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Concurrency and Computation:Practice and Experience: Published Papers for 2008
Concurrency and Computation: Practice and
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Published Papers for 2008
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2008 Volume 20 Articles
CPE1205:The Hydra Parallel Programming System
- Author(s):Franklin E. Powers,Gita Alaghband
- Department of Computer Science and Engineering, University of Colorado at Denver and Health & Sciences Center, Campus Box 109, P.O. Box 173364, Denver, CO 80217-3364, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1205
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The Hydra Parallel Programming System, a new parallel language extension to Java, and its supporting software are described. It is a fairly simple yet powerful language designed to address a number of areas that have not received much attention. One of these areas is the recompilation of parallel programs at runtime to allow a parallel program to adapt to the architecture it is executing on. The first version of this software system focuses on smaller Symmetric Multiprocessing and compatible architectures which are becoming more common. This particular class of machines has a great need for more options in the area of parallel programming among the vastly popular Java language programmers. Hydra programs will run as sequential Java on machines that do not have the parallel support or do not have an implemented Hydra runtime system without requirement of any modifications to the program. This paper describes the language, compares it with other languages (specifically with JOMP, an OpenMP implementation for Java), presents a brief discussion on compiling and executing Hydra programs, presents some sample benchmarks and their performance on three platforms, and concludes with a discussion of issues and future directions for Hydra. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1207:Active target particle swarm optimization
- Author(s):Ying-Nan Zhang,Qing-Ni Hu,Hong-Fei Teng
- School of Electronic and Information Engineering, Dalian University of Technology, Dalian 116023, People's Republic of China,School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, People's Republic of China,
- http://dx.doi.org/10.1002/cpe.1207
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
We propose an active target particle swarm optimization (APSO). APSO uses a new three-target velocity updating formula, i.e. the best previous position, the global best position and a new target position (called active target). In this study, we distinguish APSO from EPSO (extended PSO)/PSOPC (PSO with passive congregation) by the different methods of getting the active target. Note that here EPSO and PSOPC are the two existing methods for using three-target velocity updating formula, and getting the third (active) target from the obtained positions by the swarm. The proposed APSO gets the active (third) target using complex method, where the active target does not belong to the existing positions. We find that the APSO has the advantages of jumping out of the local optimum and keeping diversity; however, it also has the disadvantages of adding some extra computation expenses. The experimental results show the competitive performance of APSO when compared with PSO, EPSO, and PSOPC. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1210:A practical method to analyze workflow logic models
- Author(s):Yu Huang,Hanpin Wang,Wen Zhao,Chunxiang Xu
- Department of Computer Science, Peking University, Beijing 100871, China,National Engineering Center of Software Engineering, Peking University, Beijing 100871, China,
- http://dx.doi.org/10.1002/cpe.1210
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The analysis of workflow is crucial to the correctness of workflow applications. This paper introduces a simple and practical method for analyzing workflow logic models. Firstly, some definitions of the models and some properties, such as throughness, no-redundant-transition and boundedness, are presented. Then, we propose an approach based on synchronized reachability graphs (SRGs) to verify these properties. The SRG uses the characteristics of synchronizers in workflow logic models and mitigates the state explosion by constructing synchronized occurrence sequences rather than interleaving occurrence sequences. This paper also proposes some refined and feasible reduction rules which can preserve vital properties of workflow logic models. Using these two techniques, the SRG-based verification method can achieve higher efficiency. Furthermore, this research also develops a verification tool based on the method, presents the analysis results of some practical cases and compares our method with others. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1211:Tunneling enhanced by web page content block partition for focused crawling
- Author(s):Tao Peng,Changli Zhang,Wanli Zuo
- College of Computer Science and Technology, Jilin University, Key Laboratory of Symbol Computation and Knowledge Engineering of the Ministry of Education, Changchun 130012, China,
- http://dx.doi.org/10.1002/cpe.1211
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The complexity of web information environments and multiple-topic web pages are negative factors significantly affecting the performance of focused crawling. A highly relevant region in a web page may be obscured because of low overall relevance of that page. Segmenting the web pages into smaller units will significantly improve the performance. Conquering and traversing irrelevant page to reach a relevant one (tunneling) can improve the effectiveness of focused crawling by expanding its reach. This paper presents a heuristic-based method to enhance focused crawling performance. The method uses a Document Object Model (DOM)-based page partition algorithm to segment a web page into content blocks with a hierarchical structure and investigates how to take advantage of block-level evidence to enhance focused crawling by tunneling. Page segmentation can transform an uninteresting multi-topic web page into several single topic context blocks and some of which may be interesting. Accordingly, focused crawler can pursue the interesting content blocks to retrieve the relevant pages. Experimental results indicate that this approach outperforms Breadth-First, Best-First and Link-context algorithm both in harvest rate, target recall and target length. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1222:A comprehensive analytical model of interconnection networks in large-scale cluster systems
- Author(s):Bahman Javadi,Jemal H. Abawajy,Mohammad K. Akbari
- Computer Engineering and Information Technology Department, Amirkabir University of Technology, 424 Hafez Ave., Tehran, Iran,School of Engineering and Information Technology, Deakin University, Geelong, Vic. 3217, Australia,
- http://dx.doi.org/10.1002/cpe.1222
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The trends in parallel processing system design and deployment have been toward networked distributed systems such as cluster computing systems. Since the overall performance of such distributed systems often depends on the efficiency of their communication networks, performance analysis of the interconnection networks for such distributed systems is paramount. In this paper, we develop an analytical model, under non-uniform traffic and in the presence of communication locality, for the m-port n-tree family interconnection networks commonly employed in large-scale cluster computing systems. We use the proposed model to study two widely used interconnection networks flow control mechanism namely the wormhole and store&forward. The proposed analytical model is validated through comprehensive simulation. The results of the simulation demonstrated that the proposed model exhibits a good degree of accuracy for various system organizations and under different working conditions. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1250:The File Mover: high-performance data transfer for the grid
- Author(s):Cosimo Anglano,Massimo Canonico
- Dipartimento di Informatica, Università del Piemonte Orientale, Alessandria, Italy,
- http://dx.doi.org/10.1002/cpe.1250
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The exploration in many scientific disciplines (e.g. High-Energy Physics, Climate Modeling, and Life Sciences) involves the production and the analysis of massive data collections, whose archival, retrieval, and analysis require the coordinated usage of high-capacity computing, network, and storage resources. To obtain satisfactory performance, these applications require the availability of a high-performance, reliable data transfer mechanisms, able to minimize the data transfer time that often dominates their execution time. In this paper we present the File Mover, an efficient data transfer system specifically tailored to the needs of data-intensive applications, that exploits the overlay networks paradigm to provide superior performance with respect to conventional file transfer systems. An extensive experimental evaluation, carried out by means of a proof-of-concept implementation of the File Mover for a variety of network scenarios, shows the ability of the File Mover to outperform alternative data transfer systems. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1186:Exploring the feasibility of proactive reputations
- Author(s):Gayatri Swamynathan,Ben Y. Zhao,Kevin C. Almeroth
- Department of Computer Science, University of California at Santa Barbara, Santa Barbara, CA 93106, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1186
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Reputation mechanisms help peers in a peer-to-peer system avoid unreliable or malicious peers. In application-level networks, however, short peer lifetimes mean reputations are often generated from a small number of past transactions. These reputation values are less ‘reliable’, and more vulnerable to bad-mouthing or collusion attacks. We address this issue by introducing proactive reputations, a first-hand history of transactions initiated to augment incomplete or short-term reputation values. We present several mechanisms to generate proactive reputations, along with a statistical similarity metric to measure their effectiveness. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1187:Exploring the robustness of BitTorrent peer-to-peer content distribution systems
- Author(s):Nikitas Liogkas,Robert Nelson,Eddie Kohler,Lixia Zhang
- University of California-Los Angeles, Los Angeles, CA, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1187
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
This paper assesses BitTorrent's robustness against selfish peers who try to download content faster than their fair share by abusing existing protocol mechanisms. We present three exploits that can deliver potential benefits to a selfish peer and evaluate their impact on both public and private download sessions. Our results show that BitTorrent is quite robust against these exploits. Although selfish peers can sometimes attain high download throughput and compliant peers' download rates suffer slightly in consequence, we observe no significant degradation of the overall system's quality of service. We identify scenarios where a selfish peer could attain significant benefits at the expense of compliant peers, and discuss the protocol characteristics that render these scenarios unlikely and hence lead to the system's robustness. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1188:Gossip-based search selection in hybrid peer-to-peer networks
- Author(s):M. Zaharia,S. Keshav
- School of Computer Science, University of Waterloo, Waterloo, ON, Canada,
- http://dx.doi.org/10.1002/cpe.1188
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
We present GAB, a search algorithm for hybrid peer-to-peer networks, that is, networks that search using both flooding and a distributed hash table (DHT). GAB uses a gossip-style algorithm to collect global statistics about document popularity to allow each peer to make intelligent decisions about which search style to use for a given query. Moreover, GAB automatically adapts to changes in the operating environment. Synthetic and trace-driven simulations show that compared to a simple hybrid approach that always floods first, trying a DHT if too few results are found, GAB reduces the response time by 25-50% and the average query bandwidth cost by 45%, with no loss in recall. GAB scales well, with only a 7% degradation in performance despite a tripling in system size. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1189:TRIBLER: a social-based peer-to-peer system
- Author(s):J. A. Pouwelse,P. Garbacki,J. Wang,A. Bakker,J. Yang,A. Iosup,D. H. J. Epema,M. Reinders,M. R. van Steen,H. J. Sips
- Department of Computer Science, Delft University of Technology, The Netherlands,Department of Computer Science, Vrije Universiteit, The Netherlands,
- http://dx.doi.org/10.1002/cpe.1189
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Most current peer-to-peer (P2P) file-sharing systems treat their users as anonymous, unrelated entities, and completely disregard any social relationships between them. However, social phenomena such as friendship and the existence of communities of users with similar tastes or interests may well be exploited in such systems in order to increase their usability and performance. In this paper we present a novel social-based P2P file-sharing paradigm that exploits social phenomena by maintaining social networks and using these in content discovery, content recommendation, and downloading. Based on this paradigm's main concepts such as taste buddies and friends, we have designed and implemented the TRIBLER P2P file-sharing system as a set of extensions to BitTorrent. We present and discuss the design of TRIBLER, and we show evidence that TRIBLER enables fast content discovery and recommendation at a low additional overhead, and a significant improvement in download performance. Copyright 2007 John Wiley & Sons, Ltd.
