Showing papers in "IEEE Internet Computing in 2004"
TL;DR: Four key issues for Web service composition are described, which offer developers reuse possibilities and users seamless access to a variety of complex services.
Abstract: Web service composition lets developers create applications on top of service-oriented computing's native description, discovery, and communication capabilities. Such applications are rapidly deployable and offer developers reuse possibilities and users seamless access to a variety of complex services. There are many existing approaches to service composition, ranging from abstract methods to those aiming to be industry standards. The authors describe four key issues for Web service composition.
770 citations
TL;DR: This article addresses dynamic service selection via an agent framework coupled with a QoS ontology with the aim of enabling participants to collaborate to determine each other's service quality and trustworthiness.
Abstract: Current Web services standards lack the means for expressing a service's nonfunctional attributes - namely, its quality of service. QoS can be objective (encompassing reliability, availability, and request-to-response time) or subjective (focusing on user experience). QoS attributes are key to dynamically selecting the services that best meet user needs. This article addresses dynamic service selection via an agent framework coupled with a QoS ontology. With this approach, participants can collaborate to determine each other's service quality and trustworthiness.
615 citations
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TL;DR: "Homeland security" is a major concern for governments worldwide, which must protect their populations and the critical infrastructures that support them, which includes not only the Internet and financial infrastructure but also the complex systems that control critical infrastructure such as energy, transportation, and manufacturing.
Abstract: "Homeland security" is a major concern for governments worldwide, which must protect their populations and the critical infrastructures that support them. Information technology plays an important role in many homeland security initiatives. On one hand, it can help mitigate risk and enable effective responses to disasters of natural or human origin. Yet, its suitability for this role is plagued by questions ranging from dependability concerns to the risks that some technologies, such as surveillance, profiling and data aggregation, pose to privacy and civil liberties. On the other hand, information technology is itself an infrastructure to be protected. This includes not only the Internet and financial infrastructure but also the complex systems that control critical infrastructure such as energy, transportation, and manufacturing.
364 citations
TL;DR: The authors outline LRD findings in network traffic and explore the current lack of accuracy and robustness in LRD estimation and present recent evidence that packet arrivals appear to be in agreement with the Poisson assumption in the Internet core.
Abstract: Self-similarity and scaling phenomena have dominated Internet traffic analysis for the past decade. With the identification of long-range dependence (LRD) in network traffic, the research community has undergone a mental shift from Poisson and memory-less processes to LRD and bursty processes. Despite its widespread use, though, LRD analysis is hindered by the difficulty of actually identifying dependence and estimating its parameters unambiguously. The authors outline LRD findings in network traffic and explore the current lack of accuracy and robustness in LRD estimation. In addition, they present recent evidence that packet arrivals appear to be in agreement with the Poisson assumption in the Internet core.
316 citations
TL;DR: In previous columns, I've examined how quality of service (QoS) comes into play for service providers, consumers, and parallel transactions, and here, I'll show how it fits into composite Web services.
Abstract: An Internet application can invoke several services--a stock-trading Web service, for example, could invoke a payment service, which could then invoke an authentication service. Such a scenario is called a composite Web service, and it can be specified statically or established dynamically. Dynamic composition of Web services requires service consumers to discover service providers that satisfy given functional and nonfunctional requirements including cost and QoS requirements such as performance and availability. In previous columns, I've examined how quality of service (QoS) comes into play for service providers, consumers, and parallel transactions. Here, I'll show how it fits into composite Web services.
313 citations
TL;DR: A new smart meeting room system called EasyMeeting explores the use of multi-agent systems, Semantic Web ontologies, reasoning, and declarative policies for security and privacy.
Abstract: A new smart meeting room system called EasyMeeting explores the use of multi-agent systems, Semantic Web ontologies, reasoning, and declarative policies for security and privacy. Building on an earlier pervasive computing system, EasyMeeting provides relevant services and information to meeting participants based on their situational needs. The system also exploits the context-aware support provided by the Context Broker Architecture (Cobra). Cobra's intelligent broker agent maintains a shared context model for all computing entities in the space and enforces user-defined privacy policies.
293 citations
TL;DR: This work describes two widely different sensor network applications - emergency medical services and supply chain management - and describes how they fit into a new data-collection network based on the Hourglass publish-subscribe paradigm.
Abstract: Integrating wireless sensor networks with the traditional wired grid poses several challenges. The technical challenges center on the development of sensors and sensor network infrastructure, including the need to comply with emerging APIs for grid and Web services. Process-driven challenges, which center on the development and adoption of new business models and applications, are driving this technology. We describe two widely different sensor network applications - emergency medical services and supply chain management - and describe how they fit into a new data-collection network based on the Hourglass publish-subscribe paradigm.
