With the increasing popularity of online social networks(OSNs),more and more related applications need a com putation framework for processing large social graphs in a real-time manner.However,the existing graph processing sys tems,such as Google's Pregel,cannot achieve real-time performance due to processing the graph in global and batch man ners.Therefore,this paper proposes a new graph computation model that restricts the computation to a local area when a node is updated.In essence,it transforms the tra...