org.apache.hadoop.hbase.mapreduce

Class TableInputFormat

java.lang.Object

org.apache.hadoop.mapreduce.InputFormat<ImmutableBytesWritable,Result>

org.apache.hadoop.hbase.mapreduce.TableInputFormatBase

org.apache.hadoop.hbase.mapreduce.TableInputFormat

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable

@InterfaceAudience.Public
public class TableInputFormat
extends TableInputFormatBase
implements org.apache.hadoop.conf.Configurable

Convert HBase tabular data into a format that is consumable by Map/Reduce.

Field Summary

Fields

Modifier and Type	Field and Description
static String	INPUT_TABLE Job parameter that specifies the input table.
static String	SCAN Base-64 encoded scanner.
static String	SCAN_BATCHSIZE Set the maximum number of values to return for each call to next().
static String	SCAN_CACHEBLOCKS Set to false to disable server-side caching of blocks for this scan.
static String	SCAN_CACHEDROWS The number of rows for caching that will be passed to scanners.
static String	SCAN_COLUMN_FAMILY Column Family to Scan
static String	SCAN_COLUMNS Space delimited list of columns and column families to scan.
static String	SCAN_MAXVERSIONS The maximum number of version to return.
static String	SCAN_ROW_START Scan start row
static String	SCAN_ROW_STOP Scan stop row
static String	SCAN_TIMERANGE_END The ending timestamp used to filter columns with a specific range of versions.
static String	SCAN_TIMERANGE_START The starting timestamp used to filter columns with a specific range of versions.
static String	SCAN_TIMESTAMP The timestamp used to filter columns with a specific timestamp.
static String	SHUFFLE_MAPS Specify if we have to shuffle the map tasks.

Fields inherited from class org.apache.hadoop.hbase.mapreduce.TableInputFormatBase

MAPREDUCE_INPUT_AUTOBALANCE, MAX_AVERAGE_REGION_SIZE, NUM_MAPPERS_PER_REGION

Constructor Summary

Constructors

Constructor and Description
TableInputFormat()

Method Summary

Modifier and Type	Method and Description
static void	addColumns(Scan scan, byte[][] columns) Adds an array of columns specified using old format, family:qualifier.
static void	configureSplitTable(org.apache.hadoop.mapreduce.Job job, TableName tableName) Sets split table in map-reduce job.
static Scan	createScanFromConfiguration(org.apache.hadoop.conf.Configuration conf) Sets up a Scan instance, applying settings from the configuration property constants defined in TableInputFormat.
org.apache.hadoop.conf.Configuration	getConf() Returns the current configuration.
List<org.apache.hadoop.mapreduce.InputSplit>	getSplits(org.apache.hadoop.mapreduce.JobContext context) Calculates the splits that will serve as input for the map tasks.
protected Pair<byte[][],byte[][]>	getStartEndKeys()
protected void	initialize(org.apache.hadoop.mapreduce.JobContext context) Handle subclass specific set up.
void	setConf(org.apache.hadoop.conf.Configuration configuration) Sets the configuration.

Methods inherited from class org.apache.hadoop.hbase.mapreduce.TableInputFormatBase

calculateAutoBalancedSplits, closeTable, createNInputSplitsUniform, createRecordReader, getAdmin, getRegionLocator, getScan, getTable, includeRegionInSplit, initializeTable, setScan, setTableRecordReader

Methods inherited from class java.lang.Object

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

Field Detail

INPUT_TABLE

public static final String INPUT_TABLE

Job parameter that specifies the input table.

See Also:

Constant Field Values

SCAN

public static final String SCAN

Base-64 encoded scanner. All other SCAN_ confs are ignored if this is specified. See TableMapReduceUtil.convertScanToString(Scan) for more details.

See Also:

Constant Field Values

SCAN_ROW_START

public static final String SCAN_ROW_START

Scan start row

See Also:

Constant Field Values

SCAN_ROW_STOP

public static final String SCAN_ROW_STOP

Scan stop row

See Also:

Constant Field Values

SCAN_COLUMN_FAMILY

public static final String SCAN_COLUMN_FAMILY

Column Family to Scan

See Also:

Constant Field Values

SCAN_COLUMNS

public static final String SCAN_COLUMNS

Space delimited list of columns and column families to scan.

See Also:

Constant Field Values

SCAN_TIMESTAMP

public static final String SCAN_TIMESTAMP

The timestamp used to filter columns with a specific timestamp.

