org.apache.pig.backend.hadoop.executionengine.mapReduceLayer
Class PigMapReduce.Reduce
java.lang.Object
org.apache.hadoop.mapred.MapReduceBase
org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapReduce.Reduce
- All Implemented Interfaces:
- Closeable, org.apache.hadoop.mapred.JobConfigurable, org.apache.hadoop.mapred.Reducer<PigNullableWritable,NullableTuple,PigNullableWritable,org.apache.hadoop.io.Writable>
- Direct Known Subclasses:
- PigMapReduce.ReduceWithComparator
- Enclosing class:
- PigMapReduce
public static class PigMapReduce.Reduce
- extends org.apache.hadoop.mapred.MapReduceBase
- implements org.apache.hadoop.mapred.Reducer<PigNullableWritable,NullableTuple,PigNullableWritable,org.apache.hadoop.io.Writable>
Method Summary |
void |
close()
Will be called once all the intermediate keys and values are
processed. |
void |
configure(org.apache.hadoop.mapred.JobConf jConf)
Configures the Reduce plan, the POPackage operator
and the reporter thread |
boolean |
processOnePackageOutput(org.apache.hadoop.mapred.OutputCollector<PigNullableWritable,org.apache.hadoop.io.Writable> oc)
|
void |
reduce(PigNullableWritable key,
Iterator<NullableTuple> tupIter,
org.apache.hadoop.mapred.OutputCollector<PigNullableWritable,org.apache.hadoop.io.Writable> oc,
org.apache.hadoop.mapred.Reporter reporter)
The reduce function which packages the key and List<Tuple>
into key, Bag<Tuple> after converting Hadoop type key into Pig type. |
protected void |
runPipeline(PhysicalOperator leaf)
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
log
protected final org.apache.commons.logging.Log log
rp
protected PhysicalPlan rp
pack
protected POPackage pack
outputCollector
protected org.apache.hadoop.mapred.OutputCollector<PigNullableWritable,org.apache.hadoop.io.Writable> outputCollector
errorInReduce
protected boolean errorInReduce
initialized
protected volatile boolean initialized
PigMapReduce.Reduce
public PigMapReduce.Reduce()
configure
public void configure(org.apache.hadoop.mapred.JobConf jConf)
- Configures the Reduce plan, the POPackage operator
and the reporter thread
- Specified by:
configure
in interface org.apache.hadoop.mapred.JobConfigurable
- Overrides:
configure
in class org.apache.hadoop.mapred.MapReduceBase
reduce
public void reduce(PigNullableWritable key,
Iterator<NullableTuple> tupIter,
org.apache.hadoop.mapred.OutputCollector<PigNullableWritable,org.apache.hadoop.io.Writable> oc,
org.apache.hadoop.mapred.Reporter reporter)
throws IOException
- The reduce function which packages the key and List<Tuple>
into key, Bag<Tuple> after converting Hadoop type key into Pig type.
The package result is either collected as is, if the reduce plan is
empty or after passing through the reduce plan.
- Specified by:
reduce
in interface org.apache.hadoop.mapred.Reducer<PigNullableWritable,NullableTuple,PigNullableWritable,org.apache.hadoop.io.Writable>
- Throws:
IOException
processOnePackageOutput
public boolean processOnePackageOutput(org.apache.hadoop.mapred.OutputCollector<PigNullableWritable,org.apache.hadoop.io.Writable> oc)
throws IOException
- Throws:
IOException
runPipeline
protected void runPipeline(PhysicalOperator leaf)
throws ExecException,
IOException
- Parameters:
leaf
-
- Throws:
ExecException
IOException
close
public void close()
throws IOException
- Will be called once all the intermediate keys and values are
processed. So right place to stop the reporter thread.
- Specified by:
close
in interface Closeable
- Overrides:
close
in class org.apache.hadoop.mapred.MapReduceBase
- Throws:
IOException
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