A WS-inspection based decentralized service discovery service in OGSA

Grid service discovery (GSD) is an important part of the newly proposed OGSA (open grid services architecture). This paper describes the implementation of a specific GSD service which is realized as an extended part of the OGSI technology preview. OGSI (open grid services infrastructure) has implemented the fundamental interfaces of OGSA. It provides a container registry service for the query in grid services. However, this service does not provide full flexibility for GSD, since it only supports querying among services registered to the local service container. The implemented GSD service is a decentralized one and is based on WS-inspection. It is designed as a high-level service, which is based upon the container registry service, provided in OGSI, so that direct access towards low-level data structure is avoided. The implementation details will be discussed in this paper, including the whole GSD mechanism and some more specific discovery methods used. Some furthering issues on the GSD implementation will also be discussed in this paper. Analysis on parallel and sequential searching algorithms will be given in a separate section, based on an ideal k-way tree model of the grid topology. Other possible improvements of the GSD service will be discussed as well, for example, a better use of the WSIL to extend the flexibility of the GSD service.