240 citations
TL;DR: This work discusses design decisions, contrasts the Corba and Ice approaches, and outlines the advantages that result from a better design.
Abstract: Ice is a new object-oriented middleware platform that allows developers to build distributed client-server applications with minimal effort. While similar in concept to Corba, Ice breaks new ground by providing an object model that is both simpler and more powerful, by getting rid of inefficiencies that plagued middleware in the past, and by providing new features such as user datagram protocol (UDP) support, asynchronous method dispatch, built-in security, automatic object persistence, and interface aggregation. We discuss design decisions, contrasts the Corba and Ice approaches, and outlines the advantages that result from a better design.
233 citations
TL;DR: A framework that builds on current standards to help developers define extended service models and richer Web service abstractions is identified and its main feature is a conversation metamodel derived from an analysis of e-commerce portal sites.
Abstract: Web services are emerging as a promising technology for effectively automating interorganizational interactions. However, despite the growing interest, several issues remain to be addressed to provide Web services with benefits similar to what traditional middleware brings to intraorganizational application integration. We identify a framework that builds on current standards to help developers define extended service models and richer Web service abstractions. The framework's main feature is a conversation metamodel derived from our analysis of e-commerce portal sites.
181 citations
TL;DR: In this paper, the authors introduce a novel service retrieval approach that captures service semantics using process models, and applies a pattern-matching algorithm to find the services with the behavior the user wants.
Abstract: Online repositories are increasingly called on to provide access to services that describe or provide useful behaviors. Existing techniques for finding services offer low retrieval precision, returning many irrelevant matches. We introduce a novel service retrieval approach that captures service semantics using process models, and applies a pattern-matching algorithm to find the services with the behavior the user wants. Evaluations suggest that process-based queries offer substantially greater retrieval precision than existing approaches and scale well with the number of services being accessed.
181 citations
TL;DR: The Squid peer-to-peer information discovery system supports flexible queries using partial keywords, wildcards, and ranges and is a dimension-reducing indexing scheme that effectively maps multidimensional information space to physical peers.
Abstract: The Squid peer-to-peer information discovery system supports flexible queries using partial keywords, wildcards, and ranges. It is built on a structured overlay and uses data lookup protocols to guarantee that all existing data elements that match a query are found efficiently. Its main innovation is a dimension-reducing indexing scheme that effectively maps multidimensional information space to physical peers.
TL;DR: The XML role-based access control (X-RBAC) specification language addresses multidomain environments' policy-specification needs and provides a framework for specifying mediation policies in a multidomatic environment where RBAC policies have been employed.
Abstract: The XML role-based access control (X-RBAC) specification language addresses multidomain environments' policy-specification needs. X-RBAC is based on an extension of the widely accepted US National Institute of Standards and Technology role-based access-control (RBAC) model. In addition to allowing specification of RBAC policies and facilitating specification of timing constraints on roles and access requirements, X-RBAC provides a framework for specifying mediation policies in a multidomain environment where RBAC policies have been employed.
TL;DR: Developing any nontrivial middleware-based distributed system is hard, regardless of the middleware technology; how to deal with versioning and change management in a deployed middleware application can be complicated and costly.
Abstract: Developing any nontrivial middleware-based distributed system is hard, regardless of the middleware technology. Although technology's continuous march should make systems easier to develop, somehow the details always remain challenging. New technologies only seem to make simple things simpler; they don't help with the more complex things. Horizontal concerns, such as security, transactions, fault tolerance, load balancing, and enterprise management, never seem to get easier, regardless of what middleware development platform you choose. Dealing with versioning and change management in a deployed middleware application can be complicated and costly. A good example of versioning coming into play for distributed middleware systems is the interface between any two applications or components. Interface versioning issues apply whether the middleware explicitly employs an interface definition language (IDL), as in distributed-object systems like Corba and Microsoft COM, or whether "interfaces" really are represented as exchanged documents, as in many messaging systems.
TL;DR: This work focuses on the broker, analyzing both its interaction protocol and reasoning tasks, and describes OWL-S's exec extensions, detail their implementation's basic features, and explain how these features address the broker's reasoning problems.
Abstract: We describe about dynamic discovery and coordination of agent-based semantic Web services. Matchmaking and brokering are multiagent coordination mechanisms for Web services. Both have performance trade-offs, but the Web Ontology Language for Semantic Web Services (OWL-S) can handle extensions that address some of the shortcomings. We focus on the broker, analyzing both its interaction protocol and reasoning tasks. We also describe OWL-S's exec extensions, detail their implementation's basic features, and explain how these features address the broker's reasoning problems.
