MapReduce.MapEmitter<K,V>, MapReduce.NullObject, MapReduce.ReduceEmitter<OK,OV>, MapReduce.StageMAP_REDUCE| Modifier and Type | Method and Description |
|---|---|
void |
combine(E key,
Iterator<Long> values,
MapReduce.ReduceEmitter<E,Long> emitter)
The combine() method is logically executed at all "machines" in parallel.
|
boolean |
doStage(MapReduce.Stage stage)
A MapReduce job can be map-only, map-reduce-only, or map-combine-reduce.
|
Map<E,Long> |
generateFinalResult(Iterator<KeyValue<E,Long>> keyValues)
The key/value pairs emitted by reduce() (or map() in a map-only job) can be iterated to generate a local JVM Java object.
|
String |
getMemoryKey()
The results of the MapReduce job are associated with a memory-key to ultimately be stored in
Memory. |
static <E> GroupCountStep.GroupCountMapReduce<E> |
instance() |
void |
map(Vertex vertex,
MapReduce.MapEmitter<E,Long> emitter)
The map() method is logically executed at all vertices in the graph in parallel.
|
void |
reduce(E key,
Iterator<Long> values,
MapReduce.ReduceEmitter<E,Long> emitter)
The reduce() method is logically on the "machine" the respective key hashes to.
|
clone, equals, hashCode, storeState, toStringfinalize, getClass, notify, notifyAll, wait, wait, waitaddResultToMemory, createMapReduce, getMapKeySort, getReduceKeySort, loadState, workerEnd, workerStartpublic boolean doStage(MapReduce.Stage stage)
MapReducestage - the stage to check for definition.public void map(Vertex vertex, MapReduce.MapEmitter<E,Long> emitter)
MapReducevertex - the current vertex being map() processed.emitter - the component that allows for key/value pairs to be emitted to the next stage.public void reduce(E key, Iterator<Long> values, MapReduce.ReduceEmitter<E,Long> emitter)
MapReducekey - the key that has aggregated valuesvalues - the aggregated values associated with the keyemitter - the component that allows for key/value pairs to be emitted as the final result.public void combine(E key, Iterator<Long> values, MapReduce.ReduceEmitter<E,Long> emitter)
MapReducekey - the key that has aggregated valuesvalues - the aggregated values associated with the keyemitter - the component that allows for key/value pairs to be emitted to the reduce stage.public Map<E,Long> generateFinalResult(Iterator<KeyValue<E,Long>> keyValues)
MapReducekeyValues - the key/value pairs that were emitted from reduce() (or map() in a map-only job)public String getMemoryKey()
MapReduceMemory.public static final <E> GroupCountStep.GroupCountMapReduce<E> instance()
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