1,048 research outputs found
Forum Session at the First International Conference on Service Oriented Computing (ICSOC03)
The First International Conference on Service Oriented Computing (ICSOC) was held in Trento, December 15-18, 2003. The focus of the conference ---Service Oriented Computing (SOC)--- is the new emerging paradigm for distributed computing and e-business processing that has evolved from object-oriented and component computing to enable building agile networks of collaborating business applications distributed within and across organizational boundaries. Of the 181 papers submitted to the ICSOC conference, 10 were selected for the forum session which took place on December the 16th, 2003. The papers were chosen based on their technical quality, originality, relevance to SOC and for their nature of being best suited for a poster presentation or a demonstration. This technical report contains the 10 papers presented during the forum session at the ICSOC conference. In particular, the last two papers in the report ere submitted as industrial papers
Improving the Scalability of DPWS-Based Networked Infrastructures
The Devices Profile for Web Services (DPWS) specification enables seamless
discovery, configuration, and interoperability of networked devices in various
settings, ranging from home automation and multimedia to manufacturing
equipment and data centers. Unfortunately, the sheer simplicity of event
notification mechanisms that makes it fit for resource-constrained devices,
makes it hard to scale to large infrastructures with more stringent
dependability requirements, ironically, where self-configuration would be most
useful. In this report, we address this challenge with a proposal to integrate
gossip-based dissemination in DPWS, thus maintaining compatibility with
original assumptions of the specification, and avoiding a centralized
configuration server or custom black-box middleware components. In detail, we
show how our approach provides an evolutionary and non-intrusive solution to
the scalability limitations of DPWS and experimentally evaluate it with an
implementation based on the the Web Services for Devices (WS4D) Java Multi
Edition DPWS Stack (JMEDS).Comment: 28 pages, Technical Repor
Service-oriented architecture for device lifecycle support in industrial automation
Dissertação para obtenção do Grau de Doutor em
Engenharia Electrotécnica e de Computadores
Especialidade: Robótica e Manufactura IntegradaThis thesis addresses the device lifecycle support thematic in the scope of service oriented industrial automation domain. This domain is known for its plethora of heterogeneous equipment encompassing distinct functions, form factors, network interfaces, or I/O specifications supported by dissimilar software and hardware platforms. There is then an evident and crescent need to take every device into account and improve the agility performance during setup, control, management, monitoring and diagnosis phases.
Service-oriented Architecture (SOA) paradigm is currently a widely endorsed approach
for both business and enterprise systems integration. SOA concepts and technology
are continuously spreading along the layers of the enterprise organization envisioning
a unified interoperability solution. SOA promotes discoverability, loose coupling,
abstraction, autonomy and composition of services relying on open web standards – features that can provide an important contribution to the industrial automation domain.
The present work seized industrial automation device level requirements, constraints and needs to determine how and where can SOA be employed to solve some of the existent difficulties. Supported by these outcomes, a reference architecture shaped by distributed, adaptive and composable modules is proposed. This architecture will assist and ease the role of systems integrators during reengineering-related interventions throughout system lifecycle. In a converging direction, the present work also proposes a serviceoriented
device model to support previous architecture vision and goals by including
embedded added-value in terms of service-oriented peer-to-peer discovery and identification, configuration, management, as well as agile customization of device resources.
In this context, the implementation and validation work proved not simply the feasibility and fitness of the proposed solution to two distinct test-benches but also its relevance to the expanding domain of SOA applications to support device lifecycle in the industrial automation domain
Engineering framework for service-oriented automation systems
Tese de doutoramento. Engenharia Informática. Universidade do Porto. Faculdade de Engenharia. 201
Chapter 59: Web Services
Web services are a cornerstone of the distributed computing infrastructure that the VO is built upon yet to the newcomer, they can appear to be a black art. This perception is not helped by the miasma of technobabble that pervades the subject and the seemingly impenetrable high priesthood of actual users. In truth, however, there is nothing conceptually difficult about web services (unsurprisingly any complexities will lie in the implementation details) nor indeed anything particularly new.
A web service is a piece of software available over a network with a formal description of how it is called and what it returns that a computer can understand. Note that entities such as web servers, ftp servers and database servers do not generally qualify as they lack the standardized description of their inputs and outputs. There are prior technologies, such as RMI, CORBA, and DCOM, that have employed a similar approach but the success of web services lies predominantly in its use of standardized XML to provide a language-neutral way for representing data. In fact, the standardization goes further as web services are traditionally (or as traditionally as five years will allow) tied to a specific set of technologies (WSDL and SOAP conveyed using HTTP with an XML serialization). Alternative implementations are becoming increasingly common and we will cover some of these here. One important thing to remember in all of this, though, is that web services are meant for use by computers and not humans (unlike web pages) and this is why so much of it seems incomprehensible gobbledegook.
In this chapter, we will start with an overview of the web services current in the VO and present a short guide on how to use and deploy a web service. We will then review the different approaches to web services, particularly REST and SOAP, and alternatives to XML as a data format. We will consider how web services can be formally described and discuss how advanced features such as security, state and asynchrony can be provided. Note that much of this material is not yet used in the VO but features heavily in IVOA discussions on advanced services and capabilities
An Autonomic Cross-Platform Operating Environment for On-Demand Internet Computing
The Internet has evolved into a global and ubiquitous communication medium interconnecting powerful application servers, diverse desktop computers and mobile notebooks. Along with recent developments in computer technology, such as the convergence of computing and communication devices, the way how people use computers and the Internet has changed people´s working habits and has led to new application scenarios. On the one hand, pervasive computing, ubiquitous computing and nomadic computing become more and more important since different computing devices like PDAs and notebooks may be used concurrently and alternately, e.g. while the user is on the move. On the other hand, the ubiquitous availability and pervasive interconnection of computing systems have fostered various trends towards the dynamic utilization and spontaneous collaboration of available remote computing resources, which are addressed by approaches like utility computing, grid computing, cloud computing and public computing. From a general point of view, the common objective of this development is the use of Internet applications on demand, i.e. applications that are not installed in advance by a platform administrator but are dynamically deployed and run as they are requested by the application user. The heterogeneous and unmanaged nature of the Internet represents a major challenge for the on demand use of custom Internet applications across heterogeneous hardware platforms, operating systems and network environments. Promising remedies are autonomic computing systems that are supposed to maintain themselves without particular user or application intervention. In this thesis, an Autonomic Cross-Platform Operating Environment (ACOE) is presented that supports On Demand Internet Computing (ODIC), such as dynamic application composition and ad hoc execution migration. The approach is based on an integration middleware called crossware that does not replace existing middleware but operates as a self-managing mediator between diverse application requirements and heterogeneous platform configurations. A Java implementation of the Crossware Development Kit (XDK) is presented, followed by the description of the On Demand Internet Computing System (ODIX). The feasibility of the approach is shown by the implementation of an Internet Application Workbench, an Internet Application Factory and an Internet Peer Federation. They illustrate the use of ODIX to support local, remote and distributed ODIC, respectively. Finally, the suitability of the approach is discussed with respect to the support of ODIC
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