TL;DR: A query optimization model based on aggregating the quality of Web service parameters of different Web services, which adjusts QoWS through a dynamic rating scheme and multilevel matching in which the rating provides an assessment of Web services' behavior.
Abstract: For Web services to expand across the Internet, users need to be able to efficiently access and share Web services. The authors present a query infrastructure that treats Web services as first-class objects. It evaluates queries through the invocations of different Web service operations. Because efficiency plays a central role in such evaluations, the authors propose a query optimization model based on aggregating the quality of Web service (QoWS) parameters of different Web services. The model adjusts QoWS through a dynamic rating scheme and multilevel matching in which the rating provides an assessment of Web services' behavior. Multilevel matching allows the expansion of the solution space by enabling similar and partial answers.
TL;DR: This article places wireless grids in context, explains their basic requirements, and provides an example implementation that uses a wireless grid for distributed audio recording, and introduces articles in this special issue on wireless grid architectures and applications.
Abstract: Wireless grids, a new type of resource-sharing network, connect sensors, mobile phones, and other edge devices with each other and with wired grids. Ad hoc distributed resource sharing allows these devices to offer new resources and locations of use for grid computing. This article places wireless grids in context, explains their basic requirements, and provides an example implementation that uses a wireless grid for distributed audio recording. Finally, it introduces articles in this special issue on wireless grid architectures and applications.
TL;DR: It is shown how these two visions for the future of Web services are points in a continuum and a possible path for bridging the gap between them is discussed.
Abstract: Industry and researchers have two different visions for the future of Web services. Industry wants to capitalize on Web service technology to automate business processes via centralized workflow enactment. Researchers are interested in the dynamic composition of Web services. We show how these two visions are points in a continuum and discuss a possible path for bridging the gap between them.
TL;DR: This work addresses the impact of slow services on the overall response time of a transaction that uses several Web services in parallel and calls such applications composite Web services.
Abstract: Web services let programs submit requests to other programs over the Internet via open protocols and standards. Many traditional Web sites, including popular search engines like Google and large online bookstores are boosting their traffic through Web service APIs. A single Internet application can invoke many different Web services - for example, the metasearch engine WebSifter uses several online ontologies to refine a user's request into a more meaningful query and then submits that query to various search engines in parallel. We call such applications composite Web services. Many important challenges stem from the quality-of-service issues in composite Web services. We address the impact of slow services on the overall response time of a transaction that uses several Web services in parallel.
TL;DR: Experimental results are presented that show how intelligent filtering mechanisms can save network bandwidth inside the infrastructure and at mobile clients while preserving the accuracy of client notifications.
Abstract: Providing an up-to-date view on dynamically changing data presents difficulties. While several different data-dissemination platforms address the problem, client mobility is still a major challenge. Volatile wireless connections and resource limitations void the attempt to apply the same mechanisms that work in fixed-wired networks. The Rebeca publish-subscribe middleware implementation introduces several concepts for accommodating client mobility in publish-subscribe systems. We present experimental results that show how intelligent filtering mechanisms can save network bandwidth inside the infrastructure and at mobile clients while preserving the accuracy of client notifications.
TL;DR: A motivating example for grid computing in an enterprise environment is provided and the how resource allocation affects SLAs is discussed, which highlights the challenge of planning the capacity to guarantee quality of service in large-scale grids.
Abstract: Grid computing is already a mainstream paradigm for resource-intensive scientific applications, but it also promises to become the future model for enterprise applications. The grid enables resource sharing and dynamic allocation of computational resources, thus increasing access to distributed data, promoting operational flexibility and collaboration, and allowing service providers to scale efficiently to meet variable demands. Large-scale grids are complex systems composed of thousands of components from disjoined domains. Planning the capacity to guarantee quality of service (QoS) in such environments is a challenge because global service-level agreements (SLAs) depend on local SLAs. We provide a motivating example for grid computing in an enterprise environment and then discuss the how resource allocation affects SLAs.
TL;DR: The lightweight directory access protocol is a promising technology that provides access to directory information using a data structure similar to that of the X.500 protocol.
Abstract: Directory services facilitate access to information organized under a variety of frameworks and applications. The lightweight directory access protocol is a promising technology that provides access to directory information using a data structure similar to that of the X.500 protocol. IBM Tivoli, Novell, Sun, Oracle, Microsoft, and many other vendors feature LDAP-based implementations. The technology's increasing popularity is due both to its flexibility and its compatibility with existing applications.
