new version of the UDT network protocol called Composible-UDT, a file transfer utility based upon UDT called UDT-Gateway, and an application for building histograms on high-volume data flows called BESH (for Best Effort Streaming Histogram). For both demonstrations, we include a summary of the experimental studies performed at iGrid 2005.  相似文献   

8.
The Journal of Supercomputing - Bioinformatics allows and encourages the application of many different parallel computing approaches. This special issue brings together high-quality...  相似文献   

9.
Publish-subscribe for high-performance computing   总被引:1,自引:0,他引:1  
High-performance computing could significantly benefit from publish-subscribe communication, but current systems don't deliver the kind of performance required by applications in that domain. In response, the authors developed Echo, a high-performance event-delivery middleware designed to scale to the data rates typically found in grid environments. This article provides an overview of Echo, the infrastructure on which it's built, and the techniques used to implement it.  相似文献   

10.
PvcwCORBA:普适计算环境中间件的实现   总被引:1,自引:0,他引:1  
张向刚  刘锦德 《计算机应用》2004,24(8):10-13,17
针对普适环境的平台的多样性、资源的有限性、设备的移动性和应用高性能要求等需求,提出了其中间件的设计和实现方法,并据此构建了pvcwCORBA。通过试验验证了pvcwCORBA作为支持无线接入功能的高性能、嵌入式CORBA,能够适应普适计算环境的要求。  相似文献   

11.
PICO: a middleware framework for pervasive computing   总被引:2,自引:0,他引:2  
The pervasive information community organization is a framework for creating mission-oriented dynamic communities of autonomous software entities that perform tasks for users and devices. PICO's telemedicine example scenario demonstrates its potential as a simple, unique, and versatile middleware framework for pervasive computing.  相似文献   

12.
定义了存贮服务的基本操作模型,然后介绍了一个在校园网上提供文件存贮服务的系统设计与实现。该系统具有如下特点:①多服务器联合,多台经过增强改造的FTP服务器形成一个对用户透明的整体;②FTP服务器之间按照一定的规则自动进行备份和复制,从而提高了系统的可靠性和在故障情况下的可用性;③FTP服务器之间的协调通信由消息中间件完成,使得系统实现简捷、运行可靠;④通过对特定DNS服务器的改造,系统能够自动为用户选择一个当时性能较好的FTP服务器连接,从而不仅提高了性能,还由于负载的分散,提高了系统在非故障情况下的可用性。  相似文献   

13.
The proliferation of mobile devices coupled with Internet access is generating a tremendous amount of highly personal and sensitive data. Applications such as location-based services and quantified self harness such data to bring meaningful context to users’ behavior. As social applications are becoming prevalent, there is a trend for users to share their mobile data. The nature of online social networking poses new challenges for controlling access to private data, as compared to traditional enterprise systems. First, the user may have a large number of friends, each associated with a unique access policy. Second, the access control policies must be dynamic and fine-grained, i.e. they are content-based, as opposed to all-or-nothing. In this paper, we investigate the challenges in sharing of mobile data in social applications. We design and evaluate a middleware running on Google App Engine, named Mosco, that manages and facilitates sharing of mobile data in a privacy-preserving manner. We use Mosco to develop a location sharing and a health monitoring application. Mosco helps shorten the development process. Finally, we perform benchmarking experiments with Mosco, the results of which indicate small overhead and high scalability.  相似文献   

14.
Traditionally, middleware technologies, such as CORBA, Java RMI, and Microsoft's DCOM, have provided a set of distributed computing services that essentially abstract the underlying network services to a monolithic "black box." In a mobile operating environment, the fundamental assumption of middleware abstracting a unified distributed service for all types of applications operating over a static network infrastructure is no longer valid. In particular, mobile applications are not able to leverage the benefits of adaptive computing to optimize its computation based on current contextual situations. In this paper, we introduce the Mobile Platform for Actively Deployable Service (MobiPADS) system. MobiPADS is designed to support context-aware processing by providing an executing platform to enable active service deployment and reconfiguration of the service composition in response to environments of varying contexts. Unlike most mobile middleware, MobiPADS supports dynamic adaptation at both the middleware and application layers to provide flexible configuration of resources to optimize the operations of mobile applications. Within the MobiPADS system, services (known as mobilets) are configured as chained service objects to provide augmented services to the underlying mobile applications so as to alleviate the adverse conditions of a wireless environment.  相似文献   

