Implementing on-line techniques to allocate file resources in large distributed systems

The allocation of shared resources in a distributed system is a key aspect to achieve both low latency in accessing the resource and low bandwidth consumption. When the set of users accessing a resource dynamically changes, the allocation policy should adapt the resource placement over time. In the literature, on-line algorithms have been proposed that dynamically relocate a file in the centre of gravity of the set of users that are more frequently accessing it. However solar those algorithms have not been implemented. They must be adapted to work in real systems, and their interactions must be investigated with the existing network protocols and applications. In this work we study the behaviours of some of those algorithms in real environments. To this purpose, we devised an implementation scheme, and we measured the algorithms performance in real settings.