org.apache.parquet.hadoop

Class ParquetOutputFormat<T>

java.lang.Object

org.apache.hadoop.mapreduce.OutputFormat<K,V>

org.apache.hadoop.mapreduce.lib.output.FileOutputFormat<Void,T>

org.apache.parquet.hadoop.ParquetOutputFormat<T>

Type Parameters:

T - the type of the materialized records

Direct Known Subclasses:

ExampleOutputFormat

public class ParquetOutputFormat<T>
extends org.apache.hadoop.mapreduce.lib.output.FileOutputFormat<Void,T>

OutputFormat to write to a Parquet file It requires a WriteSupport to convert the actual records to the underlying format. It requires the schema of the incoming records. (provided by the write support) It allows storing extra metadata in the footer (for example: for schema compatibility purpose when converting from a different schema language). The format configuration settings in the job configuration:

 # The block size is the size of a row group being buffered in memory
 # this limits the memory usage when writing
 # Larger values will improve the IO when reading but consume more memory when writing
 parquet.block.size=134217728 # in bytes, default = 128 * 1024 * 1024

 # The page size is for compression. When reading, each page can be decompressed independently.
 # A block is composed of pages. The page is the smallest unit that must be read fully to access a single record.
 # If this value is too small, the compression will deteriorate
 parquet.page.size=1048576 # in bytes, default = 1 * 1024 * 1024

 # There is one dictionary page per column per row group when dictionary encoding is used.
 # The dictionary page size works like the page size but for dictionary
 parquet.dictionary.page.size=1048576 # in bytes, default = 1 * 1024 * 1024

 # The compression algorithm used to compress pages
 parquet.compression=UNCOMPRESSED # one of: UNCOMPRESSED, SNAPPY, GZIP, LZO. Default: UNCOMPRESSED. Supersedes mapred.output.compress*

 # The write support class to convert the records written to the OutputFormat into the events accepted by the record consumer
 # Usually provided by a specific ParquetOutputFormat subclass
 parquet.write.support.class= # fully qualified name

 # To enable/disable dictionary encoding
 parquet.enable.dictionary=true # false to disable dictionary encoding

 # To enable/disable summary metadata aggregation at the end of a MR job
 # The default is true (enabled)
 parquet.enable.summary-metadata=true # false to disable summary aggregation
 

If parquet.compression is not set, the following properties are checked (FileOutputFormat behavior). Note that we explicitely disallow custom Codecs

 mapred.output.compress=true
 mapred.output.compression.codec=org.apache.hadoop.io.compress.SomeCodec # the codec must be one of Snappy, GZip or LZO
 

if none of those is set the data is uncompressed.

Author:

Julien Le Dem

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.lib.output.FileOutputFormat

org.apache.hadoop.mapreduce.lib.output.FileOutputFormat.Counter

Field Summary

Fields

Modifier and Type	Field and Description
static String	BLOCK_SIZE
static String	COMPRESSION
static String	DICTIONARY_PAGE_SIZE
static String	ENABLE_DICTIONARY
static String	ENABLE_JOB_SUMMARY
static String	MEMORY_POOL_RATIO
static String	MIN_MEMORY_ALLOCATION
static String	PAGE_SIZE
static String	VALIDATION
static String	WRITE_SUPPORT_CLASS
static String	WRITER_VERSION

Fields inherited from class org.apache.hadoop.mapreduce.lib.output.FileOutputFormat

BASE_OUTPUT_NAME, PART

Constructor Summary

Constructors

Constructor and Description
ParquetOutputFormat() used when directly using the output format and configuring the write support implementation using parquet.write.support.class
ParquetOutputFormat(S writeSupport) constructor used when this OutputFormat in wrapped in another one (In Pig for example)

