Issue 3 • Date July-Sept. 2009
Services Quality and AnalyticsPage(s): 182| | PDF (35 KB)
We develop a graph-theoretic model for service-oriented networks and propose metrics that quantify the resilience of such networks under node and edge failures. These metrics are based on the topological structure of the network and the manner in which services are distributed over the network. We present efficient algorithms to determine the maximum number of node and edge failures that can be tolerated by a given service-oriented network. These algorithms rely on known algorithms for computing minimum cuts in graphs. We also present efficient algorithms for optimally allocating services over a given network so that the resulting service-oriented network can tolerate single node or edge failures. These algorithms are derived through a careful analysis of the decomposition of the underlying network into appropriate types of connected components. View full abstract»
In this paper, we introduce MPI-style Web service (MPIWS), a novel service presented as a standard Web service but integrated with MPI programming technologies to allow Web applications to run in parallel over a loosely coupled distributed environment. MPIWS takes advantage of the SOAP communication protocol, and allows direct MPI-style communication among loosely coupled services. The MPI-style communication supported by MPIWS includes both point-to-point and collective communications. In this paper, point-to-point and collective communication operations are evaluated in comparison with mpiJava. The evaluation results demonstrate that although the overhead of SOAP messaging takes a toll on performance, MPIWS is generally comparable with mpiJava sending Object data types, especially for coarse-grain applications, and outperforms mpiJava in some cases. View full abstract»
In this work, we propose a two-step, context-based semantic approach to the problem of matching and ranking Web services for possible service composition. We present an analysis of different methods for classifying Web services for possible composition and supply a context-based semantic matching method for ranking these possibilities. Semantic understanding of Web services may provide added value by identifying new possibilities for compositions of services. The semantic matching ranking approach is unique since it provides the Web service designer with an explicit numeric estimation of the extent to which a possible composition ldquomakes sense.rdquo First, we analyze two common methods for text processing, TF/IDF and context analysis; and two types of service description, free text and WSDL. Second, we present a method for evaluating the proximity of services for possible compositions. Each Web service WSDL context descriptor is evaluated according to its proximity to other services' free text context descriptors. The methods were tested on a large repository of real-world Web services. The experimental results indicate that context analysis is more useful than TF/IDF. Furthermore, the method evaluating the proximity of the WSDL description to the textual description of other services provides high recall and precision results. View full abstract»
For a system of distributed processes, correctness can be ensured by (statically) checking whether their composition satisfies properties of interest. However, Web services are distributed processes that dynamically discover properties of other Web services. Since the overall system may not be available statically and since each business process is supposed to be relatively simple, we propose to use runtime monitoring of conversations between partners as a means of checking behavioral correctness of the entire Web service system. Specifically, we identify a subset of UML 2.0 sequence diagrams as a property specification language and show that it is sufficiently expressive for capturing safety and liveness properties. By transforming these diagrams to automata, we enable conformance checking of finite execution traces against the specification. We show how our language can be used to specify the specification property system (SPS). We describe an implementation of our approach as part of an industrial system. Finally, we discuss our experience of specifying and monitoring a number of properties from three existing applications. View full abstract»
Guest Editorial: Special Section on Service-Oriented Distributed Computing SystemsPage(s): 245 - 246| | PDF (68 KB)
The rapid adoption of service-oriented architecture (SOA) in many large-scale distributed applications requires the development of adaptive service-based software systems (ASBS) with the capability of monitoring the changing system status, analyzing, and controlling tradeoffs among various quality-of-service (QoS) aspects, and adapting service configurations to satisfy multiple QoS requirements simultaneously. In this paper, our results toward the development of adaptive service-based software systems are presented. The formulation of activity-state-QoS (ASQ) models and how to use the data from controlled experiments to establish ASQ models for capturing the cause-effect dynamics among service activities, system resource states, and QoS in service-based systems are presented. Then, QoS monitoring modules based on ASQ models and SOA-compliant simulation models are developed to support the validation of the ASBS design. The main idea for developing QoS adaptation modules based on ASQ models is discussed. An experiment based on a voice communication service is used to illustrate our results. View full abstract»
Evolvability is essential for computer systems to adapt to the dynamic and changing requirements in response to instant or delayed feedback from a service environment that nowadays is becoming more and more context aware; however, current context-aware service-centric models largely lack the capability to continuously explore human intentions that often drive system evolution. To support service requirements analysis of real-world applications for services computing, this paper presents a situation-theoretic approach to human-intention-driven service evolution in context-aware service environments. In this study, we give situation a definition that is rich in semantics and useful for modeling and reasoning human intentions, whereas the definition of intention is based on the observations of situations. A novel computational framework is described that allows us to model and infer human intentions by detecting the desires of an individual as well as capturing the corresponding context values through observations. An inference process based on hidden Markov model makes instant definition of individualized services at runtime possible, and significantly, shortens service evolution cycle. We illustrate the possible applications of this framework through a smart home example aimed at supporting independent living of elderly people. View full abstract»
Aims & Scope
The scope covers all computing and software aspects of the science and technology of services innovation research and development. IEEE Transactions on Services Computing emphasizes the algorithmic, mathematical, statistical and computational methods that are central in services computing, the emerging field of Service Oriented Architecture, Web Services, Business Process Integration, Solution Performance Management, Services Operations and Management. Specifically, the transactions covers but is not limited to the following topics: Mathematical foundation of Services Computing, Service-Oriented Architecture (SOA), Service creation, development, and management, Linkage between IT services and business services, Web services security and privacy, Web services agreement and contract, Web services discovery and negotiation, Web services management, Web services collaboration, Quality of Service for Web services, Web services modeling and performance management, Solution frameworks for building service-oriented applications, Composite Web service creation and enabling infrastructures, Business and scientific applications using Web services and SOA, Business process integration and management using Web services, Standards and specifications of Services Computing, Utility models and solution architectures, Resource acquisition models in Utility Computing, Mathematical foundation of business process modeling, integration and management, Business process modeling, integration, and collaboration.
TSC is a scholarly, archival journal published quarterly.
It is noted that only service-oriented grid computing topics will be covered by TSC.
Please be sure to visit the TSC Taxonomy List. [Link to http://www.computer.org/
Meet Our Editors
Georgia Institute of Technology