Flexible Caching in Peer-to-Peer Information Systems

We view the Internet as supporting a peer-to-peer information system whose components provide services to one another. We model service providers and consumers as autonomous agents. Agents may provide services or give referrals to one another to help find trustworthy services. Once found, some services may be cached. We describe a flexible caching technique that allows peers to operate autonomously (based on their local policies), accommodates heterogeneity of peers, and enables peers to adapt by choosing policies and neighbors as best suits them. In this approach, cache entries are coupled with metadata, thereby allowing the use of heuristics and flexible queries for more informed searches. The entries that are of interest to more agents are replicated at more peers, providing on-demand performance improvement and fault tolerance