15.
Python became the preferred language for teaching in academia, and it is one of the most popular programming languages for scientific computing. This wide popularity occurs despite the weak performance of the language. This weakness is the motivation that drives the efforts devoted by the Python community to improve the performance of the language. In this article, we are following these efforts while we focus on one specific promised solution that aims to provide high-performance and performance portability for Python applications.  相似文献   

16.
With the advent of cloud computing, employing various cloud services to build highly reliable cloud applications has become increasingly popular. The trustworthiness of cloud services is a critical issue that hinders the development of cloud applications, and thus is an urgently-required research problem. Previous studies evaluate trustworthiness of services via either QoS monitoring mechanisms or user feedback ratings, while seldom they combine both of them for enhancing service trust evaluation. This paper proposes a trustworthy selection framework for cloud service selection, named TRUSS. Aiming at developing an effective trust evaluation middleware for TRUSS, we propose an integrated trust evaluation method via combining objective trust assessment and subjective trust assessment. The objective trust assessment is based on QoS monitoring, while the subjective trust assessment is based on user feedback ratings. Experiments conducted using a synthesized dataset show that our proposed method significantly outperforms the other trust and reputation methods.  相似文献   

17.
SimSET is Monte Carlo simulation software for emission tomography. This paper describes a simple but effective scheme for parallel execution of SimSET using NetSolve, a client-server system for distributed computation. NetSolve (version 1.4.1) is "grid middleware" which enables a user (the client) to run specific computations remotely and simultaneously on a grid of networked computers (the servers). Since the servers do not have to be identical machines, computation may take place in a heterogeneous environment. To take advantage of diversity in machines and their workloads, a client-side scheduler was implemented for the Monte Carlo simulation. The scheduler partitions the total decay events by taking into account the inherent compute-speeds and recent average workloads, i.e., the scheduler assigns more decay events to processors expected to give faster service and fewer decay events to those expected to give slower service. When compute-speeds and sustained workloads are taken into account, the speed-up is essentially linear in the number of equivalent "maximum-service" processors. One modification in the SimSET code (version 2.6.2.3) was made to ensure that the total number of decay events specified by the user is maintained in the distributed simulation. No other modifications in the standard SimSET code were made. Each processor runs complete SimSET code for its assignment of decay events, independently of others running simultaneously. Empirical results are reported for simulation of a clinical-quality lung perfusion study.  相似文献   

18.
移动云计算     
在延伸云到网络边缘(终端)的趋势下,移动云计算正在成为一个新兴的云服务模型。它包括许多与用户密切相关移动设备。它们直接参与到很多云的工作中,使得云边界直接延伸到了整个物理网络系统中。在这篇文章中,我们将介绍什么是移动云计算,包括其范围,目前的发展和研究的挑战。  相似文献   

19.
From cloud computing to cloud manufacturing   总被引:17,自引:0,他引:17  
Cloud computing is changing the way industries and enterprises do their businesses in that dynamically scalable and virtualized resources are provided as a service over the Internet. This model creates a brand new opportunity for enterprises. In this paper, some of the essential features of cloud computing are briefly discussed with regard to the end-users, enterprises that use the cloud as a platform, and cloud providers themselves. Cloud computing is emerging as one of the major enablers for the manufacturing industry; it can transform the traditional manufacturing business model, help it to align product innovation with business strategy, and create intelligent factory networks that encourage effective collaboration. Two types of cloud computing adoptions in the manufacturing sector have been suggested, manufacturing with direct adoption of cloud computing technologies and cloud manufacturing—the manufacturing version of cloud computing. Cloud computing has been in some of key areas of manufacturing such as IT, pay-as-you-go business models, production scaling up and down per demand, and flexibility in deploying and customizing solutions. In cloud manufacturing, distributed resources are encapsulated into cloud services and managed in a centralized way. Clients can use cloud services according to their requirements. Cloud users can request services ranging from product design, manufacturing, testing, management, and all other stages of a product life cycle.  相似文献   

20.
针对云计算[1]领域中基础设施服务在运行和管理中存在的安全问题,在传统访问控制模型的基础上综合考虑了云计算基础设施服务[2]的特点,设计了一套访问控制模型。分析了云计算中安全问题的特点及现有方案的不足之处,提出基础设施服务的安全是云计算安全的基础。根据四条设计原则在RBAC模型[3]和TE模型[4]的基础上加以改进形成了适用于云计算基础设施服务的CIRBAC模型和CITE模型,对模型中的各个模块进行了详细的设计。在基于Xen[5-6]虚拟化技术[7]的OpenStack[8]云计算环境中实现了这些访问控制模型。该模型很好地增强了云计算基础设施服务的安全性。  相似文献   

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