Distributed active catalogs and meta-data caching in descriptive name services

Today's global internetworks challenge the ability of name services and other information services to locate data quickly. The authors introduce distributed active catalog and meta-data caching for optimizing queries in this environment. The active catalog constrains the search space for a query by returning a list of data repositories where the answer to the query is likely to be found. Meta-data caching improves performance by keeping frequently used characterizations of the search space close to the user, and eliminating active catalog communication and processing costs. When searching for query responses, the techniques contact only the small percentage of the data repositories with actual responses, resulting in search times of a few seconds. A distributed active catalog and meta-data caching method was implemented in a prototype descriptive name service called Nomenclator. Performance results for Nomenclator in a search space of 1000 data repositories are presented.<>