Service-oriented architectures provide integration of interoperability for independent and loosely coupled services. Web services and the associated new standards such as WSRF are frequently used to realise such servi...
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Service-oriented architectures provide integration of interoperability for independent and loosely coupled services. Web services and the associated new standards such as WSRF are frequently used to realise such service-oriented architectures. In such systems, autonomic principles of self-configuration, self-optimisation, self-healing and self- adapting are desirable to ease management and improve robustness. In this paper we focus on the extension of the self management and autonomic behaviour of a WSRF container connected by a structured P2P overlay network to monitor and rectify its QoS to satisfy its SIAs. The SLA plays an important role during two distinct phases in the life-cycle of a WSRF container. Firstly during service deployment when services are assigned to containers in such a way as to minimise the threat of SLA violations, and secondly during maintenance when violations are detected and services are migrated to other containers to preserve QoS. In addition, as the architecture has been designed and built using standardised modern technologies and with high levels of transparency, conventional Web services can be deployed with the addition of a SLA specification.
Simulation studies of grid scheduling strategies require representative workloads to produce dependable results. Real production grid workloads have shown diverse correlation structures and scaling behavior, which are...
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Simulation studies of grid scheduling strategies require representative workloads to produce dependable results. Real production grid workloads have shown diverse correlation structures and scaling behavior, which are different than the characteristics of the available supercomputer workloads and cannot be captured by Poisson or simple distribution-based models. We present models that are able to reproduce various correlation structures, including pseudo-periodicity and long range dependence. By conducting model-driven simulation, we quantitatively evaluate the performance impacts of workload correlations in grid scheduling. The results indicate that autocorrelations in workloads result in worse system performance, both at the local and the grid level. It is shown that realistic workload modeling is not only possible, but also necessary to enable dependable grid scheduling studies.
In recent years, the amount of Internet accessible digital audiovisual media files has vastly increased. Therefore the need to describe the media (by way of metadata) has also increased significantly. MPEG-7 (finalize...
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In recent years, the amount of Internet accessible digital audiovisual media files has vastly increased. Therefore the need to describe the media (by way of metadata) has also increased significantly. MPEG-7 (finalized in 2001) provides a comprehensive and rich metadata standard for the description of multimedia content. Unfortunately, a standardized query format does not exist for MPEG-7, or other multimedia metadata. Such a standard would provide for communications between querying clients and databases, supporting cross-modal and cross-media retrieval. The lSO/lEC SC29WG11 committee decided therefore to contribute to this application space by adding such functionality as a new part of the MPEG-7 series of standards. In response to a Call for Proposals, six proposals were submitted. This paper describes the strengths of each proposal as well as the resulting draft standard for the MPEG-7 query format.
The decomposition of a software system into a set of autonomous entities (agents) is a promising modeling approach to today's distributed applications. Agent interplay in these sets of agents, so-called Multi-agen...
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The decomposition of a software system into a set of autonomous entities (agents) is a promising modeling approach to today's distributed applications. Agent interplay in these sets of agents, so-called Multi-agent systems (MAS), enables the rise of complex, i. e. self-organizing and emergent system dynamics. Engineers revise agent implementations and face the challenge to comprehend, validate and finally predict the resulting system-level behaviors. In this paper we discuss the usage of simulation models to assist engineers in examining MAS dynamics. Particularly, we show how stochastic transition systems can be inferred from agent implementations. The resulting models allow engineers to explore the stochastic processes that may underlay agent designs, facilitating both system design and validation as well as system optimization. We present tool support to assist model derivation from MAS implementations, following the established BDI agent architecture and exemplify its usage in a case study.
Message Passing is a popular mechanism used to enable inter-process communication in parallel and distributed computing. Many complex scientific and engineering applications that are executed on clusters have been dev...
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The advent of service-oriented Grid computing has resulted in the need for Grid resources such as clusters to enforce user-specific service needs and expectations. Service Level Agreements (SLAs) define conditions whi...
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The P-GRADE portal is a workflow-oriented Grid portal that originally served Globus-2 Grids. The Portal introduced an easy-to-use workflow-centric interface on top of the job oriented Globus systems. Because Globus do...
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This paper considers the composition of a DIDS (distributed Intrusion Detection System) by integrating heterogeneous IDSs (Intrusion Detection systems). A Grid middleware is used for this integration. In addition, an ...
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We propose and experiment a Social Networking Service (SNS) for local communities for tsunami disaster control. It is an easy-to-use GIS-based system with powerful GIS analysis capabilities. One of the features of the...
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ISBN:
(纸本)9780780397408
We propose and experiment a Social Networking Service (SNS) for local communities for tsunami disaster control. It is an easy-to-use GIS-based system with powerful GIS analysis capabilities. One of the features of the system is resident participation. The GIS layer structure proposed in this paper nicely supports this user participation. The system architecture and the use of the system for tsunami disaster control are discussed. We report ongoing developments in Hachinohe-City, Japan.
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