A List-Based Strategy for Optimal Replica Placement in Data Grid Systems

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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Replica placement in data grid: considering utility and risk

International Conference on Information Technology: Coding and Computing (ITCC'05) - Volume II ◽

10.1109/itcc.2005.244 ◽

2005 ◽

Cited By ~ 22

Author(s):

R.M. Rahman ◽

K. Barker ◽

R. Alhajj

Keyword(s):

Data Grid ◽

Replica Placement

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Replica Placement Strategy for Data Grid Environment

International Journal of Grid and High Performance Computing ◽

10.4018/jghpc.2013010105 ◽

2013 ◽

Vol 5 (1) ◽

pp. 70-81 ◽

Cited By ~ 3

Author(s):

Mohammed K. Madi ◽

Yuhanis Yusof ◽

Suhaidi Hassan

Keyword(s):

Resource Sharing ◽

Data Access ◽

Data Grid ◽

Computational Time ◽

Replica Placement ◽

File Transfer ◽

Large Bandwidth ◽

Multiple Copies ◽

Data Files ◽

Computational Resources

Data Grid is an infrastructure that manages huge amount of data files, and provides intensive computational resources across geographically distributed collaboration. To increase resource availability and to ease resource sharing in such environment, there is a need for replication services. Data replication is one of the methods used to improve the performance of data access in distributed systems by replicating multiple copies of data files in the distributed sites. Replica placement mechanism is the process of identifying where to place copies of replicated data files in a Grid system. Existing work identifies the suitable sites based on number of requests and read cost of the required file. Such approaches consume large bandwidth and increases the computational time. The authors propose a replica placement strategy (RPS) that finds the best locations to store replicas based on four criteria, namely, 1) Read Cost, 2) File Transfer Time, 3) Sites’ Workload, and 4) Replication Sites. OptorSim is used to evaluate the performance of this replica placement strategy. The simulation results show that RPS requires less execution time and consumes less network usage compared to existing approaches of Simple Optimizer and LFU (Least Frequently Used).

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