1. A method comprising: providing a representation of a flow network having vertices connected by arcs, wherein the vertices include a first set of vertices that provide flow to a second set of vertices over arcs connecting the first set and second set of vertices; performing, by a computer, a balancing procedure in the network that includes redistributing flows on arcs incident on the second set of vertices, wherein the balancing procedure comprises: selecting a batch of the vertices in the second set; redistributing flows on arcs incident on the selected batch of vertices; and repeating the selecting and redistributing for other batches of vertices in the second set.