CPE1190:Robust incentives via multi-level Tit-for-Tat
- Author(s):Qiao Lian,Yu Peng,Mao Yang,Zheng Zhang,Yafei Dai,Xiaoming Li
- Roxbeam Media Network Corporation, Beijing, People's Republic of China,Peking University, Beijing, People's Republic of China,Microsoft Research Asia, Beijing, People's Republic of China,
- http://dx.doi.org/10.1002/cpe.1190
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Much work has been done to address the need for incentive models in real deployed peer-to-peer networks. In this paper, we discuss problems found with the incentive model in a large, deployed peer-to-peer network, Maze. We evaluate several alternatives, and propose an incentive system that generates preferences for well-behaved nodes while correctly punishing colluders. We discuss our proposal as a hybrid between Tit-for-Tat and EigenTrust, and show its effectiveness through simulation of real traces of the Maze system. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1239:Special Issue: Recent Advances in Peer-to-Peer Systems and Security
- Author(s):Ben Y. Zhao
- University of California at Santa Barbara, U.S.A.
http://dx.doi.org/10.1002/cpe.1239
CCPE Title/Author Summary
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Abstract:
No Abstract
CPE1191:Performance prediction for a code with data-dependent runtimes
- Author(s):S. A. Jarvis,B. P. Foley,P. J. Isitt,D. P. Spooner,D. Rueckert,G. R. Nudd
- High Performance Systems Group, Department of Computer Science, University of Warwick, Coventry CV4 7AL, U.K.,Visual Information Processing Group, Department of Computing, Imperial College, London SW7 2BZ, U.K.,
- http://dx.doi.org/10.1002/cpe.1191
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
In this paper we present a predictive performance model for a key biomedical imaging application found as part of the U.K. e-Science Information eXtraction from Images (IXI) project. This code represents a significant challenge for our existing performance prediction tools as it has internal structures that exhibit highly variable runtimes depending on qualities in the input data provided. Since the runtime can vary by more than an order of magnitude, it has been difficult to apply meaningful quality of service criteria to workflows that use this code. The model developed here is used in the context of an interactive scheduling system which provides rapid feedback to the users, allowing them to tailor their workloads to available resources or to allocate extra resources to scheduled workloads. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1193:This paper is based on the conference paper submitted to the U.K. e-Science All Hands Meeting 2005
- Author(s):Robert Geldhill,Sarah Kent,Andrew Milsted,Richard Chapman,Jonathan W. Essex,Jeremy G. Frey
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K.,
- http://dx.doi.org/10.1002/cpe.1193
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
e-Malaria (http://emalaria.soton.ac.uk/) aims to bring together 16-18 year old school students with university researchers to explain aspects of computational drug design using the example of the hunt for a new anti-Malaria drug. Malaria kills a child every 30 seconds, and 40% of the world's population lives in countries where the disease is endemic. Resistance to existing drugs is increasing and there is a growing need for new compounds. This challenge is being offered to school students who will use a distributed drug search and selection system via a Web interface to design potential drugs. The project makes use of industrial code for the docking study (‘GOLD’) and as such presents valuable lessons in how to achieve the integration of industrial programs into a ‘free’ outreach environment. The results of the trials are displayed in an accessible manner, giving students an opportunity for discussion and debate both with peers and with university contacts. The initial project has been extended to provide a similar challenge for undergraduate chemists as part of a chemical informatics course at a level relevant to more advances chemical skills. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1194:AMUSE: autonomic management of ubiquitous e-Health systems
- Author(s):E. Lupu,N. Dulay,M. Sloman,J. Sventek,S. Heeps,S. Strowes,K. Twidle,S.-L. Keoh,A. Schaeffer-Filho
- Department of Computing, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.,Department of Computing Science, University of Glasgow, 17 Lilybank Gardens, Glasgow G12 8RZ, U.K.,
- http://dx.doi.org/10.1002/cpe.1194
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Future e-Health systems will consist of low-power on-body wireless sensors attached to mobile users that interact with an ubiquitous computing environment to monitor the health and well being of patients in hospitals or at home. Patients or health practitioners have very little technical computing expertise so these systems need to be self-configuring and self-managing with little or no user input. More importantly, they should adapt autonomously to changes resulting from user activity, device failure, and the addition or loss of services. We propose the Self-Managed Cell (SMC) as an architectural pattern for all such types of ubiquitous computing applications and use an e-Health application in which on-body sensors are used to monitor a patient living in their home as an exemplar. We describe the services comprising the SMC and discuss cross-SMC interactions as well as the composition of SMCs into larger structures. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1195:An ontology-based approach to handling information quality in e-Science
- Author(s):A. Preece,P. Missier,S. Embury,B. Jin,M. Greenwood
- Department of Computing Science, University of Aberdeen, Aberdeen, U.K.,School of Computer Science, University of Manchester, Manchester, U.K.,
- http://dx.doi.org/10.1002/cpe.1195
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
In this paper we outline a framework for managing information quality (IQ) in an e-Science context. In contrast to previous approaches that take a very abstract view of IQ properties, we allow scientists to define the quality characteristics that are of importance to them in their particular domain. For example, ‘accuracy’ may be defined in terms of the conformance of experimental data to a particular standard. User-scientists specify their IQ preferences against a formal ontology, so that the definitions are machine-manipulable, allowing the environment to classify and organize domain-specific quality characteristics within an overall quality management framework. As an illustration of our approach, we present an example Web service that computes IQ annotations for experiment datasets in transcriptomics. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1196:Payment and negotiation for the next generation Grid and Web
- Author(s):Jeremy Cohen,John Darlington,William Lee
- London e-Science Centre, Department of Computing, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.,
- http://dx.doi.org/10.1002/cpe.1196
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
We present a proposal for a next-generation Internet based on chargeable Web Services and Utility Computing realized by a series of open but interacting markets. We demonstrate through the U.K. e-Science project ‘A Market for Computational Services’ the development of some of the fundamental building blocks for such a Grid computational marketplace. This paper describes the motivation behind this restructuring of the Internet and Web-based activities as a series of markets and how Grid Computing technologies can contribute towards this goal. The paper details the work undertaken at the London e-Science Centre to build a framework to create and support negotiable and chargeable Web Services. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1197:Steering via the image in local, distributed and collaborative settings
- Author(s):J. D. Wood,H. Wright
- School of Computing, University of Leeds, Leeds LS2 9JT, U.K.,Department of Computer Science, University of Hull, Hull HU6 7RX, U.K.
http://dx.doi.org/10.1002/cpe.1197
CCPE Title/Author Summary
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Abstract:
Computational steering is a valuable mechanism for scientific investigation in which the parameters of a running program can be altered and the results visualized immediately. In a previous paper we put forward an architecture for computational steering that recognizes visualization as both the logical output and the input route. In this paper we investigate the practicalities of applying this architecture in local, distributed and collaborative steering. The work adopts a state-transition modelling approach, keeping parameters and results together in the display in order to present information consistently. The outcome is a manageably small set of states that could apply to many different simulations. We also present the results of a preliminary user study on the demonstrator we have constructed. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1204:Performance analysis of a semantics-enabled service registry
- Author(s):W. Fang,S. Miles,L. Moreau
- School of Electronics and Computer Science, University of Southampton, Southampton, U.K.,
- http://dx.doi.org/10.1002/cpe.1204
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Service discovery is a critical task in service-oriented architectures. In this paper, we study GRIMOIRES, the semantics-enabled service registry of the OMII software distribution, from a performance perspective. We study the scalability of GRIMOIRES against the amount of information that has been published into it. The methodology we use and the data we present are helpful for researchers to understand the performance characteristics of the registry and, more generally, of semantics-enabled service discovery. Based on this experimentation, we claim that GRIMOIRES is an efficient semantics-aware service discovery engine. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1255:Special Issue
- Author(s):Paul Watson,Simon Cox
- Newcastle University, Newcastle Upon Tyne, U.K.,Southampton University, Southampton, U.K.
http://dx.doi.org/10.1002/cpe.1255
CCPE Title/Author Summary
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Abstract:
No Abstract
CPE1266:FT-Grid: a system for achieving fault tolerance in grids
- Author(s):Jie Xu,Paul Townend,Nik Looker,Paul Groth
- School of Computing, University of Leeds, Leeds LS2 9JT, U.K.,School of Electronics and Computer Science, University of Southampton, Southampton S017 1B, U.K.
