DISTRIBUTED STORAGE ALLOCATION FOR HETEROGENEOUS SYSTEMS

摘要

Allocation of storage budget in a computer-based distributed storage system is described, where associated computer-based storage nodes have heterogeneous access probabilities. The problem is to allocate a given storage budget across the available computer-based nodes so as to store a unit-size data object (e.g. file) with a higher reliability (e.g. increased probability for the storage budget to be recovered). Efficient algorithms for optimizing over one or more classes of allocations are presented. A basic one-level symmetric allocation is presented, where the storage budget is spread evenly over an appropriately chosen subset of nodes. Furthermore, a two-level symmetric allocation is presented, where the budget is divided into two parts, each spread evenly over a different subset of computer-based storage nodes, such that the amount allocated to each node in the first subset is twice that of the second subset. Further expansion of the two-level symmetric allocation is provided with a three-level and a generic k-level symmetric allocation.