Distributed web caching reduces retrieval latency of World Wide Web (WWW) objects such as text and graphics. Conventional distributed web caching methods, however, require many query messages among cache servers, which limits their scalability and reliability. To overcome these problems, we propose a query caching method in which each cache server caches not only WWW objects but also a query history. This method of finding cached objects can reduce the number of query messages among cache servers, making it possible to construct a large-scale distributed web cache server. We also propose an algorithm for constructing efficient query relationships among cache servers.

This paper develops an efficient mechanism for extracting primary information requests from 'Seek-Object' type query messages. The mechanism consists of three steps. The first step extracts sentences which signal that the query is 'Seek-Object' type by recognizing distinctive surface expressions. The second step, biased by the expression patterns, analyzes their internal structures. The third step integrates these fragments by a partial discourse processing and represents writers' goal-directed information request; as these sentences often include referential expressions and the referred expressions are in background goal descriptions. We claim the mechanism can extract information requests fairly accurately, by showing evaluation results.