A New Replica Consistency Maintenance Method Based on Dynamic Update Rate Calculation in the Data Grid

Document Type : Original Manuscript


1 Department of Computer and Engineering, Gilan-e Gharb Branch, Islamic Azad University, Gilan-e Gharb, Iran

2 Department of Computer and Engineering., Yadegar -e- Imam Khomeini (RAH) Shahr-e-Rey Branch, Islamic Azad University, Tehran, Iran


Data Grid provides convenient services for data management and uniform access to distributed high volume data sources. Data replication is a service to facilitate and accelerate data accessing in Data Grid. But in the large-scale grid environment, the need to maintain replica consistently and ensure identical content of the various replica of a file are inevitable. This paper presents an effective consistency method that maintains replicated data consistent. In this method, the node which contains replica is responsible for managing consistency. In each node, the replica update rate is calculated based on the rate of change in the original data file and the rate of the access request to the existing replica version. The proposed model reduces access delays. The model was simulated using  OptorSim developed by European Data Grid projects. The experimental results show that our proposed model has better performance in comparison with optimistic and pessimistic approaches in terms of job execution time, effective network usage, and the total number of updates.