A totally distributed iterative scheme for web services addressing and discovery

Both web services framework and peer-to-peer networks provide a discovery process, but as current P2P systems focus more on the discovery of content in the form of common files (possibly associated with metadata), a centralized UDDI registry serves content in the form of metadata describing web services. Thus, the intersection between P2P and Web services is clear, so that it recently gained lots of interest: there is the need of finding a way to exploit the high potential of web services without paying in terms of scalability or single-point-of-failures. Our aim in this paper is two-fold: on the one hand, we want to present a high level protocol for the addressing and the discovery of web services that is totally decentralized and based on a structured P2P topology. On the other hand, we introduce a way to solve the exact match key-based routing problem, that afflicts structured P2P systems. This model guarantees that all addressed web services will be discovered in a logarithmic number of hops, as it is based on a Distributed Hash Table. One of the key innovation is the possibility of customizing the categorization of web services using tags, which are becoming very common in the so called Web 2.0.