NAS Algorithm for Semantic Query Routing Systems in Complex Networks

The modem distributed systems are acquiring a great importance in our daily lives. Each day more transactions are conducted through devices which perform queries that are dependent on the reliability, availability and security of distributed applications. In addition, those systems show great dynamism as a result of the extremely complex and unpredictable interactions between the distributed components, making it practically impossible to evaluate their behavior. In this paper, we evaluate the performance of the NAS algorithm (Neighboring-Ant Search), which is an algorithm for distributed textual query routing based on the Ant Colony System metaheuristic and SemAnt algorithm, improved with a local topological characterization metric and a classic local exploration method called lookahead, with the aim of improving the performance of the distributed search. Our results show that including local information like the topological metric and the exploration method in the Neighboring-Ant Search algorithm improves its performance 40%, in terms of the number of hops needed to locate a set of resources in a scale-free network.