org.apache.avro.mapreduce

Class AvroJob

java.lang.Object

org.apache.avro.mapreduce.AvroJob

public final class AvroJob
extends Object

Utility methods for configuring jobs that work with Avro.

When using Avro data as MapReduce keys and values, data must be wrapped in a suitable AvroWrapper implementation. MapReduce keys must be wrapped in an AvroKey object, and MapReduce values must be wrapped in an AvroValue object.

Suppose you would like to write a line count mapper that reads from a text file. If instead of using a Text and IntWritable output value, you would like to use Avro data with a schema of "string" and "int", respectively, you may parametrize your mapper with AvroKey<CharSequence> and AvroValue<Integer> types. Then, use the setMapOutputKeySchema() and setMapOutputValueSchema() methods to set writer schemas for the records you will generate.

Field Summary

Fields

Modifier and Type	Field and Description
static String	CONF_OUTPUT_CODEC The configuration key for a job's output compression codec.

Method Summary

Modifier and Type	Method and Description
static Schema	getInputKeySchema(Configuration conf) Gets the job input key schema.
static Schema	getInputValueSchema(Configuration conf) Gets the job input value schema.
static Schema	getMapOutputKeySchema(Configuration conf) Gets the map output key schema.
static Schema	getMapOutputValueSchema(Configuration conf) Gets the map output value schema.
static Schema	getOutputKeySchema(Configuration conf) Gets the job output key schema.
static Schema	getOutputValueSchema(Configuration conf) Gets the job output value schema.
static void	setDataModelClass(Job job, Class<? extends GenericData> modelClass) Sets the job data model class.
static void	setInputKeySchema(Job job, Schema schema) Sets the job input key schema.
static void	setInputValueSchema(Job job, Schema schema) Sets the job input value schema.
static void	setMapOutputKeySchema(Job job, Schema schema) Sets the map output key schema.
static void	setMapOutputValueSchema(Job job, Schema schema) Sets the map output value schema.
static void	setOutputKeySchema(Job job, Schema schema) Sets the job output key schema.
static void	setOutputValueSchema(Job job, Schema schema) Sets the job output value schema.

Methods inherited from class java.lang.Object

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

Field Detail

CONF_OUTPUT_CODEC

public static final String CONF_OUTPUT_CODEC

The configuration key for a job's output compression codec. This takes one of the strings registered in CodecFactory

See Also:

Constant Field Values

Method Detail

setInputKeySchema

public static void setInputKeySchema(Job job,
                                     Schema schema)

Sets the job input key schema.

Parameters:

job - The job to configure.

schema - The input key schema.

setInputValueSchema

public static void setInputValueSchema(Job job,
                                       Schema schema)

Sets the job input value schema.

Parameters:

job - The job to configure.

schema - The input value schema.

setMapOutputKeySchema

public static void setMapOutputKeySchema(Job job,
                                         Schema schema)

Sets the map output key schema.

Parameters:

job - The job to configure.

schema - The map output key schema.

setMapOutputValueSchema

public static void setMapOutputValueSchema(Job job,
                                           Schema schema)

Sets the map output value schema.

Parameters:

job - The job to configure.

schema - The map output value schema.

setOutputKeySchema

public static void setOutputKeySchema(Job job,
                                      Schema schema)

Sets the job output key schema.

Parameters:

job - The job to configure.

schema - The job output key schema.

setOutputValueSchema

public static void setOutputValueSchema(Job job,
                                        Schema schema)

Sets the job output value schema.

Parameters:

job - The job to configure.

schema - The job output value schema.

setDataModelClass

public static void setDataModelClass(Job job,
                                     Class<? extends GenericData> modelClass)

Sets the job data model class.

Parameters:

job - The job to configure.

modelClass - The job data model class.

getInputKeySchema

public static Schema getInputKeySchema(Configuration conf)

Gets the job input key schema.

Parameters:

conf - The job configuration.

Returns:

The job input key schema, or null if not set.

getInputValueSchema

public static Schema getInputValueSchema(Configuration conf)

Gets the job input value schema.

Parameters:

conf - The job configuration.

Returns:

The job input value schema, or null if not set.

getMapOutputKeySchema

public static Schema getMapOutputKeySchema(Configuration conf)

Gets the map output key schema.

Parameters:

conf - The job configuration.

Returns:

The map output key schema, or null if not set.

getMapOutputValueSchema

public static Schema getMapOutputValueSchema(Configuration conf)

Gets the map output value schema.

Parameters:

conf - The job configuration.

Returns:

The map output value schema, or null if not set.

getOutputKeySchema

public static Schema getOutputKeySchema(Configuration conf)

Gets the job output key schema.

Parameters:

conf - The job configuration.

Returns:

The job output key schema, or null if not set.

getOutputValueSchema

public static Schema getOutputValueSchema(Configuration conf)

Gets the job output value schema.

Parameters:

conf - The job configuration.

Returns:

The job output value schema, or null if not set.