Method Summary

Methods

Modifier and Type	Method and Description
static int	getBlockSize(org.apache.hadoop.conf.Configuration configuration) Deprecated.
static int	getBlockSize(org.apache.hadoop.mapreduce.JobContext jobContext)
static CompressionCodecName	getCompression(org.apache.hadoop.conf.Configuration configuration)
static CompressionCodecName	getCompression(org.apache.hadoop.mapreduce.JobContext jobContext)
static int	getDictionaryPageSize(org.apache.hadoop.conf.Configuration configuration)
static int	getDictionaryPageSize(org.apache.hadoop.mapreduce.JobContext jobContext)
static boolean	getEnableDictionary(org.apache.hadoop.conf.Configuration configuration)
static boolean	getEnableDictionary(org.apache.hadoop.mapreduce.JobContext jobContext)
static long	getLongBlockSize(org.apache.hadoop.conf.Configuration configuration)
org.apache.hadoop.mapreduce.OutputCommitter	getOutputCommitter(org.apache.hadoop.mapreduce.TaskAttemptContext context)
static int	getPageSize(org.apache.hadoop.conf.Configuration configuration)
static int	getPageSize(org.apache.hadoop.mapreduce.JobContext jobContext)
org.apache.hadoop.mapreduce.RecordWriter<Void,T>	getRecordWriter(org.apache.hadoop.conf.Configuration conf, org.apache.hadoop.fs.Path file, CompressionCodecName codec)
org.apache.hadoop.mapreduce.RecordWriter<Void,T>	getRecordWriter(org.apache.hadoop.mapreduce.TaskAttemptContext taskAttemptContext)
org.apache.hadoop.mapreduce.RecordWriter<Void,T>	getRecordWriter(org.apache.hadoop.mapreduce.TaskAttemptContext taskAttemptContext, org.apache.hadoop.fs.Path file)
static boolean	getValidation(org.apache.hadoop.conf.Configuration configuration)
static boolean	getValidation(org.apache.hadoop.mapreduce.JobContext jobContext)
static ParquetProperties.WriterVersion	getWriterVersion(org.apache.hadoop.conf.Configuration configuration)
WriteSupport<T>	getWriteSupport(org.apache.hadoop.conf.Configuration configuration)
static Class<?>	getWriteSupportClass(org.apache.hadoop.conf.Configuration configuration)
static boolean	isCompressionSet(org.apache.hadoop.conf.Configuration configuration)
static boolean	isCompressionSet(org.apache.hadoop.mapreduce.JobContext jobContext)
static void	setBlockSize(org.apache.hadoop.mapreduce.Job job, int blockSize)
static void	setCompression(org.apache.hadoop.mapreduce.Job job, CompressionCodecName compression)
static void	setDictionaryPageSize(org.apache.hadoop.mapreduce.Job job, int pageSize)
static void	setEnableDictionary(org.apache.hadoop.mapreduce.Job job, boolean enableDictionary)
static void	setPageSize(org.apache.hadoop.mapreduce.Job job, int pageSize)
static void	setValidation(org.apache.hadoop.conf.Configuration configuration, boolean validating)
static void	setValidation(org.apache.hadoop.mapreduce.JobContext jobContext, boolean validating)
static void	setWriteSupportClass(org.apache.hadoop.mapreduce.Job job, Class<?> writeSupportClass)
static void	setWriteSupportClass(org.apache.hadoop.mapred.JobConf job, Class<?> writeSupportClass)

Methods inherited from class org.apache.hadoop.mapreduce.lib.output.FileOutputFormat

checkOutputSpecs, getCompressOutput, getDefaultWorkFile, getOutputCompressorClass, getOutputName, getOutputPath, getPathForWorkFile, getUniqueFile, getWorkOutputPath, setCompressOutput, setOutputCompressorClass, setOutputName, setOutputPath

Methods inherited from class java.lang.Object

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

Field Detail

BLOCK_SIZE

public static final String BLOCK_SIZE

See Also:

Constant Field Values

PAGE_SIZE

public static final String PAGE_SIZE

See Also:

Constant Field Values

COMPRESSION

public static final String COMPRESSION

See Also:

Constant Field Values

WRITE_SUPPORT_CLASS

public static final String WRITE_SUPPORT_CLASS

See Also:

Constant Field Values

DICTIONARY_PAGE_SIZE

public static final String DICTIONARY_PAGE_SIZE

See Also:

Constant Field Values

ENABLE_DICTIONARY

public static final String ENABLE_DICTIONARY

See Also:

Constant Field Values

VALIDATION

public static final String VALIDATION

See Also:

Constant Field Values

WRITER_VERSION

public static final String WRITER_VERSION

See Also:

Constant Field Values

ENABLE_JOB_SUMMARY

public static final String ENABLE_JOB_SUMMARY

See Also:

Constant Field Values

MEMORY_POOL_RATIO

public static final String MEMORY_POOL_RATIO

See Also:

Constant Field Values

MIN_MEMORY_ALLOCATION

public static final String MIN_MEMORY_ALLOCATION

See Also:

Constant Field Values

Constructor Detail

ParquetOutputFormat

public ParquetOutputFormat(S writeSupport)

constructor used when this OutputFormat in wrapped in another one (In Pig for example)

Parameters:

writeSupportClass - the class used to convert the incoming records

schema - the schema of the records

extraMetaData - extra meta data to be stored in the footer of the file

ParquetOutputFormat

public ParquetOutputFormat()

used when directly using the output format and configuring the write support implementation using parquet.write.support.class

