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Towards Context-Aware Adaptable Web Services
- In WWW Alt. ’04: Proceedings of the 13th international World Wide Web conference on Alternate track papers & posters
, 2004
"... development and deployment of context-aware adaptable Web services. Web services are provided with context information about clients that may be utilized to provide a personalized behavior. Context is extensible with new types of information at any time without any changes to the underlying infrastr ..."
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Cited by 42 (0 self)
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development and deployment of context-aware adaptable Web services. Web services are provided with context information about clients that may be utilized to provide a personalized behavior. Context is extensible with new types of information at any time without any changes to the underlying infrastructure. Context processing is done by Web services, context plugins, or context services. Context plugins and context services pre- and post-process Web service messages based on the available context information. Both are essential for automatic context processing and automatic adaption of Web services to new context types without the necessity to adjust the Web services themselves. We implemented the context framework within the ServiceGlobe system, our open and distributed Web service platform.
AutoGlobe: An Automatic Administration Concept for Service-Oriented Database Applications
- Proc. of the 22nd Intl. Conference on Data Engineering (ICDE’2006), Industrial Track
, 2006
"... Future database application systems will be designed as Service Oriented Architectures (SOAs) like SAP’s NetWeaver instead of monolithic software systems such as SAP’s R/3. The decomposition in finer-grained services allows the usage of hardware clusters and a flexible serviceto-server allocation bu ..."
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Cited by 26 (11 self)
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Future database application systems will be designed as Service Oriented Architectures (SOAs) like SAP’s NetWeaver instead of monolithic software systems such as SAP’s R/3. The decomposition in finer-grained services allows the usage of hardware clusters and a flexible serviceto-server allocation but also increases the complexity of administration. Thus, new administration techniques like our self-organizing infrastructure that we developed in cooperation with the SAP Adaptive Computing Infrastructure (ACI) group are necessary. For our purpose the available hardware is virtualized, pooled, and monitored. A fuzzy logic based controller module supervises all services running on the hardware platform and remedies exceptional situations automatically. With this self-organizing infrastructure we reduce the necessary hardware and administration overhead and, thus, lower the total cost of ownership (TCO). We used our prototype implementation, called Auto-Globe, for SAP-internal tests and we performed comprehensive simulation studies to demonstrate the effectiveness of our proposed concept. 1.
A Framework for Context-Aware Adaptable Web Services
- In Proc. of the Intl. Conf. on Extending Database Technology (EDBT
, 2004
"... The trend towards pervasive computing involves an increasing number of ubiquitous, ..."
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Cited by 15 (1 self)
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The trend towards pervasive computing involves an increasing number of ubiquitous,
Quality-Oriented Handling of Exceptions in Web-Service-Based Cooperative Processes
- In Proc. EAI-Workshop 2004 - Enterprise Application Integration
, 2004
"... Web services are increasingly used to integrate heterogeneous and autonomous applications in cross-organizational cooperations. A key problem is to support a high execution quality of complex cooperative processes, e.g. in e-business or health care. One important aspect that has received little a ..."
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Cited by 10 (0 self)
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Web services are increasingly used to integrate heterogeneous and autonomous applications in cross-organizational cooperations. A key problem is to support a high execution quality of complex cooperative processes, e.g. in e-business or health care. One important aspect that has received little attention so far is the dynamic handling of exceptions during process execution. To address this problem, we propose a rule-based approach to automatically control and enforce quality constraints for web-service-based cooperative processes.
Mobile Code Enabled Web Services
- In Proc. of IEEE International Conference on Web Services (ICWS’05
, 2005
"... A primary benefit of Web Services is that they provide a uniform implementation-independent mechanism for accessing distributed services. Building and deploying such services do not benefit from the same advantages, however. Different Web Services containers are implemented in different programming ..."
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Cited by 7 (0 self)
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A primary benefit of Web Services is that they provide a uniform implementation-independent mechanism for accessing distributed services. Building and deploying such services do not benefit from the same advantages, however. Different Web Services containers are implemented in different programming languages, with different constraints and requirements placed on the programmer. Moreover, client side programmers must use the Web Service interface specified by the service developer. Therefore, the kinds of applications and uses for a Web Service are unnecessarily restrictive, constrained by the granularity of access defined by the interface and by the characteristics of the service functions. This paper describes an approach that addresses both of these drawbacks by enabling Web Service containers with the ability to accept new mobile code on the fly, and to run it within the containers, providing direct local access to the containers ' other services. The code can be specified in a small simple language (a subset of C), and translated and passed to the container in a common XML-based intermediate language called X#. This approach effectively removes the dependence on any single implementation environment. Our prototype implementation for two different containers demonstrates the feasibility of the approach, which represents a first step toward write-once deployanywhere Web Services. 1 1.
An Architecture for the Dynamic Deployment of Web Services on a Grid or the Internet
, 2005
"... This paper describes an architecture for dynamically deploying Web Services over a grid or the Internet. Distributed job scheduling systems are found at the heart of most grid computing infrastructures. They allow jobs (a combination of the code to be executed and (in many cases) the data on which i ..."
