Article ID: CPE708

Publisher John Wiley Sons, Ltd. Chichester, UK
Category Research Article
Article Title A stochastic load balancing algorithm for Computing
Volume ID 15
Issue ID 1
Date Jan 1 2003
DOI(URI) http://dx.doi.org/10.1002/cpe.708
Article ID CPE708
Author Name(s) Yuk Yin Wong1Kwong Sak Leung2Kin Hong Lee3
Author Email(s) clevin.wong@cityu.edu.hk1
Affiliation(s) Computing Services Centre, City University of Hong Kong, Tat Chee Avenue, Kln., Hong Kong 1>Department of Computer Science and Engineering, Chinese University of Hong Kong, Shatin, N.T., Hong 2 3
Keyword(s) Internet computing, stochastic load balancing, distributed systems, Java computing,
Abstract
This paper presents a stochastic dynamic load balancing algorithm for Internet computing, which is a new type of distributed computing involving heterogeneous workstations from different organizations on the Internet. To realize the practical environment, we assume the system to be comprised of heterogeneous,untrusted and non dedicated workstations connected by a non dedicated network. Our algorithm uses the product of the average processing time and the queue length of system jobs as the load index. Dynamic communication delay is included in the execution cost calculation. The transfer policy and the location policy are combined in a stochastic algorithm. State information exchange is done via information feedback and mutual updating. Simulations demonstrate that our algorithm outperforms conventional approaches over a wide range of system parameters. These results are reconfirmed by empirical experiments after we have implemented the algorithms on the Distributed Java Machine global virtual machine. Copyright 2003 John Wiley Sons, Ltd.

Article ID: CPE706

Publisher John Wiley Sons, Ltd. Chichester, UK
Category Research Article
Article Title A comparison of concurrent programming and cooperative multithreading
Volume ID 15
Issue ID 1
Date Jan 1 2003
DOI(URI) http://dx.doi.org/10.1002/cpe.706
Article ID CPE706
Author Name(s) Ronald A Olsson1Tiejun Li2Eugene F. Fodor3Aaron W. Keen4
Author Email(s) olsson@cs.ucdavis.edu1
Affiliation(s) Department of Computer Science, University of California, Davis, CA 95616, U.S.A. 12 3 4
Keyword(s) cooperative multithreading, concurrent programming, parallel and distributed programming languages, synchronization mechanisms, synchronization optimization,
Abstract
This paper presents a comparison of the cooperative multithreading model with the general concurrent programming model.It focuses on the execution time performance of a range of standard concurrent programming applications. The overall results are mixed. In some cases, programs written in the cooperative multithreading model outperform those written in the general concurrent programming model. The contributions of this paper are twofold. First, it presents a thorough analysis of the performances of applications in the different models, i.e. to explain the criteria that determine when a program in one model will outperform an equivalent program in the other. Second, it examines the tradeoffs in writing programs in the different programming styles. In some cases, better performance comes at the cost of more complicated code. Copyright 2003 John Wiley Sons, Ltd.

Article ID: CPE704

Publisher John Wiley Sons, Ltd. Chichester, UK
Category Research Article
Article Title The Virtual Laboratory: a toolset to enable distributed molecular modelling for drug design on the World Wide Grid
Volume ID 15
Issue ID 1
Date Jan 1 2003
DOI(URI) http://dx.doi.org/10.1002/cpe.704
Article ID CPE704
Author Name(s) Rajkumar Buyya1Kim Branson2Jon Giddy3DavidA Abramson4
Author Email(s) rajkumar@buyya.com1
Affiliation(s) Grid Computing and Distributed Systems Laboratory, Department of Computer Science and Software Engin 1Structural Biology, Walter and Eliza Hall Institute, Royal Parade, Parkville, Melbourne, Australia 2Welsh Science Centre, Department of Computer Science, Cardiff University, Cardiff, U.K. 3School of Computer Science and Software Engineering, Monash University, Caulfield Campus, Melbourne 4
Keyword(s) Grid computing, drug design, application scheduling, grid economy,
Abstract
Computational Grids are emerging as a new paradigm for sharing and aggregation of geographically distributed resources for solving large scale compute and data intensive problems in science, engineering and commerce. However, application development, resource management and scheduling in these environments is a complex undertaking. In this paper, we illustrate the development of a Virtual Laboratory environment by leveraging existing Grid technologies to enable molecular modelling for drug design on geographically distributed resources. It involves screening millions of compounds in the chemical database CDB against a protein target to identify those with potential use for drug design. We have used the Nimrod G parameter specification language to transform the existing molecular docking application into a parameter sweep application for executing on distributed systems. We have developed new tools for enabling access to ligand records ;molecules in the CDB from remote resources. The Nimrod G resource broker along with molecule CDB data broker is used for scheduling and on demand processing of docking jobs on the World Wide Grid ;WWG ; resources. The results demonstrate the ease of use and power of the Nimrod G and virtual laboratory tools for grid computing. Copyright 2003 John Wiley Sons, Ltd.