- Type Parameters:
ValueIn
- value type of the resulting valuesValueOut
- type for the collated result
@Beta
public interface Collator<ValueIn,ValueOut>
This interface can be implemented to define a Collator which is executed after calculation
of the MapReduce algorithm on remote cluster nodes but before returning the final result.
Collator can, for example, be used to sum up a final value.
- Since:
- 3.2