QoS‐aware replica placement for grid computing

Abstract

SUMMARYIn this paper, we consider the QoS-aware replica placement problem. Although there has been much research on the problem, most approaches focus on the average system performance and ignore the quality assurance issue. However, quality assurance is crucial, especially in heterogeneous environments. To fill this research gap, we proposed four heuristic algorithms to determine the locations of replicas in order to satisfy the quality requirements imposed by data requests. Three of the algorithms are greedy heuristics called Greedy-Cover, Cover-Partition and Multi-Source. The fourth algorithm is based on the Simulated Annealing technique. Our experiment results indicated that Greedy-Cover and the Simulated Annealing-based algorithms can find effective solutions efficiently.

Cost Optimization of Replicas in Tree Network of Data Grid with QoS and Bandwidth Constraints

“…In the second step, the replicas are placed in the extracted tree to optimize the objective function. In this regard, many works considered QoS as a constraint whilst considering replication cost as an objective function [8], [9]. Our work does not fall into this line of research.…”

“…The number of nodes n ranges from 100 to 5000 and the number children of each node follows a uniform distribution in (1)(2)(3)(4)(5) for n ≤ 1000 and [1][2][3][4][5][6][7][8][9][10] for n > 1000. It is set q with a fraction of the tree height h. That is, q = 1/4h, q = 1/2h, q = 3/4h and q = h + 1.…”