http://dx.doi.org/10.1002/cpe.1266
CCPE Title/Author Summary
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Abstract:
The FT-Grid system introduces a fault-tolerance framework that allows faults occurring in service-oriented systems to be tolerated, thus increasing the dependability of such systems. This paper presents the design, development and evaluation of FT-Grid. We show empirical evidence of the dependability benefits offered by FT-Grid by performing an experimental dependability analysis using fault-injection testing performed with the WS-FIT tool. We then illustrate a potential problem with voting-based fault-tolerance schemes in the service-oriented paradigm-namely that individual channels within a fault-tolerant system, supposed to be independent of each other, may in fact invoke common services as part of their workflow, thus increasing the potential for common-mode failure of those channels. We propose a solution to this issue by using the technique of provenance to provide FT-Grid with topological awareness. We implement a large experimental system, and-with the use of the Provenance Recording for Services system developed as part of the PASOA project at the University of Southampton-perform a large number of experiments that show that a topologically aware FT-Grid system serves as a much more dependable system than any other configuration tested, while imposing a negligible timing overhead. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1215:Specification, planning, and execution of QoS-aware Grid workflows within the Amadeus environment
- Author(s):Ivona Brandic,Sabri Pllana,Siegfried Benkner
- Institute of Scientific Computing, University of Vienna, Nordbergstraße 15, 1090 Vienna, Austria,
- http://dx.doi.org/10.1002/cpe.1215
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Commonly, at a high level of abstraction Grid applications are specified based on the workflow paradigm. However, majority of Grid workflow systems either do not support Quality of Service (QoS), or provide only partial QoS support for certain phases of the workflow lifecycle. In this paper we present Amadeus, which is a holistic service-oriented environment for QoS-aware Grid workflows. Amadeus considers user requirements, in terms of QoS constraints, during workflow specification, planning, and execution. Within the Amadeus environment workflows and the associated QoS constraints are specified at a high level using an intuitive graphical notation. A distinguishing feature of our system is the support of a comprehensive set of QoS requirements, which considers in addition to performance and economical aspects also legal and security aspects. A set of QoS-aware service-oriented components is provided for workflow planning to support automatic constraint-based service negotiation and workflow optimization. For improving the efficiency of workflow planning we introduce a QoS-aware workflow reduction technique. Furthermore, we present our static and dynamic planning strategies for workflow execution in accordance with user-specified requirements. For each phase of the workflow lifecycle we experimentally evaluate the corresponding Amadeus components. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1216:GPFlow: an intuitive environment for web-based scientific workflow
- Author(s):Asbjørn Rygg,Paul Roe,On Wong,Jiro Sumitomo
- Queensland University of Technology, Brisbane, Qld., Australia,
- http://dx.doi.org/10.1002/cpe.1216
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Increasingly scientists are using collections of software tools in their research. These tools are typically used in concert, often necessitating laborious and error-prone manual data reformatting and transfer. We present an intuitive workflow environment to support scientists with their research. The workflow, GPFlow, wraps legacy tools, presenting a high level, interactive web-based front end to scientists. The workflow backend is realized by a commercial grade workflow engine (Windows Workflow Foundation). The workflow model is inspired by spreadsheets and is novel in its support for an intuitive method of interaction enabling experimentation as required by many scientists, e.g. bioinformaticians. We apply GPFlow to two bioinformatics experiments and demonstrate its flexibility and simplicity. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1217:A preliminary version of this paper appeared in International Workshop on Workflow Systems in Grid Environments (2006).
- Author(s):Jianxun Liu,Chunjie Zhou,Jinjun Chen
- Hunan Knowledge Grid Lab, Hunan University of Science and Technology, Hunan, People's Republic of China,Faculty of Information and Communication Technologies, Swinburne University of Technology, Melbourne, Vic. 3122, Australia
http://dx.doi.org/10.1002/cpe.1217
CCPE Title/Author Summary
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Abstract:
The time model for business cooperation across organizations and in business service grid has a special and important requirement, i.e. workday calendar model (WdCM). Workflow plays an important role in modelling business processes across multi-enterprises or in service grid environments. However, current research in workflow time models does not pay sufficient attention to the differences in workday calendar between individual organizations. This paper aims to solve this problem by clarifying some basic concepts involved in the workday calendar models and presenting an XML-based framework for workday calendar expressions, i.e. WdCM. Based on this WdCM, temporal constraints and the time optimization issue of workflow processes are investigated. Finally, a case study is analysed to demonstrate the feasibility of our workday calendar model. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1218:A peak load control-based orchestration system for stable execution of hybrid services
- Author(s):Yonghwan Lee,Dugki Min
- School of Computer Science and Engineering, Konkuk University, Hwayang-dong, Kwangjin-gu, Seoul 133-701, Korea,
- http://dx.doi.org/10.1002/cpe.1218
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The prosperity of Internet results in a workflow executing engine's performance instability due to the request congestion for a short period of time. This paper proposes a peak load control (PLC) based orchestration system that can stably execute hybrid services. The PLC mechanism uses the delay time algorithm for controlling a BPEL engine's heavy peak load caused by the request congestion for a short period of time. In order to prove the stable performance of the PLC-based orchestration system, we analyze the proposed delay time algorithm. According to our experimental results, the proposed delay time algorithm can stably execute structured activities of WSBPEL specification in heavily overloaded state after the saturation phase and has an effect on controlling the states of peak load. In this paper, we also describe a hybrid service architecture model that can represent both Web Services and existing EAs as same type of services. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1219:Special Issue: First International Workshop on Workflow Systems in Grid Environments (WSGE2006)
- Author(s):Jinjun Chen,Omer F. Rana
- Centre for Information Technology Research, Faculty of Information and Communication Technologies, Swinburne University of Technology, Hawthorn, Melbourne, Vic. 3122, Australia,School of Computer Science, Cardiff University, Queen's Buildings, Newport Road, Cardiff CF24 3AA, U.K.
http://dx.doi.org/10.1002/cpe.1219
CCPE Title/Author Summary
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Abstract:
No Abstract
CPE1220:A taxonomy of grid workflow verification and validation
- Author(s):Jinjun Chen,Yun Yang
- Centre for Information Technology Research, Faculty of Information and Communication Technologies, Swinburne University of Technology, P.O. Box 218, Hawthorn, Melbourne, Vic. 3122, Australia,
- http://dx.doi.org/10.1002/cpe.1220
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
In a grid architecture, a grid workflow management system is a type of high-level grid middleware which is supposed to support modelling, redesign and execution of large-scale sophisticated scientific and business processes in many complex e-science and e-business applications. To ensure the correctness of grid workflow specification and execution, grid workflow verification and validation must be conducted. However, current research on grid workflow verification and validation is at the infancy stage and very few projects focus on them. Therefore, a systematic investigation and an overall classification of key issues in grid workflow verification and validation is helpful and should be presented so that we can keep on the right track and reduce unnecessary work as much as possible. As such, in this paper, we analyse the grid workflow verification and validation and present a taxonomy. Especially, we identify some important open points which are not discussed by the current research and hence need further investigation. The taxonomy is aimed at providing an overall picture of grid workflow verification and validation. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1221:Towards workflow simulation in service-oriented architecture: an event-based approach
- Author(s):Yanchong Zheng,Yushun Fan,Wei Tan
- National Engineering Research Center for Computer Integrated Manufacturing Systems, Department of Automation, Tsinghua University, Beijing 100084, China,
- http://dx.doi.org/10.1002/cpe.1221
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The emergence of service-oriented architecture (SOA) has brought about a loosely coupled computing environment that enables flexible integration and reuse of heterogeneous systems. On building a SOA for application systems, more and more research has been focused on service composition, in which workflow and simulation techniques have shown great potential. Simulation of services' interaction is important since the services ecosystem is dynamic and in continuous evolution. However, there is a lack in the research of services' simulation, especially models, methods and systems to support the simulation of interaction behavior of composite services. In this paper, an enhanced workflow simulation method with the support of interactive events mechanism is proposed to fulfill this requirement. At build time, we introduce an event
sub-model in the workflow meta-model, and our simulation engine supports the event-based interaction pattern at run time. With an example simulated in the prototype system developed according to our method, the advantages of our method in model verification and QoS evaluation for service compositions are also highlighted. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1226:Provenance in collection-oriented scientific workflows
- Author(s):Shawn Bowers,Timothy M. McPhillips,Bertram Ludäscher
- Genome Center, University of California, Davis, CA, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1226
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
We describe a provenance model tailored to scientific workflows based on the collection-oriented modeling and design paradigm. Our implementation within the Kepler scientific workflow system captures the dependencies of data and collection creation events on preexisting data and collections, and embeds these provenance records within the data stream. A provenance query engine operates on self-contained workflow traces representing serializations of the output data stream for particular workflow runs. We demonstrate this approach in our response to the first provenance challenge. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1236:Extracting causal graphs from an open provenance data model
- Author(s):Simon Miles,Paul Groth,Steve Munroe,Sheng Jiang,Thibaut Assandri,Luc Moreau
- School of Electronics and Computer Science, University of Southampton, U.K.,
- http://dx.doi.org/10.1002/cpe.1236
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The open provenance architecture approach to the challenge was distinct in several regards. In particular, it allows different components of the challenge workflow to independently record documentation, and for the workflow to be executed in different environments, made possible by an open, well-defined data model and architecture. Another noticeable feature is that we distinguish between the data recorded about what has occurred, process documentation, and the provenance of a data item, which is all that caused the data item to be as it is. In this view, provenance is obtained as the result of a query over process documentation. This distinction allows us to tailor the system to best address the separate requirements of recording and querying documentation. Other notable features include the explicit recording of causal relationships between both events and data items, an interaction-based world model, intensional definition of data items in queries rather than relying on explicit naming mechanisms, and styling of documentation to support non-functional application requirements such as reducing storage costs or ensuring privacy of data. In this paper, we describe how each of these features aid us in answering the challenge's provenance queries. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1237:Tackling the Provenance Challenge one layer at a time
