Multiagent and Grid Systems - Volume 3, issue 4

Authors: Herrero, Pilar | Pérez, María S.

Article Type: Editorial

DOI: 10.3233/MGS-2007-3401

Citation: Multiagent and Grid Systems, vol. 3, no. 4, pp. 353-354, 2007

Authors: Iordache, George V. | Boboila, Marcela S. | Pop, Florin | Stratan, Corina | Cristea, Valentin

Article Type: Research Article

Abstract: This paper describes a solution to the key problem of ensuring high performance behavior of the Grid, namely the scheduling of activities. It presents a distributed, fault-tolerant, scalable and efficient solution for optimizing task assignment. The scheduler uses a combination of genetic algorithms and lookup services built on a multiagent infrastructure for obtaining a scalable and highly reliable optimization tool. The experiments have been carried out on the MonALISA monitoring environment and its extensions. The results demonstrate very good behavior in comparison with other scheduling approaches.

Keywords: Grid computing, multiagent systems, scheduling, load-balancing, genetic algorithms

DOI: 10.3233/MGS-2007-3402

Citation: Multiagent and Grid Systems, vol. 3, no. 4, pp. 355-367, 2007

Authors: Ortega, Andrés Muñoz | Blaya, Juan A. Botía | Clemente, Félix J. García | Pérez, Gregorio Martínez | Skarmeta, Antonio F. Gómez

Article Type: Research Article

Abstract: Globus Toolkit version 4 (GT4) leads to a set of new services and tools. This is the culmination of a first step towards the migration to web services from previous Globus Toolkit versions. GT4 directly addresses basic issues, in the form of services, inherent to any distributed system like, for example, security, resource discovery, data movement and management, etc. However, we believe that an advanced management is still needed in the framework, in order to provide a system-wide view of these services. This is especially true in the case of security related services. They must be properly managed all across …different collaborating organizations within the grid infrastructure. This paper presents the major achievements when designing and developing a semantic-aware management framework for GT4 security services. Show more

Keywords: GT4 security services management, web service-oriented management, semantic-aware policy checking and validation

DOI: 10.3233/MGS-2007-3403

Citation: Multiagent and Grid Systems, vol. 3, no. 4, pp. 369-379, 2007

Authors: Baude, Françoise | Caromel, Denis | Leyton, Mario

Article Type: Research Article

Abstract: In this article a three staged file transfer approach for the Grid is proposed. File transfer in the Grid can take place at three stages: deployment, user application execution, and retrieval (post-execution). Each stage has it's own environmental requirements, and therefore different techniques must be applied. The contributions presented in this article can be grouped in two. First, the integration of heterogeneous resource acquisition and file transfer protocols. This allows on-the-fly deployment and retrieval of files. Secondly, an asynchronous file transfer mechanism based on active objects, wait-by-necessity, and automatic continuation. The proposed file transfer model has …been implemented using the ProActive middleware. ProActive provides, among others, a Grid infrastructure abstraction using deployment descriptors, and a programming model based on active objects with transparent futures. Finally, the proposed file transfer model is benchmarked and validated with a real case study: BLAST. Show more

Keywords: File transfer, Grid computing, deployment, active objects, BLAST

DOI: 10.3233/MGS-2007-3404

Citation: Multiagent and Grid Systems, vol. 3, no. 4, pp. 381-391, 2007

Authors: Kuliberda, Kamil | Adamus, Radoslaw | Wislicki, Jacek | Kaczmarski, Krzysztof | Kowalski, Tomasz Marek | Subieta, Kazimierz

Article Type: Research Article

Abstract: The article describes a solution to a problem of integration of distributed, heterogeneous and variously fragmented collections of data located in object-oriented databases. Basing on their investigation, authors present three methods of integration procedures for differently structured databases constituting virtual repositories in a data grid with a P2P architecture. The core of the described architecture is based on the Stack-Based Query Language (SBQL) and virtual updatable SBQL views. In the background, the system is based on a P2P architecture for data transporting and indexing. The article provides three short examples on how to apply the proposal in virtual repository. The …procedures are implemented under the integrator prototype. Show more

