Dynamic Equilibrium Replica Location Algorithms in Data Grid

Replica location is one of the key issues of data management in grid environment. Existing replica location services employ statistical location information to locate replica, lack initiative detecting mechanism for update, and equalize location information at large cost. In this paper, aimed at existing problems, combined with the characteristics of data gird, a dynamic equilibrium replica location algorithm (DERLS) was proposed. The idea underlying our DERLS algorithms consists of three parts: (1) Replica location service locates physical replica according to the density of pheromone by artificial ant spread. (2) A dynamic equilibrium technique is proposed to prevent positive feedback of basic ant algorithms. (3) Update strategy based on improved ant algorithms is used to detect new replica or resume fault replica. Experimental results show the availability and validity of the replica location in detail.