- Author(s):Carlos Scheidegger,David Koop,Emanuele Santos,Huy Vo,Steven Callahan,Juliana Freire,Cláudio Silva
- Scientific Computing and Imaging Institute, University of Utah, UT, U.S.A.,School of Computing, University of Utah, UT, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1237
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
VisTrails is a new workflow and provenance management system that provides support for scientific data exploration and visualization. Whereas workflows have been traditionally used to automate repetitive tasks, for applications that are exploratory in nature, change is the norm. VisTrails uses a new change-based provenance mechanism, which was designed to handle rapidly evolving workflows. It uniformly and automatically captures provenance information for data products and for the evolution of the workflows used to generate these products. In this paper, we describe how the VisTrails provenance data are organized in layers and present a first approach for querying this data that we developed to tackle the Provenance Challenge queries. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1238:A Semantic Web approach to the provenance challenge
- Author(s):Jennifer Golbeck,James Hendler
- MIND Lab, 8400 Baltimore Ave., Suite 200, College Park, MD 20740, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1238
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Provenance is critically important for scientific workflow systems, as it allows users to verify data, repeat experiments, and discover dependencies. The Semantic Web is a natural fit for representing provenance, as it contains explicit support for representing and inferring connections between data and processes, as well as for adding annotations to data. In this article, we present a Semantic Web approach to the Provenance Challenge (Concurrency Computat.: Pract. Exper. 2007; DOI: 10.1002/cpe.1233). We use web services, ontologies, OWL reasoners, triple stores, and the SPARQL query language to implement the workflow, represent the data and the connections within it, and execute queries. We successfully implemented and answered all of the challenge queries. The flexibility of the Semantic Web also makes it quite easy to convert different provenance systems' data representation to a form we can work with. We illustrate this by integrating data from the PASS approach into our system, and successfully executing all of the challenge queries on it as well. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1247:Automatic capture and reconstruction of computational provenance
- Author(s):James Frew,Dominic Metzger,Peter Slaughter
- Donald Bren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106-5131, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1247
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The Earth System Science Server (ES3) project is developing a local infrastructure for managing Earth science data products derived from satellite remote sensing. By ‘local,’ we mean the infrastructure that a scientist uses to manage the creation and dissemination of her own data products, particularly those that are constantly incorporating corrections or improvements based on the scientist's own research. Therefore, in addition to being robust and capacious enough to support public access, ES3 is intended to be flexible enough to manage the idiosyncratic computing ensembles that typify scientific research. Instead of specifying provenance explicitly with a workflow model, ES3 extracts provenance information automatically from arbitrary applications by monitoring their interactions with their execution environment. These interactions (arguments, file I/O, system calls, etc.) are logged to the ES3 database, which assembles them into provenance graphs. These graphs resemble workflow specifications, but are really reports-they describe what actually happened, as opposed to what was requested. The ES3 database supports forward and backward navigation through provenance graphs (i.e. ancestor/descendant queries), as well as graph retrieval. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1252:gLite Job Provenance-a job-centric view
- Author(s):Aleš Křenek,Jiří Sitera,Luděk Matyska,František Dvořák,Miloš Mulač,Miroslav Ruda,Zdeněk Salvet
- CESNET, z. s. p.o., Zikova 4, Praha, Czech Republic,
- http://dx.doi.org/10.1002/cpe.1252
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Job Provenance (JP), part of the gLite Grid middleware, is a service that keeps long-term trace on completed computations for further reference. It is a job-centric service, keeping records about job life cycle, its environment, inputs/outputs, user parameters, and annotations. During the first provenance challenge, we explored the relation between a specific job-centric Grid-oriented provenance and a more general data provenance approach. The challenge represents a use case which emphasizes fields that were not priorities in the original JP design. However, we proved that the design is sufficiently general to cope with this mode of use. We also identified several areas where it is feasible to extend the current implementation. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1253:Tracking provenance semantics in heterogeneous execution systems
- Author(s):Joe Futrelle,James Myers
- National Center for Supercomputing Applications, 1205 W. Clark St., Urbana, IL 61801, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1253
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Digital artifacts result from complex, heterogeneous work processes involving content management, process execution, and curation. Accordingly, systems for tracking provenance of digital artifacts need to be able to integrate heterogeneous descriptions produced by loosely coupled or independent software components and work processes. In the approach described in this paper, two independently developed execution environments, D2K and CyberIntegrator, were instrumented by their developers to produce process and content descriptions in the form of resource description framework (RDF) statements. Using the open-source Kowari RDF database, these heterogeneous semantic descriptions were integrated to demonstrate the general applicability of RDF databases to answering provenance-related queries. The results suggest that the ‘open-world’ semantic model provided by RDF, and the powerful query languages provided by RDF databases, can be extended to integrate a wide variety of heterogeneous provenance-related information with minimal investment in new standard API's, metadata formats, and execution environments. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1256:Tracking provenance in a virtual data grid
- Author(s):Ben Clifford,Ian Foster,Jens-S. Voeckler,Michael Wilde,Yong Zhao
- Computation Institute, University of Chicago, Chicago, IL 60637, U.S.A.,USC Information Sciences Institute, Marina Del Rey, CA, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1256
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The virtual data model allows data sets to be described prior to, and separately from, their physical materialization. We have implemented this model in a Virtual Data Language (VDL) and associated supporting tools, which provide for both the storage, query, and retrieval of virtual data set descriptions, and the automated, on-demand materialization of virtual data sets. We use a standardized data provenance challenge exercise to illustrate the powerful queries that can be performed on the data maintained by these tools, which for a single virtual data set can include three elements: the computational procedure(s) that must be executed to materialize the data set, the runtime log(s) produced by the execution of the computation(s), and optional metadata annotation(s) that associate application semantics with data and procedures. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1227:PASSing the provenance challenge
- Author(s):David A. Holland,Margo I. Seltzer,Uri Braun,Kiran-Kumar Muniswamy-Reddy
- Harvard University, Cambridge, MA, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1227
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Provenance-aware storage systems (PASS) are a new class of storage system treating provenance as a first-class object, providing automatic collection, storage, and management of provenance as well as query capabilities. We developed the first PASS prototype between 2005 and 2006, targeting scientific end users. Prior to undertaking the provenance challenge, we had focused on provenance collection and storage, without much emphasis on a query model or language. The challenge forced us to (quickly) develop a query model and infrastructure implementing this model. We present a brief overview of the PASS prototype and a discussion of the evolution of the query model that we developed for the challenge. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1228:Provenance trails in the Wings/Pegasus system
- Author(s):Jihie Kim,Ewa Deelman,Yolanda Gil,Gaurang Mehta,Varun Ratnakar
- Information Sciences Institute, University of Southern California, 4676 Admiralty Way, Marina del Rey, CA 90292, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1228
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Our research focuses on creating and executing large-scale scientific workflows that often involve thousands of computations over distributed, shared resources. We describe an approach to workflow creation and refinement that uses semantic representations to (1) describe complex scientific applications in a data-independent manner, (2) automatically generate workflows of computations for given data sets, and (3) map the workflows to available computing resources for efficient execution. Our approach is implemented in the Wings/Pegasus workflow system and has been demonstrated in a variety of scientific application domains. This paper illustrates the application-level provenance information generated Wings during workflow creation and the refinement provenance by the Pegasus mapping
system for execution over grid computing environments. We show how this information is used in answering the queries of the First Provenance Challenge. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1229:Query capabilities of the Karma provenance framework
- Author(s):Yogesh L. Simmhan,Beth Plale,Dennis Gannon
- Computer Science Department, Indiana University, Bloomington, IN 47405, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1229
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Provenance metadata in e-Science captures the derivation history of data products generated from scientific workflows. Provenance forms a glue linking workflow execution with associated data products, and finds use in determining the quality of derived data, tracking resource usage, and for verifying and validating scientific experiments. In this article, we discuss the scope of provenance collected in the Karma provenance framework used in the LEAD Cyberinfrastructure project, distinguishing provenance metadata from generic annotations. We further describe our approaches to querying for different forms of provenance in Karma in the context of queries in the first provenance challenge. We use an incremental, building-block method to construct provenance queries based on the fundamental querying capabilities provided by the Karma service centered on the provenance data model. This has the advantage of keeping the Karma service generic and simple, and yet supports a wide range of queries. Karma successfully answers all but one challenge query. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1230:Applying content management to automated provenance capture
- Author(s):Karen L. Schuchardt,Tara Gibson,Eric Stephan,George Chin
- Pacific Northwest National Laboratory, P.O. Box 999, K7-90, Richland, WA 99352, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1230
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Workflows and data pipelines are becoming increasingly valuable to computational and experimental sciences. These automated systems are capable of generating significantly more data within the same amount of time compared to their manual counterparts. Automatically capturing and recording data provenance and annotation as part of these workflows are critical for data management, verification, and dissemination. We have been prototyping a workflow provenance system, targeted at biological workflows, that extends our content management technologies and other open source tools. We applied this prototype to the provenance challenge to demonstrate an end-to-end system that supports dynamic provenance capture, persistent content management, and dynamic searches of both provenance and metadata. We describe our prototype, which extends the Kepler system for the execution environment, the Scientific Annotation Middleware (SAM) content management software for data services, and an existing HTTP-based query protocol. Our implementation offers several unique capabilities, and through the use of standards, is able to provide access to the provenance record with a variety of commonly available client tools. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1231:Mining Taverna's semantic web of provenance