Method Detail

setWriteSupportClass

public static void setWriteSupportClass(org.apache.hadoop.mapreduce.Job job,
                        Class<?> writeSupportClass)

setWriteSupportClass

public static void setWriteSupportClass(org.apache.hadoop.mapred.JobConf job,
                        Class<?> writeSupportClass)

getWriteSupportClass

public static Class<?> getWriteSupportClass(org.apache.hadoop.conf.Configuration configuration)

setBlockSize

public static void setBlockSize(org.apache.hadoop.mapreduce.Job job,
                int blockSize)

setPageSize

public static void setPageSize(org.apache.hadoop.mapreduce.Job job,
               int pageSize)

setDictionaryPageSize

public static void setDictionaryPageSize(org.apache.hadoop.mapreduce.Job job,
                         int pageSize)

setCompression

public static void setCompression(org.apache.hadoop.mapreduce.Job job,
                  CompressionCodecName compression)

setEnableDictionary

public static void setEnableDictionary(org.apache.hadoop.mapreduce.Job job,
                       boolean enableDictionary)

getEnableDictionary

public static boolean getEnableDictionary(org.apache.hadoop.mapreduce.JobContext jobContext)

getBlockSize

public static int getBlockSize(org.apache.hadoop.mapreduce.JobContext jobContext)

getPageSize

public static int getPageSize(org.apache.hadoop.mapreduce.JobContext jobContext)

getDictionaryPageSize

public static int getDictionaryPageSize(org.apache.hadoop.mapreduce.JobContext jobContext)

getCompression

public static CompressionCodecName getCompression(org.apache.hadoop.mapreduce.JobContext jobContext)

isCompressionSet

public static boolean isCompressionSet(org.apache.hadoop.mapreduce.JobContext jobContext)

setValidation

public static void setValidation(org.apache.hadoop.mapreduce.JobContext jobContext,
                 boolean validating)

getValidation

public static boolean getValidation(org.apache.hadoop.mapreduce.JobContext jobContext)

getEnableDictionary

public static boolean getEnableDictionary(org.apache.hadoop.conf.Configuration configuration)

getBlockSize

@Deprecated
public static int getBlockSize(org.apache.hadoop.conf.Configuration configuration)

Deprecated.

getLongBlockSize

public static long getLongBlockSize(org.apache.hadoop.conf.Configuration configuration)

getPageSize

public static int getPageSize(org.apache.hadoop.conf.Configuration configuration)

getDictionaryPageSize

public static int getDictionaryPageSize(org.apache.hadoop.conf.Configuration configuration)

getWriterVersion

public static ParquetProperties.WriterVersion getWriterVersion(org.apache.hadoop.conf.Configuration configuration)

getCompression

public static CompressionCodecName getCompression(org.apache.hadoop.conf.Configuration configuration)

isCompressionSet

public static boolean isCompressionSet(org.apache.hadoop.conf.Configuration configuration)

setValidation

public static void setValidation(org.apache.hadoop.conf.Configuration configuration,
                 boolean validating)

getValidation

public static boolean getValidation(org.apache.hadoop.conf.Configuration configuration)

getRecordWriter

public org.apache.hadoop.mapreduce.RecordWriter<Void,T> getRecordWriter(org.apache.hadoop.mapreduce.TaskAttemptContext taskAttemptContext)
                                                                 throws IOException,
                                                                        InterruptedException

Specified by:

getRecordWriter in class org.apache.hadoop.mapreduce.lib.output.FileOutputFormat<Void,T>

Throws:

IOException

InterruptedException

getRecordWriter

public org.apache.hadoop.mapreduce.RecordWriter<Void,T> getRecordWriter(org.apache.hadoop.mapreduce.TaskAttemptContext taskAttemptContext,
                                                               org.apache.hadoop.fs.Path file)
                                                                 throws IOException,
                                                                        InterruptedException

Throws:

IOException

InterruptedException

getRecordWriter

public org.apache.hadoop.mapreduce.RecordWriter<Void,T> getRecordWriter(org.apache.hadoop.conf.Configuration conf,
                                                               org.apache.hadoop.fs.Path file,
                                                               CompressionCodecName codec)
                                                                 throws IOException,
                                                                        InterruptedException

Throws:

IOException

InterruptedException

getWriteSupport

public WriteSupport<T> getWriteSupport(org.apache.hadoop.conf.Configuration configuration)

Parameters:

configuration - to find the configuration for the write support class

Returns:

the configured write support

getOutputCommitter

public org.apache.hadoop.mapreduce.OutputCommitter getOutputCommitter(org.apache.hadoop.mapreduce.TaskAttemptContext context)
                                                               throws IOException

Overrides:

getOutputCommitter in class org.apache.hadoop.mapreduce.lib.output.FileOutputFormat<Void,T>

Throws:

IOException