The power of indirect ties in friend-to-friend storage systems

Friend-to-Friend (F2F) storage systems were shown to suffer from two significant limitations. First, users with a small set of friends are penalized by lack of available storage for their needs, while users with many friends get overloaded with resource requests. Second, friends are typically in close geographical proximity to each other, and thus their online times are synchronized, leading to low data availability when they are offline. This paper addresses these concerns by expanding the set of storage resources while still using a measure of social incentives. It proposes an indirect tie measurement to compute the social strength between possibly distant nodes in a social network. Using datasets from co-authorship networks and a video gaming community, we show that the social strength-based mechanism more than doubles the set of storage candidates motivated by social incentives, invites socially low connected users to contribute more resources and improves data availability by up to 6.5 times. We also show that our method complemented with simple load balancing strategies significantly improves peer engagement and workload distribution in F2F storage systems.