org.apache.hadoop.hbase.client
Class MetaScanner

java.lang.Object
  extended by org.apache.hadoop.hbase.client.MetaScanner

public class MetaScanner
extends Object

Scanner class that contains the .META. table scanning logic and uses a Retryable scanner. Provided visitors will be called for each row. Although public visibility, this is not a public-facing API and may evolve in minor releases.


Nested Class Summary
static interface MetaScanner.MetaScannerVisitor
          Visitor class called to process each row of the .META.
 
Constructor Summary
MetaScanner()
           
 
Method Summary
static List<HRegionInfo> listAllRegions(org.apache.hadoop.conf.Configuration conf)
          Lists all of the regions currently in META.
static List<HRegionInfo> listAllRegions(org.apache.hadoop.conf.Configuration conf, boolean offlined)
          Lists all of the regions currently in META.
static void metaScan(org.apache.hadoop.conf.Configuration configuration, MetaScanner.MetaScannerVisitor visitor)
          Scans the meta table and calls a visitor on each RowResult and uses a empty start row value as table name.
static void metaScan(org.apache.hadoop.conf.Configuration configuration, MetaScanner.MetaScannerVisitor visitor, byte[] userTableName)
          Scans the meta table and calls a visitor on each RowResult.
static void metaScan(org.apache.hadoop.conf.Configuration configuration, MetaScanner.MetaScannerVisitor visitor, byte[] userTableName, byte[] row, int rowLimit)
          Scans the meta table and calls a visitor on each RowResult.
static void metaScan(org.apache.hadoop.conf.Configuration configuration, MetaScanner.MetaScannerVisitor visitor, byte[] tableName, byte[] row, int rowLimit, byte[] metaTableName)
          Scans the meta table and calls a visitor on each RowResult.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MetaScanner

public MetaScanner()
Method Detail

metaScan

public static void metaScan(org.apache.hadoop.conf.Configuration configuration,
                            MetaScanner.MetaScannerVisitor visitor)
                     throws IOException
Scans the meta table and calls a visitor on each RowResult and uses a empty start row value as table name.

Parameters:
configuration - conf
visitor - A custom visitor
Throws:
IOException - e

metaScan

public static void metaScan(org.apache.hadoop.conf.Configuration configuration,
                            MetaScanner.MetaScannerVisitor visitor,
                            byte[] userTableName)
                     throws IOException
Scans the meta table and calls a visitor on each RowResult. Uses a table name to locate meta regions.

Parameters:
configuration - config
visitor - visitor object
userTableName - User table name in meta table to start scan at. Pass null if not interested in a particular table.
Throws:
IOException - e

metaScan

public static void metaScan(org.apache.hadoop.conf.Configuration configuration,
                            MetaScanner.MetaScannerVisitor visitor,
                            byte[] userTableName,
                            byte[] row,
                            int rowLimit)
                     throws IOException
Scans the meta table and calls a visitor on each RowResult. Uses a table name and a row name to locate meta regions. And it only scans at most rowLimit of rows.

Parameters:
configuration - HBase configuration.
visitor - Visitor object.
userTableName - User table name in meta table to start scan at. Pass null if not interested in a particular table.
row - Name of the row at the user table. The scan will start from the region row where the row resides.
rowLimit - Max of processed rows. If it is less than 0, it will be set to default value Integer.MAX_VALUE.
Throws:
IOException - e

metaScan

public static void metaScan(org.apache.hadoop.conf.Configuration configuration,
                            MetaScanner.MetaScannerVisitor visitor,
                            byte[] tableName,
                            byte[] row,
                            int rowLimit,
                            byte[] metaTableName)
                     throws IOException
Scans the meta table and calls a visitor on each RowResult. Uses a table name and a row name to locate meta regions. And it only scans at most rowLimit of rows.

Parameters:
configuration - HBase configuration.
visitor - Visitor object.
tableName - User table name in meta table to start scan at. Pass null if not interested in a particular table.
row - Name of the row at the user table. The scan will start from the region row where the row resides.
rowLimit - Max of processed rows. If it is less than 0, it will be set to default value Integer.MAX_VALUE.
metaTableName - Meta table to scan, root or meta.
Throws:
IOException - e

listAllRegions

public static List<HRegionInfo> listAllRegions(org.apache.hadoop.conf.Configuration conf)
                                        throws IOException
Lists all of the regions currently in META.

Parameters:
conf -
Returns:
List of all user-space regions.
Throws:
IOException

listAllRegions

public static List<HRegionInfo> listAllRegions(org.apache.hadoop.conf.Configuration conf,
                                               boolean offlined)
                                        throws IOException
Lists all of the regions currently in META.

Parameters:
conf -
offlined - True if we are to include offlined regions, false and we'll leave out offlined regions from returned list.
Returns:
List of all user-space regions.
Throws:
IOException


Copyright © 2011 The Apache Software Foundation. All Rights Reserved.