DAROS: Distributed User-Server Assignment and Replication for Online Social Networking Applications
In this paper, the authors introduce and study the problem of assigning users to servers and data replication in a distributed manner for Online Social Networking (OSN) applications. Typical OSN applications such as Facebook and Twitter are built on top of an infrastructure of servers, which handle the users data storage and communications. Thus, for a given user's communication pattern, the loads of the servers depend critically on the assignment of users to servers. A good assignment will reduce the overall load of the system. Furthermore, by replicating data across the servers judiciously, the overall load can also be further reduced. Unfortunately, this optimal assignment and data replication problem is NP-hard.