HyperLogLog

HyperLogLog processor provides an implementation is an algorithm for the count-distinct problem, approximating the number of distinct elements in a multiset. Calculating the exact cardinality of the distinct elements of a multiset requires an amount of memory proportional to the cardinality, which is impractical for very large data sets.

Example

hyperloglog:
  name: distinctIMSICounter
  hash type: HASH64
  log2m: 3
  registry width: 3
  fields:
    - imsi

Attributes

Attribute	Description	Data Type	Required
name	name of the counter	String
hash type	Hashing algorithm to be applied to event field. Supported types: DEFAULT (object hashcode), HASH32, HASH64	Long Default: DEFAULT
log2m	the number of probabilistic HLL registers	Integer Default: 11
registry width	The size (width) each register in bits. Supported range between 1 to 8 bits.	Integer Default: 5
fields	List of fields to perform distinct counts	List

Computation

The distinct count computation occurs for every see with the result being added to the output event as a named map of field and associated counts using the provided name.

Additional Information

See wikipedia for more information