THE IMPACT OF DATA REPLICATION ON JOB SCHEDULING PERFORMANCE IN HIERARCHICAL DATA GRID

In data-intensive applications data transfer is a primary cause of job execution delay. Data access timedepends on bandwidth. The major bottleneck to supporting fast data access in Grids is the high latenciesof Wide Area Networks and Internet. Effective scheduling can reduce the amount of data transferredacross the internet by dispatching a job to where the needed data are present. Another solution is to use adata replication mechanism. Objective of dynamic replica strategies is reducing file access time whichleads to reducing job runtime. In this paper we develop a job scheduling policy and a dynamic datareplication strategy, called HRS (Hierarchical Replication Strategy), to improve the data accessefficiencies. We study our approach and evaluate it through simulation. The results show that ouralgorithm has improved 12% over the current strategies.