Results 1 - 10
of
300
QoS Computation and Policing in Dynamic Web Service Selection
- WWW2004
, 2004
"... The emerging Service-Oriented Computing (SOC) paradigm promises to enable businesses and organizations to collaborate in an unprecedented way by means of standard web services. To support rapid and dynamic composition of services in this paradigm, web services that meet requesters' functional r ..."
Abstract
-
Cited by 137 (2 self)
- Add to MetaCart
(Show Context)
The emerging Service-Oriented Computing (SOC) paradigm promises to enable businesses and organizations to collaborate in an unprecedented way by means of standard web services. To support rapid and dynamic composition of services in this paradigm, web services that meet requesters' functional requirements must be able to be located and bounded dynamically from a large and constantly changing number of service providers based on their Quality of Service (QoS). In order to enable quality-driven web service selection, we need an open, fair, dynamic and secure framework to evaluate the QoS of a vast number of web services. The fair computation and enforcing of QoS of web services should have minimal overhead but yet able to achieve su#cient trust by both service requesters and providers. In this paper, we presented our open, fair and dynamic QoS computation model for web services selection through implementation of and experimentation with a QoS registry in a hypothetical phone service provisioning market place application.
Automated Generation of BPEL Adapters
- In Proc. of ICSOC’06, volume 4294 of LNCS
, 2006
"... Abstract. The heterogeneous, dynamic, distributed, and evolving nature of Web services calls for adaptation techniques to overcome various types of mismatches that may occur among services developed by different parties. In this paper we present a methodology for the automated generation of (service ..."
Abstract
-
Cited by 73 (6 self)
- Add to MetaCart
(Show Context)
Abstract. The heterogeneous, dynamic, distributed, and evolving nature of Web services calls for adaptation techniques to overcome various types of mismatches that may occur among services developed by different parties. In this paper we present a methodology for the automated generation of (service) adapters capable of solving behavioural mismatches among BPEL processes. The adaptation process, given two communicating BPEL processes whose interaction may lock, builds (if possible) a BPEL process that allows the two processes to successfully interoperate. A key ingredient of the adaptation methodology is the transformation of BPEL processes into YAWL workflows. 1
A taxonomy of Data Grids for distributed data sharing, management, and processing
- ACM Computing Surveys
"... Data Grids have been adopted as the platform for scientific communities that need to share, access, transport, process and manage large data collections distributed worldwide. They combine high-end computing technologies with high-performance networking and wide-area storage management techniques. I ..."
Abstract
-
Cited by 56 (8 self)
- Add to MetaCart
Data Grids have been adopted as the platform for scientific communities that need to share, access, transport, process and manage large data collections distributed worldwide. They combine high-end computing technologies with high-performance networking and wide-area storage management techniques. In this paper, we discuss the key concepts behind Data Grids and compare them with other data sharing and distribution paradigms such as content delivery networks, peer-to-peer networks and distributed databases. We then provide comprehensive taxonomies that cover various aspects of architecture, data transportation, data replication and resource allocation and scheduling. Finally, we map the proposed taxonomy to various Data Grid systems not only to validate the taxonomy but also to identify areas for future exploration. Through this taxonomy, we aim to categorise existing systems to better understand their goals and their methodology. This would help evaluate their applicability for solving similar problems. This taxonomy also provides a ”gap analysis ” of this area through which researchers can potentially identify new issues for investigation. Finally, we hope that the proposed taxonomy and mapping also helps to provide an easy way for new practitioners to understand this complex area of research. 1
End-to-End Support for QoSAware Service Selection, Invocation and Mediation in VRESCo. Retrieved November 10, 2009, from Vienna University of Technology: http://www.infosys.tuwien.ac.at/Staff/michlmayr/papers/TUV1841-2009-03.pdf (Technical Report
, 2009
"... Abstract—Service-Oriented Computing has recently received a lot of attention from both academia and industry. However, current service-oriented solutions are often not as dynamic and adaptable as intended because the publish-find-bind-execute cycle of the Service-Oriented Architecture triangle is no ..."