TL;DR: Proposed extensions to the object-oriented hypermedia design method (OOHDM) are described and their new mechanisms allow developers to specify and implement processes explicitly by dealing with activity semantics and states.
Abstract: State-of-the-art Web applications include both navigational elements and business processes, but most Web application design methods treat business processes as just another kind of navigation. The authors' extensions to the object-oriented hypermedia design method (OOHDM) aim to remedy this situation. Rather than using navigation to emulate business processes, their new mechanisms allow developers to specify and implement processes explicitly by dealing with activity semantics and states. We describe proposed extensions to OOHDM and explore their use at an online retail store.
TL;DR: It is shown that the communication quality of current 802.11 ad hoc networks is low, and users can experience strong fluctuations in link quality as a result, and key factors that cause these fluctuations are identified.
Abstract: Mobile ad hoc wireless networks will extend the Internet into new territory, making Web services available "anytime, anywhere." This creates new markets in such areas as pervasive computing and traffic management. We show that the communication quality of current 802.11 ad hoc networks is low, and that users can experience strong fluctuations in link quality as a result. They identify key factors that cause these fluctuations and derive implications for application development. In particular, applications must tolerate frequent disconnections, network partitioning, and latency variations that are far more severe than in conventional networks.
TL;DR: As Web services have matured, they've also acquired the need for asynchronous push capabilities, and the details required by the service for sending a reply are implicit in the RPC network connection.
Abstract: As Web services have matured, they've also acquired the need for asynchronous push capabilities. Early Web services, such as those for getting traffic or weather reports or for performing currency exchange-rate calculations, were seemingly all remote procedure calls-oriented. In an RPC system, the receiver typically performs the requested service and sends a response back to the caller over the same connection on which the request arrived, which means the details required by the service for sending a reply are implicit in the RPC network connection. Unfortunately, these kinds of implied communication details are wholly inadequate for asynchronous push Web services.
TL;DR: This work focuses on two types of business processes (contract and executable) and provides an interface protocol to represent interoperability patterns between them and proposes a proposed methodology for business process choreography.
Abstract: We describe a proposed methodology for business process choreography. We focus on two types of business processes (contract and executable) and provide an interface protocol to represent interoperability patterns between them. The approach is designed to let existing processes, usually managed by an enterprise's own internal workflow management system, collaborate.
TL;DR: An algorithm that draws on context mobility elements, such as the user's travel direction and speed, to form personal service areas to provide tourist information to mobile users based on thesepersonal service areas and the users' preferences is described.
Abstract: Location-based mobile services let wireless mobile users access Web-based information about resources in their immediate vicinities. The authors describe an algorithm that draws on context mobility elements, such as the user's travel direction and speed, to form personal service areas. Their experimental context-aware tourist information system (CATIS) leverages XML technologies and Web services to provide tourist information to mobile users based on these personal service areas and the users' preferences. Because Web service performance depends on the underlying databases, the authors also developed a layered caching scheme for storing environmental data to improve response time.
TL;DR: 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.
Abstract: 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.
TL;DR: This case study demonstrates the accuracy of passive simple network measurement protocol (SNMP) measurements at low loss rates and reveals that common methods for active probing for packet loss suffer from high variance and from the effects of end-host interface loss.
Abstract: Empirical analysis of Internet traffic characteristics should not be biased by the measurement methodology used to gather data. We compare probe-(active) and router-based (passive) methods for measuring packet loss both in the laboratory and in a wide-area network. The laboratory case study demonstrates the accuracy of passive simple network measurement protocol (SNMP) measurements at low loss rates; the wide-area experiments show that active-probe loss-rate measurements don't correlate with those measured by SNMP from routers in a live network. This case study's findings also reveal that common methods for active probing for packet loss suffer from high variance and from the effects of end-host interface loss.
TL;DR: The AUML notation is a UML profile dedicated to agents that tries to simplify the transition from software engineering to multiagent system engineering and to exploit UML extension capabilities such as stereotypes and constraints.
Abstract: From the earliest days of multiagent system development, the need has existed for both a methodology and a modeling notation that assist in design. The agent UML community has responded by developing the AUML notation - a UML profile dedicated to agents that tries to simplify the transition from software engineering to multiagent system engineering. The idea behind AUML is to exploit UML extension capabilities such as stereotypes and constraints. AUML crystallizes a growing concern for agent-based modeling representations and lets designers move smoothly from software development to agent development.