Spatial Sorting of Binary Metadata Documents via Nature-Inspired Agents in Grids

This paper introduces Antares, an algorithm that is able to replicate and relocate metadata documents that describe Grid resources. These documents, or "resource descriptors", are indexed through binary strings that can either represent topics of interest, specifically in the case that resources are text files, or be the result of the application of a locality preserving hash function, that maps similar resources into similar keys. The process is driven by ant-like agents that travel the Grid through P2P interconnections and, by the application of ad hoc probability functions, copy and move descriptors so as to locate descriptors indexed by identical or similar keys into neighbor Grid hosts. The effectiveness of Antares has been verified by event-driven simulation which proves that ant operations allow to achieve replication and spatial sorting of descriptors, regardless of the length of binary keys.