@Internal public class FirstReducer<T> extends Object implements GroupReduceFunction<T,T>, GroupCombineFunction<T,T>
|Constructor and Description|
|Modifier and Type||Method and Description|
The combine method, called (potentially multiple timed) with subgroups of elements.
The reduce method.
public void reduce(Iterable<T> values, Collector<T> out) throws Exception
values- All records that belong to the given input key.
out- The collector to hand results to.
Exception- This method may throw exceptions. Throwing an exception will cause the operation to fail and may trigger recovery.
public void combine(Iterable<T> values, Collector<T> out) throws Exception
values- The elements to be combined.
out- The collector to use to return values from the function.
Exception- The function may throw Exceptions, which will cause the program to cancel, and may trigger the recovery logic.
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