See Also:

Constant Field Values

SCAN_TIMERANGE_START

public static final String SCAN_TIMERANGE_START

The starting timestamp used to filter columns with a specific range of versions.

See Also:

Constant Field Values

SCAN_TIMERANGE_END

public static final String SCAN_TIMERANGE_END

The ending timestamp used to filter columns with a specific range of versions.

See Also:

Constant Field Values

SCAN_MAXVERSIONS

public static final String SCAN_MAXVERSIONS

The maximum number of version to return.

See Also:

Constant Field Values

SCAN_CACHEBLOCKS

public static final String SCAN_CACHEBLOCKS

Set to false to disable server-side caching of blocks for this scan.

See Also:

Constant Field Values

SCAN_CACHEDROWS

public static final String SCAN_CACHEDROWS

The number of rows for caching that will be passed to scanners.

See Also:

Constant Field Values

SCAN_BATCHSIZE

public static final String SCAN_BATCHSIZE

Set the maximum number of values to return for each call to next().

See Also:

Constant Field Values

SHUFFLE_MAPS

public static final String SHUFFLE_MAPS

Specify if we have to shuffle the map tasks.

See Also:

Constant Field Values

Constructor Detail

TableInputFormat

public TableInputFormat()

Method Detail

getConf

public org.apache.hadoop.conf.Configuration getConf()

Returns the current configuration.

Specified by:

getConf in interface org.apache.hadoop.conf.Configurable

Returns:

The current configuration.

See Also:

Configurable.getConf()

setConf

public void setConf(org.apache.hadoop.conf.Configuration configuration)

Sets the configuration. This is used to set the details for the table to be scanned.

Specified by:

setConf in interface org.apache.hadoop.conf.Configurable

Parameters:

configuration - The configuration to set.

See Also:

Configurable.setConf( org.apache.hadoop.conf.Configuration)

createScanFromConfiguration

public static Scan createScanFromConfiguration(org.apache.hadoop.conf.Configuration conf)
                                        throws IOException

Sets up a Scan instance, applying settings from the configuration property constants defined in TableInputFormat. This allows specifying things such as:

• start and stop rows
• column qualifiers or families
• timestamps or timerange
• scanner caching and batch size

Throws:

IOException

initialize

protected void initialize(org.apache.hadoop.mapreduce.JobContext context)
                   throws IOException

Description copied from class: TableInputFormatBase

Handle subclass specific set up. Each of the entry points used by the MapReduce framework, TableInputFormatBase.createRecordReader(InputSplit, TaskAttemptContext) and TableInputFormatBase.getSplits(JobContext), will call TableInputFormatBase.initialize(JobContext) as a convenient centralized location to handle retrieving the necessary configuration information and calling TableInputFormatBase.initializeTable(Connection, TableName). Subclasses should implement their initialize call such that it is safe to call multiple times. The current TableInputFormatBase implementation relies on a non-null table reference to decide if an initialize call is needed, but this behavior may change in the future. In particular, it is critical that initializeTable not be called multiple times since this will leak Connection instances.

Overrides:

initialize in class TableInputFormatBase

Throws:

IOException

addColumns

public static void addColumns(Scan scan,
                              byte[][] columns)

Adds an array of columns specified using old format, family:qualifier.

Overrides previous calls to Scan.addColumn(byte[], byte[])for any families in the input.

Parameters:

scan - The Scan to update.

columns - array of columns, formatted as family:qualifier

See Also:

Scan.addColumn(byte[], byte[])

getSplits

public List<org.apache.hadoop.mapreduce.InputSplit> getSplits(org.apache.hadoop.mapreduce.JobContext context)
                                                       throws IOException

Calculates the splits that will serve as input for the map tasks. The number of splits matches the number of regions in a table. Splits are shuffled if required.

Overrides:

getSplits in class TableInputFormatBase

Parameters:

context - The current job context.

Returns:

The list of input splits.

Throws:

IOException - When creating the list of splits fails.

See Also:

InputFormat.getSplits( org.apache.hadoop.mapreduce.JobContext)

getStartEndKeys

protected Pair<byte[][],byte[][]> getStartEndKeys()
                                           throws IOException

Overrides:

getStartEndKeys in class TableInputFormatBase

Throws:

IOException

configureSplitTable

public static void configureSplitTable(org.apache.hadoop.mapreduce.Job job,
                                       TableName tableName)

Sets split table in map-reduce job.