Package com.linkedin.venice.hadoop.mapreduce.datawriter.reduce

Class VeniceReducer

java.lang.Object

com.linkedin.venice.hadoop.task.datawriter.AbstractDataWriterTask

com.linkedin.venice.hadoop.task.datawriter.AbstractPartitionWriter

com.linkedin.venice.hadoop.mapreduce.datawriter.reduce.VeniceReducer

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.hadoop.io.Closeable, org.apache.hadoop.mapred.JobConfigurable, org.apache.hadoop.mapred.Reducer<org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable>

Direct Known Subclasses:

VeniceKafkaInputReducer

public class VeniceReducer
extends AbstractPartitionWriter
implements org.apache.hadoop.mapred.Reducer<org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable>

VeniceReducer will be in charge of producing the messages to Kafka broker. Since VeniceMRPartitioner is using the same logic of DefaultVenicePartitioner, all the messages in the same reducer belongs to the same topic partition. The reason to introduce a reduce phase is that BDB-JE will benefit with sorted input in the following ways: 1. BDB-JE won't generate so many BINDelta since it won't touch a lot of BINs at a time; 2. The overall BDB-JE insert rate will improve a lot since the disk usage will be reduced a lot (BINDelta will be much smaller than before);

Nested Class Summary

Nested classes/interfaces inherited from class com.linkedin.venice.hadoop.task.datawriter.AbstractPartitionWriter

AbstractPartitionWriter.ChildWriterProducerCallback, AbstractPartitionWriter.DuplicateKeyPrinter, AbstractPartitionWriter.PartitionWriterProducerCallback, AbstractPartitionWriter.VeniceWriterMessage

Field Summary

Fields

Modifier and Type	Field	Description
static final String	MAP_REDUCE_JOB_ID_PROP

Fields inherited from class com.linkedin.venice.hadoop.task.datawriter.AbstractDataWriterTask

TASK_ID_NOT_SET

Constructor Summary

Constructors

Constructor	Description
VeniceReducer()

Method Summary

Modifier and Type	Method	Description
void	configure(org.apache.hadoop.mapred.JobConf job)
protected void	configureTask(VeniceProperties props)	Allow implementations of this class to configure task-specific stuff.
protected AbstractVeniceWriter<byte[],byte[],byte[]>	createBasicVeniceWriter()
protected PubSubProducerCallback	getCallback()
protected DataWriterTaskTracker	getDataWriterTaskTracker()
protected boolean	getExceedQuotaFlag()
protected org.apache.hadoop.mapred.JobConf	getJobConf()
protected long	getTotalIncomingDataSizeInBytes()	Return the size of serialized key and serialized value in bytes across the entire dataset.
protected boolean	hasReportedFailure(DataWriterTaskTracker dataWriterTaskTracker, boolean isDuplicateKeyAllowed)
void	reduce(org.apache.hadoop.io.BytesWritable key, Iterator<org.apache.hadoop.io.BytesWritable> values, org.apache.hadoop.mapred.OutputCollector<org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable> output, org.apache.hadoop.mapred.Reporter reporter)
protected void	setExceedQuota(boolean exceedQuota)
protected void	setHadoopJobClientProvider(HadoopJobClientProvider hadoopJobClientProvider)
protected void	setVeniceWriter(AbstractVeniceWriter veniceWriter)
protected void	setVeniceWriterFactory(VeniceWriterFactory factory)

Methods inherited from class com.linkedin.venice.hadoop.task.datawriter.AbstractPartitionWriter

close, extract, getDerivedValueSchemaId, initDuplicateKeyPrinter, isEnableWriteCompute, logMessageProgress, processValuesForKey, recordMessageErrored

Methods inherited from class com.linkedin.venice.hadoop.task.datawriter.AbstractDataWriterTask

configure, getEngineTaskConfigProvider, getPartitionCount, getTaskId, isChunkingEnabled, isRmdChunkingEnabled, setChunkingEnabled

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.io.Closeable

close

Field Details

MAP_REDUCE_JOB_ID_PROP

public static final String MAP_REDUCE_JOB_ID_PROP

See Also:

• Constant Field Values

Constructor Details

VeniceReducer

public VeniceReducer()

Method Details

getJobConf

protected org.apache.hadoop.mapred.JobConf getJobConf()

configure

public void configure(org.apache.hadoop.mapred.JobConf job)

Specified by:

configure in interface org.apache.hadoop.mapred.JobConfigurable

reduce

public void reduce(org.apache.hadoop.io.BytesWritable key,
 Iterator<org.apache.hadoop.io.BytesWritable> values,
 org.apache.hadoop.mapred.OutputCollector<org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable> output,
 org.apache.hadoop.mapred.Reporter reporter)

Specified by:

reduce in interface org.apache.hadoop.mapred.Reducer<org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable,org.apache.hadoop.io.BytesWritable>

getDataWriterTaskTracker

protected DataWriterTaskTracker getDataWriterTaskTracker()

Overrides:

getDataWriterTaskTracker in class AbstractPartitionWriter

getExceedQuotaFlag

protected boolean getExceedQuotaFlag()

Overrides:

getExceedQuotaFlag in class AbstractPartitionWriter

setVeniceWriter

protected void setVeniceWriter(AbstractVeniceWriter veniceWriter)

Overrides:

setVeniceWriter in class AbstractPartitionWriter

setExceedQuota

protected void setExceedQuota(boolean exceedQuota)

Overrides:

setExceedQuota in class AbstractPartitionWriter

hasReportedFailure

protected boolean hasReportedFailure(DataWriterTaskTracker dataWriterTaskTracker,
 boolean isDuplicateKeyAllowed)

Overrides:

hasReportedFailure in class AbstractPartitionWriter

getCallback

protected PubSubProducerCallback getCallback()

Overrides:

getCallback in class AbstractPartitionWriter

configureTask

protected void configureTask(VeniceProperties props)

Description copied from class: AbstractDataWriterTask

Allow implementations of this class to configure task-specific stuff.

Overrides:

configureTask in class AbstractPartitionWriter

Parameters:

props - the job props that the task was configured with.

getTotalIncomingDataSizeInBytes

protected long getTotalIncomingDataSizeInBytes()

Description copied from class: AbstractPartitionWriter

Return the size of serialized key and serialized value in bytes across the entire dataset. This is an optimization to skip writing the data to Kafka and reduce the load on Kafka and Venice storage nodes. Not all engines can support fetching this information during the execution of the job (eg Spark), but we can live with it for now. The quota is checked again in the Driver after the completion of the DataWriter job, and it will kill the VenicePushJob soon after.

Overrides:

getTotalIncomingDataSizeInBytes in class AbstractPartitionWriter

Returns:

the size of serialized key and serialized value in bytes across the entire dataset

setHadoopJobClientProvider

protected void setHadoopJobClientProvider(HadoopJobClientProvider hadoopJobClientProvider)

createBasicVeniceWriter

protected AbstractVeniceWriter<byte[],byte[],byte[]> createBasicVeniceWriter()

Overrides:

createBasicVeniceWriter in class AbstractPartitionWriter

setVeniceWriterFactory

protected void setVeniceWriterFactory(VeniceWriterFactory factory)

Overrides:

setVeniceWriterFactory in class AbstractPartitionWriter