A data traffic monitor for determining a heavy distinct hitter (HDH) in a data stream, the data stream comprising a plurality of element-value (e,v) pairs, includes a HDH module, the HDH module configured to receive the plurality of (e,v) pairs from the data stream; and a counter block in communication with the HDH module, the counter block comprising a plurality of hash functions, and further comprising a respective pair of distinct counting primitives associated with each hash function of the plurality of hash functions, wherein each of the plurality of (e,v) pairs is added to one of the distinct counting primitives of the respective pair of distinct counting primitives for each of the plurality of hash functions in each of the plurality of counter blocks.