- Author(s):Jun Zhao,Carole Goble,Robert Stevens,Daniele Turi
- School of Computer Science, University of Manchester, Manchester M13 9PL, U.K.,
- http://dx.doi.org/10.1002/cpe.1231
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Taverna is a workflow workbench developed as part of the UK's myGrid project. Taverna's provenance model captures both internal provenance locally generated in Taverna and external provenance gathered from third-party data providers. This model also supports overlaying secondary provenance over the primary logs and lineage. This design is motivated by the particular properties of bioinformatics data and services used in Taverna. A Semantic Web of provenance, Ouzo, is built to combine the above different provenance by means of semantic annotations. This paper shows how Ouzo can be mined by a provenance usage component, Provenance Query and Answer (ProQA). ProQA supports provenance retrievals as well as provenance abstraction, aggregation, and semantic reasoning. ProQA is implemented as a suite APIs which can be deployed as provenance services to compose system provenance workflows that analyse experiment results using the provenance records. We show how these features of Taverna's provenance support us in answering the questions from the provenance challenge workshop and a set of additional provenance queries. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1232:Addressing the provenance challenge using ZOOM
- Author(s):Sarah Cohen-Boulakia,Olivier Biton,Shirley Cohen,Susan Davidson
- Department of Computer and Information Science, University of Pennsylvania, Levine Hall, 3330 Walnut St, Philadelphia, PA 19104, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1232
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
ZOOM* UserViews presents a model of provenance for scientific workflows that is simple, generic, and yet sufficiently expressive to answer questions of data and step provenance that have been encountered in a large variety of scientific case studies. In addition, ZOOM builds on the concept of composite step-classes - or sub-workflows - which is present in many scientific workflow systems to develop a notion of user views. This paper discusses the design and implementation of ZOOM in the context of the queries posed by the provenance challenge, and shows how user views affect the level of granularity at which provenance information can be seen and reasoned about. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1234:From computation models to models of provenance: the RWS approach
- Author(s):Bertram Ludäscher,Norbert Podhorszki,Ilkay Altintas,Shawn Bowers,Timothy McPhillips
- Department of Computer Science, University of California, Davis, CA, U.S.A.,San Diego Supercomputer Center, UC, San Diego, CA, U.S.A.,Genome Center, University of California, Davis, CA, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1234
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Scientific workflows often benefit from or even require advanced modeling constructs, e.g. nesting of subworkflows, cycles for executing loops, data-dependent routing, and pipelined execution. In such settings, an often overlooked aspect of provenance takes center stage: a suitable model of provenance (MoP) for scientific workflows should be based upon the underlying model of computation (MoC) used for executing the workflows. We can derive an adequate MoP from a MoC (such as Kahn's process networks) by taking into account the assumptions that a MoC entails, and by recording the observables which it affords. In this way, a MoP captures or at least better approximates ‘real’ data dependencies for workflows with advanced modeling constructs. As a specific instance, we elaborate on the Read-Write-ReSet model, a simple and flexible MoP suitable for a number of different MoCs. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1235:Automatic capture and efficient storage of e-Science experiment provenance
- Author(s):Roger S. Barga,Luciano A. Digiampietri
- Microsoft Research, One Microsoft Way Redmond, WA 98052, U.S.A.,Institute of Computing, University of Campinas, Sao Paulo, Brazil
http://dx.doi.org/10.1002/cpe.1235
CCPE Title/Author Summary
CCPE Metadata
Abstract:
For the first provenance challenge, we introduce a layered model to represent workflow provenance that allows navigation from an abstract model of the experiment to instance data collected during a specific experiment run. We outline modest extensions to a commercial workflow engine so it will automatically capture provenance at workflow runtime. We also present an approach to store this provenance data in a relational database. Finally, we demonstrate how core provenance queries in the challenge can be expressed in SQL and discuss the merits of our layered representation. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1240:On the evaluation of flooding-based search strategies in peer-to-peer networks
- Author(s):Rossano Gaeta,Matteo Sereno
- Dipartimento di Informatica, Università di Torino, Torino, Italy,
- http://dx.doi.org/10.1002/cpe.1240
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
This paper develops a directed generalized random graphs based analytical modeling framework to compare several variations of the basic flooding search strategy in unstructured decentralized peer-to-peer networks. To validate the model predictions, we designed and implemented a distributed crawler architecture that is able to efficiently capture snapshots of the top-level Gnutella overlay topology. The snapshots are used to obtain simulation results that are used to assess the accuracy of our model. The model predictions are then used to compute system-oriented performance indexes (the average and the coefficient of variation of the number of query messages) as well as user-oriented measures (the probability of finding at least one replica of a resource, the average search time). The trade-off between the optimization of system-oriented measures and the improvement of user-oriented quality indexes is investigated for several variations of the basic flooding strategy suggesting that adding control parameters to the basic flooding mechanism might prove beneficial in this class of systems. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1241:Segregation and scheduling for P2P applications with the interceptor middleware system
- Author(s):Cosimo Anglano
- Dipartimento di Informatica, Università del Piemonte Orientale, Via Bellini 25/g, 15100 Alessandria, Italy
http://dx.doi.org/10.1002/cpe.1241
CCPE Title/Author Summary
CCPE Metadata
Abstract:
Very large size peer-to-peer systems are often required to implement efficient and scalable services, but usually they can be built only by assembling resources contributed by many independent users. Among the guarantees that must be provided to convince these users to join the P2P system, particularly important is the ability of ensuring that P2P applications and services run on their nodes will not unacceptably degrade the performance of their own applications because of an excessive resource consumption. In this paper we present the Interceptor, a middleware-level application segregation and scheduling system, which is able to strictly enforce quantitative limitations on node resource usage and, at the same time, to make P2P applications achieve satisfactory performance even in face of these limitations. A proof-of-concept implementation has been carried out for the Linux operating system, and has been used to perform an extensive experimentation aimed at quantitatively evaluating the Interceptor. The results we obtained clearly demonstrate that the Interceptor is able to strictly enforce quantitative limitations on node resource usage, and at the same time to effectively schedule P2P applications. Copyright 2007 John Wiley & Sons, Ltd.
CPE1242:Lightweight emulation to study peer-to-peer systems
- Author(s):Lucas Nussbaum,Olivier Richard
- Laboratoire d'Informatique de Grenoble-LIG, ENSIMAG-Antenne de Montbonnot, 51 avenue Jean Kuntzmann, 38330 Montbonnot Saint-Martin, France,
- http://dx.doi.org/10.1002/cpe.1242
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The current methods used to test and study peer-to-peer systems (namely modeling, simulation or execution on real testbeds) often show limits regarding scalability, realism and accuracy. This paper describes and evaluates P2PLab, our framework to study peer-to-peer systems by combining emulation (use of the real studied application within a configured synthetic environment) and virtualization. P2PLab is scalable (it uses a distributed network model) and has good virtualization characteristics (many virtual nodes can be executed on the same physical node by using process-level virtualization). Experiments with the BitTorrent file-sharing system complete this article and demonstrate the usefulness of this platform. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1243:Optimizing the finger tables in Chord-like DHTs
- Author(s):Giovanni Chiola,Gennaro Cordasco,Luisa Gargano,Alberto Negro,Vittorio Scarano
- DISI, Università di Genova, Italy,DIA, Università di Salerno, Italy,
- http://dx.doi.org/10.1002/cpe.1243
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The Chord protocol is the best known example of implementation of logarithmic complexity routing for structured peer-to-peer networks. Its routing algorithm, however, does not provide an optimal trade-off between resources exploited (the size of the finger table) and performance (the average or worst-case number of hops to reach destination). Cordasco et al. showed that a finger table based on Fibonacci distances provides lower number of hops with fewer table entries. In this paper we generalize this result, showing how to construct an improved finger table when the objective is to reduce the number of hops, possibly at the expense of an increased size of the finger table. Our results can also be exploited to guarantee low routing time in case a fraction of nodes fails. Copyright 2007 John Wiley & Sons, Ltd.
CPE1244:P2PPerf: a framework for simulating and optimizing peer-to-peer-distributed computing applications
- Author(s):J.-B. Ernst-Desmulier,Julien Bourgeois,François Spies
- Laboratoire d'Informatique de l'Université de Franche-Comté (LIFC), LIFC - Centre Numérica, Cours Leprince-Ringuet - BP 21126, F-25201 Montbéliard cedex, France,
- http://dx.doi.org/10.1002/cpe.1244
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Peer-to-peer paradigm is more and more studied by the distributed computing community. Indeed, this type of architecture has interesting properties like the absence of centralized topology, fault tolerance or dynamic reorganization of the network. However, managing these networks is complex and the acceleration of the distributed applications is not ensured. That is why it is necessary to predict the performance as soon as possible in design and development phases, to bypass bottlenecks and to correct part of the applications that slow down the execution time. In this context, we propose P2PPerf: a simulation tool that aims at predicting performance and the execution time of a distributed application before its finalization. P2PPerf has been tested on JNGI: a P2P distributed computing application using the JXTA platform. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1245:Neighbourhood maps: decentralized ranking in small-world P2P networks
- Author(s):Matteo Dell'Amico
- DISI - Dipartimento di Informatica e Scienze dell'Informazione, Università degli Studi di Genova, Via Dodecaneso 35, 16146 Genova, Italy
http://dx.doi.org/10.1002/cpe.1245
CCPE Title/Author Summary
CCPE Metadata
Abstract:
Reputation in P2P networks is an important tool to encourage cooperation among peers. It is based on ranking of peers according to their past behaviour. In large-scale real-world networks, a global centralized knowledge about all nodes is neither affordable nor practical. For this reason, reputation ranking is often based on local history knowledge available on the evaluating node. This criterion is not optimal, since it ignores useful data about interactions with other peers. In our approach, evaluations of past history create recommendations between nodes, that will be used to form a network called web of trust. Under the assumption that the web of trust has the ubiquitous small-world property, we propose a simple, scalable and decentralized method, called neighbourhood maps, which approximates rankings calculated using link-analysis techniques, exploiting the short-distance characteristics of small-world networks. We test our algorithms using data from the OpenPGP web of trust, a real-world network of trust relationships, and by developing a simple simulation of a file-sharing network using an evolutive approach. Our results show that it is sufficient to have maps having size , where n is the size of the network, in order to have good results. Copyright 2007 John Wiley & Sons, Ltd.