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Cited by 6 (1 self)
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This paper describes an architecture for dynamically deploying Web Services over a grid or the Internet. Distributed job scheduling systems are found at the heart of most grid computing infrastructures. They allow jobs (a combination of the code to be executed and (in many cases) the data on which it is to operate) to be created by clients and dynamically routed to available, remote computing resources for execution. In recent years, there has been a trend towards utilising Web Services to build grid and other distributed applications. An application is represented as a set of services that communicate through the exchange of messages. However, if the computational requirements of a service cannot be met by its hosting environment then a job must be created and sent to a distributed job scheduling system for execution on a suitable host. Therefore, application writers must deal with the complexity of managing two different types of computational entities: services and jobs. The Dynasoar project is investigating an alternative approach in which there are no jobs, but only services. A service can be dynamically deployed on an available host in order to utilise its computational power, if
Dynamically deploying web services on a grid using dynasoar
- In ISORC
, 2006
"... Dynasoar is an infrastructure for dynamically deploying Web Services over a Grid or the Internet. It enables an approach to Grid computing in which distributed applications are built around services instead of jobs. Dynasoar automatically deploys a service on an available host if no existing deploym ..."
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Cited by 5 (4 self)
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Dynasoar is an infrastructure for dynamically deploying Web Services over a Grid or the Internet. It enables an approach to Grid computing in which distributed applications are built around services instead of jobs. Dynasoar automatically deploys a service on an available host if no existing deployments exist, or if performance requirements cannot be met by existing deployments. This is analogous to remote job scheduling, but offers the opportunity for improved performance as the cost of moving and deploying the service can be shared across the processing of many messages. A key feature of the architecture is that it makes a clear separation between Web Service Providers, who offer services to consumers, and Host Providers, who offer computational resources on which services can be deployed, and messages sent to them processed. Separating these two components and defining their interactions, opens up the opportunity for interesting new organisational / business models. 1.
Flexible Service Provisioning in Multi-Agent Systems
, 2008
"... Service-oriented computing is an increasingly popular approach for providing applications, computational resources and business services over highly distributed and open systems (such as the Web, computational Grids and peer-to-peer systems). In this approach, service providers advertise their offer ..."
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Cited by 5 (4 self)
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Service-oriented computing is an increasingly popular approach for providing applications, computational resources and business services over highly distributed and open systems (such as the Web, computational Grids and peer-to-peer systems). In this approach, service providers advertise their offerings by means of standardised computer-readable descriptions, which can then be used by software applications to discover and consume appropriate services without human intervention. However, despite active research in service infrastructures, and in service discovery and composition mechanisms, little work has recognised that services are offered by inherently autonomous and self-interested entities. This autonomy implies that providers may choose not to honour every service request, demand remuneration for their efforts, and, in general, exhibit uncertain behaviour. This uncertainty is especially problematic for the service consumers when services are part of complex workflows, as is common in many application domains, such as bioinformatics, large-scale data analysis and processing, and commercial supply-chain management. In order to address this uncertainty, we propose a novel algorithm for provisioning services for complex workflows (i.e., for selecting suitable services for the constituent tasks of a workflow). This algorithm uses probabilistic performance information about providers to reason about service
Environments
"... service Abstract: Replication is one of the main techniques aiming to improve Web services ’ (WS) quality of service (QoS) in distributed environments, including clouds and mobile devices. Service replication is a way of improving WS performance and availability by creating several copies or replica ..."
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Cited by 4 (0 self)
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service Abstract: Replication is one of the main techniques aiming to improve Web services ’ (WS) quality of service (QoS) in distributed environments, including clouds and mobile devices. Service replication is a way of improving WS performance and availability by creating several copies or replicas of Web services which work in parallel or sequentially under defined circumstances. In this paper, a generalized replication process for distributed environments is discussed based on established replication studies. The generalized replication process consists of three main steps: sensing the environment characteristics, determining the replication strategy, and implementing the selected replication strategy. To demonstrate application of the generalized replication process, a case study in the telecommunication domain is presented. The adequacy of the selected replication strategy is demonstrated by comparing it to another replication strategy as well as to a non-replicated service. The authors believe that a generalized replication process will help service providers to enhance QoS and accordingly attract more customers. 1
Robust Execution of Service Workflows Using Redundancy and Advance Reservations
- Ieee Transactions on Services Computing
"... Abstract—In this paper, we develop a novel algorithm that allows service consumers to execute business processes (or workflows) of interdependent services in a dependable manner within tight time-constraints. In particular, we consider large interorganizational service-oriented systems, where servic ..."
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Cited by 3 (0 self)
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Abstract—In this paper, we develop a novel algorithm that allows service consumers to execute business processes (or workflows) of interdependent services in a dependable manner within tight time-constraints. In particular, we consider large interorganizational service-oriented systems, where services are offered by external organizations that demand financial remuneration and where their use has to be negotiated in advance using explicit service-level agreements (as is common in Grids and cloud computing). Here, different providers often offer the same type of service at varying levels of quality and price. Furthermore, some providers may be less trustworthy than others, possibly failing to meet their agreements. To control this unreliability and ensure end-to-end dependability while maximizing the profit obtained from completing a business process, our algorithm automatically selects the most suitable providers. Moreover, unlike existing work, it reasons about the dependability properties of a workflow, and it controls these by using service redundancy for critical tasks and by planning for contingencies. Finally, our algorithm reserves services for only parts of its workflow at any time, in order to retain flexibility when failures occur. We show empirically that our algorithm consistently outperforms existing approaches, achieving up to a 35-fold increase in profit and successfully completing most workflows, even when the majority of providers fail. Index Terms—Business process dependability, managing and adaptively controlling end-to-end dependability properties, managing, establishing, and assessing interorganizational trust relationships. Ç 1
