Communication-Efficient Query Answering with Quality Guarantees in Client-Server Applications

We study how to reduce costs in client-server web based applications with dynamic data on the server. Client-side caching can help mitigate costs because the client can use the cached data to answer queries. Allowing some tolerance on the data staleness to answer queries makes it possible to significantly reduce costs. For example, if the user can tolerate data that was received 2 hours ago, we can use the cached data to provide the answer and to save some costs. In this paper we present useful algorithms under different cost models, we provide 2-approximation offline algorithm, as well as (k+1) competitive online algorithm and family of Heuristics. We validate our methods through extensive experiments.