## Uses of Class
org.apache.hadoop.mapreduce.Reducer

Packages that use Reducer
org.apache.hadoop.examples: Hadoop example code.
org.apache.hadoop.mapred: A software framework for easily writing applications which process vast amounts of data (multi-terabyte data-sets) parallelly on large clusters (thousands of nodes) built of commodity hardware in a reliable, fault-tolerant manner.
org.apache.hadoop.mapreduce
org.apache.hadoop.mapreduce.lib.reduce

Uses of Reducer in org.apache.hadoop.examples

Subclasses of Reducer in org.apache.hadoop.examples
`static class` `SecondarySort.Reduce` A reducer class that just emits the sum of the input values.
`static class` `WordCount.IntSumReducer`

Uses of Reducer in org.apache.hadoop.mapred

Methods in org.apache.hadoop.mapred with parameters of type Reducer

`protected static

`<INKEY,INVALUE,OUTKEY,OUTVALUE> Reducer.Context`

`

`Task.createReduceContext(Reducer<INKEY,INVALUE,OUTKEY,OUTVALUE> reducer, Configuration job, TaskAttemptID taskId, RawKeyValueIterator rIter, Counter inputKeyCounter, Counter inputValueCounter, RecordWriter<OUTKEY,OUTVALUE> output, OutputCommitter committer, StatusReporter reporter, RawComparator<INKEY> comparator, Class<INKEY> keyClass, Class<INVALUE> valueClass)`

Uses of Reducer in org.apache.hadoop.mapreduce

Methods in org.apache.hadoop.mapreduce that return types with arguments of type Reducer
`Class<? extends Reducer<?,?,?,?>>` `JobContext.getCombinerClass()` Get the combiner class for the job.
`Class<? extends Reducer<?,?,?,?>>` `JobContext.getReducerClass()` Get the `Reducer` class for the job.

Method parameters in org.apache.hadoop.mapreduce with type arguments of type Reducer
`void` `Job.setCombinerClass(Class<? extends Reducer> cls)` Set the combiner class for the job.
`void` `Job.setReducerClass(Class<? extends Reducer> cls)` Set the `Reducer` for the job.

Uses of Reducer in org.apache.hadoop.mapreduce.lib.reduce

Subclasses of Reducer in org.apache.hadoop.mapreduce.lib.reduce
`class` `IntSumReducer<Key>`
`class` `LongSumReducer<KEY>`

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