Hybrid Approach for Consistency Management in OptorSim Simulator

One of the principal motivations to use the grids computing and data grids comes from the applications using of large sets from data, for example, in High-Energy physics or Life Science to improve the total output of the software environments used to carry these applications on the grids, data replication are deposited on various selected sites. In the field of the grids the majority of the strategies of replication of the data and scheduling of the jobs were tested by simulation. Several simulators of grids were born. One of the most simulators interesting for our study is the OptorSim tool. In this paper, we present an extension of the OptorSim simulator by a consistency management module of the replicas in the Data Grids. This extension corresponds to a hybrid approach of consistency, it inspired by the pessimistic and optimistic approaches of consistency. This suggested approach has two vocations, in the first time, it makes it possible to reduce the response times compared with the completely pessimistic approach, in the second time, it gives a good quality of service compared with the optimistic approach. Keyword: Data Grid, Replication, Consistency, OptorSim, Optimistic approach, Pessimistic approach