org.apache.hadoop.hbase.util

Interface RegionSplitter.SplitAlgorithm

All Known Implementing Classes:

RegionSplitter.DecimalStringSplit, RegionSplitter.HexStringSplit, RegionSplitter.NumberStringSplit, RegionSplitter.UniformSplit

Enclosing class:

RegionSplitter

public static interface RegionSplitter.SplitAlgorithm

A generic interface for the RegionSplitter code to use for all it's functionality. Note that the original authors of this code use RegionSplitter.HexStringSplit to partition their table and set it as default, but provided this for your custom algorithm. To use, create a new derived class from this interface and call RegionSplitter.createPresplitTable(org.apache.hadoop.hbase.TableName, org.apache.hadoop.hbase.util.RegionSplitter.SplitAlgorithm, java.lang.String[], org.apache.hadoop.conf.Configuration) or RegionSplitter#rollingSplit(TableName, SplitAlgorithm, Configuration) with the argument splitClassName giving the name of your class.

Method Summary

Modifier and Type	Method and Description
byte[]	firstRow() In HBase, the first row is represented by an empty byte array.
byte[]	lastRow() In HBase, the last row is represented by an empty byte array.
String	rowToStr(byte[] row)
String	separator()
void	setFirstRow(byte[] userInput) Set the first row
void	setFirstRow(String userInput) In HBase, the last row is represented by an empty byte array.
void	setLastRow(byte[] userInput) Set the last row
void	setLastRow(String userInput) In HBase, the last row is represented by an empty byte array.
byte[]	split(byte[] start, byte[] end) Split a pre-existing region into 2 regions.
byte[][]	split(byte[] start, byte[] end, int numSplits, boolean inclusive) Some MapReduce jobs may want to run multiple mappers per region, this is intended for such usecase.
byte[][]	split(int numRegions) Split an entire table.
byte[]	strToRow(String input)

Method Detail

split

byte[] split(byte[] start,
             byte[] end)

Split a pre-existing region into 2 regions.

Parameters:

start - first row (inclusive)

end - last row (exclusive)

Returns:

the split row to use

split

byte[][] split(int numRegions)

Split an entire table.

Parameters:

numRegions - number of regions to split the table into

Returns:

array of split keys for the initial regions of the table. The length of the returned array should be numRegions-1.

Throws:

RuntimeException - user input is validated at this time. may throw a runtime exception in response to a parse failure

split

byte[][] split(byte[] start,
               byte[] end,
               int numSplits,
               boolean inclusive)

Some MapReduce jobs may want to run multiple mappers per region, this is intended for such usecase.

Parameters:

start - first row (inclusive)

end - last row (exclusive)

numSplits - number of splits to generate

inclusive - whether start and end are returned as split points

firstRow

byte[] firstRow()

In HBase, the first row is represented by an empty byte array. This might cause problems with your split algorithm or row printing. All your APIs will be passed firstRow() instead of empty array.

Returns:

your representation of your first row

lastRow

byte[] lastRow()

In HBase, the last row is represented by an empty byte array. This might cause problems with your split algorithm or row printing. All your APIs will be passed firstRow() instead of empty array.

Returns:

your representation of your last row

setFirstRow

void setFirstRow(String userInput)

In HBase, the last row is represented by an empty byte array. Set this value to help the split code understand how to evenly divide the first region.

Parameters:

userInput - raw user input (may throw RuntimeException on parse failure)

setLastRow

void setLastRow(String userInput)

In HBase, the last row is represented by an empty byte array. Set this value to help the split code understand how to evenly divide the last region. Note that this last row is inclusive for all rows sharing the same prefix.

Parameters:

userInput - raw user input (may throw RuntimeException on parse failure)

strToRow

byte[] strToRow(String input)

Parameters:

input - user or file input for row

Returns:

byte array representation of this row for HBase

rowToStr

String rowToStr(byte[] row)

Parameters:

row - byte array representing a row in HBase

Returns:

String to use for debug & file printing

separator

String separator()

Returns:

the separator character to use when storing / printing the row

setFirstRow

void setFirstRow(byte[] userInput)

Set the first row

Parameters:

userInput - byte array of the row key.

setLastRow

void setLastRow(byte[] userInput)

Set the last row

Parameters:

userInput - byte array of the row key.