Lilliput: A Storage Service for Lightweight Peer-to-Peer Online Social Networks

P2P-based social networking services are severely challenged by churn and the lack of reliable service providers, especially considering the high frequency of posts and profile updates of their users. Improved consistency and data availability shall facilitate better acceptance, which in turn will enhance privacy, an inherent benefit of this class of systems. We present Lilliput, a P2P storage primitive designed with the characteristics of Online Social Network workloads in mind. Lilliput separates the storage of static bulk data (videos and photo albums) from the essential social glue (e.g. basic profile information, frequent updates, notifications, and personal messages): it provides the latter through agile, lightweight replica groups. Extensive simulations show that Lilliput ensures high data availability (99.07% to 99.64%) and consistency, with a small bandwidth usage under realistic usage and load models.