1. A method, comprising: receiving, by a server having a processor and memory, flow data associated with a traffic flow, the flow data tagged with a data source identifier identifying a data source exporting the flow data, a source site identifier identifying a source site associated with a source device of the traffic flow wherein the source site identifier identifies a geographical location of the source device, and a destination site identifier identifying a destination site associated with a destination device of the traffic flow wherein the destination site identifier identifies a geographical location of the destination device; determining, by the server, at least one authoritative data source for each site and metric type using at least one selection rule; receiving, by the server, a query for de-duplicated flow data, wherein the query includes a designation of a particular metric type and a designation of one of a source site identifier associated with a particular source site and a destination site identifier associated with a particular destination site; and generating, by the server, de-duplicated flow data based on the particular metric type, data source identifier, source site identifier, destination site identifier and particular flow data associated with the determined at least one authoritative data source.