Developing Apache Storm Applications
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Trident Aggregations

In addition to functions and filters, Trident defines a number of aggregator interfaces that allow topologies to combine tuples.

There are three types of Trident aggregators:

  • CombinerAggregator

  • ReducerAggregator

  • Aggregator

As with functions and filters, Trident aggregations are applied to streams via methods in the Stream class, namely aggregate(), partitionAggregate(), and persistentAggregate().