MetaScanner (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.client.MetaScanner

```
@InterfaceAudience.Private
public class MetaScanner
extends Object
```
Scanner class that contains the hbase:meta table scanning logic. Provided visitors will be called for each row. Although public visibility, this is not a public-facing API and may evolve in minor releases.
Note that during concurrent region splits, the scanner might not see hbase:meta changes across rows (for parent and daughter entries) consistently. see HBASE-5986, and MetaScanner.DefaultMetaScannerVisitor for details.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`MetaScanner.DefaultMetaScannerVisitor` A MetaScannerVisitor that skips offline regions and split parents
`static interface`	`MetaScanner.MetaScannerVisitor` Visitor class called to process each row of the hbase:meta table
`static class`	`MetaScanner.MetaScannerVisitorBase`
`static class`	`MetaScanner.TableMetaScannerVisitor` A MetaScannerVisitor for a table.

Constructor Summary

Constructors
Constructor and Description

MetaScanner()

Constructors
Constructor and Description
`MetaScanner()`

Method Summary

Methods
Modifier and Type	Method and Description
`static NavigableMap<HRegionInfo,ServerName>`	`allTableRegions(org.apache.hadoop.conf.Configuration conf, Connection connection, TableName tableName, boolean offlined)` Deprecated. Use `allTableRegions(Connection, TableName)` instead
`static NavigableMap<HRegionInfo,ServerName>`	`allTableRegions(Connection connection, TableName tableName)` Lists all of the table regions currently in META.
`static HRegionInfo`	`getHRegionInfo(Result data)` Deprecated. Use `MetaTableAccessor.getRegionLocations(Result)`
`static List<HRegionInfo>`	`listAllRegions(org.apache.hadoop.conf.Configuration conf, Connection connection, boolean offlined)` Lists all of the regions currently in META.
`static List<RegionLocations>`	`listTableRegionLocations(org.apache.hadoop.conf.Configuration conf, Connection connection, TableName tableName)` Lists table regions and locations grouped by region range from META.
`static void`	`metaScan(Connection connection, 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(Connection connection, MetaScanner.MetaScannerVisitor visitor, TableName userTableName)` Scans the meta table and calls a visitor on each RowResult.
`static void`	`metaScan(Connection connection, MetaScanner.MetaScannerVisitor visitor, TableName userTableName, byte[] row, int rowLimit)` 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(Connection connection,
            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.
    Visible for testing. Use metaScan(Connection, MetaScannerVisitor, TableName) instead.
    
    Parameters:
    visitor - A custom visitor
    
    Throws:
    
    IOException - e
  - metaScan
```
public static void metaScan(Connection connection,
            MetaScanner.MetaScannerVisitor visitor,
            TableName userTableName)
                     throws IOException
```
    Scans the meta table and calls a visitor on each RowResult. Uses a table name to locate meta regions.
    
    Parameters:
    connection - connection to use internally (null to use a new instance)
    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(Connection connection,
            MetaScanner.MetaScannerVisitor visitor,
            TableName 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.
    Visible for testing. Use metaScan(Connection, MetaScannerVisitor, TableName) instead.
    
    Parameters:
    connection - to scan on
    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
  - getHRegionInfo
```
@Deprecated
public static HRegionInfo getHRegionInfo(Result data)
```
    Deprecated. Use MetaTableAccessor.getRegionLocations(Result)
    
    Returns HRegionInfo object from the column HConstants.CATALOG_FAMILY:HConstants.REGIONINFO_QUALIFIER of the catalog table Result.
    
    Parameters:
    data - a Result object from the catalog table scan
    
    Returns:
    HRegionInfo or null
  - listAllRegions
```
public static List<HRegionInfo> listAllRegions(org.apache.hadoop.conf.Configuration conf,
                               Connection connection,
                               boolean offlined)
                                        throws IOException
```
    Lists all of the regions currently in META.
    
    Parameters:
    conf - configuration
    connection - to connect with
    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
  - allTableRegions
```
@Deprecated
public static NavigableMap<HRegionInfo,ServerName> allTableRegions(org.apache.hadoop.conf.Configuration conf,
                                                              Connection connection,
                                                              TableName tableName,
                                                              boolean offlined)
                                                            throws IOException
```
    Deprecated. Use allTableRegions(Connection, TableName) instead
    
    Lists all of the table 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:
    Map of all user-space regions to servers
    
    Throws:
    
    IOException
  - allTableRegions
```
public static NavigableMap<HRegionInfo,ServerName> allTableRegions(Connection connection,
                                                   TableName tableName)
                                                            throws IOException
```
    Lists all of the table regions currently in META.
    
    Parameters:
    connection -
    tableName -
    
    Returns:
    Map of all user-space regions to servers
    
    Throws:
    
    IOException
  - listTableRegionLocations
```
public static List<RegionLocations> listTableRegionLocations(org.apache.hadoop.conf.Configuration conf,
                                             Connection connection,
                                             TableName tableName)
                                                      throws IOException
```
    Lists table regions and locations grouped by region range from META.
    
    Throws:
    
    IOException

Class MetaScanner

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

MetaScanner

Method Detail

metaScan

metaScan

metaScan

getHRegionInfo

listAllRegions

allTableRegions

allTableRegions

listTableRegionLocations