Optimal methods for object management in coordinated en-route web caching for tree networks and autonomous systems

Abstract

This paper first addresses the problem of computing the optimal locations for placing copies of an object among the enroute caches in coordinated enroute web caching for tree networks, such that the overall cost gain is maximised. We formulate this problem as an optimisation problem and consider both unconstrained and constrained cases. The constrained case includes constraints on the cost gain per node and on the number of copies to be placed. We also derive low cost, dynamic programming based algorithms that provide optimal solutions for these cases. To the best of our knowledge, these problems have not been studied previously. Second, we present a solution for coordinated enroute web caching for autonomous systems, based on the solution for coordinated enroute web caching for tree networks. Finally, we implement the algorithms and compare our methods with existing ones. The simulation results show that our methods outperform existing algorithms for both coordinated enroute web caching for linear topology and object placement at individual nodes.