1. A method for detecting a hierarchical heavy hitter from a stream of packets, comprising: receiving a packet from the stream of packets; associating a key with a field of the packet; applying an adaptive trie data structure, where each node of the adaptive trie data structure is associated with the key; and using via a processor the adaptive trie data structure to determine the hierarchical heavy hitter, wherein the hierarchical heavy hitter comprises a hierarchical aggregate of entities that account for a threshold portion of a total activity in the stream of packets.