A self-organizing scheme for cache consistency

Previous studies have shown that an increasing fraction of the data on the WWW is fast-changed, such as news, sports scores, stock prices, and so on. An important issue to cache such dynamic content is the maintenance of consistency. We propose a self-organizing caching scheme to ensure the users get the up-to-date documents all along even if the documents are fast-changed. This scheme combines the mechanism of client polling and that of server pushing based on a mechanism of self-organizing multicast trees. The trees are created, optimized and destroyed automatically according to the rate of change and location of the dynamic document and the network conditions, such as the capacity, the traffic load. Meanwhile we derive a formula for cache nodes to determine which documents should be cached.