Quota: Rationing server resources in peer-assisted online hosting systems

The increasingly popular online hosting systems are designed to provide versatile and convenient platforms for content hosting and sharing. To guarantee adequate levels of service quality while conserving prohibitive server costs, such systems are often designed to integrate peer bandwidth contributions with strategic server resource provisioning in a complementary and transparent manner. This paper seeks to explore the design space of new protocols to allocate scarce server resources-including both storage space and bandwidth-in peer-assisted online hosting systems. The objective is to maximize the use of limited server storage and bandwidth resources to guarantee adequate levels of service quality, with respect to file availability and downloading performance, while taking full advantage of peer assistance. We identify a number of unique challenges involved in such systems, and propose our design of resource allocation protocols to address these challenges, based on both mathematical analysis and practical implementations. Using real world data sets that we have collected, we evaluate our protocol design through extensive experimental studies from different perspectives, which demonstrate the effectiveness of our design and offer a number of practical guidelines.