Speculative data dissemination and service to reduce server load, network traffic and service time in distributed information systems

We present two server-initiated protocols to improve the performance of distributed information systems (e.g. WWW). Our first protocol is a hierarchical data dissemination mechanism that allows information to propagate from its producers to servers that are closer to its consumers. This dissemination reduces network traffic and balances load amongst servers by exploiting geographic and temporal locality of reference properties exhibited in client access patterns. Our second protocol relies on "speculative service", whereby a request for a document as serviced by sending, in addition to the document requested, a number of other documents that the server speculates will be requested in the near future. This speculation reduces service time by exploiting the spatial locality of reference property. We present results of trace-driven simulations that quantify the attainable performance gains for both protocols.