Keywords: Grid, virtual repository, peer-to-peer, virtual network, OODBMS, transparent integration, distributed system

DOI: 10.3233/MGS-2007-3405

Citation: Multiagent and Grid Systems, vol. 3, no. 4, pp. 393-410, 2007

Authors: Wierzbicki, Adam | Kaszuba, Tomasz

Article Type: Research Article

Abstract: The development of complex applications that use the Peer-to-Peer computing model is restrained by security and trust management concerns, despite evident performance benefits. An example of such an application of P2P computing is P2P Massive Multi-user Online Games, where cheating by players is simple without centralized control or specialized trust management mechanisms. The article presents new techniques for trust enforcement that use cryptographic methods and are adapted to the dynamic membership and resources of P2P systems. The proposed approach to trust management differs significantly from previous work in the area that mainly used reputation. The paper describes a comprehensive trust …management infrastructure for P2P MMO games that enables to recognize and exclude cheating players while keeping the performance overhead as low as possible. While the architecture requires trusted centralized components (superpeers), their role in trust management is limited to a minimum and the performance gains of using the P2P computing model are preserved. The performance of the proposed trust management architecture is validated by a prototype implementation in an MMO game. Show more

Keywords: Peer-to-Peer computing, trust management, reputation, cryptography, massive multiplayer online games, pastry, scribe, bluetooth, implementation, security, performance

DOI: 10.3233/MGS-2007-3406

Citation: Multiagent and Grid Systems, vol. 3, no. 4, pp. 411-428, 2007

Authors: Vázquez-Poletti, J.L. | Huedo, E. | Montero, R.S. | Llorente, I.M.

Article Type: Research Article

Abstract: In order to achieve a reasonable degree of performance and reliability, Metascheduling has been revealed as a key functionality of the grid middleware. The aim of this paper is to provide a comparative analysis between two major grid scheduling philosophies: a semi-centralized approach, represented by the EGEE Workload Management System, and a fully distributed approach, represented by the Grid Way Metascheduler. The distributed approach follow a loosely-coupled philosophy for the Grid resembling the end-to-end principle, which has fostered the spectacular development and diffusion of the Internet and, in particular, Web technologies in the past decade. The comparative is both theoretical, …through a functionality checklist, and experimental, through the execution of a fusion physics plasma application on the EGEE infrastructure. This paper not only includes a standard analysis with the obtained times, but also a complex analysis based on a performance model. Show more

Keywords: Grid computing, metascheduling, EGEE WMS, Grid Way, fusion physics

DOI: 10.3233/MGS-2007-3407

Citation: Multiagent and Grid Systems, vol. 3, no. 4, pp. 429-439, 2007

Authors: Sánchez, Alberto | Pérez, María S. | Gueant, Pierre | Montes, Jesús | Herrero, Pilar | Cortes, Toni

Article Type: Research Article

Abstract: Data transfer in a grid environment has become one critical activity in a large number of applications that require access to huge volumes of data. In these scenarios, characterized by large latencies, poor performance and complex dependencies, the use of approaches such as multiagents or parallel I/O can provide a great benefit. However, all the attempts to improve the performance of data transfer in grids should achieve the interoperability with already established data transfer schemes. GridFTP is one of the most known and used data grid transfer protocols. This paper describes MAPFS-DSI, a modification of the GridFTP server, …based on a multiagent parallel file system. MAPFS-DSI increases the performance of data transfers, but keeping the interoperability with existing GridFTP servers. Show more

Keywords: Data transfer, GridFTP, parallel file system, multiagent system, MAPFS

DOI: 10.3233/MGS-2007-3408

Citation: Multiagent and Grid Systems, vol. 3, no. 4, pp. 441-451, 2007