CPE1246:Design and analysis of a scalable algorithm to monitor chord-based p2p systems at runtime
- Author(s):Andreas Binzenhöfer,Gerald Kunzmann,Robert Henjes
- Institute of Computer Science, University of Würzburg, Würzburg, Germany,Institute of Communication Networks, Technical University of Munich, Munich, Germany,
- http://dx.doi.org/10.1002/cpe.1246
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Peer-to-peer (p2p) systems are a highly decentralized, fault tolerant, and cost-effective alternative to the classic client-server architecture. Yet companies hesitate to use p2p algorithms to build new applications. Due to the decentralized nature of such a p2p system the carrier does not know anything about the current size, performance, and stability of its application. In this paper, we present an entirely distributed and scalable algorithm to monitor a running p2p network. The snapshot of the system enables a telecommunication carrier to gather information about the current performance parameters of the running system as well as to react to discovered errors. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1251:Special Issue: Hot Topics in Peer-to-Peer Systems
- Author(s):Luigi V. Mancini
- Dipartimento di Informatica, Universita di Roma ‘La Sapienza’, 113 Via Salaria, 00198 Roma, Italy
http://dx.doi.org/10.1002/cpe.1251
CCPE Title/Author Summary
CCPE Metadata
Abstract:
No Abstract
CPE1288:Linyphi: creating IPv6 mesh networks with SSR
- Author(s):Pengfei Di,Johannes Eickhold,Thomas Fuhrmann
- System Architecture Group, Computer Science Department, University of Karlsruhe, Karlsruhe, Germany,
- http://dx.doi.org/10.1002/cpe.1288
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Scalable source routing (SSR) is a self-organizing routing protocol which is especially suited for networks that do not have a well-crafted structure, e.g. ad hoc and mesh networks. SSR works on a flat identifier space. As a consequence, it can easily support host mobility without requiring any location directory or other centralized service. SSR is based on a virtual ring structure, which is used in a chord-like manner to obtain source routes to previously unknown destinations. It has been shown that SSR requires very little per node state and produces very little control messages. In particular, SSR has been found to outperform other ad hoc routing protocols such as ad hoc on-demand distance vector routing, optimized link-state routing, or beacon vector routing. In this paper we present Linyphi, an implementation of SSR for wireless access routers. Linyphi combines IPv6 and SSR so that unmodified IPv6 hosts have transparent connectivity to both the Linyphi mesh network and the IPv4/v6 Internet. We give a basic outline of the implementation and demonstrate its suitability in real-world mesh network scenarios. Furthermore, we illustrate the use of Linyphi for distributed applications such as the Linyphone peer-to-peer VoIP application. Copyright © 2008 John Wiley & Sons, Ltd.
CPE1269:Special Issue: The 2nd International Conference on Semantics, Knowledge and Grid
- Author(s):Geoffrey C. Fox,Hai Zhuge
- Community Grids Laboratory, School of Informatics, Indiana University, Bloomington, IN 47404, U.S.A.,China Knowledge Grid Research Group, Institute of Computing Technology, Chinese Academy of Sciences, Beijing, China
http://dx.doi.org/10.1002/cpe.1269
CCPE Title/Author Summary
CCPE Metadata
Abstract:
No Abstract
CPE1270:Efficient global checkpointing algorithms for mobile agents
- Author(s):Jin Yang,Jiannong Cao,Weigang Wu
- Internet and Mobile Computing Lab, Department of Computing, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong,
- http://dx.doi.org/10.1002/cpe.1270
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
As a widely used fault-tolerance technique, checkpointing can be divided into three categories: independent checkpointing, coordinated checkpointing, and communication-induced checkpointing (CIC). Independent checkpointing and coordinated checkpointing have been widely used in the design of fault-tolerant mobile agent systems, but CIC has not attracted much attention. CIC is flexible, efficient, and scalable, which is desirable for mobile agent (MA) systems. Furthermore, CIC can be well integrated with independent checkpointing for reliable MA migrations. In this paper, we propose two CIC-based checkpointing algorithms for MA systems. The Basic-CIC algorithm is developed by applying the classic CIC technique to MA systems, while the deferred message processing-based CIC (DM-CIC) improves the time efficiency by deciding when to make the forced checkpointing. Simulation results show that DM-CIC is stable and can help the system recover fast from failures. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1271:Semantic representation of scientific documents for the e-science Knowledge Grid
- Author(s):Xiangfeng Luo,Ning Fang,Bo Hu,Kai Yan,Huizhe Xiao
- Digital Content Computing and Semantic Grid Group, Key Lab. of Grid Technology, Shanghai University, Shanghai 200072, China,
- http://dx.doi.org/10.1002/cpe.1271
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Semantic representation of a topic is the basic element representation of a scientific document, which can be reflected by keywords' relations and their weights, as well as the state values of co-occurring keywords in a documental fragment in which a topic is discussed. Concept lattice and probability statistical methods are proposed to generate fuzzy cognitive maps (FCMs) as the original semantic representation of documental fragments (SRDFs) for the e-science Knowledge Grid. The additive capability of FCMs is used to merge SRDFs for reducing the noise and redundant information hidden in the original SRDFs. The loss of documental information in the merging process of SRDFs is measured by the proposed semantic merging entropy. Based on the distributional property of keywords on SRDFs, semantic distribution entropy is introduced to evaluate the change of keywords' distribution on SRDFs with the merging process. The semantic representation of a scientific document is automatically generated by the interconnection of the merged SRDFs belonging to one domain. The generating, merging and evaluating methods of the semantic representation of a scientific document are validated by experiments. The proposed semantic representation highlights the relations among keywords and topics, which reduces the complexity of document analysis in an e-science Knowledge Grid effectively. Copyright 2007 John Wiley & Sons, Ltd.
CPE1272:Resource space view tour mechanism
- Author(s):Jin Liu,Xiang Li,Liang Feng
- Key Lab of Intelligent Information Processing, Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100080, China,
- http://dx.doi.org/10.1002/cpe.1272
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The resource space model is a new semantic data model for managing various resources. On the basis of the model, this paper proposes a view mechanism for finding and reusing legacy resource spaces according to users' idiosyncratic interests. It establishes a flexible reorganizing mechanism of legacy resource spaces to reduce redundant work. As a viewpoint organization strategy, the resource subject tree is proposed as an effective way of discovering desirable resource space views. A case study is presented to demonstrate the proposed approach. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1273:Semantic patterns for user-interactive question answering
- Author(s):Tianyong Hao,Dawei Hu,Liu Wenyin,Qingtian Zeng
- Department of Computer Science, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China,Department of Computer Science and Technology, Shandong University of Science and Technology, Qingdao 266510, China
http://dx.doi.org/10.1002/cpe.1273
CCPE Title/Author Summary
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Abstract:
A new type of semantic pattern is proposed in this paper, which can be used by users to post questions and answers in user-interactive question answering (QA) systems. The necessary procedures of using semantic patterns in a QA system are also presented, which include question structure analysis, pattern matching, pattern generation, pattern classification and answer extraction. Both the manual creation method and the automatic generation method are proposed for patterns for different applications. A pattern instantiation level metrics is also presented for the predication of the quality of generated or learned patterns. We implemented a user interface for using the semantic pattern in our QA system, which allows users to effectively post and answer questions. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1274:Modeling language and tools for the semantic link network
- Author(s):Hai Zhuge,Kehua Yuan,Jin Liu,Junsheng Zhang,Xiaofeng Wang
- China Knowledge Grid Research Group, Key Lab of Intelligent Information Processing, Institute of Computing Technology, Chinese Academy of Sciences, P.O. Box 2704-28, 100080 Beijing, China,
- http://dx.doi.org/10.1002/cpe.1274
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The semantic link network (SLN) is the extension of the hyperlink Web by attaching semantics to hyperlinks. It is an approach to construct a semantic overlay on Web resources. The specification of the semantics of the SLN model is an essential issue of SLN application. This paper proposes a modeling language for SLN consisting of an algebraic definition for SLN, a SLN metamodel and a Unified Modeling Language (UML) profile for SLN. The SLN metamodel specifies the primitives of the modeling language. The UML profile for SLN defines the specific syntax on SLN to make the modeling language understandable and usable. The development of the SLN builder implementing this language and the graphical SLN browser is introduced. This work is a part of the SLN model. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1275:Semantic knowledge facilities for a web-based recipe database system supporting personalization
- Author(s):Liping Wang,Qing Li,Guozhu Dong,Yu Li
- Department of Computer Science, City University of Hong Kong, Hong Kong SAR, China,Department of Computer Science and Engineering, Wright State University, Dayton, OH, U.S.A.,Department of Computer Science, Hong Kong Baptist University, Hong Kong SAR, China
http://dx.doi.org/10.1002/cpe.1275
CCPE Title/Author Summary
CCPE Metadata
Abstract:
The recent explosive proliferation of interesting and useful data over the Web such as various recipes, while providing people with readily available information, brings out a challenging issue on how to manage such non-conventional data effectively. To respond to the challenge, we have been developing a Web-based recipe database system called Dish_Master to manage recipes in a novel way, which not only covers the static recipe attributes but also elucidates the dynamic cooking behaviors. In this paper, we present several semantic knowledge facilities devised in Dish_Master, including a set of semantic modeling and knowledge constructs to effectively represent recipe data, rules and constraints, and user profile aspects. With such a rich set of semantic knowledge facilities, Dish_Master lays down a solid foundation of providing users with personalized services such as adaptation and recommendation. Users can benefit from the system's real-time consultation and automatic summarization of cuisine knowledge. The usefulness and elegance of Dish_Master are demonstrated through an experimental prototype system. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1276:XML Metadata Services
- Author(s):Mehmet S. Aktas,Geoffrey C. Fox,Marlon Pierce,Sangyoon Oh
- Community Grids Lab, Bloomington, Indiana University, IN 47403, U.S.A.,Computer Engineering Department, Ajou University, South Korea
http://dx.doi.org/10.1002/cpe.1276
CCPE Title/Author Summary
CCPE Metadata
Abstract:
As service-oriented architecture principles have gained importance, an emerging need has appeared for methodologies to locate desired services that provide access to their capability descriptions. These services must typically be assembled into short-term service collections that, together with code execution services, are combined into a meta-application to perform a particular task. To address the metadata requirements of these problems, we introduce a hybrid Information Service to manage both stateless and stateful (transient) metadata. We leverage the two widely used Web Service standards: Universal Description, Discovery and Integration (UDDI) and Web Services Context (WS-Context), in our design. We describe our approach and experiences when designing ‘semantics’. We report the results from a prototype of the system that is applied to a mobile environment for optimizing Web Service communications. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1214:Methodology for modelling SPMD hybrid parallel computation
- Author(s):L. M. Liebrock,S. P. Goudy
- New Mexico Institute of Mining and Technology, Computer Science Department, Socorro, NM 87801, U.S.A.,Sandia National Laboratories, Albuquerque, NM 87185, U.S.A.
