Economic Model for Consistency Management of Replicas in Data Grids with OptorSim Simulator

2012 ◽

pp. 42-57

Author(s):

Ghalem Belalem ◽

Naima Belayachi ◽

Radjaa Behidji ◽

Belabbes Yagoubi

Keyword(s):

Load Balancing ◽

Large Scale ◽

Data Grids ◽

Distributed Resources ◽

Data Set ◽

Large Scale Systems ◽

Consistency Management ◽

Geographically Distributed ◽

Replication Technique ◽

Improve Service Quality

Data grids are current solutions to the needs of large scale systems and provide a set of different geographically distributed resources. Their goal is to offer an important capacity of parallel calculation, ensure a data effective and rapid access, improve the availability, and tolerate the breakdowns. In such systems, however, these advantages are possible only by using the replication technique. The use of this technique raises the problem of maintaining consistency of replicas of the same data set. In order to guarantee replica set reliability, it is necessary to have high coherence. This fact, however, penalizes performance. In this paper, the authors propose studying balancing influence on replica quality. For this reason, a service of hybrid consistency management is developed, which combines the pessimistic and optimistic approaches and is extended by a load balancing service to improve service quality. This service is articulated on a hierarchical model with two levels.

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Policy Driven Negotiation to Improve the QoS in Data Grid

Encyclopedia of E-Business Development and Management in the Global Economy ◽

10.4018/978-1-61520-611-7.ch105 ◽

2010 ◽

pp. 1041-1056

Author(s):

Ghalem Belalem

Keyword(s):

Large Scale ◽

Data Access ◽

Data Grid ◽

Management Service ◽

Replica Placement ◽

Data Grids ◽

Large Scale Systems ◽

Consistency Management ◽

Access Latency ◽

Replicated Data

Data grids have become an interesting and popular domain in grid community (Foster and Kesselmann, 2004). Generally, the grids are proposed as solutions for large scale systems, where data replication is a well-known technique used to reduce access latency and bandwidth, and increase availability. In splitting of the advantages of replication, there are many problems that should be solved such as, • The replica placement that determines the optimal locations of replicated data in order to reduce the storage cost and data access (Xu et al, 2002); • The problem of determining which replica will be accessed to in terms of consistency when we need to execute a read or write operation (Ranganathan and Foster, 2001); • The problem of degree of replication which consists in finding a minimal number of replicas without reducing the performance of user applications; • The problem of replica consistency that concerns the consistency of a set of replicated data. This consistency provides a completely coherent view of all the replicas for a user (Gray et al 1996). Our principal aim, in this article, is to integrate into consistency management service, an approach based on an economic model for resolving conflicts detected in the data grid.

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Improvement on Reading and Writing for Replica Consistency

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.187.232 ◽

2011 ◽

Vol 187 ◽

pp. 232-236

Author(s):

Xun Yi Ren ◽

Ru Chuan Wang ◽

Xiao Dong Ma

Keyword(s):

Experimental Results ◽

Master Node ◽

Data Grids ◽

Reading And Writing ◽

Consistency Management ◽

Proposed Model ◽

Replica Consistency

Maintaining consistency among replicas is an important technique for improving the efficiency of data grids. In order to improve replica consistency management, one fast reading and writing method is proposed, where two update algorithms is applied to accelerate Maintaining consistency among replicas. The first layer is synchronization writing form one peer to many peers at the same time, thus avoiding repeat read and writing of replica from the primary node. In second algorithm the node with good bandwidth is elected as new master node to enlarge the number of concurrent update streams. The experimental results show that the proposed model can reduce complete time compared with lazy copy, positive copy in some scenes.

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An Approach Based on Market Economy for Consistency Management in Data Grids with Optorsim Simulator

Web Engineering Advancements and Trends ◽

10.4018/978-1-60566-719-5.ch016 ◽

2010 ◽

pp. 269-280

Author(s):

Ghalem Belalem ◽

Belabbes Yagoubi ◽

Samah Bouamama

Keyword(s):

Quality Of Service ◽

Response Times ◽

Data Access ◽

Data Grids ◽

Distributed Resources ◽

Suggested Approach ◽

Consistency Management ◽

Geographically Distributed ◽

Large Systems

Data Grids are currently solutions suggested to meet the needs of scale large systems. They provide highly varied and geographically distributed resources of which the goal is to ensure fast and effective data access. This improves availability, and tolerates breakdowns. In such systems, these advantages are not possible without the use of replication. The use of the technique of replication poses a problem in regards to the maintenance of the consistency of the same data replicas; the strategies of replication of the data and scheduling of jobs were tested by simulation. Several grid simulators were born. One of the most interesting simulators for this study is the OptorSim tool. In this chapter, the authors present an extension of the OptorSim by a consistency management module of the replicas in Data Grids; they propose a hybrid step which combines the economic models conceived for a hierarchical model with two levels. This suggested approach has two vocations, the first allowing a reduction in response times compared to an pessimistic approach, the second gives the good quality of service compared to optimistic approach.

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Load Balancing to Increase the Consistency of Replicas in Data Grids

International Journal of Distributed Systems and Technologies ◽

10.4018/jdst.2010100104 ◽

2010 ◽

Vol 1 (4) ◽

pp. 42-57 ◽

Cited By ~ 3

Author(s):

Ghalem Belalem ◽

Naima Belayachi ◽

Radjaa Behidji ◽

Belabbes Yagoubi

Keyword(s):

Load Balancing ◽

Large Scale ◽

Data Grids ◽

Distributed Resources ◽

Data Set ◽

Large Scale Systems ◽

Consistency Management ◽

Geographically Distributed ◽

Replication Technique ◽

Improve Service Quality

Data grids are current solutions to the needs of large scale systems and provide a set of different geographically distributed resources. Their goal is to offer an important capacity of parallel calculation, ensure a data effective and rapid access, improve the availability, and tolerate the breakdowns. In such systems, however, these advantages are possible only by using the replication technique. The use of this technique raises the problem of maintaining consistency of replicas of the same data set. In order to guarantee replica set reliability, it is necessary to have high coherence. This fact, however, penalizes performance. In this paper, the authors propose studying balancing influence on replica quality. For this reason, a service of hybrid consistency management is developed, which combines the pessimistic and optimistic approaches and is extended by a load balancing service to improve service quality. This service is articulated on a hierarchical model with two levels.

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Dynamic Negotiation Mechanism for Improving Service Quality for Replicas in Data Grids

Transdisciplinary Advancements in Cognitive Mechanisms and Human Information Processing ◽

10.4018/978-1-60960-553-7.ch006 ◽

2011 ◽

pp. 99-114

Author(s):

Ghalem Belalem

Keyword(s):

Service Quality ◽

Large Scale ◽

Hybrid Approach ◽

Data Grid ◽

Data Grids ◽

Computing Power ◽

Consistency Management ◽

Practical Operation ◽

Negotiation Mechanism ◽

Technical Replication

In order not to be limited in term of calculation, storage and communication, the concept of grid, which does not cease evolving, makes it possible to offer a practical operation of work unified as well as a great storage and computing power. To manage the division in the data grid, technical replication is used, but in spite of their advantages, the competitor access to the data could involve inconsistencies, from where the great challenge to ensure the consistency management between replicas of object. In this chapter, we describe model double-layered adapted to the applications on a large scale and which represents the support of the hybrid approach of consistency management of replicas based on pessimistic and optimistic approaches. This hybrid approach present an adapted mechanism based on the various negotiation forms between virtual consistency agents to be able to reduce the number of conflicts between replicas in data grids.

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