Abstract
-
Cited by 44 (21 self)
- Add to MetaCart
(Show Context)
Abstract—Service-Oriented Computing has recently received a lot of attention from both academia and industry. However, current service-oriented solutions are often not as dynamic and adaptable as intended because the publish-find-bind-execute cycle of the Service-Oriented Architecture triangle is not entirely realized. In this paper, we highlight some issues of current web service technologies, with a special emphasis on service metadata, Quality of Service, service querying, dynamic binding, and service mediation. Then, we present the Vienna Runtime Environment for Service-Oriented Computing (VRESCo) that addresses these issues. We give a detailed description of the different aspects by focusing on service querying and service mediation. Finally, we present a performance evaluation of the different components, together with an end-to-end evaluation to show the applicability and usefulness of our system. Index Terms—Web services publishing and discovery, metadata of services interfaces, advanced services invocation framework. Ç 1
Model evolution by runtime parameter adaptation
- International Conference on Software Engineering
, 2009
"... Models can help software engineers to reason about design-time decisions before implementing a system. This paper focuses on models that deal with non-functional prop-erties, such as reliability and performance. To build such models, one must rely on numerical estimates of various pa-rameters provid ..."
Abstract
-
Cited by 43 (4 self)
- Add to MetaCart
(Show Context)
Models can help software engineers to reason about design-time decisions before implementing a system. This paper focuses on models that deal with non-functional prop-erties, such as reliability and performance. To build such models, one must rely on numerical estimates of various pa-rameters provided by domain experts or extracted by other similar systems. Unfortunately, estimates are seldom cor-rect. In addition, in dynamic environments, the value of pa-rameters may change over time. We discuss an approach that addresses these issues by keeping models alive at run time and feeding a Bayesian estimator with data collected from the running system, which produces updated param-eters. The updated model provides an increasingly bet-ter representation of the system. By analyzing the updated model at run time, it is possible to detect or predict if a de-sired property is, or will be, violated by the running imple-mentation. Requirement violations may trigger automatic reconfigurations or recovery actions aimed at guarantee-ing the desired goals. We illustrate a working framework supporting our methodology and apply it to an example in which a Web service orchestrated composition is modeled through a Discrete Time Markov Chain. Numerical simula-tions show the effectiveness of the approach. 1.
Associating assertions with business processes and monitoring their execution
- Int. Conf. on Service-Oriented Computing (ICSOC 2004
, 2004
"... Business processes that span organizational borders describe the interaction between multiple parties working towards a common objective. They also express business rules that govern the behavior of the process and account for expressing changes reflecting new business objectives and new market situ ..."
Abstract
-
Cited by 35 (3 self)
- Add to MetaCart
(Show Context)
Business processes that span organizational borders describe the interaction between multiple parties working towards a common objective. They also express business rules that govern the behavior of the process and account for expressing changes reflecting new business objectives and new market situations. In our previous work we developed a service request language and support framework that allow users to formulate their requests against standard business processes. In this paper we extend this approach by presenting a framework capable of automatically associating business rules with relevant processes involved in a user request. This framework plans and monitors the execution of the request against services underlying these processes. Definitions and classifications of business rules (named assertions in the paper) are given together with an assertion language for expressing them. The framework is able to handle the non-determinism typical for service-oriented computing environments and it is based on the interleaving of planning and execution.
Towards a Unified Service Description Language for the Internet of Services: Requirements and First Developments
"... Service-oriented Architectures (SOA) and Web services leverage the technical value of solutions in the areas of distributed systems and cross-enterprise integration. The emergence of Internet marketplaces for business services is driving the need to describe services, not only from a technical level ..."
Abstract
-
Cited by 30 (10 self)
- Add to MetaCart
(Show Context)
Service-oriented Architectures (SOA) and Web services leverage the technical value of solutions in the areas of distributed systems and cross-enterprise integration. The emergence of Internet marketplaces for business services is driving the need to describe services, not only from a technical level, but also from a business and operational perspective. While, SOA and Web services reside in an IT layer, organizations owing Internet marketplaces are requiring advertising and trading business services which reside in a business layer. As a result, the gap between business and IT needs to be closed. This paper presents USDL (Unified Service Description Language), a specification language to describe services from a business, operational and technical perspective. USDL plays a major role in the Internet of Services to describe tradable services which are advertised in electronic marketplaces. The language has been tested using two service marketplaces as use cases. 1.