http://dx.doi.org/10.1002/cpe.1214
CCPE Title/Author Summary
CCPE Metadata
Abstract:
This research defines and analyzes a methodology for deriving a performance model for SPMD hybrid parallel applications. Hybrid parallelism combines shared memory and message passing computing models.
Creation of a model based on complexity analysis of an application code and its data structures.
Enhancement of a static complexity model by dynamic factors to capture execution time phenomena, such as memory hierarchy effects.
Quantitative analysis of model characteristics and the effects of perturbations in measured parameters.
These research results are presented in the context of a hybrid parallel implementation of a sparse linear algebra kernel. A model for this kernel is derived and analyzed using the methodology. Application of the model on two large parallel computing platforms provides case studies for the methodology. Operating system issues, machine balance factor, and memory hierarchy effects on model accuracy are examined. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1223:RLANG
- Author(s):J. H. Nyström,P. W. Trinder,D. J. King
- School of Mathematical and Computer Sciences, Heriot-Watt University, Edinburgh, U.K.,UK Software & Systems Engineering Research Group, Motorola Labs, Basingstoke, U.K.
http://dx.doi.org/10.1002/cpe.1223
CCPE Title/Author Summary
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Abstract:
Currently most distributed telecoms software is engineered using low- and mid-level distributed technologies, but there is a drive to use high-level distribution. This paper reports the first systematic comparison of a high-level distributed programming language in the context of substantial commercial products. Our research strategy is to reengineer some C++/CORBA telecoms applications in ERLANG, a high-level distributed language, and make comparative measurements. Investigating the potential advantages of the high-level ERLANG technology shows that two significant benefits are realized. Firstly, robust configurable systems are easily developed using the high-level constructs for fault tolerance and distribution. The ERLANG code exhibits resilience: sustaining throughput at extreme loads and automatically recovering when load drops; availability: remaining available despite repeated and multiple failures; dynamic reconfigurability: with throughput scaling near-linearly when resources are added or removed. Secondly, ERLANG delivers significant productivity and maintainability benefits: the ERLANG components are less than one-third of the size of their C++ counterparts. The productivity gains are attributed to specific language features, for example, high-level communication saves 22%, and automatic memory management saves 11% - compared with the C++ implementation. Investigating the feasibility of the high-level ERLANG technology demonstrates that it fulfils several essential requirements. The requisite distributed functionality is readily specified, even although control of low-level distributed coordination aspects is abrogated to the ERLANG implementation. At the expense of additional memory residency, excellent time performance is achieved, e.g. three times faster than the C++ implementation, due to ERLANG's lightweight processes. ERLANG interoperates at low cost with conventional technologies, allowing incremental reengineering of large distributed systems. The technology is available on the required hardware/operating system platforms, and is well supported. Copyright 2007 John Wiley & Sons, Ltd.
CPE1248:A definition of and linguistic support for partial quiescence
- Author(s):Billy Yan-Kit Man,Hiu Ning (Angela) Chan,Andrew J. Gallagher,Appu S. Goundan,Aaron W. Keen,Ronald A. Olsson
- Department of Computer Science, University of California, Davis, CA 95616, U.S.A.,Computer Science Department, California Polytechnic State University, San Luis Obispo, CA 93407, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1248
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The global quiescence (GQ) of a distributed computation (or distributed termination detection) is an important problem. Some concurrent programming languages and systems provide GQ detection as a built-in feature so that programmers do not need to write special synchronization code to detect quiescence. This paper introduces partial quiescence (PQ), which generalizes quiescence detection to a specified part of a distributed computation. PQ is useful, for example, when two independent concurrent computations that both rely on GQ need to be combined into a single program. The paper describes how we have designed and implemented a PQ mechanism within an experimental version of the JR concurrent programming language, and have gained experience with several representative applications. Our early results are promising qualitatively and quantitatively. Copyright 2007 John Wiley & Sons, Ltd.
CPE1249:InterGrid: a case for internetworking islands of Grids
- Author(s):Marcos Dias de Assunção,Rajkumar Buyya,Srikumar Venugopal
- Grid Computing and Distributed Systems (GRIDS) Laboratory, Department of Computer Science and Software Engineering, The University of Melbourne, Parkville, Melbourne, Vic. 3010, Australia,
- http://dx.doi.org/10.1002/cpe.1249
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Over the last few years, several nations around the world have set up Grids to share resources such as computers, data, and instruments to enable collaborative science, engineering, and business applications. These Grids follow a restricted organizational model wherein a Virtual Organization (VO) is created for a specific collaboration and all interactions such as resource sharing are limited to within the VO. Therefore, dispersed Grid initiatives have led to the creation of disparate Grids with little or no interaction between them. In this paper, we propose a model that: (a) promotes interlinking of islands of Grids through peering arrangements to enable InterGrid resource sharing; (b) provides a scalable structure for Grids that allow them to interconnect with one another and grow in a sustainable way; (c) creates a global Cyberinfrastructure to support e-Science and e-Business applications. This work identifies and proposes architecture, mechanisms, and policies that allow the internetworking of Grids and allows Grids to grow in a similar manner as the Internet. We term the structure resulting from such internetworking between Grids as the InterGrid. The proposed InterGrid architecture is composed of InterGrid Gateways responsible for managing peering arrangements between Grids. We discuss the main components of the architecture and present a research agenda to enable the InterGrid vision. Copyright 2007 John Wiley & Sons, Ltd.
CPE1281:Special Issue: Middleware for Grid Computing
- Author(s):Bruno Schulze,David Abramson,Radha Nandkumar,Rajkumar Buyya
- National Lab for Scientific Computing, Petropolis, RJ, Brazil,Monash University, Clayton Campus, Australia,National Center for Supercomputing Applications, Urbana, IL, U.S.A.,The University of Melbourne, Melbourne, Australia
http://dx.doi.org/10.1002/cpe.1281
CCPE Title/Author Summary
CCPE Metadata
Abstract:
No Abstract
CPE1282:the 4th International Workshop on Middleware for Grid Computing (MGC'06)
- Author(s):Luiz F. Bittencourt,Edmundo R. M. Madeira
- Institute of Computing, State University of Campinas, Campinas, São Paulo, Brazil,
- http://dx.doi.org/10.1002/cpe.1282
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
A scheduler must consider the heterogeneity and communication delays when scheduling dependent tasks on a grid. The task-scheduling problem is NP-Complete in general, which led us to the development of a heuristic for the associated optimization problem. In this work we present a dynamic adaptive approach to schedule dependent tasks onto a grid based on the Xavantes grid middleware. The developed dynamic approach is applied to the Path Clustering Heuristic, and introduces the concept of rounds, which take turns sending tasks to execution and evaluating the performance of the resources. The adaptive extension changes the size of rounds during the process execution, taking task attributes and resources performance as parameters, and it can be adopted in other task schedulers. The experiments show that the dynamic round-based and adaptive schedule can minimize the effects of performance losses while executing processes on the grid. Copyright 2007 John Wiley & Sons, Ltd.
