1. A system to manage clustering of a streaming graph for analysis of a social network, the system comprising: a memory comprising a computer program, a vertex structure storing vertices of the streaming graph, and a cluster structure storing a first cluster and a second cluster of the streaming graph, a cluster size of each of the first and second clusters not exceeding a maximum cluster size, where vertex represents one of a plurality of users on the social network, wherein each cluster structure comprises a plurality of cluster entries and a plurality of edge structures that represent edges of the streaming graph and each edge structure comprises two of the vertices, wherein the edges comprise first connected edges of the first cluster and second connected edges of the second cluster, wherein each edge represents one of a plurality of computer messages exchanged between two of the users; and a processor configured to execute the program to cluster the streaming graph using the structures and the maximum cluster size, wherein the program is configured to receive a new computer message exchanged between a first user and a second user among the users, create a new edge representing the new computer message by connecting a first end of an edge to insert to a first vertex of the first cluster associated with the first user and connecting a second other end of the edge to insert to a second vertex of the second cluster associated with the second user to form a third cluster; continuously delete an oldest edge of the third cluster until it results in a fourth cluster not exceeding the maximum cluster size comprising at least some of the first connected edges and a fifth cluster not exceeding the maximum cluster size comprising at least some of the second connected edges, upon determining a cluster size of the third cluster exceeds the maximum cluster size, wherein one of the fourth and fifth clusters includes the new edge.