Monitoring, Prediction and Prevention of SLA Violations in Composite Services
- In Proceedings of the IEEE International Conference on Web Services
, 2010
"... We propose the PREvent framework, which is a system that integrates event-based monitoring, prediction of SLA violations using machine learning techniques, and auto-mated runtime prevention of those violations by triggering adaptation actions in service compositions. PREvent im-proves on related wor ..."
Abstract
-
Cited by 25 (6 self)
- Add to MetaCart
(Show Context)
We propose the PREvent framework, which is a system that integrates event-based monitoring, prediction of SLA violations using machine learning techniques, and auto-mated runtime prevention of those violations by triggering adaptation actions in service compositions. PREvent im-proves on related work in that it can be used to prevent violations ex ante, before they have negatively impacted the provider’s SLAs. We explain PREvent in detail and show the impact on SLA violations based on a case study. I.
Connecting Client Objectives with Resource Capabilities: An Essential Component for Grid Service
- Management Infrastructures”, in ACM International Conference on Service Oriented Computing
, 2004
"... In large-scale, distributed systems such as Grids, an agreement between a client and a service provider specifies service level objectives both as expressions of client requirements and as provider assurances. Ideally, these objectives are expressed in a high-level, service- or application-specific ..."
Abstract
-
Cited by 23 (8 self)
- Add to MetaCart
(Show Context)
In large-scale, distributed systems such as Grids, an agreement between a client and a service provider specifies service level objectives both as expressions of client requirements and as provider assurances. Ideally, these objectives are expressed in a high-level, service- or application-specific manner rather than requiring clients to detail the necessary resources. Resource providers on the other hand, expect low-level, resource specific performance criteria that are uniform across applications and can easily be interpreted and provisioned. This paper presents a framework for Grid service management that addresses this gap between high-level specification of client performance objectives and existing resource management infrastructures It identifies three levels of abstraction for resource requirements that a service provider needs to manage, namely: detailed specification of raw resources, virtualization of heterogeneous resources as abstract resources, and performance objectives at an application level. The paper also identifies three key functions for managing service level agreements, namely: translation of resource requirements across abstraction layers, arbitration in allocating resources to client requests, and aggregation and allocation of resources from multiple lower level resource managers. One or more of these key functions may be present at each abstraction layer of a service level manager. Thus, the composition of these functions across resource abstraction layers enables modeling of a wide array of management scenarios. We present a framework that supports these functions: it uses the service metadata and/or service performance models to map client requirements to resource capabilities, it uses business value associated with objectives in allocation decisions to arbitrate between competing requests, and it allocates resources based on previously negotiated agreements.
Cost-Based Optimization of Service Compositions
, 1841
"... For providers of composite services preventing cases of SLA violations is crucial. Previous work has established runtime adaptation of compositions as a promising tool to achieve SLA conformance. However, in order to get a realistic and complete view of the decision process of service providers, the ..."
Abstract
-
Cited by 22 (15 self)
- Add to MetaCart
(Show Context)
For providers of composite services preventing cases of SLA violations is crucial. Previous work has established runtime adaptation of compositions as a promising tool to achieve SLA conformance. However, in order to get a realistic and complete view of the decision process of service providers, the costs of adaptation need to be taken into account. In this paper we formalize the problem of finding the optimal set of adaptations, which minimizes the total costs arising from SLA violations and the adaptations to prevent them. We present possible algorithms to solve this complex optimization problem, and detail an end-to-end system based on our earlier work on the PREvent (prediction and prevention based on event monitoring) framework, which clearly indicates the usefulness of our model. We discuss experimental results that show how the application of our approach leads to reduced costs for the service provider, and explain the circumstances in which different algorithms lead to more or less satisfactory results.