CPE1283:Tunable scheduling in a GridRPC framework
- Author(s):A. Amar,R. Bolze,Y. Caniou,E. Caron,A. Chis,F. Desprez,B. Depardon,J.-S. Gay,G. Le Mahec,D. Loureiro
- LIP Laboratory (UMR CNRS, ENS Lyon, INRIA, UCBL 5668), GRAAL Project, 46 Allée d'Italie, F-69364 Lyon Cedex 07, France,
- http://dx.doi.org/10.1002/cpe.1283
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Among existing grid middleware approaches, one simple, powerful, and flexible approach consists of using servers available in different administrative domains through the classic client-server or remote procedure call paradigm. Network Enabled Servers (NES) implement this model, also called GridRPC. Clients submit computation requests to a scheduler, whose goal is to find a server available on the grid using some performance metric. The aim of this paper is to give an overview of a NES middleware developed in the GRAAL team called distributed interactive engineering toolbox (DIET) and to describe recent developments around plug-in schedulers, workflow management, and tools. DIET is a hierarchical set of components used for the development of applications based on computational servers on the grid. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1284:Coordinating access control in grid services
- Author(s):David W. Chadwick,Linying Su,Romain Laborde
- Computing Laboratory, University of Kent, Canterbury CT2 7NF, U.K.,Institut de Recherche en Informatique de Toulouse (IRIT), Université Paul Sabatier, 118 Route de Narbonne F-31062, Toulouse Cedex 9, France
http://dx.doi.org/10.1002/cpe.1284
CCPE Title/Author Summary
CCPE Metadata
Abstract:
We describe how to control the cumulative use of distributed grid resources by using coordination-aware policy decision points (coordinated PDPs) and an SQL database to hold ‘coordination’ data. When access to a resource is granted, obligations in the security policy ensure that the coordination database is updated. The coordination database is a normal grid service providing distributed access to the coordinated PDPs. Access to the databases is secured by the grid security infrastructure (GSI) and its own PDP, so that only authorized users (the coordinated PDPs) can access it. A coordinated PDP is imbedded into the Globus Toolkitv4 authorization chain as a custom PDP so that any grid service can be protected by a security policy that provides a coordination capability. Each coordinated PDP uses the services of an uncoordinated PDP to make its access control decisions, so that any existing stateless PDP can be supplemented with a coordination capability. We provide performance results for the coordinated PDPs and compare these with two stateless PDPs. Virtually the entire performance penalty of using coordinated PDPs is accounted for by the heavy costs of using GSI to secure communications between the coordinated PDPs and the coordination database. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1285:A service-oriented Grid environment for integration of distributed kidney models and resources
- Author(s):Xingchen Chu,Andrew Lonie,Peter Harris,S. Randall Thomas,Rajkumar Buyya
- Grid Computing and Distributed Systems Lab, Department of Computer Science and Software Engineering, The University of Melbourne, Melbourne, Vic., Australia,Department of Information Systems, The University of Melbourne, Melbourne, Vic., Australia,Faculty Information Technology (IT) Unit, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Vic., Australia,IBISC (Informatiques, Biologie Intégrée et Systèmes Complexes) FRE 2873, CNRS/Université d'Evry-Val d'Essonnes, 91000 Evry, France,
- http://dx.doi.org/10.1002/cpe.1285
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
In this paper, we present a Grid computing platform that provides experimental scientists and analysts with access to computational simulations and knowledge databases hosted in separate laboratories around the world involved with human and animal kidney research. No single laboratory can develop these resources in isolation, and the community of users should no longer need to be dependent upon the specific programming environment in which applications have been developed. This work aims at exploiting the power of high-bandwidth communications networks for collaborative research and for shared access to knowledge resources. This platform is developed within a specialist community of renal scientists but will be transferable to any other field of research requiring interaction between published literature and databases, theoretical models and simulations and the formulation of effective experimental design. Copyright © 2008 John Wiley & Sons, Ltd.
CPE1286:A replicated file system for Grid computing
- Author(s):Jiaying Zhang,Peter Honeyman
- Center of Information Technology Integration, University of Michigan, Ann Arbor, MI, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1286
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
To meet the rigorous demands of large-scale data sharing in global collaborations, we present a replication scheme for NFSv4 that supports mutable replication without sacrificing strong consistency guarantees. Experimental evaluation indicates a substantial performance advantage over a single-server system. With the introduction of a hierarchical replication control protocol, the overhead of replication is negligible even when applications mostly write and replication servers are widely distributed. Evaluation with the NAS Grid Benchmarks demonstrates that our system provides comparable and often better performance than GridFTP, the de facto standard for Grid data sharing. Copyright 2008 John Wiley & Sons, Ltd.
CPE1260:Proceedings of the First International Workshop on Virtualization Technology in Distributed Computing
- Author(s):H. Howie Huang,John F. Karpovich,Andrew S. Grimshaw
- Department of Computer Science, University of Virginia, 151 Engineer's Way, P.O. Box 400740, Charlottesville, VA 22904, U.S.A.,
- http://dx.doi.org/10.1002/cpe.1260
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
The average PC now contains a large and increasing amount of storage with an ever greater amount left unused. We believe there is an opportunity for organizations to harness the vast unused storage capacity on their PCs to create a very large, low-cost, shared storage system. What is needed is the proper storage system architecture and software to exploit and manage the unused portions of existing PC storage devices across an organization and make it reliably accessible to users and applications. We call our vision of such a storage system Storage@desk (SD). This paper describes our first step towards the realization of SD-a study of machine and storage characteristics and usage in a model organization. We studied 729 PCs in an academic institution for 91 days, monitoring the configuration, load and usage of the major machine subsystems, i.e. disk, memory, CPU and network. To further analyze the availability characteristics of storage in an SD system, we performed a trace-driven simulation of some basic storage allocation strategies. This paper presents the results of our data collection efforts, our analysis of the data, our simulation results and our conclusion that an SD system is indeed feasible and holds promise as a cost-effective way to create massive storage systems. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1262:Java multithreading-based parallel approximate arrow-type inverses
- Author(s):George A. Gravvanis,Victor N. Epitropou
- Department of Electrical and Computer Engineering, School of Engineering, Democritus University of Thrace, 12, Vas. Sofias Street, GR 67100 Xanthi, Greece,
- http://dx.doi.org/10.1002/cpe.1262
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
A new parallel shared memory Java multithreaded design and implementation of the explicit approximate inverse preconditioning, for efficiently solving arrow-type linear systems on symmetric multiprocessor systems (SMPs), is presented. A new parallel algorithm for computing a class of optimized approximate arrow-type inverse matrix is introduced. The performance on an SMP, using Java multithreading, is investigated by solving arrow-type linear systems and numerical results are given. The parallel performance of the construction of the optimized approximate inverse and the explicit preconditioned generalized conjugate gradient square scheme, using a dynamic workload scheduling, is also presented. Copyright © 2007 John Wiley & Sons, Ltd.
CPE1263:An adaptive extension library for improving collective communication operations
- Author(s):O. Hartmann,M. Kühnemann,T. Rauber,G. Rünger
- Department of Computer Science, Chemnitz University of Technology, 09107 Chemnitz, Germany,Department of Mathematics and Physics, Bayreuth University, 95445 Bayreuth, Germany,
- http://dx.doi.org/10.1002/cpe.1263
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
In this paper, we present an adaptive extension library that combines the advantage of using a portable MPI library with the ability to optimize the performance of specific collective communication operations. The extension library is built on top of MPI and can be used with any MPI library. Using the extension library, performance improvements can be achieved by an orthogonal organization of the processors in 2D or 3D meshes and by decomposing the collective communication operations into several consecutive phases of MPI communication. Additional point-to-point-based algorithms are also provided. The extension library works in two steps, an a priori configuration phase detecting possible improvements for implementing collective communication for the MPI library used and an execution phase selecting a better implementation during execution time. This allows an adaptation of the performance of MPI programs to a specific execution platform and communication situation. The experimental evaluation shows that significant performance improvements can be obtained for different MPI libraries by using the library extension for collective MPI communication operations in isolation as well as in the context of application programs. Copyright 2007 John Wiley & Sons, Ltd.
CPE1264:Babylon: middleware for distributed, parallel, and mobile Java applications
- Author(s):Willem van Heiningen,Steve MacDonald,Tim Brecht
- Integrative Biology, Hospital for Sick Children, Toronto, Ont., Canada,David R. Cheriton School of Computer Science, University of Waterloo, Waterloo, Ont., Canada,
- http://dx.doi.org/10.1002/cpe.1264
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Babylon is a collection of tools and services that provide a 100% Java-compatible environment for developing, running and managing parallel, distributed and mobile Java applications. It incorporates features such as object migration, asynchronous method invocation, and remote class loading, while providing an easy-to-use interface. Additionally, Babylon enables Java applications to seamlessly create and interact with remote objects, while protecting those objects from other applications by implementing access restrictions and separate namespaces. The implementation of Babylon centers around dynamic proxies, a feature first available in Java 1.3, that allow proxy objects to be created at runtime. Dynamic proxies play a key role in achieving the goals of Babylon. The potential cluster computing benefits of the system are demonstrated with experimental results, which show that sequential Java applications can achieve significant performance benefits from using Babylon to parallelize their work across a cluster of workstations. Copyright 2008 John Wiley & Sons, Ltd.
CPE1280:Distributing RePast agent-based simulations with HLA
- Author(s):R. Minson,G. K. Theodoropoulos
- School of Computer Science, University of Birmingham, Birmingham B15 2TT, U.K.,
- http://dx.doi.org/10.1002/cpe.1280
- CCPE Title/Author Summary
- CCPE Metadata
- Abstract:
Large, experimental multi-agent system (MAS) simulations are highly demanding tasks, both computationally and developmentally. Agent toolkits provide reliable templates for the design of even the largest MAS simulations, without offering a solution to computational limitations. Conversely, distributed simulation architectures offer performance benefits, but the introduction of parallel logic can complicate the design process significantly. The motivations of distribution are not limited to this question of processing power. True interoperation of sequential agent-simulation platforms would allow agents designed using different toolki